January 2008
Examiners’ Report
NEBOSH National Diploma in Occupational Health and Safety
Examiners’ Report N EB O S H N at i o n a l D i p l o m a i n O c c u p a t i o n a l H ea l t h a n d S af e t y J a n u a r y 2 00 8 e x am i n a t i o n s
CONTENTS
Introduction
2
Unit A – Managing health and safety
3
Unit B – Hazardous agents in the workplace
12
Unit C – Workplace and work equipment
21
Examination technique
28
©
2008 NEBOSH, Dominus Way, Meridian Business Park, Leicester LE19 1QW tel: 0116 263 4700
fax: 0116 282 4000
email:
[email protected]
website: www.nebosh.org.uk
The National Examination Board in Occupational Safety and Health is a registered charity, number 1010444 T(s):exrpts/D/D-0801
DW/DA/REW
Introduction NEBOSH first introduced a National Diploma in Occupational Safety and Health in 1989 but, in response to the emergence of national competency standards in this area, the Diploma was offered in two parts from 1997 – with Diploma Part 2 set at the same level as the previous Diploma. The current version of the NEBOSH Diploma was introduced in 2004 to meet the requirements of the revised national vocational standards in “Occupational Health and Safety Practice”, published by ENTO (formerly the Employment National Training Organisation and now an independent standards setting body working alongside the Sector Skills Councils and other organisations). The relevant standard was published as a level 4 standard within the national framework and the Diploma was therefore designed as a level 4 qualification. However, in 2005, the Qualifications and Curriculum Authority (QCA) changed the national qualifications framework by dividing level 4 into three separate levels – levels 4, 5 and 6 – and the Diploma was placed at the highest of these (ie level 6). This is a level of assessment that is approximately equivalent to that of an honours degree. This does not mean that the Diploma qualification is the equivalent of a degree since most degrees require three years of full-time study; rather, it signifies that the depth of academic skill (but not necessarily the breadth of knowledge) required by the qualification corresponds to a degree level programme. It should be borne in mind, though, that the Diploma is a vocational rather than a purely academic qualification and so such comparisons are not straightforward. As a QCA-accredited level 6 qualification, the Diploma satisfies the academic requirements for graduate membership of the recognised professional body, the Institution of Occupational Safety and Health (IOSH), leading – after satisfying the requirements of two years’ initial professional development and peer review – to Chartered Safety and Health Practitioner (CMIOSH). The NEBOSH Diploma is divided into four individually assessed Units. The qualification is achieved on successful completion of all four Units, three Units being assessed by means of a 3-hour examination and the fourth Unit being assessed by means of a workplace based assignment (or for pre-2007 enrolments the completion of three 3 hour examinations and three workplace based assignments). Both parts of the assessment must be completed to a satisfactory standard). This Examiners’ Report refers to the examination component only. The Diploma is a professional level qualification and the requirements are demanding, as befits any qualification that allows entry into a profession, particularly one that has chartered status. The NEBOSH National Diploma syllabus assumes that candidates will have the broad basic knowledge of health and safety that is provided by a level 3 qualification in occupational health and safety, in particular the NEBOSH National General Certificate (NGC). While this is not mandatory, it should be noted that the syllabus content includes both knowledge expected of student’s equivalent to having undertaken such a programme of study, and content that will have been covered in a level 3 course of study. The Diploma requires academic rigour and the demonstration of a much higher level of understanding of theoretical, technical and legal issues. Students without a grounding (eg GCSE or A-level) in mathematics, physics, chemistry or biology, for instance, may need to devote time to gain knowledge of some of the basic concepts that underpin much of the syllabus content. In addition, students with limited or no experience of studying for a higher level qualification will need to develop their study, research and examination skills in order to maximise their chances of success. Success in the Diploma depends not on the regurgitation of learned facts but on demonstrating an understanding of how the theory can be applied and adapted in a practical setting in order to achieve high standards of health and safety at work. Given the breadth of the subject, this is not an easy task but, with concerted effort on the part of the student, it is achievable.
The results from the three Unit examinations on this occasion show pass rates of 46%, 74% and 65% (Units A, B and C respectively). One reason why these figures were not higher may be due to poor examination technique, which is addressed at the end of this Report. However, the comments from Examiners suggest that some candidates are simply unprepared for the level of the Diploma and show both a lack of knowledge of key material (theoretical, technical and/or legal issues) and an understanding of how the concepts should be applied to often complex situations. This Report provides some pointers in this respect but the onus for acquiring the level of knowledge and understanding required must rest with the student, with the help and support of course providers. On a positive note, while Examiners’ Reports inevitably concentrate on some of the weaknesses found in candidates’ answers, every examination produces some excellent scripts from candidates who have obviously put much effort into their studies in order to achieve success. Such effort does not go unrecognised. 2
UNIT A – Managin g health and safety
General comm ents To be successful in this part of the examination process, candidates need to be prepared to deliver and apply a level of knowledge commensurate with the Diploma qualification. As always, there were some excellent answers with maximum or near maximum marks being achieved on most questions by a small number of candidates, but not necessarily the same candidates on each occasion. Where candidates achieved low marks overall, this was generally for at least one of the following three reasons. Firstly, candidates were not always armed with the degree of understanding and detail required at this level. This was particularly evident in the answers provided to Questions 5 and 10 for example. Candidates setting out on a course of study for the National Diploma need to ask themselves whether they have provided for the necessary preparation, revision and examination question practice that is important for maximising their chances of success in the examination; this is a very different level of examination from the NEBOSH National General Certificate and yet a number of the scripts marked were little better than those provided by Certificate candidates. Secondly, many candidates achieved less than their possible potential through focusing on only a limited range of issues on a question that had scope for a broader range to be tackled. Questions 1 and 4 provided examples of this. Examination question practice, with feedback provided by course providers, together with the use of answer plans (on section B questions in particular) are important elements in trying to maximise marks. Thirdly, candidates wasted much time and lost many opportunities for marks by failing to read the question carefully, not relating their answers to the question asked or the scenario set, and providing information that was not asked for or required. This was a particular issue in Questions 9 and 11.
Section A – all questions compulsor y
Question 1
(a)
(b)
Regulation 5 of the Management of Health and Safety at Work Regulations 1999 places legal duties on employers in respect of health and safety management arrangements. Outline the duties concerned.
(5)
Explain how compliance with the corporate risk management principles set down in the ‘Turnbull Report’ on ‘Internal Control’ could support good health and safety management in an organisation.
(5)
Regulation 5 of the Management of Health and Safety at Work Regulations requires an employer to make appropriate arrangements given the size of the undertaking and the nature of activities, for the effective planning, organisation, control, monitoring and review of the measures introduced for the control of risks. Where five or more persons are employed, the arrangements need to be in writing. In answering part (b) of the question, candidates should have explained that the Turnbull Report describes an approach to risk management that includes all business risks. Compliance with the principles in the report requires the preparation of clear policies which highlight management’s commitment; risk evaluation through a process of risk assessment; management processes that control risk to an acceptable level; effective monitoring arrangements; clear communication and reporting arrangements; a process of internal audit and annual review of risk controls at Board level and a statement to shareholders on outcomes. In their answers, candidates should have recognised that the above are very similar to and would therefore be supportive of the elements of an effective health and safety management system in an organisation. Answers to this question varied in quality. In part (a), some candidates confused the requirements of Regulation 5 with those of Regulations 3 or 7 and even those of section 2(3) of the HSW Act while others based their response on HSG 65 rather than the detail of Regulation 5 itself. In the second part of the question, a lack of knowledge of the “Turnbull Report” was obvious in many responses. 3
Question 2
Explain the ‘domino’ and ‘multi-causality’ theories of accident causation, including their respective uses and possible limitations in accident investigation and prevention.
(10)
In explaining the “domino” theory of accident causation, candidates were expected to provide an outline of Heinrich’s five step model and then to explain the development of that model by Bird and Loftus. The domino model can assist in the structuring of accident investigations and, for the Bird and Loftus variant at least, encourages the search for underlying causations including deficiencies in the management system. Both versions of the model, however, encourage simplistic, straight chain thinking that may tend to restrict the search for multiple accident causes; are reactive rather than proactive and are therefore not useful in predicting the likelihood of accidents; and the Heinrich version in particular, encourages a focus on immediate rather than underlying causation. The key features of the theory of “multi-causality” include multiple underlying failings, organisational, cultural or managerial, that interact with each other and with local circumstances to produce accident events at unpredictable times and locations. The model also shows a link between the number of underlying failings in an organisation and the probability of accidents occurring. The value of the model in accident investigation and prevention is that it encourages the search for multiple underlying failures either as part of accident investigation or by active monitoring measures and also encourages the use of more systematic accident analysis techniques such as fault tree and event tree analysis. However, it tends to be a complex process, requires more time and resources to identify the full causation picture and there are practical difficulties in reaching a decision on the extent of an investigation. There were many good answers provided for this question, though some candidates lost marks because they did not examine the possible limitations of the theories, and particularly of “multi-causality”, in accident investigation and prevention.
Question 3
(a)
A mixing vessel that contains solvent and product ingredients must be thoroughly cleaned every two days for process reasons. Cleaning requires an operator to enter the vessel, for which a permit-to-work is required. During a recent audit of permit records it has been discovered that many permits have not been completed correctly or have not been signed back. Outline possible reasons why the permit system is not being properly adhered to.
