NEBOSH IGC Summary – week 2Element 1:- Workplace hazards & risk control Hazards to pedestrians Slips, trips and falls (on same level) Falls from height Objects moving, flying or falling Collisions with moving vehicles Causes of slips, trips & falls (accidents on walkways or Staircases) 1- Old age 2- Sensory impairment e.g. Poor eyesight 3- Unsuitable foot wear 4-Slippery surface e.g. polished floor 5- Spillage e.g. oil on floor 6 During the floor cleaning 7- Poor lighting / limited vision because of the dust or fog 8- Uneven surface 9-moving from one kind of floor surface to another 10- Carrying heavy / large loads 11- Poor physical condition / ill health / consciousness problems 12- Rainy weather without suitable drainage system 13- Poor housekeeping / Obstacles on the walkway (e.g. protrusions) 14- Bad organisation or layout of the work place 15- Lack of attention / distractions 16- Alcohol & drugs 17- Fatigue & exhaustion 18- Loose / Untied shoe laces 19- Poor emergency procedures: people crowding, panicking & rushing to evacuate 20- Not using the handrails 21- Not keeping 3 points of contact 22- Walking backwards e.g. banks man 23- Broken steps / different heights 24- Running, jumping & Horseplay May 2012 by Dr Osama Abdel-Wahab
[email protected] Page 1 NEBOSH IGC Summary – week 2 Working at height Hazards of working at height Fall of people Fall of objects Collapse Overturn Contact with overhead services Precautions & Control measures: - Avoid working at height by using long tools or machines - Reduce height as much as possible - Reduce duration & frequency of working at height - it is - Using proper working platform, carrying out pre use inspection & regular maintenance - PPE e.g. safety harness, fall arrestors & helmets with strap - Edge protection & Safety net - Ensure Safe access & egress to the work place Precautions & Control measures of working on ANY roof: The above precautions PLUS: - Using crawl boards - Locating & covering the lights on the roof (if any) Hazards of ladders Fall of people Fall of objects Collapse Overturn Contact with overhead services Precautions & Control measures: - Ladder resting with both feet on a levelled firm floor - Distance between the ladder & the wall in the ratio 1 : 4 - Rested & fixed against solid surface - Suitable for the task, approved, inspected & in good condition - Fixed & secured at the top - 3 steps extra length at the top - Only one person at a time - Keeping 3 points of contact - PPE e.g. gloves,safety shoes, coveralls & helmets with straps - Clean firm non-slip steps - Should only be used as a mean of access NOT as a working platform May 2012 by Dr Osama Abdel-Wahab
[email protected] Page 2 NEBOSH IGC Summary – week 2 Independant tied Scaffold Draw and label key parts of an independent Tied Scaffold Control measures & precautions - Designed, erected, inspected, altered & maintained by competent certified people Should be suitable for the job & certified Inspected before each shift & after any accident, incident or adverse weather conditions Avoid overloading or exceeding SWL Use of guard rails & toe boards Stop work in adverse weather conditions e.g. strong wind it is PPE e.g. helmets with strap & safety harness May 2012 by Dr Osama Abdel-Wahab
[email protected] Page 3 NEBOSH IGC Summary – week 2 Mobile Tower Scaffold Hazards Fall of people Fall of objects Collapse Overturn Contact with overhead services Precautions & control measures Above precautions for independant tied scaffold PLUS: - Positioned on firm ground Use of outriggers to broaden base & locking the wheels Braced & tied to permenant structure People and materials removed before moving Mobile Elevated Work Platforms (MEWP) Hazards - Fall of people - Fall of objects - Collapse - Overturn - Contact with overhead services - Crushing between carrier and a fixed structure or inbetween the Scissors lift Accidetns, Collapse or overturning of MEWP caused by Equipment failure Unsuitable ground conditions Defective or unused outriggers Unsuitable MEWP or in bad condition (lack of maintenance) Overloading Struck by load or vehicles Incompetent operator Interference with controls by others Strong wind / storms Precautions & control measures = Same like Tower scaffold May 2012 by Dr Osama Abdel-Wahab
