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NEBOSH
WEEK 2 – ELEMENT 7
Physical and Psychological (Hazards & Control)
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Decibel, Lepd dB(A) dB(Decibel) = Unit of measure of loudness (on logarithmic scale) A= A weighted-frequency most closely resembling human hearing (filter) Daily Personal Noise Exposure (Lepd) Total noise exposure individual is subjected to during a working day averaged averaged over 8 hour period
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Decibel, Lepd dB(A) dB(Decibel) = Unit of measure of loudness (on logarithmic scale) A= A weighted-frequency most closely resembling human hearing (filter) Daily Personal Noise Exposure (Lepd) Total noise exposure individual is subjected to during a working day averaged averaged over 8 hour period
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Anatomy of the Ear
Outer ear
Middle ear
Inner ear
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Health effects of Noise Chronic: a) Tinnitus
(ringing in the ear, over-stimulation of the hair cells)
b) Permanent threshold shift (permanent damage) c) Loss of frequency
(damage to hair cells)
Acute: a) Trauma from loud noise ( explosion, Burst eardrum) b) Temporary threshold shift
(hearing affected at
specific frequency)
c) Short term tinnitus (over-stimulation of the auditory nerves)
d) Secondary effects (stress, loss of concentration)
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How does noise get to us? (2) There are three main ways noise can be transmitted: 1) Direct Through the air from noise source to receiver
2) Reflected Via walls, ceilings, and other structures
3) Ground and structure Structure borne through wall or floor
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Noise transmission Paths Reflected
Direct Noise Source
Ground and structure
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Noise Control Techniques
Source
Path
Receiver
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Noise Control Techniques Source: Design, maintenance/lubrication, reduce speed/energy Path: location, enclosure, silencers, absorption, damping, isolation, lagging, screens Receiver: ear protection, job rotation
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Source reduction on Plant
Tighten loose equipment
Regular lubrication
Eliminate unnecessary leaks
Properly adjust machinery
Padded containers for catching components
Switch equipment off especially fans
Use rubber or plastic bushes
Specify noise emissions levels in orders
Check condition and performance of installed noise control equipment
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Path of Noise prevention Techniques Location Move source away from noise sensitive area Enclosure Surrounding the noise source with sound insulating material (care to be taken not to overheat machine) Silencers Reducing noise from exhaust pipes etc. using absorbent materials or baffles Absorption Surrounding/obstructing noise source with absorbent materials (e.g. foam)
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Path of noise control techniques Damping Reduction in structure borne noise by the use of rubber/cork, springs etc.
Isolation Protection of persons from sound source by distance or sound proofed rooms
Lagging Insulation of pipes to reduce sound transmission
Screens Acoustic screens placed on the path
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Practical measures to reduce exposure to excessive noise Lubrication and maintenance Change the process/design Reduce energy Isolation Silencing Enclosure Insulation Absorption Damping Reduce time of exposure PPE
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Types of Hearing Protection Ear Plugs Comfort Hygiene
Ear Defenders Comfort Reusable
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Assumed Protection Noise attenuation devices typically increase the pressure drop of the air distribution system, increasing its energy consumption Attenuation in dB Frequency (Hz)
63
125
250
500
1000
2000
3150
4000
6300
8000
Mean Attenuation (dB)
19.8
19.9
20.0
22.2
24.1
30.7
38.8
41.4
41.5
40.8
Standard Deviation (dB)
7.5
7.8
6.4
4.9
3.5
4.3
4.5
4.7
4.5
5.9
Assumed Protection (dB)
12.3
12.1
13.6
17.3
20.6
26.4
34.5
36.7
37.0
34.9
Taking the igures for assumed protection, it becomes immediately obvious that noise in the lower frequency range is more difficult to protect against.