(b)
(5)
A sister company operating the same process has demonstrated that the vessel can be cleaned by installing fixed, high pressure spray equipment inside the vessel which would eliminate the need for vessel entry. You are keen to adopt this system for safety reasons but the Board has requested a cost-benefit analysis of the proposal. Outline the principles of cost-benefit analysis in such circumstances. (Detailed discus sion of individ ual cost elements is not required).
(5)
There are many reasons to account for the failure to adhere to a permit to work system. They include the lack of competence of both the permit issuer and the receiver; the level of training and information that has been given to both; a poor health and safety culture within the organisation; routine violations; pressure to complete the task and the complexity and impracticability of the system which makes it difficult to understand. Additionally, there could have been an inadequate level of supervision, a lack of routine monitoring and the nonavailability of the permit issuer to effect the “sign back” and cancel the permit once the work had been completed. There were many good answers provided for this part of the question.
4
Part (b), however, proved to be a bigger challenge, and candidates tended to write in general terms possibly because they did not have a good grasp of the principles of costbenefit analysis. The preparation of a cost-benefit analysis would involve calculating the total costs, including capital and on going of each option. Wherever possible, the benefits that would accrue from the use of the proposed system should be quantified and these would include process efficiency gains, lower operating costs and a reduction in accidents and cases of ill-health and their associated costs. Once the costs and benefits of the proposal have been identified, a comparison might then be made with those of the system currently in use.
Question 4
Outline a range of external individuals and bodies to whom, for legal or good practice reasons, an organisation may need to provide health and safety information AND in EACH case, state the broad type of information to be provided.
(10)
The question required candidates to identify the external bodies and individuals to whom an organisation may need to provide health and safety information for legal or good practice reasons. Whilst in general, the answers provided were to a reasonable standard, some candidates did not read the question with sufficient care and outlined external individuals and bodies who should provide information to the organisation rather than the other way around. Some candidates identified relevant bodies but failed to state the type of information which should be provided. Candidates who did best were those who structured their answers under the headings of ‘body or individual’ and ‘type of information’. Individuals and bodies who would be provided with information for legal reasons included the enforcing authorities with respect to information required by RIDDOR or as part of inspection or investigation activities; the emergency services on the inventories of potentially hazardous/flammable materials used or stored on the site and on the means of access and egress, customers who have to be given health and safety information on articles and substances they might use for work activities; members of the public concerning information on emergency action plans for major hazards; visiting contractors who need to be advised on safe working arrangements and procedures; waste disposal contractors who should be given information on controlled or hazardous waste produced by the organisation; transport companies who should be given information on the precautions to be taken in transporting hazardous substances from the organisation’s site; solicitors or courts who would have to be given information regarding civil claims and other employers who by virtue of MHSWR must be advised of risks to their health and safety arising from the activities of the organisation. It would, additionally, be good practice to supply information ; to trade associations and trade unions on performance and social responsibilities; and to shareholders on the organisation’s level of performance as far as health and safety was concerned.
Question 5
Describe, with practical examples, the statutory duties set down in Section 4 of the Health and Safety at Work etc Act 1974. Your answer should contain a description of the duty holders, the duties concerned and those whom the Section is designed to protect.
(10)
This question should not have posed any problems to those candidates with knowledge of section 4 of the HSW Act. The section imposes duties on persons in control of non-domestic premises which are made available to others, who are not their employees, as a place of work or as a place where plant or substances are provided for their use. The duties include ensuring that the premises, the means of access and egress to them and the plant and substances provided for use are safe and without risks to health, so far as is reasonably practicable The measures that it will be reasonable to expect the duty holder to take will depend both on the degree of control which they have and on reasonable foreseeability.
5
Many candidates did not attempt this question, and those who did generally demonstrated a poor grasp of the requirements of the section. This perhaps suggested reluctance on the part of some candidates to study the primary sources of material for the examination.
Question 6
An advertising campaign was used to promote improvement in safety standards within a particular organisation. During the period of the campaign the rate of reported accidents significantly increased, and the campaign was considered to be a failure. (a)
(b)
Suggest, with reasons, why the rate of reported accidents may have been a poor measure of the campaign’s effectiveness.
(2)
Outline FOUR proactive (active) monitoring techniques which might be used to assess the organisation’s health and safety performance.
(8)
Candidates could have identified that a reason why the number of reported accidents had increased was because they may have previously been under reported and that raised awareness, prompted by the advertising campaign, could have led to previously unreported accidents now being reported and that, in the absence of any other data, it would be almost impossible to tell whether or not the increase was “real”. Using the number of reported accidents is an unsatisfactory way of measuring the effectiveness of the campaign since the anticipated improvement in health and safety standards may not be apparent until some time after the campaign has ended. In answering part (b), proactive monitoring techniques which might be used to assess the organisation’s health and safety performance include physical inspections of the workplace to identify hazards and unsafe conditions; safety audits where the systematic critical examination of all aspects of an organisation’s health and safety performance against stated objectives is carried out; safety tours involving unscheduled inspections to observe the workplace in operation without prior warning; safety sampling of a specific area or particular items of plant with repeat sampling to observe trends; safety surveys involving in depth examinations of specific issues or procedures; environmental monitoring and/or health surveillance; safety climate measures such as the use of employee questionnaires; behavioural observation and measuring health and safety performance against set targets. The second part of the question was better answered than the first though some candidates did confuse proactive with reactive monitoring methods. A few candidates incorrectly considered activities such as training, tool box talks and accident investigation to be proactive monitoring techniques.
6
Section B – three from fiv e questions to be attempted
Question 7
(a)
Outline the principles, application and limitations of Event Tree Analysis as a risk assessment technique.
(b)
(6)
A mainframe computer suite has a protective system to mitigate the effects of fire. The system comprises a smoke detector connected by a power supply to a mechanism for releasing extinguishing gas. It has been estimated that a fire will occur once every five years (f=0.2/year). Reliability data for the system components are as follows: Component Detector Power supply Extinguishing gas release mechanism (i) (ii)
Reliability 0.9 0.99 0.95
Construct an event tree for the above scenario to calculate the frequency of an uncontrolled fire in the computer suite. Suggest ways in which the reliability of the system could be improved.
(10) (4)
Event Tree Analysis is based upon binary logic and is often used to estimate the likelihood of success or failure of safety systems. It starts with the initiating event and ends with the probability of a situation being controlled or not. It is limited by the lack of knowledge of component reliability and other data and since it considers only two possibilities – success or failure – it does not take into account partial downgrade (ie limited success). For part (b), candidates were asked to construct an event tree for the scenario described in the question. An acceptable answer would have been: detector
power
gas
SUCCESS p (success) = 0.2 - 0.031 = 0.169
0.95 0.99
FAILURE
0.9 0.05
Fire 0.01
f=0.2/yr
0.2 x 0.9 x 0.99 x 0.05 = 0.009 0.2 x 0.9 x 0.01 =0.002
0.1
0.2 x 0.1 = 0.02
p (failure) = 0.009 + 0.002 + 0.02 = 0.031 per year f = once every 32 yrs
Marks were awarded for the general construction of the tree; for calculations of failure rates from component reliability data; for calculation of system failure rate from individual failure rates; for conversion of failure rate per year to failure every “X” years which in this case was once in every thirty two years. In answering part (c), candidates could have suggested ways such as choosing more reliable components or using components in parallel. . Credit was given for recognising that the detector was the least reliable component and so would be a logical first choice for such techniques. Installing a second independent but parallel system was also a way of improving the reliability of the system. This was not a popular question, but those who did attempt it generally achieved reasonable marks though in some cases more detail was required on the principles, applications and limitations of Event Tree Analysis. Some candidates confused event trees and fault trees.
7
Question 8
An employee suffered a fractured skull when he fell three metres from storage racking as he was loading cartons onto a pallet held on the forks of a lift truck. A subsequent investigation found that the managers of the company were aware that it was common practice for employees to be lifted up on the forks of the vehicle and for them to climb up the outside of the racking. (a)
(b)
Outline the legal actions that might be available to the injured person in a claim for compensation, and the tests that would have to be made for the actions to succeed. Explain the meaning of ‘general’ and ‘special’ damages that may be awarded in the event of a successful claim AND giv e examples of the factors that are considered in calculating their value.
