OTHM Unit 5 - Copy.pptx

Introduction to Confined Spaces “any place, including any chamber, tank, vat, silo, pit, trench, pipe, sewer, flue, well or other similar space in which, by virtue of its enclosed nature, there arises a reasonably foreseeable specified risk”…. Introduction to Confined Spaces …the foreseeable speci...

Introduction to Confined Spaces “any place, including any chamber, tank, vat, silo, pit, trench, pipe, sewer, flue, well or other similar space in which, by virtue of its enclosed nature, there arises a reasonably foreseeable specified risk”…. Introduction to Confined Spaces …the foreseeable specified risks are: • Fire or explosion. • Loss of consciousness from gas, fumes, vapour, lack of oxygen. • Drowning. • Asphyxiation/ entrapment in free-flowing solid. • Loss of consciousness from increased body temperature. Factors to be Assessed • General condition of the confined space ‒ ‒ ‒ ‒ ‒ Previous contents . Residues. Contamination. Oxygen deficiency and oxygen enrichment. Physical dimensions. • Hazards arising from the work ‒ ‒ ‒ Cleaning chemicals. Sources of ignition. Increasing temperature. • Hazards from outside the space ‒ Ingress of substances. ‒ Emergency rescue. Safe System of Work for Entry • Do not work inside a confined space if possible. • Carry out a risk assessment. • Develop safe system of work. • Develop emergency arrangements. • Use permit to work. • Use only trained, competent personnel. Safe System of Work for Entry • • • • Supervision. Competency. Communication. Atmospheric testing/monitoring. • Ventilation. • Removal of residues. • Isolation, lock-off of in-feeds and outfeeds. • Isolation, lock-off of electrical/mechanical hazards. • PPE. • Access/egress. • Fire prevention. • Lighting. • Suitability of individuals. • Emergency/rescue procedures. Risk Assessment Factors for Lone Working Workers who are separated from their work colleagues. Lack assistance if things go wrong. Communication with colleagues more difficult, i.e.: • Out of eyesight. • Out of earshot. Safe System of Work for Lone Working • No lone working for high-risk activities, e.g. confined spaces. • Remote supervision. • Logging workers’ locations. • Mobile phones or radios. • Lone worker alarm systems. • Procedures for lone workers. • Emergency procedures. • Training for workers. Typical Risks Relating to Vehicle Movements • Loss of control: Due to driver error, environmental or mechanical reasons. • Overturning: Laterally or longitudinally. • Collisions: With other vehicles, pedestrians or fixed objects. Loss of Control and Overturning Factors that can cause a forklift truck to overturn: • Cornering while being driven too fast. • Uneven loading of the forks. • Driving over potholes. • Driving with the load elevated, especially cornering. • Uneven tyre pressures. • Driving across a slope (rather than straight up/down the fall line). • Excessive braking. • Collisions, especially with kerbs. Risk Factors Factors that can increase the risk of collisions: • Driving too fast. • Inadequate lighting. • Reversing without the help of a banksman. • Blind spots, such as corners and entrances. • Bad weather conditions (e.g. rain). • Obstructed visibility (e.g. overloaded forklift truck). • Poor design of pedestrian walkways and crossing points. • Lack of vehicle maintenance. Non-Movement-Related Hazards Typical non-movement-related hazards arise from: • Loading: manual and mechanical. • Overloading: exceeding the safe working load of the vehicle. • Unloading: tipping operations, etc. • Securing: to sheet a lorry. • Coupling: attaching trailers. • Maintenance work: working at height. Workplace Transport Control Measures • Eliminate the hazard. • Create a safe place. • Create a safe person. • Risk assessment: ‒ ‒ ‒ ‒ ‒ Identify the hazards. Identify the groups at risk. Evaluate the risk. Record and implement. Review. Risk Assessment Measures necessary to control risks created by vehicle operations can be grouped under: • Workplace environment. • Vehicle. • Driver. The Workplace Environment • • • • • Vehicle-free zones. Pedestrian-free zones. Traffic route layout. Segregation. Marked walkways and crossings • Separate access points. • Speed limits. • Vehicle movements managed. • Good visibility. • Signage. • Well lit, maintained roads/pathways. • Avoid gradients. • Barriers at changes in levels, e.g. loading docks. Group Exercise What controls could reduce the risks in areas where vehicles are reversing? The Workplace Environment Site rules for safe vehicle parking of a forklift truck: • Apply the handbrake. • Lower the forks and tip the mast forwards. • Remove the key. • Do not obstruct a traffic route. • Do not obstruct a pedestrian route. • Do not obstruct emergency escape routes. The Workplace Environment Control measures to reduce risk of accident from reversing vehicles: • Avoid reversing by using one-way systems. • High-visibility clothing. • Segregate pedestrians • Good lighting. and vehicles. • Banksmen. • Good visibility from • Training for drivers and vehicles. pedestrians. • Reversing alarms and beacons. • Mirrors to reduce blind spots. Risk Assessment Factors 1.Identify the hazards: ‐ ‐ ‐ ‐ ‐ Journey distance. Driving hours. Work schedule. Stress. Weather conditions. 2.Identify who may be harmed. 3.Evaluate the risks: ‐ ‐ ‐ Eliminate the need to travel. Travel by a safer means. If road travel take sensible precautions. 4.Record the findings. 