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Reasons for lack of wearing of hearing protection Poor fit Resistance to use Uncomfortable Incompatibility Interference Hygiene Supervision Deterioration Abuse
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Types of Ionising Radiation Alpha Beta Gamma X-Ray Neutron
NEBOSH
The Penetrating Power of Different Types of Radiation
Skin or paper stops Alpha
Thin aluminium stops Beta
Thick Lead stops Gamma
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Why Is Radioactivity So Useful Easy to detect Easy to locate radiating radioisotopes Radiation can be very penetrating Can be used to look inside solid objects Non Destructive testing Radiation can destroy living cells Useful for sterilizing – Kills micro-organisms Destroying cancer cells
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Paper Machine
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Non Destructive Testing (NDT)
Using X or Gamma Radiation Sources
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X-Rays
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Harmful Effects Effects of Ionising Ioni sing Radiation Acute Effects Somatic Somatic - Damage to exposed person mild nausea to severe illness, diarrhoea, headaches, death local exposure can lead to reddening of the skin/hair loss Genetic Genetic - Damage to reproductive cells
Chronic Effects Somatic – Chronic effects as above plus various types of cancer (e.g. lung cancer among uranium miners) Genetic Genetic - Damage to offspring offspring of exposed (Reduced reproductive success )
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Protection Prot ection Against Ionising
Time Dose rate is directly proportional to exposure time
Distance All points equidistant from the source have same effect
Shielding placing a physical barrier between the source and the individual
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Other types of protection against ionising radiation
Personal Protective Equipment
Environmental Environmen tal and personal monitoring
Training and supervision
Good hygiene practices
Correct disposal of radiation materials
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Employer may have to appoint Radiation Protection Advisor: To advise provide expert advice on the protection of persons from radiation (often consultants) Radiation Protection Supervisor: To ensure that work with radiation is carried out properly
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Non-Ionising Radiation Ultra-violet Infra-red Lasers Microwave
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Ultra-Violet / Infra-Red Ultra-Violet Welding, sun rays Two main hazards effects on skin and eyes
Infra-red Hot metal e.g. foundries Heat and for eyes risk of cataracts
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Lasers In Use
Cutting
Surgery
Eyes are more vulnerable to damage from mild retina burns to permanent blindness
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Microwave
Risk of burns to skin and eyes
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Protection against non-Ionising radiation
Shielding
Distance between source and person
Reducing duration of exposure
Personal protective equipment
Protective creams
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Workplace Environment and Welfare Requirements Working Environment Ventilation, Temperature, Space, Lighting, Workstations, Seating Safety Floors, Traffic Routes, Falls, Falling Objects, Windows, Doors Maintenance Equipment, Cleanliness, Window cleaning Welfare Facilities Toilets, Wash stations, Drinking Facilities Clothing, Meal Facilities and smoking
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Working Environment
Lighting
Thermal
Space
Noise
Ventilation
Vibration
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Health and Safety effects of inadequate lighting
Eye strain
Headaches
Poor posture
Tripping over unseen objects
Increased likelihood of error
Increased time to evacuate
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Factors to consider in the provision of adequate lighting The tasks being undertaken The layout and size of work area The equipment being used Availability of natural lighting Suitability of artificial lighting The shift patterns Glare from computer screens Areas in shadow Maintenance/replacement of faulty lighting Requirement for emergency lighting
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Working in Hot Environment Health Effects Skin Burns Dehydration Heat Exhaustion
Heat Cramps Heat Cataracts Heat Strokes Heat Stress Radiant heat burns © TWI Gulf WLL36 2008
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Working in Hot Environment Protective Measures Medical pre-selection Acclimatisation Cold Drinks Minimise Exposure Shielding and refuges Regular work breaks Ventilation Control of humidity Suitable clothing Health Surveillance Reducing hot/cold at source Mechanical aids
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Working in a Cold Environment
Health Effects Onset of fatigue Shivering Loss of Dexterity Cold burns Frostbite Hypothermia
Precautions Thermal clothing Reduced Exposure Monitoring Fail safe mechanisms Alarms for cold stores
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Room dimensions and space
3m
11 m3 for each person of clear space 1.9 m 1.9 m
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Workstations and Seating The health effects of working in a seated position:
Vertebral and muscular damage
High blood pressure
Circulation problems e.g. thrombosis
Suitable seat for sedentary work:
Good lumbar support
Ability to adjust the seat back and seat height
Provision of foot rests
Stability of the seat base
Swivel ability
Provision of arm rests
Suitable seat material for the environment
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Welfare Requirements
Sanitary Conveniences
Washing Facilities
Drinking Water
Accommodation for clothing
Facilities for changing clothing
Facilities for eating meals
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Sanitary Conveniences Number of People At Work
Number of Water Closets
Number of Wash Stations
1 to 5
1
1
6 to 25
2
2
26 to 50
3
3
51 to 75
4
4
76 to 100
5
5
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Working Environmental Factors that Can Create Stress
Inadequate Lighting
Cramped/dirty/untidy conditions
Poor Layout (Privacy/Security)
Glare, Temperature/Humidity
Inadequate ventilation/stale air
Noise, Vibration
Inadequate welfare facilities
Inclement weather conditions
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ERGONOMICS Definition: Study of relationship between a worker and the working environment or The design of a task around the requirements of individual human capability
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Ergonomics •
People vary enormously in height, weight, strength etc
•
The equipment designed to average man
•
This leads to physical injuries
The Cranfield Man 1.35m
AVERAGE
DIMENSION
CRANFIELD MAN
1.75m
HEIGHT
1.35 m
0.48m
SHOULDER WIDTH
0.61m
1.83m
ARM SPAN
2.44m
1.07m
ELBOW HEIGHT
0.76m
OPERATOR
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Ergonomic Assessment Organisation: Supervision, procedures, breaks shift patterns
Equipment or process: Human limitations, Analyse task etc.