(14)
(6)
Part (a) of the question required candidates to outline how the torts of negligence and breach of statutory duty could apply to a given scenario. They should have included that, in order to succeed in an action for negligence, the claimant would need to prove that a duty of care was owed to them, that the duty was breached and that their injuries occurred as a result of the breach. Damages may only be recovered for the types of damage that are reasonably foreseeable. Some detail of these stages as they applied to the scenario was required – for instance, that the employer had not done everything that could reasonably be expected to prevent a foreseeable accident in that a safe system of work had not been provided. Marks were also available for reference to relevant case law such as Wilsons & Clyde Coal v English [1938] and General Cleaning Contractors v Christmas [1953]. The claimant would also be able to pursue a civil action for a breach of statutory duty. For this claim to succeed he would need to prove that he was within the class of persons the statute was designed to protect (he was an employee acting in the course of his employment); that his injury was of the type that the requirements of the statute were intended to prevent; that a duty was placed on the defendant which he had failed to meet and that the injury sustained was a direct result of this failure. Additionally, he would have to counter any argument that the legislation involved did not allow for civil action to be taken. Candidates needed to refer to examples of specific statutes that had been breached and could give rise to the action e.g. the Work at Height Regulations 2005, The Management of Health and Safety at Work Regulations 1999 and the Provision and Use of Work Equipment Regulations 1998.. Marks were again available for those candidates who included references to relevant case law such as Corn v Weirs Glass. Some good answers were provided for this part of the question though a few candidates were unable to differentiate between negligence and breach of statutory duty. Answers to part (b) were not to the same standard with many candidates uncertain as to the difference between general and special damages that might be awarded in the event of a successful claim. General damages are based on estimated financial costs, such as loss of future earnings and ongoing medical costs, as well as sums awarded for pain and suffering and the reduction in the claimant’s quality of life and amenity. The amount awarded for this last item will depend on such factors as age, lack of mobility, degree of disfigurement, inability to pursue sports, hobbies and other interests, and diminished eligibility for marriage and other social relationships. Special damages may be awarded where the exact sum is calculable such as itemised legal expenses, the loss of earnings prior to trial and the costs that have accrued in making alterations to property as a direct result of a disability resulting from a workplace accident.
8
Question 9
(a)
(b)
(c)
A fatal accident at work has occurred. Identify the authorities that might be involved in investigating the accident or in initiating and/or conducting criminal prosecutions AND out li ne the involvement of each authority in these circumstances.
(5)
Following an initial investigation into a fatal accident at work, an enforcing authority inspector wishes to make a further visit to the workplace where the accident occurred so that statements can be taken from witnesses and others, including the Managing Director. Prosecution under the Health and Safety at Work etc Act 1974 is being considered. The Managing Director, who was controlling work at the scene when the accident occurred, has refused permission for the inspector to make a further visit and to take statements. Outline the specific powers of inspectors that are relevant to this issue and the possible courses of action that the inspector may pursue.
(8)
With reference to relevant cases, describe the legal difficulties that had arisen in trying to secure convictions for corporate manslaughter under common law (and which have lead to the introduction of the Corporate Manslaughter and Corporate Homicide Act 2007).
(7)
In answering part (a) of the question candidates could have chosen either those authorities who might be involved in investigating a fatal work accident in England and Wales or those with a similar involvement in Scotland. In England and Wales, the accident would be investigated by the HSE or the relevant Local Authority who would subsequently decide whether to p rosecute for breaches of the HSW Act or Regulations and who could conduct summary proceedings in the Magistrates’ Court or brief a barrister if the case was to be heard on indictment in the Crown Court. The police might also investigate the circumstances of the accident with respect to manslaughter or suspicious death and refer their findings to the Crown Prosecution Service to make a decision whether a prosecution for manslaughter should proceed. Additionally, a separate investigation into the death of the individual/individuals would be carried out by the Coroner. In Scotland, the HSE or the Local Authority would similarly be involved in investigating the accident but would then advise the Procurator Fiscal who would decide whether to prosecute for breaches of the HSW Act or Regulations. The Procurator Fiscal would conduct the proceedings in the Sheriff’s court. The involvement of the police in the investigation is identical to that in England and Wales but on completion of their enquiries they would report to the Crown Office who would decide whether to institute proceedings for manslaughter. The case would be conducted by a senior law officer from the Crown Office. The involvement of the Coroner in Scotland is similar to that in England and Wales. Most candidates identified the authorities who would be involved in investigating the accident but were often unable to outline what their involvement would be. With reference to the scenario described in part (b), inspectors have the power to enter premises at any reasonable time, taking with them another authorised person if this is thought necessary and also a member of the police if obstruction is anticipated; to require any person to answer questions and to sign a declaration of truth as to their answers (though statements which may incriminate the interviewee, such as the Managing Director in this case, would not be admissible as evidence in any subsequent prosecution); and to be entitled to reasonable facilities and assistance from the person in control of the premises. The possible courses of action that the inspector might pursue include re-visiting the premises with a colleague or police officer to take statements; consider arranging interviews with witnesses at an alternative venue; carrying out a voluntary interview of the Managing Director under caution; and prosecuting the Managing Director both for obstructing him/her in the course of his/her duties and for preventing other persons from being interviewed by him/her. Candidates seemed to have difficulty in deciding what was required for this part of the question. Instead of referring to the specific powers and courses of action to deal with the obstructive Managing Director, they gave a general inventory of the inspector’s powers. 9
For part (c), candidates should have described that the legal hurdles that had to be surmounted to achieve a conviction for corporate manslaughter included the need to identify gross negligence in an individual acting at “controlling mind” level within an organisation. It was hard to pinpoint fault in an individual at that level and organisations with large and diffuse management structures made the task particularly difficult. Cumulative management failings amounting to gross negligence were not sufficient to meet the specific legal criteria for conviction. Marks were also available for those candidates who referred to relevant cases involving the application of corporate manslaughter to work related incidents such as the Herald of Free Enterprise, the Southall rail crash and Lyme Bay. In general most candidates were unable to give a clear explanation of the legal difficulties involved.
Question 10
(a)
(b)
Outline the meaning and relevance of the following terms in the context of controlling human error in the workplace: (i)
‘ergonomics’;
(ii)
‘anthropometry’;
(iii)
‘task analysis’.
(6)
Excluding ergonomic issues, outline ways in which human reliability in the workplace may be improved. In your answer, consider ‘individual’, ‘job’ and ‘organisational’ issues.
(14)
For part (a) of the question, an acceptable outline of the meaning and relevance of ergonomics in the context of controlling human error in the workplace would have been – the design of equipment, task and environment to take account of human limitations and capabilities; that of anthropometry – the collection of data on human physical dimensions and its application to equipment design; and that of task analysis – the breaking down of tasks into successively more detailed actions and the analysis of the scope for human error with each action. Definitions offered were often poor and many candidates were unable to connect their outlines to the stated objective of controlling human error in the workplace. Some confused anthropometry with anthropology. In part (b), candidates were asked to outline ways in which human reliability in the workplace might be improved, structuring their answers round individual, job and organisational issues. As far as the individual is concerned, this would involve careful selection taking into account skills, qualifications and aptitude; the provision of appropriate training both at the induction stage and to meet subsequent job specific needs; the consideration of the special needs of those who may be more vulnerable; monitoring personal safety performance; using workplace incentive schemes and assessing job satisfaction and providing health surveillance and a counselling service for those recognised as suffering from the effects of stress. Issues connected with the job include the introduction of task analysis for critical tasks; the design of work patterns and shift organisation to minimise stress and fatigue; the use of job rotation to counter monotony; the introduction of good communication arrangements between individuals, shifts and groups and using a sufficient number of personnel to avoid constant time pressures. Finally, for issues connected with the organisation, candidates could have referred to the development of a positive health and safety culture; the provision of good leadership example and commitment; the introduction of effective health and safety management systems and maximising employee involvement in health and safety issues; ensuring effective arrangements for employee consultation; the introduction of procedures for change management and the provision of an adequate level of supervision. Human reliability plays a significant role in health and safety at the workplace and it was disappointing to note that many candidates did not have a good understanding of this issue. Despite the wording of the question, some candidates outlined ergonomic issues.
10
Question 11
A forklift truck is used to move loaded pallets in a large distribution warehouse. On one particular occasion the truck skidded on a patch of oil. As a consequence the truck collided with an unaccompanied visitor and crushed the visitor’s leg. (a)
State, with reasons, why the accident should be investigated.
(4)
(b)
Assume that the initial responses of reporting and securing the scene of the accident have been carried out. Outline the steps which should be followed in order to collect evidence for an investigation of the accident.
(8)
The investigation reveals that there have been previous skidding incidents which had not been reported and the company therefore decides to introduce a formal system for reporting ‘near miss’ incidents. Outline the factors that should be considered when developing and implementing such a system.
(8)
(c)
This question was one of the more popular in Section B and candidates generally produced answers to an acceptable standard even though some did appear to be running out of time. There are many reasons for investigating accidents such as to identify their causes, both immediate and underlying; to prevent a recurrence; to assess compliance with legal requirements; to demonstrate management’s commitment to health and safety and to restore employee morale; to obtain information and evidence for use in the event of any subsequent civil claim; to provide useful information for the costing of accidents and for identifying trends and to identify the need to review risk assessments and safe systems of work. Better answers to part (b) were those that outlined the steps to be followed in a realistic chronological order including taking photographs and making sketches and taking measurements of the scene of the accident before anything was disturbed; obtaining any CCTV footage available; examining the condition of the fork lift truck and determining its speed at the time of the accident; determining the load that was being carried, the safe working load of the truck and any forward visibility problems with the load in place; finding out the reasons for the oil spillage, the emergency spillage procedures in place and the reasons why they were not followed on this occasion; assessing the competence of the fork lift truck driver and examining the workplace to determine any contributing environmental factors such as the condition of the floor and the standard of lighting and interviewing relevant witnesses such as the visitor where this is possible and reception personnel to identify current working practices as opposed to the laid down written procedures for dealing with visitors. Unfortunately, despite the wording of the question, some candidates went into long explanations of accident reporting procedures and of methods of securing the scene. Those who did best in answering part (c) referred to the obstacles that might prevent the system from working effectively and outlined a range of practical, communication and management issues referring to factors such as: arriving at and setting out a clear definition of a “near miss”; holding consultations with employees on the proposed system; arranging for information and training to be given to all employees; ensuring that the reporting methods are simple and easy to operate and establishing clear reporting lines; introducing and practising a no blame culture; arranging for investigation of incidents by line management to identify and implement any remedial action necessary; ensuring the introduction of a reporting back procedure to persons and groups involved and ensuring that reports on the incidents are collated, the data analysed and remedial action taken monitored on a regular basis.