5.Review. Evaluating the Risks If road travel is the preferred option then look at: • The driver. • The vehicle. • The journey. And base controls around these factors. The Driver Competency: • Drivers’ licences checked. • Experience and ability. Training: • Advanced or defensive driving courses. • Vehicle safety, pre-use inspection. Fitness and health: • Medical examination. • Eyesight checks. • Drugs policy. The Vehicle Suitability: • Minimum requirements, standards. • Insurance and valid regulatory certificate if private vehicles used. Condition: • Maintained. • Pre-use inspections. • Defect reporting. The Vehicle • Safety equipment: ‒ Seat belts, airbags, head restraints. ‒ Emergency triangles, first-aid kit, spare tyre. ‒ Fire extinguisher. • Safety-critical information: ‒ Tyre pressures, headlight and restraint adjustments, etc. • Ergonomic: ‒ Adjustability of seat position and posture. • Mobile phone use The Journey Routes Scheduling • Avoid hazards, e.g. town centres. • Avoid peak times. • Avoid fatigue times, e.g. 2–6am, 2–4pm. • Select low-risk roads, e.g. motorways. • Avoid roadworks. • Flexible deadlines. The Journey Time: • Realistic, e.g. route, weather, breaks. • Rest breaks. • Statutory requirements, e.g. lorry drivers (HGV). Distance: • Use other transport. • Not excessive. Weather conditions: • Reliable weather forecasts. • No driving/additional safety advice in bad weather. The Effects of Exposure to Noise • Construction workers: ‒ Plant, machinery, e.g. concrete breakers. • Uniformed services: ‒ Small arms and artillery. • Entertainment sector workers: ‒ Loud music. • Manufacturing sector workers: ‒ Industrial machinery. • Call centre staff: ‒ Acoustic shock from headsets. The Effects of Exposure to Noise Physical effects: • Temporary: ‒ ‒ Reduction in hearing ‒ Tinnitus. Noise-induced hearing loss (permanent threshold shift). ‒ • Stress. • Concentration problems. (temporary threshold shift). Ringing in ears (temporary tinnitus). • Permanent: ‒ Psychological effects: Inability to hear vehicles, Terminologies Terminology • Sound pressure: ‒ The number of pressure waves per ‒ The air pressure of second sound waves moving through the air. • A-weighting: Expressed in decibels ‒ Sound pressure level (dB). corrected to match • Decibel (dB): human hearing sensitivity. ‒ The unit of sound pressure level; • C-weighting: subjectively the ‒ Sound pressure level ‘loudness’. corrected for impulse • Frequency: noise. Decibel Levels Measurement in dB(A) 0 Sound Faintest audible sounds 20-30 Quiet library 50-60 Conversation 65-75 Loud radio 90-100 Power drill 140 Jet aircraft taking off 25m away Noise Exposure Standards The two factors which determine the degree of harm are: • Noise level. • Duration of exposure. A noise assessment is undertaken to measure noise levels and durations of exposure. This is then used to make an estimate of workers’ personal exposure to noise. Personal exposure is then compared to the legal standards. Measurements and assessment must be undertaken by a competent person. Noise Exposure Standards Personal noise exposure: ● The daily personal noise exposure (LEP,d) is a worker’s calculated 8-hour noise exposure. ● Worker’s exposure to single peaks of exposure (impulse noise) is also measured - this is the peak sound pressure. Noise Exposure Standards • Subject to national laws around the world. • No harmonised standards. • In the UK, these are laid out in the Control of Noise at Work Regulations 2005. • Follow EU directive. Noise Exposure Standards • Lower exposure action values: ‒ ‒ a daily or weekly personal noise exposure of 80 dB(A); and a peak sound pressure of 135 dB (C) for impulse noise. • Upper exposure action values: ‒ ‒ a daily or weekly personal noise exposure of 85 dB(A); and a peak sound pressure of 137 dB(C) for impulse noise. • Limit values: ‒ ‒ a daily or weekly personal noise exposure of 87 dB(A); and a peak sound pressure of 140 dB(C) for impulse Noise Exposure Standards: Actions Triggered Lower Exposure Action Value: 80 dB(A) LEP,d ● Carry out noise assessment. ● Provide information, instruction and training. ● Make hearing protection available. Noise Exposure Standards: Actions Triggered Upper Exposure Action Value: 85dB(A) LEP,d ● Carry out a noise assessment. ● Reduce noise exposure by engineering means, ALARP. If noise is still above 85dB(A): ● Mandatory hearing-protection zone. ● Information, instruction and training. ● Provide hearing protection and enforce use. ● Health surveillance. Noise Exposure Standards: Actions Triggered Exposure Limit Value: 87 dB(A) LEP,d ● Immediately prevent exposure and reduce below the limit value. The ELV is an absolute ceiling above which exposure must not go. Group Exercise A noise survey has been carried out and there are two work areas of concern: • Machine shop - noise levels 83 dB(A) throughout the shift. • Wood-working area - noise levels 90 dB(A) throughout the shift. Discuss the actions that would need to be taken in each area. Basic Noise Control Measures How Noise Travels from Source to Receiver Basic Noise Control Measures Reduce noise at source • Eliminate. • Substitute. • Modify the process. • Maintenance. • Damping. • Silencing. Interrupting the pathway • Insulation. • Isolation. • Absorption. Protect the receiver • Acoustic haven. • Hearing protection. Hearing Protection Ear defenders (muffs): • Encase the ear and bones surrounding the ear. Ear plugs: • Fit into the ear canal. Group Exercise Discuss the relative advantages and limitations of ear defenders (muff type) and ear plugs as forms of hearing protection. Hearing Protection Whichever type of hearing protection is chosen, arrangements should be made for: • Information, instruction, training. • Safe storage. • Cleaning. • Maintenance. • Replacement. Group Exercise Identify occupations at risk from noiseinduced hearing loss and the potential causes. Health Effects of Exposure to Vibration Hand-Arm Vibration effects: Hand-Arm Vibration Syndrome (HAVS) • • • • Vibration white finger (blanching). Nerve damage. Muscle weakening. Joint damage. Carpal tunnel syndrome. Typical vibration white finger (Source: HSE Guidance L140) (Reproduced under the terms of the Open Government Licence) Health Effects of Exposure to Vibration • Whole-body vibration effects: ‒ Back pain. • Occupations: ‒ Drivers. ‒ E.g. dumper truck driving. The Assessment of Vibration Exposure Control of Vibration at Work Regulations 2005 • Vibration ‘dose’ determined by: ‒ Vibration magnitude. ‒ Duration of exposure. • Personal exposure is estimated. • Called ‘eight-hour energy equivalent vibration magnitude’ or ‘A(8)’. • This is compared to legal standards. Vibration Exposure Standards The daily exposure action value is: • 2.5 m.s-2 A(8) for hand-arm vibration. • 0.5 m.s-2 A(8) for whole-body vibration. The daily exposure limit value is: • 5.0 m.s-2 A(8) for hand-arm vibration. • 1.15 m.s-2 A(8) for whole-body vibration. Vibration Exposure Standards At or above the daily exposure action value: At or above the daily exposure