[email protected] Page 4 sewage.Type of soil . gas pipes. CAT (cable avoidance tools) Issue permit to work Safe digging procedures (follwoing SSOW) Use competent workers – it is PPE e. spores) .Fall of objects e.NEBOSH IGC Summary – week 2 Suspended access cradle Hazards Fall of people Fall of objects Collapse Overturn Contact with overhead services Crushing between carrier and a fixed structure Precautions & control measures = Same like Tower scaffold Excavations Main hazards .com Page 5 . tools or fluids causing flooding .Contamination (sewage.g. helmets & safety shoes Improving evironmental factors such as lighting & ventillation Ensure safe access & egress May 2012 by Dr Osama Abdel-Wahab DR47241@yahoo. coveralls.Contact with underground services (electrical cables.Undermining foundations Precautions & control measures Plan the job using location maps Locate & avoid underground cables e.g.Access and egress (being a confined space: Difficults access & egress.g.Removal of soil .Collapse of the excavation (Caving) .Overturn of vehicles close to edge .Fall of people . Hazardous atmospheres . telephone) . steel toe safety shoes Safe access & egress Issue pertmit to work & other legislative documents Site Precautions for children .Warning signs & Posters .Fencing & barriers all around the site .Monitoring the area with CCTV Cameras .Reduce heights of materials May 2012 by Dr Osama Abdel-Wahab
[email protected] schools & provide information to the people in charge .Take children to site on visits (arranging class trips to the site) .Lock the vehicles & remove the keys .Security guards & patrols . helmets.g.com Page 6 .Lock away hazardous chemicals . Gases. reflective vest . fumes and vapours Asbestos Lead Silica Noise Vibration Ionising radiation Biological hazards Control measures & Precautions: Pre-demolition surveys & area maps Safe method of demolition & safe organized demolition sequence Competent workers Evacuating near buildings if needed PPE e.Cover holes & excavations .NEBOSH IGC Summary – week 2 Demolition Methods of Demolition Hand-held tools Machine Chemical agents (Explosives) Hazards of Demolition Safety hazards: Fall of People Fall of objects Premature collapse Contact with underground & overhead services Fire & Explosion Electricity Health hazards.Remove ladders & prevent access to scaffolds . radio.Apply the handbrake and the wheel chock to prevent rolling away .To be parked in the designated parking area (on a levelled surface not Blocking Walkways or exits) .Remove the key & keep it with the responsible person / place.Put gears (controls) in neutral position. Driver selection Suitable age Medical examination & Routine medical checks at regular intervals Assessment after prolonged absences Competence (KATE.Fire and Explosions Additional hazards of electric – battery fork lifts .NEBOSH IGC Summary – week 2 Element 2: Transport hazards and risk control Hazards of vehicles including fork lift trucks (General) .Overturning .Loss of loads .Hydrogen gas released during battery charging .Corrosives leading to burns . .They are quiet (People may not hear them coming) Procedures to follow when parking fork lift trucks .com Page 7 .Switch off engine.Inhalation of fumes .Overloading .Mast slightly tilted forward .Collision with pedestrians. lights.Electricity problems . buildings or other vehicles .Surround the forklift with cones & barriers to prevent trips over the Forks.. etc. ..Manual handling of battery during recharging .Forks to be resting on the floor . Proper qualifying training & Refresher training) May 2012 by Dr Osama Abdel-Wahab DR47241@yahoo. . steel toe safety shoes & High visibility jackets Driver training & qualification Using ground guides in reversing (Signallers / Banks men) Avoid reversing if possible e.com Page 8 .g. CCTV cameras or mirrors on vehicles & at blind corners Setting speed limits for cars e. One-way systems. adequate lighting & reduced noise Avoid sharp or blind bends Vision panels in doors or transparent doors Sufficiently wide entrances. drive through parking. circling the vehicles Reversing alarms (audible & visual) Refuges & Barriers in loading docks May 2012 by Dr Osama Abdel-Wahab DR47241@yahoo. gateways & traffic routes Vision aids e.g. proper signs & Floor marking Segregation between vehicular route & pedestrian route Suitable designated parking areas Proper environmental conditions e.g.g.NEBOSH IGC Summary – week 2 Safety of pedestrians in vehicle moving areas Precautions to prevent collision between vehicles and pedestrians Precautions to ensure safety of vehicles operation - Setting & enforcement of site traffice rules.g. 20 km/h Designated marked crossing points for pedestrians FOPS ROPS PPE e. smokers or existing medical condition Constraints on space Environment (low temperature) Control measures: Improve or fix above plus:Automate or mechanise task Use correct tools and equipment it is May 2012 by Dr Osama Abdel-Wahab DR47241@yahoo. Ergonomics is the study of designing equipment and devices that fit the human body. how to fit the work to the worker. pulling or over reaching movements Symptoms Numbness & tingling in fingers Pain in hands or arms Restriction of joint movement Soft tissue swelling Examples for WRULDs Tendonitis Epicondylitis Carpal Tunnel Syndrome Risk factors to consider Force exerted Duration & frequency of operation Repetition of movement without rest or recovery time (frequent breaks) Awkward Posture Vulnerability e.com Page 9 .Musculoskeletal hazards & risk control Ergonomics: The relation & interaction between the work & the worker. In other words. and its cognitive abilities.g.NEBOSH