11
UNIT B – Hazardous agents in the workplace
General comm ents All questions were based clearly on the content of the published syllabus and a balance was achieved between questions that required specific technical knowledge relating to occupational health risks and their measurement and control and those that addressed workplace issues in a more general way. In the event, candidates tended to perform better on the latter type of question – for instance Question 2 relating to the hierarchy of control measures to minimise the risks to employees of developing HAVS and Question 3 on the practical steps to be taken to minimise the risks of contracting Leptospirosis, while they did not do so well on the former. The answer to Question 8 on the measurement of exposure to methanol was a particular example of this. However, good marks were obtained by a number of candidates for several of the questions and this should provide some reassurance to those who were unsuccessful on this occasion. A prerequisite for success is the accumulation of knowledge in order to gain a high level of understanding that can be demonstrated in the examination. This requires a significant amount of study on the part of candidates, together with structured revision and practice in writing examination answers. It was apparent on this occasion that several candidates were unprepared for the examination, which hopefully they will be able to address for a future occasion.
Section A – all questions compulsor y
Question 1
A process in a textile mill produces high levels of heat and steam. (a)
(b)
Identify FOUR parameters that could be measured when making an assessment of the thermal environment stating in EACH case the name of an instrument that can be used to measure this parameter.
(4)
Outline the ways of reducing thermal stress amongst employees in the textile mill, with reference to both the thermal environment AND other controls.
(6)
Part (a) of the question required candidates to identify parameters that could be measured in making an assessment of the thermal environment and the instrumentation to be used. They could have referred to parameters such as ambient temperature (mercury or alcohol thermometer), air velocity (anemometer or Kata thermometer), relative humidity (psychrometer) and radiant heat (black globe thermometer). While some candidates could identify a parameter they were then unable to name an instrument to measure it. Answers to part (b) were to a reasonable standard. Ways of reducing the risk of thermal stress amongst employees would initially involve seeking to control heat generation at source by the use of screens or barriers. Reducing the effects of the heat could be achieved through the provision of ventilation and de-humidifying equipment; the provision of appropriate (isotonic) fluids; the provision of suitable clothing (cool and/or loose); and reducing the number of employees exposed to the hostile environment by having a sufficient number of employees available to reduce work rate/pressure and to allow for job rotation with breaks away from the hot environment. Additionally there would be a need to carry out pre-employment screening of those to be involved and on-going health surveillance of current employees; to provide training on the risks of working in such an environment and the control measures to be adopted, and to introduce employees gradually to the environment to achieve acclimatisation. Some candidates referred to the provision of suitable clothing but then gave no further information on what would be considered suitable.
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Question 2
Hand-arm vibration syndrome (HAVS) can be caused by frequent and prolonged use of hand-held power tools. (a)
Identify the symptoms of hand-arm vibration syndrome.
(2)
(b)
Describe a hierarchy of control measures that could be used to minimise the risks to employees of developing HAVS when using such power tools.
(8)
Symptoms of hand-arm vibration syndrome were generally identified well by most candidates. They included: loss of feeling, numbness, tingling and loss of dexterity in the tips of the fingers; blanching (white finger); an increase in the severity of the symptoms during cold weather and the progressive nature of the condition, affecting more fingers or parts of fingers and leading possibly to gangrene. Good answers to part (b) of the question considered both organisational and technical control measures relevant to the use of hand-held power tools and presented them in an appropriate hierarchy. Technical control measures would start with the consideration of alternative work methods to eliminate the task, but if this was not practicable, to automating or mechanising the work; avoiding tools that are too small and not powerful enough since these prolong the task and of course the exposure; replacing the equipment with a lower vibration model and introducing a system of regular maintenance to ensure vibration was kept to its designed level. Organisational control measures would include ensuring the organisation’s purchasing policy takes account of vibration emissions (as well as other requirements); changing work station design to minimise loads on hands, wrists and arms, for instance by the use of jigs or suspension systems to grip heavy tools; planning work schedules to limit time of exposure to vibration; providing warm clothing and a warm environment to encourage good blood circulation; referring those experiencing early symptoms to the occupational health department; having a surveillance programme in place and finally ensuring that employees receive adequate information and training on the risks associated with the process, the symptoms of the syndrome and the control measures that should be followed. There was the occasional mistaken suggestion that the wearing of gloves could lessen the direct effects of vibration.
Question 3
(a)
(b)
The risk of contracting Leptospirosis is a concern to windsurfers at a local water sports centre. Provide advice to these windsurfers which outlines: (i)
the ill-health effects associated with this disease;
(2)
(ii)
why windsurfers might be at risk.
(2)
Outline the practical steps that the centre’s instructors can take to minimise the risks to themselves.
(6)
In most cases Leptospirosis causes a flu-like illness with severe headaches and myalgia in the lower back and legs. Other possible ill-health effects include fever, vomiting, abdominal pain, skin rashes and conjunctival haemorrhage. The more severe form of the disease causes jaundice and liver damage which may end in death. The most common carriers of the disease are rats. They emit bacteria in their urine and since they are incontinent they distribute it everywhere they go. Normally this is inactivated once it dries out but if it enters water (and rats tend to live in close proximity to water), the bacteria can remain viable for longer periods. The bacteria can then enter the windsurfers’ bodies through cuts or abrasions to the skin and through mucous membranes, and particularly if water is swallowed. Many candidates were not able show to a sufficiently clear understanding of this transmission process that was essential to advising why windsurfers might be at risk.
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Practical steps which the windsurfers should take must be aimed at preventing water entering the body. They include measures such as maximising dry training to limit the potential contact time; showering after being in water and washing hands thoroughly before eating; taking care not to swallow water; wearing protective footwear and minimising skin contact by wearing a full-body dry suit; protecting all existing cuts and abrasions with waterproof dressings; seeking medical advice and treatment for any cuts or bites received whilst in the water; washing down equipment and dry suits and reporting any sighting of rats to ensure effective rodent control in and around water. A number of candidates simply thought that the careful disposal of litter was an important practical step. Whilst this may help to eliminate a potential food source for the rats, it will not help to eradicate them. While this question was generally well answered there were some candidates who confused leptospirosis with legionella and described legionnella type controls. Other novel practical steps that could be taken included recruiting a cat and wearing a nose clip to avoid inhaling vapour!
Question 4
A company producing pre-prepared pasta dishes requires operatives to pick up small pasta pieces from a delivery conveyor and transfer them to foil trays on a separate conveyor. This work is carried out standing in front of the conveyors on an 8 hour shift basis. Following complaints from a number of employees about pains in their arms and shoulders you have been asked to undertake an ergonomic risk assessment for this operation and make recommendations. (a)
(b)
Outline the ergonomic risk factors to be taken into account when making such an assessment, indicating how these may be contributing to the problems experienced by the employees in this situation.
(5)
Total automation of the process is not possible. Suggest other control measures that could be taken to reduce the ill-health effects being experienced by employees.
(5)
In carrying out an ergonomic risk assessment of the operation described in the scenario, the factors that would need to be taken into account include the repetitive nature of the task involving frequent movements of the upper body to pick up the pasta and place it in foil trays; the continuous nature of the operation over an eight hour shift; the posture adopted by the operators including standing and reaching from one conveyor to another; the expected work rate and the speed of the conveyors; the height of the conveyor in relation to that of the employees and the total pattern of continuous work with the number and length of the breaks allowed. In answering the second part of the question, candidates were expected to suggest control measures such as adjusting the height of the conveyors and re-positioning them in parallel; arranging the work so that it might be carried out from both sides of the conveyor to prevent over reaching; providing seating for the operators to enable them to change their position from time to time; reducing the speed of the feed conveyor; introducing job rotation with other less demanding tasks; providing information to the employees on the benefits of changing their posture and stretching on a regular basis; encouraging them to report any problems that might arise and carrying out pre-employment health screening to determine existing problems which might make applicants unsuitable for the task. Some candidates provided an answer in the form of a general ergonomic risk assessment without addressing the issues contained in the scenario and taking into account the specific type of work involved. Others made a great issue of the load – the pasta – without concluding that it was insignificant.
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Question 5
When respiratory protective equipment is in use it may not provide the level of protection stated by the manufacturer. Outline the possible reasons for this.
(10)
This question was not well answered and many candidates seemed to have a lack of knowledge of the reasons why respiratory protective equipment may not provide the level of protection stated by the manufacturer. Examiners expected candidates to outline a range of reasons such as a poor air flow or a reduction in battery power; the fitting of incorrect cartridges or a failure to replace them before saturation; equipment incorrectly fitted or incompatible with other personal protective equipment being worn; the presence of other contaminants resulting in a decrease in saturation time; inadequate training in its use and particularly in the care that should be taken in its removal; poor maintenance and inadequate storage resulting in the face piece being left exposed; damage occurring during use and inadequate monitoring and supervision to ensure the equipment was always used when required and the fact that the equipment might not have been manufactured to the appropriate standards.