limit value: • 2.5 m.s-2 for HAVS, • 0.5 m.s-2 for WBV: • 5 m.s-2 for HAVS, • 1.15 m.s-2 for WBV: ‒ ‒ ‒ ‒ Vibration risk assessment. Reduce exposure level. Training. Health surveillance. ‒ ‒ Vibration risk assessment. Reduce exposure below the ELV. Basic Vibration Control Measures • Reduce vibration at source: ‒ ‒ ‒ ‒ Eliminate. Substitute. Change work technique. Maintenance. • Duration: ‒ ‒ • Person: ‒ • Interrupt the pathway: ‒ Isolate. Limit time exposed. Job rotation. PPE. Role of Health Surveillance At or above the exposure action value. Health surveillance allows: • Identification of workers with: ‒ Pre-existing vibration damage. ‒ New vibration damage. • Removal/exclusion of such workers from vibration sources. • Investigation of vibration sources to rectify problems. The Types of Radiation and their Health Effects Two types: • Non-ionising: ‒ Does not cause ionisation in the material that absorbs it. ‒ E.g. visible light. • Ionising: ‒ Does cause ionisation in the material that absorbs it. ‒ E.g. X-rays. Types of Non-Ionizing Radiation • Ultraviolet (UV): ‒ high-frequency, electromagnetic radiation (light) emitted by white-hot materials, such as the arc produced during arcwelding. • Visible light: ‒ electromagnetic radiation between the UV and IR frequencies and visible to the human eye. • Infrared (IR): ‒ lower-frequency, electromagnetic radiation (light) emitted by red-hot materials, such as molten metal being poured into castings. • Microwaves: ‒ lower-frequency, electromagnetic radiation emitted by a microwave generator. • Radiowaves: ‒ lower-frequency, electromagnetic radiation emitted by an Typical Occupational Sources of NonIonising Radiation Types Sources Health Effects Ultraviolet (UV) Sunlight Arc welding Skin burns Arc eye (photokeratitis) Skin cancer Visible light Lasers Temporary blindness Infrared (IR) Red-hot steel Glass manufacture Redness and skin burns, retinal burns, cataracts Microwaves Food preparation Telecommunication s Internal heating Organ damage Radiowaves Radio, TV Radar Internal heating Organ damage Group Exercise You are going on holiday to a hot country with long hours of sunshine. Discuss how you will protect yourself from sunburn from the UV light. Controlling Exposure to NonIonising Radiation Types Protection Ultraviolet (UV) ● Cover exposed skin ● Protect eyes Visible light, lasers ● Low class: avoid shining in eyes ● High class: eye protection, shielding, non-reflective surfaces Infrared (IR) ● Cover exposed skin ● Protect eyes Microwaves ● Safe distance ● Isolate and lock off Radiowaves ● Safe distance ● Isolate and lock off Types of Ionising Radiation • Alpha Particles ‒ Smoke detectors and science labs. • Beta Particles ‒ Science labs and thickness gauges. • X-rays ‒ Medical radiography and baggage security scanners. • Gamma-rays ‒ Industrial radiography for non-destructive testing of metal and welds. • Neutrons ‒ Nuclear power stations. Health Effects • Acute Health Effects ‒ ‒ ‒ ‒ Radiation sickness and diarrhoea. Hair loss. Anaemia (red blood cell damage). Reduced immune system (white blood cell damage). • Chronic Health Effects ‒ ‒ ‒ Cancer. Genetic mutations. Birth defects. Basic Means of Controlling Exposure to Ionising Radiation • Time ‒ ‒ Minimise exposure. Dose proportional to time. • Distance ‒ ‒ Alpha and beta can’t travel long distances through air. Other forms obey the inverse square law: double the distance = quarter the dose. • Shielding ‒ Using material such as lead. Group Exercise A pregnant woman is in need of an X-ray for a suspected broken bone. Discuss the control measures in the X-ray department of a hospital using: • time, • distance, • shielding, to structure your answer. Basic Means of Controlling Exposure to Ionising Radiation Ionising Radiations Regulations 2017 Dose limits on exposure: • General public < 1mSv per year. • Workers < 20mSv per year. The Regulations require that a risk assessment be carried out. This should be done by a competent person. A Radiation Protection Adviser and Radiation Protection Supervisors may need to be appointed. Basic Radiation Protection Strategies Basic protection strategies that apply in all cases: • Eliminate exposure so far as is reasonably practicable. • Reduce exposure to the lowest level reasonably practicable. • Do not exceed the relevant radiation dose limits. • Risk-assessed by a competent person. • Training and information. • Health surveillance. Role of Monitoring and Health Surveillance Types of examination include: • Skin checks. • Respiratory checks. • Exposure records. • Sickness records. Principles of Fire Fuel: A combustible material or substance consumed during the combustion process. Oxygen: From the air (which is 21% oxygen) or oxygen-rich substances (oxidising agents). Heat or ignition source: Energy to start the combustion process. Principles of Fire Fire is a rapid chemical process in which oxygen combines with another substance (‘fuel’) in the presence of a source of heat. This reaction is called combustion. During this reaction, heat, flames and smoke are produced. Classification of Fire This is the EU system. There is no formal Class E. ‘Electrical fires’ is used for electrical equipment. Principles of Heat Transmission and Fire Spread • Direct burning. • Convection: ‒ Inside. ‒ Outside. • Conduction. • Radiation. Principles of Heat Transmission and Fire Spread Convection Radiation Conducti on Group Exercise Suggest common causes of fire in the workplace. Causes • Electrical equipment. • Deliberate ignition (arson). • Hot work. • Smoking. • Cooking appliances. • Heating appliances. • Unsafe use and storage of flammable liquids and gases. • Mechanical heat. • Chemical reactions. Consequences • People killed and injured. • Damage to buildings and contents including smoke damage. • Environmental damage, e.g. water runoff. Control Measures to Minimise the Risk of Fire in a Workplace Control combustible and flammable materials: • Solids, liquids, gases. Control ignition sources: • Systems of work, smoking, arson. Use of electrical equipment in flammable atmospheres: • Hazardous area classification. Systems of work: • Hot processes, machinery, electrical equipment. Good housekeeping: • General tidiness, waste