The Individual: Physical capability, knowledge, attitude
Environment: Temperature, noise, space, lighting etc.
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Causes of WRULDs WRULDs are caused by:
Repetitive finger, hand, or arm movements, e.g. assembly line work, key board operators
Twisting movements, e.g. meat and poultry preparation
Squeezing, e.g. using pliers, scissors
Pushing, pulling, lifting or reaching movements, e.g. assembling packing boxes.
Work on a production line.
Bricklaying
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Symptoms of Work related Upper Limb Disorders 1) Numbness or tingling in fingers etc. 2) Pain 3) Restriction in joint movement 4) Soft tissue swelling
In addition to symptoms ..Redness, swelling and limitation of movement
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WRULDs Injuries Injury
Description
Symptoms
Causes
Tenosyno vitis
Inflammation of the tendons and or tendon sheaths
Aching, tenderness, swelling, extreme pain, difficulty using hand
Repetative movements often non strenuous
Tendonitis
Inflammation of the area where the muscle and tendon join
Pain swelling, tenderness and redness of hand, wrist
Repetative movements
Carpal Tunnel Syndrome
Pressure on the nerves which pass up the wrist
Tingling, pain and numbness in the thumb and fingers
Repetitive work with bent wrist. Use of vibrating tools
Tension neck or shoulders
Inflammation of the neck and shoulder muscles
Localised pain in the neck or shoulders
Having to maintain a rigid position
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WRULDS - Prevention
Identify at risk jobs (frequent hand and arm movement) Reduce the force frequency and duration Design of the task Design of the equipment Design of the work station Automate the process Job rotation Regular breaks Training Employees in correct use of tools Medical surveillance Assessment of individuals for the task
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Health Effects of DSE 1) Musculoskeletal disorders (hand, arm, shoulder & neck) 2) Eye and eyesight problems (temporary visual fatigue) 3) Fatigue and stress (high speed, less breaks, lack of social interaction)
Other minor or alleged health effects 1. Epilepsy ( a common chronic neurological disorder) 2. Facial dermatitis (itching, reddening) 3. Radiation (electromagnetic) 4. Effects on pregnant women - (stress)
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DSE Users who are they?
Uses DSE for continuous or near continuous spells of an hour or more at a time
Uses DSE more or less daily
Has to transfer information quickly to or from DSE
Needs high levels of attention and concentration
Highly dependant on DSE
No choice in the use or non-use of DSE
Requires special training or skills
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D.S.E. Assessment Organisation: Job rotation, Breaks Individual: Physical Characteristics, Training Environmental: Noise, Lighting, Glare, Temperature, Space etc. Equipment: Height/position of keyboard and screen, seating posture, design of chair, screen definition and colour, adjustability of equipment
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D.S.E. Workstation Layout 1) Good lighting 2) No glare, distracting reflection 3) Noise to a minimum 4) Ample legroom to allow postural movement 5) Minimise glare (windows) 6) Suitable software 7) Screen suitable position 8) Ample work surfaces 9) Suitable chair/adjustable 10) Footrest if necessary 11) Suitable environment
© TWI Gulf WLL54 2008
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Other DSE Requirements Plan work with breaks Provision of eye/eyesight test Training and information •
Risks from DSE work
•
Importance of good posture
Laptops (design, usage) The Mouse (good posture & technique)
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Display Screen Equipment: Laptops
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Health Effects of Vibrating tools Acute: Tingling or pins and needles in the hands and extremities
Chronic: Numbness and blanching of the fingers Swollen painful joints Reduction in manual dexterity Reduction in the sensation of touch
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Risk Factors of vibrating tools
Frequency of the equipment Magnitude of the energy Strength of the grip and other forces Time of exposure Frequency of exposure Low temperature Individual factors
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Control Measures for vibrating tools
Eliminate the use of vibrating tools Select low vibration equipment Maintenance of equipment and tools Reducing grip force required Reducing exposure time Introducing health surveillance Provision of gloves and heated pads Information and training on risks and indication of injury
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Stress Is d e f i n e d a s t h e r e ac t i o n p e o p l e h a v e t o e x c e s s i v e p r e s s u r es o r o t h e r t y p es o f d e m a n d s p l a c ed u p o n t h e m
Home
Work
Sickness
Kind of work
Children
Physical conditions