Question 6
(a)
(b)
Outline, using a relevant example, why and how a retrospective case control study is carried out.
(5)
Outline factors that affect the reliability of this type of study.
(5)
In answering part (a) of this question, Examiners were looking to candidates to outline a retrospective case control study involves looking for a link between cause (exposure) and effect (disease) and determining if there is a dose/response link. The method involves the use of two groups, one with the disease and one without. The study starts at a point in the past and follows the first group forward in order to determine past exposure histories using records of employment, medical records and interviews to collect data. These are compared with the control group who do not have the disease. Relevant examples would involve exposure to asbestos or silica. For part (b), candidates could have referred to factors such as the size of the group; the availability and accuracy of historical data on exposure and health effects; the accuracy of diagnosis and of the recall of the individuals concerned; the fact that non-occupational exposure may have occurred; life-style factors such as diet, smoking and the consumption of alcohol may have contributed to the current ill-health; the possibility of selection bias in that the group may not be representative of the exposed population; and the possible effect of other occupational exposures. There was a general lack of understanding of the nature of a retrospective case study and how it might be carried out, with some candidates describing a prospective study. Very few identified the fundamental links between cause and effect and dose and response while others discussed health surveillance in vague terms with minimal reference to the significance or accuracy of medical records or exposure data.
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Section B – three from fiv e questions to be attempted
Question 7
A catalogue distribution company employs 300 employees as drivers, warehouse operatives and office staff, processing telephone and internet orders. (a)
(b)
Identify the possible functions of this company’s occupational health department: (i)
when recruiting new employees;
(4)
(ii)
when an employee returns to work after ill-health.
(5)
Outline other ways in which the occupational health department can assist the management team to improve health and safety within this organisation. (You do not need to consid er those functions you have already addressed in part a).
(11)
During the recruitment of new employees, the occupational health department would have an important part to play in carrying out screening of the applicants and reviewing their health history so that they might be in a position to advise management on their suitability for employment. In particular they would need to check the fitness and ability of potential warehouse staff to undertake manual handling tasks, check the eyesight of applicants for positions as drivers whether of road or internal vehicles and also screen them for evidence of the possible mis-use of alcohol or other substances. Additionally it would be important to carry out eyesight tests on those who would be employed in the office to use display screen equipment. As for those employees preparing to return to work after a period of ill-health, an assessment of their current health condition would enable recommendations to be made to management on whether the return should be phased or whether the employee should be redeployed on other or lighter duties. This would necessitate liaison with the employee’s GP and where necessary arranging for or even providing rehabilitation treatment in house. In answering part (b), candidates were expected to outline other ways in which the occupational health department could assist management in improving health and safety in the organisation such as maintaining health records of employees and carrying out monitoring of sickness absence; providing first aid treatment and training for employees appointed as first aiders; providing information and advice to employees on weight management, exercise and smoking cessation; undertaking health surveillance; providing training in manual handling and the management of stress; providing an input to the development of policies and procedures and participating in management team meetings and meetings of the health and safety committee; making a specialist input to risk assessments and liaising with the enforcement authority on health issues. This proved to be a popular question. However, the standard of responses given was no more than average. In answering part (a), some candidates ignored the given scenario and gave only generic material which lacked detail and made little reference to the stated work groups. In answering the second part of the question, a few ignored the instruction in bold type and repeated themselves, wasting valuable time. Others became confused between the roles of the occupational health department and the occupational hygienist and only a few referred to the possible input at a more strategic level.
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Question 8
Methanol (an organic solvent) is being used in the production of a specialist coating. An operative’s measurement of exposure to the methanol varies throughout his 8 hour working day. The results of measurement of his exposure are as follows: Table 1 Task undertaken by operative
Duration of Task
Measuring out and adding methanol Adding other components to the mix Supervision of mixing and decanting Clean down of equipment using solvents
15 minutes 1 hour 2 hours 2 hours
Exposure to Methanol (ppm) 280 90 150 170
Assume that exposure is zero at all other times. (a)
(b)
Calculate the 8 hour Time-Weighted Average (TWA) exposure to methanol for the operative. Your answer should include detailed working to show you understand how the exposure is determined.
(8)
Information relating to methanol in EH40 Workplace Exposure Limits is as follows: Table 2
Substance
Methanol
CAS Number
67-56-1
Workplace Exposure Limit Long-term exposure Short-term exposure limit (8-hour TWA limit (15-minute limit reference reference period) period) 3 3 ppm mg/m ppm mg/m 200 266 250 333
Comments
Sk R11, 23/24/25, 39/23/24/25
Using your results from part (a), the original exposure information in Table 1 AND by selecting the relevant data from Table 2, explain what actions might be required by the employer in order to comply with the Control of Substances Hazardous to Health (COSHH) Regulations 2002. (c)
Describe how the personal exposure of the operative to methanol can be measured.
(8) (4)
For part (a) of the question the 8 hour Time-Weighted Average (TWA) to methanol for the operative would be determined by the following calculation: ((280x 0.25) + (90x1) + (150x2) + 170x2) + (0x2.75)) /8 giving a TWA of 100ppm. It was essential that candidates clearly showed the various steps involved in making this calculation in order to achieve maximum marks available. Those that made simple arithmetical errors but used the correct method of calculation still received some credit. In answering part (b), candidates, using their answers to part (a) and the information given in Table 2, were expected to explain that the long term exposure did not exceed the workplace exposure limit (WEL) and consequently the existing control measures could continue to be applied and monitored on a regular basis. The short term exposure during measuring out and adding the methanol does exceed the WEL by 30 ppm and consequently the employer would need to introduce further control measures for these operations such as substituting a less hazardous solvent for the methanol; introducing automation for the dispensing and charging of the solvent; installing local exhaust ventilation or improving the standard of that already fitted; providing the operative with respiratory protective equipment to reduce inhalation and ensuring that they wore gloves to protect from splashes since methanol could be absorbed through the skin. Additionally, in order to comply with the COSHH Regulations, there may be a need to carry out a measurement of the exposure to other components involved in the process and to compare the results with the WELs quoted in EH40, investigating any synergistic or additive effects. 17
Further measurements may also have to be undertaken to determine if the STEL is exceeded at any time during the completion of the other described tasks. Finally a system of on going monitoring would have to be introduced to determine the effectiveness of the additional control measures that had been introduced. For part (c), the personal exposure of the operative to methanol can be measured by the use of a sample tube packed with sorbent material fixed by means of a clip-on collar in the breathing zone. A known volume of air would be drawn across the tube by means of a pump and the methanol absorbed onto the sorbent material. The methanol could then be desorbed in a laboratory by the use of thermal or solvent desorption and analysed using gas chromatography. A number of samples would have to be taken. This was not a popular question but there were some good answers produced, at least for parts (a) and (b). Part (c), however, was poorly answered with very few candidates providing an acceptable description of how the measurement of personal exposure might be carried out. There was some confusion apparent between personal monitoring and grab sampling and the methods suggested ranged from the use of stain tubes to film badges. This lack of technical knowledge is a concern.
Question 9
The prevalence of drug use amongst all workers is estimated to be 1 in 10 and the Health and Safety Executive estimates that alcohol is the cause of up to 5% of all absences from work. (a) (b)
Outline specific signs that an employer can look for when attempting to identify if an employee has a drug or alcohol problem.
(10)
Identify the situations in which it may be appropriate for an employer to introduce an employee drugs and alcohol testing programme AND outline the practical difficulties which must be taken into account when introducing such a programme.
(10)
Specific signs the an employer might look for in attempting to identify if an employee has a drug or alcohol misuse problem include: sudden mood changes, unusual irritability or aggressive or erratic behaviour; a tendency to become confused; abnormal fluctuations in concentration and energy levels; impaired job performance and a tendency to suffer an increased number of accidents; poor time keeping; an increase in short term sickness absence; deterioration in relationships with colleagues, customers or managers; dishonesty or theft; the smell of alcohol or the presence of drugs paraphernalia; slurred speech and poor coordination; a change in appearance, for example becoming untidy when previously the employee had been well groomed and the appearance of needle marks or the covering of limbs in an attempt to hide them and dilated pupils or blood-shot eyes. This part of the question was generally well answered. For part (b), candidates were expected to identify situations such as pre-employment as part of the job selection process; as an ongoing deterrent where employees have a safety critical role such as train drivers or track side workers; following an accident or incident where it is suspected that drugs or alcohol might have been a factor; as part of a rehabilitation or return to work programme and in situations where drug or alcohol misuse has been identified as a problem, for example where evidence of the specific signs identified in answers to the first part of the question has been noted. The practical difficulties in introducing a drugs and alcohol testing programme include the need to obtain the consent of individual employees and to ensure that their terms and conditions of employment are amended to include the obligation to comply with the testing programme. The maintenance of confidentiality is also an important factor as is also informing employees of the procedure that will be followed in the event of the results of a test being found to be positive. In order to carry out a programme of testing, suitable facilities will be required together with appropriate equipment and competent personnel to carry out the testing and these will require financing. Additionally, the reliability of the testing methods will have to be ensured with care being taken to use properly calibrated equipment and accredited laboratories. Finally, in assessing the results of a test, the effects of prescribed medication will have to be taken into account.