IGC Summary – week 2 Element 3:. Causes of WRULDs Repetitive movements of fingers. its movements. hands or arms Twisting movements Squeezing Hammering Pushing. stress & Discomfort Workstation requirements Adequate lighting (general & local lighting) Minimum noise Suitable legroom Suitable screen at eye level Keyboard at suitable distance Suitable software Organized work surface Footrest if necessary Document holder if needed Suitable work chair Characters of the Suitable Seat Good lumbar support Comfortable material with good width and depth Adjustable (Ability to adjust seat back and height) Stable base (5 legs or 5 points of contact with the ground) Ability to swivel Provision of arm rests Other control measures: .Adequate breaks (regular & mini breaks) .Eye sight testing & medical checkup .com Page 10 .it is May 2012 by Dr Osama Abdel-Wahab
[email protected] IGC Summary – week 2 Health effects of DSE use (Display Screen Equipment) Upper limb disorders (WRULDs) Eye and eyesight effects Epilepsy Facial dermatitis Electro magnetic radiation effect on pregnant women Fatigue. Repetitive handling without adequate breaks or recovery time .g.Handling excessive loads . abrasions. energy. pregnancy or illness Competence (Manual handling Training. Environment Constraints on posture / Space Floor condition & type of floor surface Level of housekeeping Hot/Cold/ humid conditions or strong wind Environmental factors e.Prolonged handling of loads especially if including excessive: Bending. bruises (Contusions). Job rotation / sufficient rest or recovery (breaks) Team lifting Any need for excessive pulling. Height. Muscle Sprains. Stamina. slipped disc (Disc prolapsed). twisting. Size. Hernia Activities at risk . physical abilities & experience) PPE Task Number of boxes needed to be lifted Duration & frequency of the job Vertical & Horizontal distance where the load will be lifted to. Burns Internal: Fractures. Difficulty to grasp Stability (centre of gravity) Sharp edges Hot / cold surface Contents (hazardous or not) Individual Gender Physical capability. twisting & over reaching Factors affecting the manual handling: Load Weight. pushing. ligaments tears.NEBOSH IGC Summary – week 2 Manual Handling Manual Handling Injuries External: Cuts. bending & overreaching. Tendon tears. Lighting remember LITE May 2012 by Dr Osama Abdel-Wahab DR47241@yahoo. Shape Rigidity. stooping. joint dislocation.com Page 11 . Put down the load then slide into position Mechanical lifting equipment - Forklifts Conveyors Cranes Hoists CONVEYORS Hazard Entanglement Drawing in Sharp edges Items jamming conveyor Fall of objects Riding or crossing conveyor Impact with objects Noise Manual handling Electricity Control measures & Precautions Guards.Reduce duration & frequency of manual handling tasks . No loose clothing Pop out rollers.) .Lift the load keeping the back straight & bending only the knees .PPE e. gloves & safety shoes .Team lifting . guards Edge guards.com Page 12 . trolley . barriers Bridges.NEBOSH IGC Summary – week 2 Hierarchy of control to reduce manual handling injuries: .it is (manual handling training .Dividing the load into smaller packages (less weight) . complete enclosure Helmets Ear plugs Mechanical handling & it is Maintenance & good selection May 2012 by Dr Osama Abdel-Wahab
[email protected] aids e.Avoid manual handling (automate or mechanise the job by using forklifts.Keep the Load close to the body while walking .Walk Smoothly avoiding jerky movements .Assess the load . cranes.Ensure secure & firm grip with PPE .Follow safe system of work (safe handling technique) Kinetic Handling Technique (safe way of lifting a box) .g.Get as Close as possible to the load with suitable feet position . eliminate edges Adequate design. hoists or conveyors) . nip guards Edge protection. etc.g..Check the route . Clear pathway avoiding any obstructions .Ensure suitable weather conditions and stop the lifting operation in adverse weather conditons e. color coded lifting accessories & correct slinging technique .Avoiding overhead services such as power lines .NEBOSH IGC Summary – week 2 Hazards of CRANES Fall of people Fall of objects Collapse Overturn Contact with overhead services Types of CRANES Mobile Tower Gantry Overhead Gantry Types of HOISTS Chain hoist Goods hoist Patient hoist (rescue hoist) Safe use of Cranes (Precautions for ANY safe mechanical lifting) .com Page 13 . Release the tension first to avoid load tackling May 2012 by Dr Osama Abdel-Wahab
[email protected] Good visibility with adequate lighting & reduced nosie .Load to be lifted vertically and to correct height & kept near ground when travelling .Suitable certified. balanced & guided by tag lines .Segregation of working area by barriers & warning signs so one could walk under the load . Gloves.Competent crane operators & banks men using good means of communications & agreed signals .g.g.Ensure load is secured.Visual & Audible alarms to warn that lifting is taking place . strong wind .Avoid exceeding of the SWL .PPE e.Use of outriggers . steel toe safety shoes and reflective jackets .Suitable ground conditions (firm levelled surface) .When the load is placed on the ground.Suitable certified crane . Dissipation of stored energy e.) Ejection Draw labelled diagram of each one Entanglement Traps (Drawing in) May 2012 by Dr Osama Abdel-Wahab