Marital
Uncertainty
Financial
Conflict
Travel
Kind of jobs
Bereavement
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Health Effects of Stress PHYSICAL EFFECTS
BEHAVIOURAL EFFECTS
•
Raised heat rate
•
•
Increased sweating
•
•
Headaches
•
Dizziness
•
Drink or smoke more
•
Blurred vision
•
Difficulty sleeping
Aching neck and shoulders
•
Poor concentration
•
Inability to deal with tasks
•
•
•
Skin rashes Lower resistance to infection
Increased anxiety Irritability and sudden mood changes
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Work Problems of Stress Results
Lack of motivation
This reflects in relationships at work as
Lack of commitment
Poor timekeeping
Increases in mistakes
Tension between colleagues and supervisor
Increases in absence
Poor service to clients
Poor decision making
Ind. Relationship Problems
Poor planning
Increase in discipline Problems
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Problems that lead to stress
Culture of the organisation
Shift work, Unsociable hours, Excessive Overtime
Job insecurity, fear of redundancy
Repetitive/Monotonous work
Lack of breaks and control over job
Work rate too high or too low
The working environment
Relationships (supervisors & peers)
Harassment and bullying
Fear of violence
Lack of communication
Personal & social factors
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Management action to avoid Stress Clear company objectives Selection of employees, training, clear defined roles, clear work objectives Good communication Realistic work schedules Close employee involvement Training and development of staff Impartial investigation of stress Policies to recognise and deal with stress Good management support Consistency of treatment
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Stress control measures Individual
Job
• Selecting employees
• Clearly defined roles
• Training
• Comfortable working environment • Realistic work schedules • Grievance procedure • Investigation of stress (signs / complaints) • Work flexibility
Organisation • Clear work objectives • Communication • Employee involvement • Management support, training and development • Management of change • Risk management, openness • Management style
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VIOLENCE AT WORK HSE Definition: Any incident in which a person is abused, threatened or assaulted in circumstances relating to their work
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Areas of Violence at Work Internal Violence By fellow employees and this can involve bullying External Violence Physical, verbal aggression and assault by people outside the organisation
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Persons at Risk
Work involving direct contact with public (Hospitals, Benefits offices, Shops)
Work where money or valuables stored
Stressful and emotive circumstances exist
Work with people suffering mental impairments (Illness, Injury, Substance abuse)
Working alone (taxi Drivers)
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Preventative Measures (1) 1) Queue management and information (The time customers have to spend waiting to pay the queue)
and their experiences in
–
2) Less face to face contact 3) Use “cashless systems” 4) Check credentials and locations 5) Avoid lone working in high risk areas 6) Call in systems for lone workers 7) Arrangements for Staff working late
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Preventative Measures (2) 8) Employee training 9) Change public waiting areas 10) Provide staff with escape routes 11) Video Cameras, alarms, visible security 12) Protective screens/security codes 13) Wider counters/higher floor staff side
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Drugs and Alcohol at Work
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Drugs and Alcohol at Work
All new applicants will be screened Random testing will be applied automatically. Test will apply to all staff Testing will be carried out after specific incidents Training for supervision to recognise the problem What help the employer will make available to the employee If an employee brings to the attention of the employer they have a problem it will be treated with confidence. What are the disciplinary actions the employer will take
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Welding Hazards Electric shock
(arc welding)
Oxygen enrichment
(gas welding)
Manual handling (cylinder handling) Fire risk (sparks) Eye damage (UV) Burns (hot metal) Fume inhalation Tripping over cables Musculoskeletal problems
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Hazards of Busy hotel kitchen
Electrical and mechanical hazards associated with machinery such as food mixers & processors Hot surfaces Sharp implements Wet or obstructed floors increasing the risk of slips, trips & falls Boiling water & hot cooking oils causing burns; Manual handling hazards Health hazards (e.g. foodstuffs causing allergic reactions); & cleaning materials that may be corrosive Hot, busy environment of a commercial kitchen