18
Answers to part (b) were not to the same standard as those provided for the first part of the question with most candidates displaying no real understanding of the situations where a testing programme might be appropriate and concentrating only on the difficulties associated with cost and confidentiality.
Question 10
A&B Printing Ltd operates a number of large printing machines producing promotional magazines for the retail trade. They recognise that exposure to noise is a problem for all operatives within the open plan print workshop and so the company plan to undertake a noise survey. (a)
(b)
Identify the different types of equipment that could be used to measure exposure to noise, making reference to their respective features and roles in assessing noise exposure.
(10)
Following the noise survey the company decide to fit an acoustic enclosure to one of the large printing machines. Outline the design features of such an enclosure.
(10)
Part (a) of the question was designed to assess candidates’ understanding of the instrumentation that could be used in the assessment of noise in the workplace. An answer including the roles and capabilities of simple sound pressure level meters (SLMs), integrating meters and personal noise dosimeters was expected with reference being made to the working environment in which they might be used such as relatively constant or fluctuating noise levels or for peripatetic workers and their contribution to, and accuracy in, measuring or assessing Leq and LEP,d. Credit was also available for dealing with other related issues such as calibration, the use of an octave band filter set on SLM and integrating meters for assessing hearing protection adequacy and engineering noise control, the use of a SLM appropriate for the degree of precision required, the use of peak noise functions and the training needs of users. Answers to this part of the question were generally to a good standard though a few candidates did show some confusion between the different types and uses of noise measuring equipment. In comparison, the standard of answers provided for part (b) was poor with many candidates showing little understanding of the critical design features of an acoustic enclosure. There was often confusion between an acoustic enclosure and a noise haven. Examiners expected candidates to outline design features such as: the need for it to be of double skin construction with the walls and top being made of sound insulating material, robust enough to withstand the working environment; double glazing to be fitted where windows were considered to be essential and the use of flexible connectors in pipes and ducts leading into and out of the enclosure to form vibration breaks. Additionally, the enclosure should be effectively sealed at floor level, the internal surfaces should be lined to prevent reverberant build up, any ducts into the enclosure should be lined with absorptive material and if ventilation of the enclosure was required, it might be provided by means of acoustic louvers. The printing machinery would need to be mounted on dampers, with operating controls situated on the outside of the enclosure and the material entry and exit points soundproofed. Finally, removable panels would need to be fitted to the enclosure to provide access for maintenance.
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Question 11
A manufacturer uses hydrochloric acid in an open tank with a surface area of 3m2 to remove rust from sheet steel. This creates acid mist in the immediate work area and the company has decided to install a local exhaust ventilation (LEV) system. (a)
Identify the key components of this LEV system.
(b)
Outline the essential design features of each component of this LEV system.
(12)
Explain the legal requirements for inspection and testing of this LEV system.
(3)
(c)
(5)
For part (a) candidates should have identified key components of the system such as a capture hood or canopy with lip extraction, ducting, a filter or air cleaning device, a fan and an outlet or exhaust. For part (b), they should have gone on to outline the essential design features of these components. The hood would need to be of a suitable size to cover the tank and have a face velocity adequate to capture the acid mist. Because of the acidic nature of the contaminant, the ducting would have to be corrosion resistant (polypropylene or stainless steel), be smooth with rounded bends, of size appropriate for the required transport velocity and provided with access for testing and maintenance. Filtering would probably be by means of a wet scrubber, possibly in combination with an alkali neutraliser, with appropriate means for disposing of effluent. The fan, either axial or centrifugal, would need to be corrosion resistant, of sufficient power to provide the necessary extraction velocity and be designed to minimise noise generation. The exhaust outlet should be located following consideration of all environmental implications including noise and should be fitted with a weather cowl and deflector baffles to prevent the entry of vermin. There were not many candidates who referred to the importance of face and duct velocity while a few described a filter suitable for solid particles only. Regulation 9 of the COSHH Regulations 2002 requires a thorough examination and test of a local exhaust ventilation system to be carried out by a competent person at least once in every period of fourteen months. A record of the examinations must be kept available for at least five years from the date on which they were carried out - though this was missed by many. While in general, answers to this part of the question were to a good standard, there were some candidates who ignored the requirements for inspection and testing included in the COSHH Regulations and referred to the general inspection requirements contained in PUWER and risk assessment strategies under MHSWR.
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UNIT C – Workplace and wo rk equipment
General comm ents Unit C addresses the technical aspects of safety and this paper is therefore designed to test candidates’ knowledge and understanding of some of these technical issues. While some candidates met the challenge admirably, there were many that showed confusion and a lack of technical knowledge. Overall, there was much reliance placed on general and generic statements that neither demonstrated the level of technical understanding required nor, very often, addressed the specific question asked. As a result, the questions that produced the better answers were those that centred largely on procedural rather than technical matters such as Question 6 on the issues to be included in a fire safety training session for employees and Question 8 on the design features and procedural arrangements to minimise the risks associated with the movement of vehicles in the workplace. In questions where a greater amount of technical content was required such as Question 3 on the CNC system fitted to a lathe and more worryingly Question 11 on the design and use of fixed and automatic guards, candidates fared less well. Examiners noted in particular that many answers provided by candidates for the questions in Section B of the paper obtained marks which were disappointingly low because they did not contain the depth and breadth of knowledge expected and required at Diploma level.
Section A – all questions compulsor y
Question 1
Outline: (a)
the factors affecting the likelihood of an agricultural tractor overturning;
(6)
(b)
the measures that may be necessary to minimise the risk, or limit the effects, of a tractor overturning.
(4)
For part (a) candidates should have referred to factors affecting the possibility of overturning such as the angle of slope and direction of travel on gradients; uneven or soft ground; speed on cornering; wheel width; the condition and pressure of tyres; the effects of trailers and other attachments including power take-off seizure and the level of competence of the driver. In their answers to part (b) candidates were expected to outline measures such as seat restraints and roll-over protection to mitigate the effects of an overturn. Other appropriate measures to minimise the risk of tractor overturn include restricting the use of tractors on steep gradients; fitting counterbalance weights; fitting wider tyre and maintaining them on a regular basis; fitting a power take-off torque limiter such as shear pins and providing training for drivers. In general answers provided were to a reasonable standard though there were on occasions some generic measures suggested for part (b) which would not be possible in the scenario described. Some candidates lost marks because they provided lists instead of the outline required.
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Question 2
With the aid of labelled sketches, outline the characteristic features of, and factors that promote, the following types of materials failure: (a)
brittle fracture;
(5)
(b)
ductile fracture.
(5)
For this question, candidates were expected to outline with the aid of labelled sketches, the characteristic features of and factors that promote brittle and ductile fractures. This was one of the most poorly answered questions on the paper with many candidates showing a lack of knowledge of the two stated modes of failure. Others, while they could describe the end result, seemed not to understand how and why the failure occurred. There was general confusion with other modes of failure with some candidates describing fatigue rather than brittle fracture. A brittle fracture generally occurs without warning or prior evidence of distress. It is a crystalline structure failure with minimal plastic or elastic deformation. There are generally characteristic “chevron” marks from the point of initiation and the failure is sudden from rapid stress loading. The factors promoting a brittle fracture are high tensile stresses, residual or locked in stresses, sudden loading which does not give the material time to deform plastically, case hardening, low temperatures and the degree of brittleness of the material. A ductile fracture generally has a smooth fracture surface with plastic deformation of the material before final fracture. There is evidence of necking and the final fracture is often brittle because there is insufficient material left to sustain a load. This type of failure generally occurs as the result of a single stress overload though other promoting factors include high temperatures, cold work hardening and the plasticity of the material.
Question 3
A manually operated lathe is to be fitted with a Computer Numeric Control (CNC) system. Outline the additional risks that this may introduce and the measures required to minimise such risks.
(10)
This was again a poorly answered question with some candidates appearing to have little knowledge of a CNC system. They therefore ignored the word “additional” and outlined risks associated with the normal operation of the lathe rather than those associated with the CNC system. The fitting of a computer numeric control to a manually operated lathe would introduce additional risks such as an increase in the speed of the machine and the potential rise in noise levels that could accompany this increase; the possibility of unexpected movements; errors in programming and software; risks arising during setting and teaching operations together with those arising from the operators’ unfamiliarity with the system. Measures that would be required to minimise the risks include the completion of a risk assessment for the new system; the provision of fixed or interlocked guards to prevent access during the automatic cycle; the provision of manual operation for setting and cleaning such as a hold to run system; the relocation of the controls outside the danger zone; the provision of additional training for operators and maintenance staff; updating the instruction manual for using, setting, cleaning and maintaining the machine and carrying out regular testing of the software.
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Question 4
The residents of a village have recently been affected by a fallout of dust on their cars and property. They allege that the dust comes from a cement works situated a few miles away. Outline the steps that should be taken by those responsible for the cement works in order to investigate whether emissions from the works are the cause of the problem.