[email protected] suitable PPE e.Initial integrity . safety shoes.com Page 14 .g.Segregation of the work place by means of barriers & warning signs Safe means of access .Isolation of power source (disconnection & lock out tag out) .g.Work equipment hazards & risk control Suitability of the work equipment .Ensure that all workers doing the job are Competent enough .Emergency procedures / SSOW Mechanical Hazards of Machinery (ENTICE) Entanglement Traps (drawing in – crush / shear) Impact Contact (stab/puncture – cuts – abrasions – burns – etc.g.Place of use Precautions for maintenance Work . adequate lighting & good ventilation .Ensure safe environmental conditions e.NEBOSH IGC Summary – week 2 Element 4:.Purpose for use .Issue permit to work if the job is high risk or non-routine as example if the whole body or the whole arm of the worker will be inside the machine . earthing for electricity or leaving the hot surface to cool down . coveralls and safety glasses . release stored pressure. NEBOSH IGC Summary – week 2 Traps (Crush / shear) Contact (puncture / stab) Contact (abrasions) May 2012 by Dr Osama Abdel-Wahab Imapct Contact (cuts) Ejection
[email protected] Page 15 . Cement Mixer. dust.Cylinder mower & trimmer Retail Machinery:. noise. ejection of materials May 2012 by Dr Osama Abdel-Wahab Disadvantages Not linked to machine controls No protection when removed Full access to dangerous parts when removed More difficult to remove: not practical when frequent access required Tends to be left unfixed when frequent access required May hamper visibility DR47241@yahoo. pressure sensitive mats and two hand control system) Training.NEBOSH IGC Summary – week 2 Non-Mechanical Hazards of Machinery Chemical / biological hazards Ergonomics / Manual Handling Electricity / Noise Fire / Explosion Vibration / Radiation / Ultra violet radiation Temperature extremes Dust and fumes Office machinery: . photo electric cells.Waste Compactor & Checkout Conveyor Construction Machinery:. Advantages Minimal maintenance Only defeated by deliberate act Visual inspection is enough May protect against other hazards e.A physical barrier.com Page 16 . Appliances (Holders / Push Sticks) & Protection devices (Trip device.Photocopier and document Shredder Manufacturing / Maintenance Machinery: Bench top grinder and Pedestal drill Agricultural Machinery: . safety trip wire. Instruction. and Supervision (it is) and PPE Fixed Guards:. Circular Saw & petrol chainsaw Machinery Hierarchy of Controls (FIAT) Fixed guards Interlocking guards. Adjustable guards & Automatic sweep guards. kept at its place at all times. Information. not linked to the machine controls and usually requires a tool to remove it. has no moving parts.g. such as Trip device. etc.com Page 17 .ear plugs for noise . two types of this guard: 1) Manual (fixed) type and 2) Automatic type Automatic Sweep Guard Where the guard pushes the worker away from the danger zone Protection Appliances:.hair nets for hair entanglement GLOVES should be banned near rotating shafts May 2012 by Dr Osama Abdel-Wahab
[email protected] IGC Summary – week 2 Interlocking Guard: . photo electric system. PPE: such as .Linked to the machine controls so that the worker can’t gain access when the machine is in a dangerous condition ALSO opening the guard causes the machine to become safe Advantages Allow safe access for feeding materials (frequent opening) Convenient to use Less likely to be deliberately defeated Speeds up operations Disadvantages Increase the complexity of the machine Difficult to test and maintain May need a brake or time delay May fail to danger Regular maintenance required Adjustable Guards the length of the guard could be adjusted (changed) according to the length of the material being used.such as holders & push sticks Protection devices:. who is authorized to use it.steel toe safety shoes for crush injuries .coveralls for chemical splash & entanglement . safety trip wire.goggles for ejected material . how & when to be maintained. pressure sensitive mat & two hand control device iT is: on how the machine is operated safely. com Page 18 .Nature of contact (grip or touch) .Current (amperes) .Apply CPR if needed .Time .Current path through the body . general health condition. children with thin skin) Emergency action on finding someone in contact with electricity .Isolate the supply if possible or move the person away from the source of electricity using an insulating material e. wood .Electrical Safety Hazards of Electricity Be SAFE Burns Shock Arcing Fire Explosions • Burns Internal burns to the body organs & external burns to the skin 3 degrees Melting any worn metals e.Call for help .g.Individual factors (age.Treat burns if any .NEBOSH IGC Summary – week 2 Element 5:.Conductivity or resistance of the body .Remain with casualty till emergency services arrive • Arcing When electricity has sufficient potential to jump across insulating material such as air May 2012 by Dr Osama Abdel-Wahab