control and disposal. Control of Ignition Sources • Electrical equipment. • Hot work. • Smoking. • Cooking and heating appliances. • Mechanical heat. • Deliberate ignition. Systems of Work Permit to work for control of hot work: • Remove flammable materials from the area. • Cover items that can’t be removed. • Sweep the floor. • Damp down wooden floors. • Provide suitable fire extinguishers. • Ensure ‘fire-watcher’ present in the area. • Check area after work has finished. Good Housekeeping • Waste-free. • Tidy. • Well-ordered. • Pedestrian routes clear. Group Exercise Consider the storage of flammable liquids, e.g. acetone, petrol, etc. Discuss safe storage arrangements if such substances were used at work. Properties of Common Building Materials Concret e: Steel: Brick: Timber: Usually performs well in a fire. Severely affected by high temperatures. Usually very resistant. Thin timber will burn quite quickly; thick timber will survive for longer. Surface treatment can improve fire performance: • Encasing steel in concrete. • Intumescent paint. • Insulation. • Wall coverings. Properties of Common Building Materials Insulation: • Must be fire retardant. Wall coverings: • Can be flammable so need to be carefully selected. Protection of Openings and Voids Openings: • e.g. service conduits, air handling ducts. Voids: • e.g. stairwells, voids between floors, roof voids. Protection: • Self-closing shutters. • Fire break walls. • Procedure to seal any new openings, e.g. with fire-retardant foam. • Fire Detection and Alarm Systems Simplest system: ‒ Someone shouts ‘Fire!’ • Simple with more noise: ‒ Hand bell, whistle or air horn. • Manually operated fire alarm: ‒ Manual call points. • Interlinked smoke alarm: ‒ Links normally unoccupied rooms to interlinked smoke alarms. • Automatic fire detection and alarm: ‒ Automatic detectors, manual call points, linked to sounders/lights. The sophistication will depend on the complexity of Fire Detection and Alarm Systems Smoke detectors: • Detect small smoke particles. • Very sensitive, early warning. • Two main types: ionising and optical. • Can give rise to false alarms. Heat detectors: • Detect excess heat generated by a fire. • Less sensitive, later warning. • Two main types: rate of rise and fixed temperature. • May not detect fires that are giving off smoke but not much heat. Portable Fire-Fighting Equipment • Fire extinguisher. • Fire blankets: ‒ Physically smother fires, e.g. fat fires in kitchens. • Hose reels: ‒ Used in large buildings for fire teams. • Sprinkler systems: ‒ Sited in buildings and warehouses. ‒ Automatically dowses the fire. Extinguishing Media Siting, Maintenance and Training • On fire exit routes. • Close to exit doors. • Close to specific hazards. • Fixed to the wall or on stand/trolley. • Clearly visible. • Signed. • Unobstructed access. Siting, Maintenance and Training Inspection: • Regular and frequent to ensure they are: ‒ In place (firing pin). ‒ In good working order. Maintenance: • Ensure they remain in safe working order. • Once a year. • Certificated engineer. • Inspection, testing, dismantling. Siting, Maintenance and Training • Theory training. • Types of extinguisher. • Hands-on experience. • Records kept in line with local regulations. Access for Fire and Rescue Services The requirements for vehicle access differ depending on the: • Presence of fire mains. • Size of the building. • Type of fire appliance to be used. • For small buildings without a fire main, access for a pump appliance should be provided to 15% of the perimeter. • For large, high-rise buildings, the entire perimeter will need to be accessible. • Site should have an emergency plan including liaison with fire service. • Familiarisation visits may be carried out. Means of Escape • Available to every person in the workplace. • Does not require use of lifts (expect in special cases). • Must take person to a place of safety. • Two or more separate routes may be required. • Travel distance should be short. • Adequate width. • Clearly signed. • Appropriately lit. • Emergency lighting. • No obstructions. Travel Distances Depends on: • Number of people occupying a room. • Travel distance to nearest available: ‒ Final exit - to a place of total safety. ‒ Storey exit - into protected stairway. ‒ Separate fire compartment - containing final exit. • Fire risk. • Number of alternative escape routes available. Stairs and Passageways • Fire-resistant protection. • Adequate width: ‒ Consider wheelchair users. • Unobstructed. • No storage of materials or equipment. Doors • • • • Easy to operate. Adequate width. Open in direction of travel. Not locked. Emergency (Escape) Lighting • At night or where there is no natural light. • To indicate escape routes. • To indicate call points and fire-fighting equipment. • Regular maintenance. • Routine inspection/testing. Exit and Directional Signs • Standard shape. • Standard colour. • Pictogram. • Easy to interpret. • Clearly visible. Assembly Points • Safe distance from building. • Safe location. • Further escape possible if needed. • Must not impede fire-fighters. • Clearly signed. • 'Refuges' for disabled workers. Group Exercise Under your tutor’s direction, take a tour of an area of the building you are in. Note: • Fire compartment, e.g. stairwells, fire doors, etc. • Travel distances. • Fire detection and alarms. • Fire extinguishers, etc. • Emergency lighting, signage. Emergency Evacuation Procedures Emphasis is on personal safety: • Sound the alarm. • Get out of the building. • Stay out of the building. More complex procedures needed for some workplaces, e.g. hospitals. Fire Marshals Typical duties: • Check all areas are evacuated. • Assist disabled/infirm workers. • Ensure fire escape routes are kept clear. • Ensure windows and doors are closed. • Conduct roll call at assembly point. Roll Call • Ensure all persons accounted for. • May not be practical, e.g. supermarkets. • Provision for the Infirm and Disabled Staff with disabilities may need personal evacuation plans: ‒ Assist with travel downstairs. ‒ Alert those with hearing impairment. • May need to consider temporary disabilities, e.g. use of crutches. • Consider also evacuation of young/elderly. Building Plans and