(10)
This question presented a not unknown scenario involving allegations of dust contamination from residents of a village situated a short distance away from a cement works. It involved a typical investigative process which would deal with the factors to be examined in order to confirm or dismiss them. Answers in general were to a reasonable standard though some candidates did not take the logical problem solving approach and elected to pay off the complainants by way of compensation, which was not the answer that was required. In order to investigate whether the dust causing the problem emanated from the cement works, management would first need to carry out a desk study involving contact with the residents and a research into historical records, weather patterns, possible links with the prevailing wind direction and the existence of other potential sources of dust in the area. They would need additionally to check the plant for obvious faults and carry out continuous monitoring of the emissions on site together with off site background monitoring. Analysis of dust collected from the village would also help to establish whether it matched that produced at the alleged source. It would also be in management’s interest to consult and liase with officials from the Local Authority and, dependent on the location of the works, with members of the Environment Agency or the Scottish Environmental Protection Agency.
Question 5
With examples of actual incidents, describe the principles and effects of a vapour cloud explosion.
(10)
A vapour cloud explosion may be confined for example in a tank or vessel or unconfined. Its key principles include the presence of flammable vapour at a concentration between the upper and lower explosive limits and an ignition source that exceeds the minimum ignition energy. Unconfined vapour clouds may travel a considerable distance before igniting or they may be dispersed to a concentration below the lower explosive limit depending on conditions. The effects of vapour cloud explosions include overpressure, thermal effects and the emission of debris. In confined explosion cases, vessel or containment rupture may occur resulting in a rapid release of liquefied gas. In unconfined explosion cases, damage to people and property may be caused by the pressure wave and thermal radiation. Suitable examples could have included Flixborough 1974, Abbeystead 1984, Grangemouth 1987 and Buncefield 2005. While most candidates were able to describe the effects of a vapour cloud explosion, fewer were able to give an adequate description of the principles involved. There was confusion in many minds between a vapour cloud explosion and a BLEVE and some candidates did not provide examples of actual incidents while others, in error, mentioned Bhopal in their list.
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Question 6
Outline the issues that should be included in a fire safety training session for employees.
(10)
There were many good answers to this question which was concerned with the issues to be covered in a fire safety training session for employees such as: the principles of the fire triangle; the basic elements of fire prevention such as the storage of flammable materials, good housekeeping and the need to prevent the accumulation of rubbish; the action to be taken on discovering a fire such as raising the alarm, the procedure for calling the fire service and the action to be taken by personnel on hearing the alarm; the location and use of fire fighting equipment with practical training for selected employees; the escape routes and exits from the premises together with the assembly points and the roll calls that would have to be carried out; the arrangements for the evacuation of people with disabilities and for assisting visitors and members of the public; the identity and role of fire wardens and marshals; the importance of fire evacuation practices and drills and issues directly concerned with personal behaviour such as refraining from re-entering the building after evacuation until instructed to do so.
Section B – three from fiv e questions to be attempted
Question 7
(a) (b) (c)
Outline the duties of designers under the Construction (Design and Management) Regulations 2007 (CDM 2007).
(6)
Give examples of the ways in which designers can affect the health and safety performance of a construction project.
(4)
A contractor is to be engaged to demolish a disused factory. Give examples of the information that the client should provide to the tendering contractors to fulfil their duty under CDM 2007.
(10)
Under the Construction(Design and Management) Regulations 2007, designers have a duty to avoid in designs foreseeable risks to the health and safety of any person carrying out the construction work, involved in future maintenance or cleaning of the structure or using the structure as a workplace –(the Workplace Regulations contain provisions relating to the design of materials used in the construction of a workplace); to provide with their design sufficient information to assist the client, other designers and contractors to comply with their duties under the CDM Regulations; to provide information as required for the Health and Safety file and to check that the client is aware of their duties under the Regulations and, in the case of a notifiable project, that the required notification has been made. This part of the question was generally well answered with most candidates showing a good understanding of the duties of designers under the Regulations. In contrast, however, part (b) caused difficulties and many candidates showed an inability to identify examples of practical ways in which designers might affect health and safety performance on a construction project. Examiners were expecting them to provide examples such as specifying safer materials from a COSHH perspective; reducing manual handling risks by minimising block size; promoting safer construction methods for example by arranging for windows to be fitted from inside the building and ensuring that risks from working at height are reduced to a minimum. For part (c), candidates should have given examples of information such as the location of buried services; details of hazardous and flammable substances stored on the site; possible contamination of the ground or drains; the location of other hazards such as asbestos; details of weaknesses in the structure such as fragile roofs or the presence of rot; ground conditions such as possible instability and the existence of culverts; previous use of the land; means of access to the site and traffic routes; the proximity of neighbours; details of the project coordinator if the project is notifiable and the Health and Safety file if there is one in existence. This last part of the question was well answered with most candidates showing a good understanding of the demolition process. 24
Question 8
Outline the design features and procedural arrangements that may need to be considered in order to minimise risks associated with movement of vehicles in the workplace.
(20)
This was a very popular question with most candidates, however there were a few whose answers lacked the necessary depth and breadth to satisfy an “outline” answer. In outlining the design features that should be considered in order to minimise risks associated with the movement of vehicles in the workplace, candidates should have referred to matters such as the provision of traffic routes with a smooth and stable surface and of sufficient width and headroom for the types of vehicle that will use them; the elimination of sharp bends, blind corners and steep gradients with the siting of convex mirrors on those corners that cannot be avoided; the installation of a one way system to minimise the need for reversing; the inclusion of passing places for vehicles; the introduction of speed limits and the provision of speed retarders; the provision of a good standard of lighting for the routes and particularly for the transition areas between the inside and outside of buildings; the segregation of vehicles and pedestrians including separate access and egress and the provision of clearly marked crossing places. As for procedural arrangements, they would include the selection and training of competent drivers who would be subjected to regular health screening; the provision of information on site rules for visitors including drivers visiting the site; the introduction of procedures for the regular maintenance both of the traffic routes and of in-house vehicles and for the reporting of defects; the rigorous enforcement of speed limits and the provision and use of high visibility clothing by employees working in close proximity to traffic routes.
Question 9
(a)
(b)
(c)
With respect to UK mains voltage electricity outline the factors that determine the severity of the effects of an electric shock.
(6)
For each of the following protective devices describe their principles of operation: (i)
residual current devices;
(3)
(ii)
fuses;
(3)
(iii)
110v centre tapped to earth reduced voltage systems.
(3)
Outline other design features of electrical systems intended to improve safety.
(5)
In answering part (a) of this question, credit was given for reference to factors including the voltage, the nature of the current (whether alternating or direct), the body resistance of the individual with reference to age, gender, the amount of moisture (perspiration) on the body and the type of footwear worn, the route taken by the current through the body, the speed of action of any protective measures and the environmental conditions, such as the floor material and the presence of water. Knowledge of Ohm’s Law was useful in relating the size of current to voltage and resistance. In answering part (b), candidates were expected to explain that a residual current device is designed as a shock limiting device and not for system protection. It operates on an earth leakage fault. Any differential in the current passing through the line (neutral) and phase (live) conductors is detected, operating a switch to cut off the electrical supply to the apparatus and preventing severe electric shock. The device should operate within 30 to 50 milliseconds of the fault being detected.
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A fuse is a device placed in the live side of a circuit, designed to automatically cut off the power supply to the circuit within a given time when the current flow in the circuit exceeds a given value and produces sufficient heat to melt the fuse which is designed to do so at a predetermined temperature. It prevents the overload of an electrical system and overheating of electrical wiring. However, its speed of operation is generally too slow to protect people from electric shock. One of the better ways of reducing the risk from electricity is to reduce the voltage, achieved by the use of a step down transformer. A common reduction is to 110 volts and a transformer used to attain the reduction is described as centre tapped to earth in that the secondary winding of the transformer is earthed to its centre thus ensuring that the maximum voltage from live to earth involved in an electric shock will be 55 volts. For part (c), candidates could have outlined other design features intended to improve safety such as the selection of suitable cables and placing them out of reach wherever possible; the provision of effective means of isolation to ensure the secure disconnection and separation of electrical equipment from every source of energy; the use of earthed systems and Class 1 equipment or double insulated Class 2 equipment; the use of circuit breakers and the introduction of earth free zones. This was not a popular question and of those who did attempt it, many provided answers with inadequate descriptions of the principles of operation of the stated protective devices. Knowledge of basic electrical theory seemed lacking in many cases.
Question 10
As part of its water treatment system, a manufacturer is to install a plant suitable for the reception and storage of a strong acid and a strong alkali, both of which will be delivered in bulk tankers. Outline the safety provisions required for the design, operation and maintenance of the proposed plant.
(20)
This question was a popular choice and produced a number of reasonable answers. There were, however, a few candidates who considered that acids and alkalis were necessarily flammable or explosive while others ignored the word “outline” and produced lists. Candidates who divided the question into its component parts, ie design, operation and maintenance and dealt with the detail of these issues in turn achieved more success. Under the design issues, it was expected that candidates would deal with the need for the storage tanks and pipe work to be constructed of suitable chemical resistant material; the design and positioning of the delivery inlets to prevent connection being made to the wrong tank; the positioning of the storage tanks in separate bunds with the bunds being capable of holding the entire contents of the tanks plus 10%; the fitting of level indicators and high level alarms to prevent overfilling; the provision of good vehicle access including a hard standing for tankers with facilities for spill containment and the provision of a good standard of lighting. Operational issues should have included the introduction of a safe system of work including emergency procedures to deal with spillages and the provision and maintenance of a contingency supply of neutralising and absorbent materials and water; providing training for the personnel involved including tanker drivers in the risks associated with the operation and the control measures to be followed and the provision of personal protective equipment such as chemical suits, chemical resistant gloves and full face protection. In outlining the issues connected with maintenance, candidates were expected to refer to the arrangements for the examination and testing of safety critical plant; the use of permit to work systems; the completion of the flushing out of tanks and pipe work and their isolation before the start of maintenance work; regular cleaning of the bunds and the provision of training to maintenance staff in emergency procedures.