[email protected] .g.Check ABC . watches or rings • Shock electric shock (Electrocution) Factors affecting / influencing severity of electrical shock . trapped in machinery or getting in contact with chemicals or hot surface Pre use visual inspection to ensure good insulation and that wiring and casing are free from damage Using approved suitable equipment & in good condition Avoid home made or temporary connections Always pull the plug NEVER the Lead & Avoid continous flexing Use the suitable protective systems such as May 2012 by Dr Osama Abdel-Wahab DR47241@yahoo. insulating gloves & safety shoes Avoid overloading circuits Regular preventive maintenance for the electrical equipment including thermographic tests Safe correct routing of cables to avoid being ran over by vehicles.NEBOSH IGC Summary – week 2 • Fire Causes of Electrical Fires Inadequate circuits Overloading electrical circuits Incorrect fuses Damaged insulation Loose connections Using flammable materials too close to electrical equipment Overheating of cables on coils Inadequate ventilation for electrical equipment & cables • Explosion Ignition of gas Secondary Effects of Electricity Falls from height Throw off (away from the source of electricity) Unintentional movement of machine Failure / De-activation of control measures & security systems Loss of information Tripping over cables Loss of corporate reputation Health effects of Electricity on the body External burns to the skin Internal burns to the body organs Irregular heartbeat (Fibrillation) Stopping of the heart (cardiac arrest) Stopping of breathing (Respiratory paralysis) Muscular contractions Damage to nervous system Precautions to ensure safety of portable electrical equipment Ensure competence of workers : KATE PPE e. dragged over rough surface.com Page 19 .g. e. professional installation Protection defeated if removed
[email protected] IGC Summary – week 2 Protective systems: Fuse:. breaking the circuit at excessive currents Advantages Cheap and readily available Protects equipment Disadvantages Does not protect the individual from shock Slow to operate Inaccurate Unsuitable or wrong fuse may be used Easy to override Could need tools to replace Circuit Breakers:.Electromagnetic device which perform the same function as fuses i.com Page 20 .Electricity will always try reach earth and earthing means providing a path to earth lower than the human body Advantages May prevent indirect shock by providing a very low resistance path to earth Readily identified May 2012 by Dr Osama Abdel-Wahab Disadvantages Specialist testing and maintenance. break the circuit at excessive current although slightly faster Advantages Automatically switch or trip under fault conditions No tools to reset Not easy to override No reset until fault cleared Protects against overload Disadvantages Does not protect the individual from shock Earthing:.A weak link designed to melt. com Page 21 .By reducing the voltage present system the consequences of electrical shock can be greatly reduced Advantages Available voltage difference is 55V ac .The disconnection and separation of the electrical equipment from every source of electrical equipment in such a way that the disconnection and separation is secure (Lock out & Tag out) Advantages Safest option as it eliminates electricity May be physically locked off Disadvantages May isolate other equipment May be reconnected unless locked off Prevents live fault finding Battery operated tools:.Using battery instead of electrical wires Advantages Minimal risk during normal use Range not restricted by cable No trailing cable = No tripping hazards or overheating cables Disadvantages Limited battery capacity Limited power output Precautions need to be followed during mains charging Heavier More expensive Reduced voltage systems:.NEBOSH IGC Summary – week 2 Isolation:.injury is highly unlikely Colour coded cabling system for easy recognition May 2012 by Dr Osama Abdel-Wahab Disadvantages Specialist equipment required for 110 V Lead from supply to transformer at higher voltages and will need protection with a RCD DR47241@yahoo. g.NEBOSH IGC Summary – week 2 Residual Current Device (RCD):.Covering live parts by two separated layers of insulation Advantages Two layers of insulation prevent user contact with any live parts No earth required May 2012 by Dr Osama Abdel-Wahab Disadvantages Physical damage may defeat double insulation No earth provided in double insulation extension leads. When the level differs by a preset