Emergency Escapes Fire plans should include: • Who is likely to be in premises. • Action to be taken on discovering fire. • Escape routes. • Fire-fighting equipment. • Action to be taken after evacuation. • Training. Training and Information Information on fire safety procedures for: • Employees. • Contractors. • Visitors and the public. Training for staff: • • • • Who use portable extinguishers. Fire marshals. Assist disabled or infirm people. Members of the fire team. Fire Drills • Usually once or twice a year. • Allows staff to practise procedures. • Allows for testing of those procedures. • Records kept. Forms of Chemical Agents • Solid. • Dust. • Fumes. • Gas. • Mist. • Vapour. • Liquid. • Fibres. The physical form greatly affects the hazard presented and the route of entry into the body. Forms of Biological Agents • Fungi: ‒ e.g. farmer’s lung. • Bacteria: ‒ e.g. Legionnaires’ disease, leptospirosis. • Viruses: ‒ e.g. HIV, hepatitis B. Acute and Chronic Health Effects Acute: Chronic: • Short-term effect. • Long-term effect. • High levels of • Lower levels of exposure. exposure. • Short exposure time. • Long exposure time, • Quick effect, e.g. e.g. multiple exposure to high exposures to concentration of asbestos. chlorine gas. Both acute and chronic effects: e.g. organic solvent, alcohol Classification of Chemicals Hazardous to Health • Physico-chemical effects: ‒ e.g. highly flammable, explosive or oxidising. • Health effects: ‒ e.g. toxic, carcinogenic. • Environmental effects: ‒ e.g. harmful to aquatic life. European Regulation (EC) No 1272/2008 on Classification, Labelling and Packaging of Substances and Mixtures (CLP Regulation). Classification of Chemicals Hazardous to Health • Acute Toxicity − Small doses cause death or serious illness. • Skin Corrosion/Irritation − Destroys living skin tissue or causes inflammation. • Serious Eye Damage/Eye Irritation − Destroys eye tissue or causes inflammation. • Respiratory or Skin Sensitisation − Causes asthma or allergic dermatitis. Classification of Chemicals Hazardous to Health • Germ Cell Mutagenicity − Causes hereditary genetic mutation. • Carcinogenicity − Causes cancer. • Reproductive Toxicity − Causes sterility or is harmful to unborn child. • Specific Target Organ Toxicity − Causes damage to specific body organs. • Aspiration Hazard − Harmful if inhaled into the lungs. Classification of Chemicals Hazardous to Health Sensitising agents (chemicals): • Respiratory sensitisers: ‒ Causes occupational asthma, e.g. flour dust, isocyanates. • Skin sensitisers: ‒ Cause allergic dermatitis, e.g. epoxy resin. Dermatitis: Non-infectious skin condition where the skin becomes dry, flaky, cracked and painful. • Primary Contact Dermatitis: ‒ Skin reacts at point of contact only, remove agent and skin recovers. • Allergic or Secondary Contact Dermatitis: ‒ Sensitisation reaction; dermatitis all over skin. Group Exercise How can a chemical or biological organism enter the body? Which is the highest risk route of entry and why? Routes of Entry • Inhalation: ‒ Inhalable dust (all particles). ‒ Respirable dust (only smaller particles). • Ingestion. • Absorption through the skin. • Injection through the skin: ‒ Needle-stick. ‒ Cuts and grazes. ‒ Bites. Defence Mechanisms The body has two main defence mechanisms to combat attack by biological agents and damage by chemicals: • Cellular (internal) defence – cells fight bacteria and other toxins from blood, respiratory and ingestion entry routes. • Superficial (external) defence – protects against toxins that enter through the skin and contaminants in the nose and throat. Assessment of Health Risks 1.Identify the hazardous substances present and the people who might potentially be exposed. 2.Gather information about the substance. 3.Evaluate the health risk. 4.Identify any controls needed and implement them. 5.Record the assessment and action taken. 6.Review. Assessment of Health Risks • Hazardous nature of substance. • Potential ill-health effects. • Physical forms. • Routes of entry. • Quantity. • Concentration. • Number of people. • Frequency of exposure. • Duration of exposure. • Control measures. Product Labels Set requirements: • Name of substance/mixture. • Hazardous components. • Risk phrases indicating danger. • Precautions. • Details of supplier. Group Exercise Safety Data Sheets Outline the type of information you would need to know about a domestic weed killer in order to assess the risks. Safety Data Sheets 1. Identification of substance and supplier. 9. Physical/chemical properties. 2. Hazard identification. 10.Stability and reactivity. 3. Composition of ingredients. 11.Toxicological information. 4. First-aid measures. 12.Ecological information. 5. Fire-fighting measures. 6. Accidental release measures. 7. Handling and storage. 8. Exposure controls/PPE. 13.Disposal considerations. 14.Transport information. 15.Regulatory information. Limitations of Information • Information sources provide general information only. • Don’t consider the specific conditions of use. • Individual susceptibility. • Mixed exposures. • Based on current knowledge. Occupational Exposure Limits • Around the world, there are different Occupational Exposure Limits (OELs) for hazardous substances: ‒ There is no global standard. • In the UK, they are called Workplace Exposure Limits (WELs). • They set a maximum limit of exposure that can’t be exceeded over a given time period. • WELs have legal status under the COSHH Regulations. Occupational Exposure Limits Definition of WEL: “The maximum concentration of an airborne substance, averaged over a reference period, to which employees may be exposed by inhalation” Short-Term and Long-Term Limits Term Short-Term Exposure Limits (STELs) Long-Term Exposure Limits (LTELs) Time period Reasons for limits 15 minutes Combat acute effects Very high exposure for a short time 8 hours Combat chronic effects Lower exposure over longer period The Purpose of Time-Weighted Averages A worker might be exposed to different levels of a hazardous substance throughout the working day. The STELs prevent them being exposed to harmful levels of the substance over short periods of time where this would cause acute effects. The LTELs prevent them being exposed