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Question 11
(a)
Outline what is meant by the term ‘fixed guard’ and ‘automatic guard’ in relation to machinery safety AND i denti fy the circumstances where each type of guard might be appropriate, giving a typical example in EACH case. (8)
(b)
Describe the factors to be considered in the design and use of: (i)
fixed guards; and
(6)
(ii)
automatic guards
(6)
to ensure that machine operators are adequately protected. In answering part (a) of the question, candidates should have outlined that a fixed guard is a guard which is not connected in any way to the controls, motion or hazardous condition of a machine and is fixed to the machine in such a manner for example with screws, nuts or by welding that it can only be opened or removed by the use of special tools or by the destruction of the means of fixing. It is an appropriate method of providing protection against mechanical hazards when infrequent or no access is required to dangerous parts of a machine during its normal operation. A typical example of its use would be as a guard for a belt and pulley drive. An automatic guard is a guard connected to the machine mechanism which, when the machine is operated, pushes the operator away from the danger area. It is generally used on slow moving, long stroke machines such as certain types of press. Part (b) required a description of the factors to be considered both in the design and use of fixed and automatic guards to ensure that the protection provided is adequate. With respect to the design features of a fixed guard, candidates should have referred to factors such as: the material of construction, which should be sufficiently robust to withstand the rigours of the workplace and be able to contain any ejected material, but still allow sight of the process when required; the method of fixing, usually requiring the use of a special tool for the guard’s removal; the need to ensure that any necessary openings in guards are such that they do not allow access to the dangerous parts (a function of the size of any opening in relation to the distance to the hazard); and the need to address the possibility of the guard reverberating and exacerbating a noise problem. Factors to be considered in the use of fixed guards include monitoring and supervision to ensure that the guard is not compromised, safe systems of work for the carrying out of maintenance operations with the guard removed, and the provision of information and training for both operators and maintenance staff. As for automatic guards, factors to be considered would be the compatibility of the guard with the machine function and the convenience of its use; the speed of movement of the machine since this type of guard would be inappropriate on fast moving machines; the height and reach of the operator; the force of movement of the guard together with the possibility that the operator might be crushed between the guard and an adjacent fixed object or structure; the possibility that the guard might fail to danger; the ease or difficulty with which the guard could be defeated and the training that would have to be given to operating and maintenance staff. The standard of answers to this question was disappointing particularly since it dealt with a subject which is regularly examined at all levels. There appeared to be a distinct lack of knowledge of the term automatic guard with many confusing it with an interlocking guard while Examiners were concerned at the apparent lack of understanding of the basic requirements of PUWER.
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Examination technique Introduction Preparation for the examination in terms of diligent study, completion of coursework requirements and structured revision are naturally all essential elements of examination preparation. The focus here, however, is on the need for candidates to familiarise themselves with the format and requirements of the examination papers in order to prepare a strategy for approaching them on the day. Good examination technique will not make up for any gaps in knowledge or lack of understanding of syllabus material. The primary emphasis should therefore be placed on gaining the degree of knowledge and understanding appropriate to the Diploma award. However, candidates who have studied hard in order to achieve the standard required sometimes let themselves down by a failure to demonstrate their understanding in the examination. Part of any study and revision programme should therefore aim to develop a good examination technique so that candidates can do full justice to their efforts. Approach t o the examinatio n papers Each Unit examination paper is identical in format, with six short-answer questions (Section A) and five longanswer questions (Section B). All questions in Section A are compulsory and three questions must be attempted from Section B. For Section A questions, candidates should show that they recognise the main issues relating to the subject of the question, but they are not required to go into great depth on any of these issues, even though they might be tempted to do so. Such temptation should be resisted; marks are often available for providing a certain level of detail – sufficient, perhaps, to show why the issue identified is relevant and that the principles are understood – but beyond this there are no further marks to be gained. This does not mean, though, that answers should be superficial; the technical, legal and other issues expected at Diploma level still need to be addressed, but often in less depth than they would be on a Section B question. It should be noted that both sections on the paper are equally weighted so that candidates must be careful not to spend too much time on one section such that they leave insufficient time to complete the other. In terms of the marks available, providing incomplete answers to a couple of questions on Section A will have less serious consequences than being unable to answer one of the Section B questions due to pressure of time. The selection of questions to be answered in Section B will normally be made in the reading time that is allowed before the start of the examination. Candidates should use this time to read each question carefully to ensure that its specific requirements are understood. They should not be influenced solely by the subject matter of a particular question but must ensure that their knowledge of that subject extends to the specific aspects addressed by the question. Nothing will be gained by demonstrating an in-depth knowledge of aspects of the subject that are not asked for. It is expected that candidates will spend approximately twice as long on an answer to a Section B question than they spent on each Section A question. The Examiners will therefore expect answers to be given in greater depth to justify this additional time. The amount of detail that might be accepted as sufficient for a satisfactory answer to a Section A question will normally be considered totally inadequate as an answer in Section B. Here, candidates are given the opportunity to demonstrate not only that they are able to identify the relevant issues but also, where required, that they can tell the Examiner about them in some depth. Approach t o individ ual quest ions Before starting an answer, candidates should read the question again, and re-read it until they are certain that they understand exactly what is being asked. Every word of the question is there for a reason, and much depends on taking note of the signposts contained in the question. Whilst writing an answer, candidates may have to return to the question several times in order to ensure continued relevance. Under the stressful conditions of an examination, it is quite easy to misunderstand a question or to wander off into more familiar territory. All too often, Examiners are faced with what would have been an excellent answer if only a different question had been asked. In such situations, the Examiner is unable to award marks and the candidate has wasted much valuable time.
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Candidates should pay close attention to the ‘action verb’ or instruction in each question, for this defines the depth of answer required. Many of the questions in Section A start with the instruction to ‘outline’ or ‘identify’, which is used to indicate that little depth is required. Even so, candidates should note the differences between the instructions. Candidates who, for instance, provide a simple list of points when an outline is required will not be able to take full advantage of the available marks. In Section B, use will often be made of other instructions, such as ‘describe’ or ‘explain’. ‘Bullet point’ answers to questions such as these will be considered unsatisfactory. Occasionally, specific instructions – for instance, to draft a management brief – are given. Credit will be given to answers that follow such instructions for, again, there is a reason for their inclusion. Issues identified in a management brief, for instance, should be explained and justified in such a way that a person unfamiliar with occupational health and safety will be able to understand their relevance. It should also be noted that questions, particularly those in Section B, may start with a scenario. It is important to remember that this is used as a signpost both to direct and to constrain an answer and that generalised answers which do not make specific reference to the situation described will earn few marks. Candidates should try to picture the scene in their minds while answering the question in order to focus on the key issues more easily. Some questions are divided into two or more parts, where the marks available for each part are clearly shown. Candidates should use the allocation of marks to guide their efforts and they should not spend a disproportionate amount of time on a part that offers few marks when more marks are available elsewhere. Inevitably, answers that bear a coherent structure fare better than those that are disjointed and where points are jotted down almost as they come to mind. In order to produce a structured answer, candidates need to think clearly about what is being asked. Very often, particularly for Section B questions, candidates will need to use an answer plan in order to ensure that all relevant points are identified in the actual answer. The form that this plan takes is a matter of personal preference but it is important, having identified the key points, that they are not forgotten when writing the answer. Candidates should therefore continually refer back to the plan whilst writing their answer. There is no need to cross out an answer plan since it may contain a creditworthy point that has not been developed in the full answer (due to pressure of time, perhaps). However, it will help the Examiner if an answer plan is headed as such. Summary The Diploma requires more than just a general understanding of health and safety issues. It requires candidates to demonstrate technical competence and an insight into the subject that should be expected of a health and safety professional dealing with complex risk issues. Answers that might have been acceptable for the National General Certificate will be considered woefully inadequate at Diploma level and candidates may have to develop further their techniques for demonstrating the level of knowledge and understanding required. Opportunities that are made available by programme organisers to do this should be eagerly taken, and advice given by tutors that reinforces, or adds to, the suggestions given here should be absorbed. It should be borne in mind that Examiners enjoy being able to award marks and have no hesitation in doing so when they are deserved. The ease with which they are able to do this, however, rests with the candidate. Although a good knowledge of the breadth and depth of the Diploma syllabus is vital, success in the examination ultimately depends upon the ability to demonstrate this knowledge in a logical and meaningful way.
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The National Examination Board in Occupational Safety and Health Dominus Way Meridian Business Park Leicester LE19 1QW telephone +44 (0)116 2634700 fax +44 (0)116 2824000 email
[email protected] www.nebosh.org.uk