value the RCD will open rapidly and interrupt the supply Advantages Rapid and sensitive Difficult to defeat Easy to use. test and reset Disadvantages May isolate crucial equipment if one RCD covers a number of distribution points.It compares the current flowing into the system with the current flowing out. which could fail Only protects against earth leakage faults (no overload protection) Cannot be reset with a fault on the circuit Double Insulation:. freezers and computers Mechanical device.com Page 22 . e. therefore defeats protection if used with equipment that requires an earth DR47241@yahoo. Heat is radiated through the air causing heating of a materials at a distance from the fire.The flame and a combustible fuel are in direct contact and the fuel heats up and eventually ignites. and allows fire to spread from one room to another.Hot air current rises up to replace cooler air . spark Fire point:.The temperature at which gas & vapour will sustain a flame when ignited by an external source of ignition e. Radiation:. causing the build up of hot and unburned gases under ceilings etc. etc. Conduction: Heat travels within solid material from the hot part to cooler part Convection:.The temperature at which gas & vapour will ignite momentarily by an external source of ignition e.com Page 23 .g.The temperature at which gas & vapour will ignite without any external source of ignition.Fire safety The fire triangle: Fuel (Combustible material) Heat (Source of ignition) Oxygen (air) Causes of fire Arson Smoking & smokers’ materials Oil/gas heating equipment and portable heaters Unsafe storage of flammable materials Use of flammable liquids or gases in unsuitable areas Hot work: welding.NEBOSH IGC Summary – week 2 Element 6:.g. cutting. Methods of Heat Transfer Direct burning:. May 2012 by Dr Osama Abdel-Wahab DR47241@yahoo. Mechanical heat (Sparks/friction) PLUS causes of electrical fires page 19 Flash point:. spark Auto-Ignition (Self ignition):. or citrate) extinguishes the fire by forming a soapy foam blanket over the burning oil and by cooling the oil.NEBOSH IGC Summary – week 2 Classes of fire A B C D F Carbonaceous material (Combustible solids) EXAMPLE: Wood & paper Flammable liquids EXAMPLE: Alcohol & Petrol Flammable gases EXAMPLE: Butane. carbonate. Dry powder or Aqueous Film Forming Foam (AFFF) Dry powder. In the UK the use of Halon gas is now prohibited except under certain situations such as on aircraft and in the military and police May 2012 by Dr Osama Abdel-Wahab
[email protected] Page 24 . AFFF or CO2 Dry powder or CO2 Special powder or dry sand Wet chemicals For Electrical Dry powder or CO2 Wet Chemicals (potassium acetate. methane & propane Metals EXAMPLE: Aluminium & Magnesium Cooking oil EXAMPLE: Vegetable oil & animal fats Electrical Classified according to the source of ignition rather than fuel Source Types of fire extinguishers For class A For class B For class C For class D For class F Water. Roll calls . Emergency lighting & illuminating signs . Emergency lighting & illuminating signs Assembly points (Muster points) Regular drills & practices on evacuation Precautions to ensure safe evacuation in the event of fire .com Page 25 .Automatic contact with the emergency services & fire department .g. exit signs.Closing the windows & fire doors after leaving .NEBOSH IGC Summary – week 2 Precautions to prevent & control risk of fire AND to minimise the risk to people in the event of fire - - Eliminate / reduce the amount of flammable materials Segregate fuel & ignition sources Good level of housekeeping to prevent accumulation of waste paper Good security measures to prevent arson Safe storage of flammable material Compartmentation: dividing the building into isolated units (compartments) by means of fire doors & fire walls so that any fire in any of these units will be contained there & won’t spread to the rest of the building Proper regular maintenance for all types of equipment Electrical safety it is & following SSOW Suitable fire alarms & fire detectors.Special consideration for disabled people.Muster point / assembly point (clearly identified & proper location) . smoke detectors . exit signs. . pregnant women. hose reels .Unobstructed means of escape with reasonable travel distances fire doors.Fire marshals & fire wardens helping in the above May 2012 by Dr Osama Abdel-Wahab
[email protected] means of raising alarms (visual & audible) .Regular drills & practices on evacuation .Safe evacuation plan.Adequate fire detection equipments e. sprinklers. whose reels and fire extinguishers Unobstructed means of escape with reasonable travel distances. Fire marshals to guide the employees during the evacuation Suitable means of fire fighting such as water sprinklers.Adequate fire fighting equipment such as: Fire extinguishers. . etc. fire doors. Fibrosis of the lung: isolating the affected non-functioning part from the rest of the healthy lung .Sebum: the oily substance secreted by the skin to prevent it from dryness .The hair in the nose acting as a filter to purify the air from the dust particles .Melanin: responsible for the pigmentation of the skin. . Skin defences . . more melanin makes the skin darker providing more protection from the sun and ultra violet light .Keratin: Forming the protective hard layer of the skin . rash and inflammation to fight any infection of the skin May 2012 by Dr Osama Abdel-Wahab