to harmful levels over the full working day where this would cause chronic effects. Limitations of Exposure Limits Being below a limit does not prove it is safe: • Only concerned with inhalation. • No account of individual sensitivity or susceptibility. • No account of synergistic or combined effects. • Invalid if normal environmental conditions change. • Some limits do not consider all possible health effects of a substance. End of Module Exercise 1. What are OELs? What are they known as in the UK? 2. What is the difference between: • An 8-hour TWA? • A 15-minute STEL? Group Exercise A gardener is spraying a weed killer in a domestic garden in windy conditions. The gardener has no means of washing his hands, etc., and the house owners have children and a dog. The weed killer is an organophosphate labelled ‘toxic’. Using the ‘hierarchy of control’, discuss how the risk may be reduced. The Practical Control of Exposure • Elimination or substitution. • Process change. • Reduce exposure times. • Enclosure and segregation. • Local Exhaust Ventilation (LEV). • Dilution ventilation. • Respiratory protective equipment. • Other PPE. • Personal hygiene and protection regimes. • Health surveillance. Elimination or Substitution and Process Change • Elimination or substitution: ‒ Eliminate process, e.g. outsource painting. ‒ Change work, e.g. screw rather than glue. ‒ Dispose of unwanted stock. ‒ Substitute hazardous for non-hazardous, e.g. irritant to non-hazardous floor cleaner, or corrosive to irritant. ‒ Change physical form of substance to one that’s less harmful. • Process change: ‒ Apply solvent by brush instead of spraying. ‒ Vacuum rather than sweep. Reduce Exposure Times ● Double the time, double the dose; half the time, half the dose. ● Minimise the time period over which people are working with hazardous substances. ● Link to OELs. Enclosure and Segregation Enclosure: Segregation: • Totally enclose the substance. • Prevent access to it. • Keep people away. • Designated areas. Local Exhaust Ventilation Group Exercise Discuss how the effectiveness of LEV may be reduced. Effectiveness of Local Exhaust Ventilation Will be reduced by: • Poorly positioned intake hoods. • Damaged ducts. • Excessive amounts of contamination. • Ineffective fan. • Blocked filters. • Build-up of contaminant in the ducts. • Sharp bends in ducts. • Unauthorised additions to the system. Inspection of Local Exhaust Ventilation • Routine visual inspection: ‒ Integrity checks, e.g. filters, contaminant build-up, etc. • Planned preventive maintenance: ‒ e.g. replacing filters, lubricating fan bearings, etc. • Periodic testing: ‒ ‒ Ensure air velocities are adequate. COSHH requirement every 14 months. Dilution Ventilation • Diluting the contaminant. • Changes the air. • Passive dilution – vents. • Active dilution – powered fans. • Used where: – WEL is high. – Formation of gas or vapour is slow. – Operators are not close to contamination. • Important to know whether contaminant is lighter or heavier than air. Dilution Ventilation Passive Dilution Ventilation Dilution Ventilation Limitations are: • Not suitable for highly toxic substances. • Compromised by sudden release of large quantities of contaminant. • Do not work well: ‒ For dust. ‒ For point sources. • Dead areas may exist: ‒ Where there is little air movement. Respiratory Protective Equipment Two types: • Respirators: ‒ Filter contaminated air from the atmosphere around the wearer. • Breathing Apparatus (BA): ‒ Provide breathable air from a separate source. Selection, Use and Maintenance of Respiratory Protective Equipment Factors to consider: • Concentration of the contaminant and its hazards. • Physical form of the substance. • Compatibility with other items of PPE. • Shape of the user’s face. • Facial hair. • Level of protection offered by the RPE. • Physical requirements of the job. • Presence or absence of oxygen. • Physical fitness of the wearer. • Duration of time that it Selection, Use and Maintenance of Respiratory Protective Equipment Users should understand: • How to fit the RPE. • How to test it to ensure that it is working effectively. • The limitations of the item. • Any cleaning requirements. • Any maintenance requirements (e.g. how to change filter). Other Personal Protective Equipment • Hand protection: ‒ ‒ Gloves, gauntlets. Chemicals, biological agents, physical injury. • Eye protection: ‒ Spectacles, goggles, visors. • Body protection: ‒ Overalls, aprons, whole-body protection. Health Surveillance Health monitoring: • Looks for signs and symptoms of disease. • E.g. bakery workers have lung function tests to check for asthma because flour dust is a respiratory sensitiser. Biological monitoring: • Looks for the contaminant in blood, urine or breath. • E.g. lead in blood for a lead-worker. Screening on first employment: • To establish a ‘baseline’. Asbestos Use: • • • • • • Asbestos cement roofs. Ceiling tiles. Fire break walls. Floor tiles. Downpipes. Pipe lagging. Health Risks Associated with Asbestos Diseases: • Asbestosis. • Lung cancer. • Mesothelioma. • Diffuse pleural thickening. Managing Asbestos in Buildings The Control of Asbestos Regulations 2012 require: • Awareness of presence of asbestos by occupiers/owners. • Need for an asbestos management plan. • Maintaining an Asbestos Register – identifying locations. • Record of regular inspections. • Monitoring the condition. Left alone and undisturbed, asbestos will Blood-Borne Viruses Any virus present in and transmissible by blood; e.g. Human Immunodeficiency Virus (HIV) and hepatitis virus. Hepatitis B and C: • ‒ Transmitted in blood and other body fluids. ‒ Risk to healthcare workers, fire-fighters, police, waste disposal workers, etc. ‒ Symptoms are jaundice, liver damage. ‒ Can be a chronic disease. Blood-Borne Viruses Typical controls for hepatitis: • PPE: gloves, eye protection. • Disposal of material as clinical waste. • Prevention of needle-stick injuries. • Decontamination and disinfection. • Vaccination. • Accident procedures, e.g. needle-stick injuries. Carbon Monoxide Colourless, odourless gas: • By-product of partial combustion, e.g. poorly maintained boilers. • Inhalation hazard. • Prevents red blood cells transporting oxygen. • Chemical