[email protected] serves: the sense of touch in the skin .The change of direction to the larynx so the dust particles in the air would stick to the nasal wall .Chemical & biological health hazards & risk control Respiratory defences (Body defences against dust) .Sweating: Cooling down the skin and killing harmful organisms .wetness of the nose (mucus) so the dust would stick to it & will be trapped and will go no further inside the lung .Blisters.Tears and blinking of the eyes (not part of the respiratory defences) Digestive defences (Body defences against ingested substances) .Hair: protecting and filtering the skin .The hair cells in the respiratory tract (Ciliary escalator) pushing the dust upwards till it reach the throat where it could be removed from the body .Turbulent motion of the air in the nose and the centrifugal force which will throw the dust to the sides sticking to the mucus .Vomiting & diarrhoea which get rid of the toxins and the harmful substance out of the body.NEBOSH IGC Summary – week 2 Element 7:.The immunity system of the body: White Blood Cells (WBC) in the alveoli .com Page 26 . the useful bacteria and the strong acid (HCL) which will destroy the harmful substances inside the stomach.Digestive juices & enzymes.Smell & taste protecting the person from eating or drinking harmful substances or bad food.Sneezing and coughing which would expel the dust outside the respiratory system . Dryness and cracking of skin. rash. there is none which is not a poison.Irritation of the skin. Blisters.com Page 27 .Pain .NEBOSH IGC Summary – week 2 Other defences . skin & lungs Organic solvents liver. hotness.Allergic / Sensitive Symptoms: .g. redness.g. and in severe cases: Ulcers & infections Protective measures against dermatitis (Precautions) Eliminate the substance Substitution by a less hazardous one Reduce duration & frequency of exposure to the substance Medical checkup for the workers Good hygiene practices PPE e. Inflammation.Tears & Blinking of the eye . Target Organs: The part / parts of the body which could be affected by an external substance Example: Inhalation of asbestos fibres will affect the lung causing cancer (asbestosis) SO the target organ of the asbestos is the lung Other examples: Mercury.Hormones e. skin & lungs Also see examples page 34 Local effect: The effect of the substance happens at the same point of contact Systemic effect: The effect of the substance happens away from the point of contact May 2012 by Dr Osama Abdel-Wahab
[email protected] / Contact 2. gloves and coveralls Barrier creams Extractor fans & LEV it is Dose-response relationship All substances are poisons. Adrenalin Types of Dermatitis: 1. swelling. The right dose differentiates a poison and a remedy. Lead brain & nervous system Ammonia eyes. 0 micron) Fume Mist Smoke Vapour • - Forms of biological agents: Fungi Bacteria Viruses Routes of entry into the body (chemical agents) .Identification of health hazards: • - Forms of chemical agents: Dust: Total inhalable & Respirable dust (0. Occupational Hygiene & Health hazards 1.Control of health hazards 1.Injection . EXAMPLE: Alcohol intoxication due to consuming large amount of alcohol in short time.Ingestion .Inhalation .Direct entry (open wounds) . it is usually reversible.Measurement of health hazards 3.com Page 28 .Assessment of health hazards 4. Chronic effect: Adverse health effects resulting from prolonged & repeated exposure to a small dose of the harmful substance producing a gradual & latent effect which usually stays unrecognized for several years. it is usually irreversible EXAMPLE: Liver damage (cirrhosis) caused by consuming small amount of Alcohol for many years.5 – 7.NEBOSH IGC Summary – week 2 Acute effect: Adverse health effects resulting from single or short term exposure to a large dose of the harmful substance producing an immediate or rapid effect.Identification of health hazards 2.Absorption May 2012 by Dr Osama Abdel-Wahab DR47241@yahoo. weak acids & alkalis Corrosive: Substances which on contact with living tissue may destroy it by burning Example: acids (sulphuric acid) and alkalis (caustic soda) Harmful: Substances which if swallowed. Example: Bromine & Benzene Teratogenic: Substances which cause harmful effects to the embryo (baby) inside the uterus of the pregnant woman. prolonged or repeated contact with skin or mucous membrane may cause inflammation (Dermatitis) Example: Petrol. Example: Drugs & medications May 2012 by Dr Osama Abdel-Wahab