asphyxiation: ‒ Low levels (0.005%) – worsening headache. ‒ High levels (1.3%) – rapid unconsciousness and death. Carbon Monoxide Typical controls: • Competent engineers for gas systems. • Maintenance and testing of boilers and flues. • Good ventilation. • LEV for workshop vehicle exhausts. • Siting of equipment containing combustion engines. • CO alarms. • Confined space entry controls. Cement Used to make mortar and concrete. Harmful effects: • Irritation of the: ‒ Eyes. ‒ Respiratory tract. ‒ Skin. • Corrosive burns to skin on repeated/prolonged contact. • Allergic dermatitis. Cement Typical controls: • Eliminating or reducing exposure. • PPE - gloves, dust masks, eye protection. • Removal of contaminated clothing. • Good hygiene and washing skin on contact. Legionella Bacteria Health Risk • Water-loving soil bacteria. • Infests water systems. • Water sprayed to form a mist creates inhalation risk. • ‘Flu-like fever followed by pneumonia. • Legionnaires’ disease. Legionella Bacteria Management controls: • • Risk assessment, written control scheme and review of control measures. Nominated responsible person. Practical controls: • • • • • • • • Avoid water temperatures between 20°C and 45°C. Avoid water stagnation. Avoid using material that can harbour bacteria and provide them with nutrients. Control the release of water spray. Keep water, storage systems and equipment clean. Use water (chemical) treatments where necessary. Carry out water sampling and analysis. Ensure correct and safe operation and maintenance of water systems. Leptospira Bacteria Leptospirosis: • Infected urine from: rats, mice, cattle and horses. • Contaminated water in contact with cuts, grazes, etc. • Occupations at risk are dairy farmers, sewage workers, water sports instructors. • ’Flu-like symptoms, jaundice, liver damage (Weil’s disease). Typical controls: • Preventing rat infestation – good housekeeping, pest control. • Good personal hygiene. • PPE, especially gloves. • Covering cuts and grazes. • Issuing ‘at risk cards’ to workers. Silica • • • • Component of rock (quartz). Found in quarries, pottery and construction industry. Inhalation hazard (respirable crystalline silica). Causes scar tissue to form in lungs (silicosis). Typical controls: • • • • • Alternative work methods. Dust suppression by water. LEV. RPE. Health surveillance. Wood Dust • Inhalation hazard – causes irritation. • May cause asthma. • Some hardwoods can cause cancer. Typical controls: • • • • LEV. Vacuuming rather than sweeping. RPE. Health surveillance. Types of Work Equipment • • • • • Simple hand tools. Hand-held power tools. Single machines. Mobile work equipment. Machine assemblies. Suitability Work equipment should be carefully selected to ensure it is appropriate for the: • Task. • Environment and conditions. Employers in the EU have to ensure that any equipment they purchase for work use has a CE mark and complies with European standards. Suitability EU ‘Machinery Directive’ (2006/42/EC) Manufacturers are required to: ● Meet the ‘essential health and safety requirements’. ● Create a technical file. ● Fix a Conformité Européenne (CE) mark. ● Provide a written Declaration of Conformity. ● Provide written information on hazards, risk, safe use and maintenance of equipment. In the UK similar requirements for UKCA marking exist under the Supply of Machinery (Safety) Regulations 2008. Preventing Access to Dangerous Parts of Machinery Access to dangerous parts is prevented or movement of dangerous parts is stopped: • fixed guards, • other guards and protection devices, • protection appliances, • information, instruction, training and supervision, to the extent that it is practicable. Restricting Use The use is restricted to trained and competent operators for equipment that: • Is highly specialised. • Has a range of hazards. Maintenance of work equipment restricted to trained and competent persons. Information, Instruction and Training Provided for: • Work equipment users: ‒ Low-risk equipment – reading instructions. ‒ High-risk equipment – formal training, check effectiveness. • Managers. • Maintenance staff: ‒ To minimise risk. ‒ To understand maintenance requirements. Information, Instruction and Training Users of work equipment should: • Only operate equipment they are authorised to use. • Operate equipment in accordance with instruction and training. • Only use equipment for its intended purpose. • Carry out safety checks before using equipment. • Not use equipment if it is unsafe. • Report defects immediately. • Not use equipment under the influence of drugs or alcohol. • Keep equipment clean and maintained in safe working order. Maintenance Requirements Maintenance regimes: • Planned preventive maintenance: ‒ E.g. car engine oil change. ‒ Scheduled at regular intervals. • Condition-based maintenance: ‒ E.g. vehicle brake pads. ‒ Following routine inspection. • Breakdown maintenance: ‒ Emergency repairs. Group Exercise Maintenance is often seen as a ‘highrisk’ activity. What is it about maintenance work that increases the risk? Maintenance Requirements During maintenance, staff at greater risk because: • Guards and enclosures removed. • Safety devices removed or disabled. • Equipment partially or completely dismantled. • Power sources exposed. • Stored power released, e.g. compressed spring. • Access awkward. • Manual handling heavy parts. • Additional hazards, e.g. power tools. • Pressure to get the equipment running quickly. Maintenance Requirements Additional precautions during maintenance work: • Competent staff. • Power sources isolated/locked off. • Stored power released or secured or: ‒ Cover live parts with insulating material. ‒ Use additional PPE. • If dangerous moving parts are accessed: ‒ Run at very slow speed. ‒ Fit purpose-made maintenance guards. • Precautions for safe access. • Use manual handling aids. Equipment Controls and Environmental Factors Controls should be: • Well designed, easy to use. • Suitably located. • Easily identifiable. • In good working order. • Compliant with relevant standards. Emergency stops: • Buttons. • Pull cords. Equipment Controls and Environmental Factors • Equipment should: ‒ Be stable. ‒ Have controls appropriately marked. ‒ Have appropriate warning signs. • Lighting should be: ‒ Adequate. ‒ Suitable (note ‘stroboscopic’ effect). ‒ Environmentally suitable. • Space should be adequate. Hazards and Controls for Hand Tools Include: • Hammer. • Chisel. • Screwdriver. • Axe. Group Exercise Discuss: • what accidents can occur with hand-held tools, and • how the tools became damaged. Hazards and Controls for Hand Tools Hazards: • Tool may shatter. • Handle may come loose. • Tool may be blunt requiring excessive force. • Human error, e.g. hit thumb with hammer. • Misuse, e.g. wrong tool for job. Hazards and Controls for Hand Tools Controls: • Tools suitable for the task and environment of use. • Information, instruction and training. • Visual inspection of tools. • Substandard tools repaired or discarded. • Maintenance of tools. • Supervision of practices. Hazards and Controls for Portable Power Tools Higher risk because: • Forces are greater, meaning potential for very severe injury. • Additional hazards present, such as: ‒ ‒ ‒ ‒ ‒ ‒ ‒ Electricity. Petrol. Noise. Vibration. Dust. Ejected material. Trip hazards. Hazards and Controls for Portable Power Tools Controls: • Careful selection: ‒ Task. ‒ Environment. • Instructions: ‒ Manufacturer's instructions. ‒ In-house rules. • Training and information, competence. • Supervision. • Routinely inspected. • Repair or disposal of unsafe tools. • Regular maintenance - by competent staff. Hazards and Controls for Portable Power Tools Requirements of safe practice: • Tools used within design specification (e.g. disc speeds). • Guards and safety devices in place. • PPE used. • Power cables controlled. • Ejected parts controlled, e.g. secured work area. • Control of any noise, dust, vibration. • Safe storage and handling of fuel (e.g. petrol). • Inspection and testing of electrical equipment. Mechanical and NonMechanical Hazards Mechanical hazards: • Contact with or being caught up by moving parts. Non-mechanical hazards: • From power source or things being emitted by the machine. Mechanical Hazards • Crushing. • Shearing. • Cutting or severing. • Entanglement. • Drawing in or trapping. • Impact. • Stabbing or puncture. • Friction or abrasion. • High-pressure fluid injection. Mechanical Hazards Crushing Mechanical Hazards Shearing Mechanical Hazards Cutting or Severing Mechanical Hazards Entanglement Mechanical Hazards Drawing in or Trapping Mechanical Hazards Impact Mechanical Hazards Stabbing or Puncture Mechanical Hazards Friction or Abrasion Mechanical Hazards High-Pressure Fluid Injection • Injuries caused by liquids released under pressure. • May have small entry wound but travel through tissue. Group Exercise What are the non-mechanical hazards which are associated with machinery? Non-Mechanical Hazards • • • • • • • • • • Electricity. Noise. Vibration. Hazardous substances. Ionising radiation. Non-ionising radiation. Extreme temperatures. Ergonomics. Slips, trips and falls. Fire and explosion. End of Module 9.3 Exercise 1. Identify the mechanical hazards. 2. Identify the nonmechanical hazards. Machinery Safeguarding Methods • Fixed guards. • Interlocked guards. • Adjustable/self-adjusting guards. • Sensitive protective equipment (trip devices). • Two-hand controls. • Hold-to-run controls. • Emergency stop controls. • Protective appliances. • Personal protective equipment. • Information, instruction, training and supervision. Machinery Safeguarding Methods Types of machinery guards: Fixed. Interlocked. Adjustable/self adjusting. Trip. Fixed Guards • Completely prevent access to dangerous parts of machinery. • Are fixed in place. • Require a tool for removal: ‒ Limitation. Group Discussion Apart from the mechanical hazards, what hazards can fixed guards provide protection against? Group Discussion Apart from the mechanical hazards, what hazards can fixed guards provide protection against? • Electricity. • Radiation. • Hot surfaces. • Noise. • Ejection of swarf or dust. Interlocked Guards Guard open: • Power to the machine is disabled when the guard is open and it will not operate until the guard is in place. Guard closed: • the guard is locked shut until the machine has returned to a safe condition; or • the act of opening the guard stops the dangerous parts of the machinery and disables power. Interlocked Guards Limitations: • Can bypass the system. • Person may gain access by closing the guard around them. • Needs rule to be enforced. Adjustable and Self-Adjusting Guards Used when it is not possible to prevent access to dangerous parts. Adjustable guard: • Set manually to a range of positions by the operator. Self-adjusting guard: • Usually spring-loaded to adjust itself to the workpiece. • Requires no adjustment by the operator. Sensitive Protective Equipment (Trip Devices) • Not a physical barrier. • Use sensors to detect presence of operator and stop the machine. • They include: ‒ Pressure mats. ‒ Trip bars. ‒ Photoelectric devices. • Limitations? Two-Hand Controls Designed to protect the operator's hands: • Controls should be more than a hand span apart. • Must activate at the same time. • Releasing controls must stop the machine immediately. • Limitations? Emergency Stop Controls • Should bring the machine to a safe stop as quickly as possible. • Machine can only be restarted using the reset button. • Release of the button should not restart the machine. • Limitations? Protective Appliances Designed to keep operators’ hands away from danger. Include: • Push-sticks. • Jigs. • Clamps. Specific Machinery Examples – Hazards and Control Measures Manufacturing and maintenance machinery: • Bench-top grinder. • Pedestal drill. Agricultural and horticultural machinery: • Cylinder mower. • Strimmer or brush-cutter. • Chainsaw. Retail machinery: • Compactor. Construction machinery: • Cement mixer. • Bench-mounted circular saw. Group Exercise Choose one of the ‘specific machines’ and outline: • The hazards (mechanical and nonmechanical). • Control measures. Requirements for Guards and Safety Devices • Meets relevant standards. • Strong and robust. • Compatible with machine operation. • Not easy to defeat. • Allows vision. • Allows ventilation. • Easy to maintain. • Designed to allow for maintenance. • Does not increase overall risk.