[email protected] IGC Summary – week 2 Classification of Hazardous Substances Irritant: Non-corrosive substances which through immediate. cement Toxic: A poisonous substance which may cause acute or chronic damage to health or DEATH Example: Arsenic Very Toxic: A poisonous substance which may cause acute or chronic damage to health or DEATH even in low quantity Example: Cyanide Carcinogenic: Substances which cause disorders to cell growth that may lead to cancer (malignant tumours) Example: Asbestos Mutagenic: Substances which cause changes to the chromosomes (DNA / genetic material) leading to hereditary defects in the offspring of the affected person.com Page 29 . cement. inhaled or penetrated the skin may cause damage to health (cause diseases – ill health) Example: Petrol. First aid measures 5.Regulatory information 16.Exposure control & Personal protection 9.Stability & Reactivity 11.Fire fighting measures 6. manuals. types of hazards. details of the substances used. experts.Identification of the substance & Manufacturers’ information 2.Toxicological information 12.Other Occupational Exposure Limits (OEL) • Long-term exposure limit (LTEL) 8 hour • Short-term exposure limit (STEL) 15 minute Limits are expressed in: – ppm (parts per million) for gases and vapours – mg/m3 for airborne particles such as dust and fume 2.NEBOSH IGC Summary – week 2 Material Safety Data sheet (MSDS) = Information on hazard data sheet 1.Measurement of health hazards: THREE survey techniques:1) Initial appraisal: Gathering information such as OEL. people affected. from different sources such as MSDS.Accidental release measures 7. risks.Hazard identification 4. etc.Handling & Storage 8.Composition & information on ingredients 3.Transport information 15.Physical & Chemical properties 10.Disposal consideration 14.Ecological information 13.com Page 30 . and precautions. 2) Basic survey: Qualitative observations: Smoke tube & Dust lamp Quantitative observations: Stain tube detector (Grab sampler) May 2012 by Dr Osama Abdel-Wahab DR47241@yahoo. chemical reagent Fused tip Scale divisions Disadvantages Inaccurate Positioning of tube affects reading Only a snap shot Inefficient Chemical use only Substance specific 3) Full survey: Direct reading instruments: such as Carbon dioxide gas analyzer Indirect reading instruments: • Passive (by diffusion) such as radiation badge / film badge • Active (powered by mechanical pump) such as H2S detector 3.com Page 31 . e. silica gel.g.Assessment of health hazards: Risk assessment (5 STEPS AS USUAL) May 2012 by Dr Osama Abdel-Wahab
[email protected] IGC Summary – week 2 Diagram of Chemical stain tube detector (Grab Sampler) Glass tube Direction of flow READ 1 Fused tip Pre-layer Advantages Low cost Takes little time Immediate result Little training needed Information during spillage Good for coarse indication 2 3 5 10 20 Porous granules. com Page 32 .Eye protection such as goggles to protect from corrosives or ammonia .Respiratory protection such as breathing apparatus to protect from chlorine or ammonia . job rotation.NEBOSH IGC Summary – week 2 4.Barrier creams Discipline May 2012 by Dr Osama Abdel-Wahab DR47241@yahoo. adequate breaks. or avoid the activity or process e.g.Control of health hazards: Eliminate: remove the substance.g.Protective clothing such as chemical splash suits to protect from acids & biological agents . pressure jetting a blocked drain instead of using dissolving chemicals Reduce: reduce the risk by - reducing the duration / frequency of exposure to the hazard substituting the material with a less hazardous one e. using water based paint instead of solvent based paint OR using granular material instead of powder Isolate: - Total Enclosure of the machine inside a glove box Worker to be isolated inside a ventilated control room Control - Engineering Control: LEV & adequate maintenance for equipment Administrative control: Change the work pattern or method. good levels of Hygiene and housekeeping & providing the needed it is PPE: .Hand & skin protection such as gloves to protect from detergents or solvents . Wear & tear of fan blades .NEBOSH IGC Summary – week 2 Labelled diagram of Local Exhaust Ventilation (LEV) LEV becomes inefficient because of:.Increased contaminant level .Unauthorised modifications .Full / damaged dust collection bags .com Page 33 .Lack of proper maintenance .Hood damaged or not well positioned .Blocked / damaged filter .Failure of operators to use it properly .Poor design of the LEV (inadequate capacity) Checks / inspection: opposite of above May 2012 by Dr Osama Abdel-Wahab
[email protected] settings .Blocked / damaged ducts . & the liver. dizziness & loss of consciousness and in extreme cases leading to death. flushed “pink” appearance and ultimately asphyxiation and death • Chlorine A greenish toxic gas with a pungent smell.NEBOSH IGC Summary – week 2 Examples of chemical agents (hazardous substances) & Target Organs • Ammonia Strongly corrosive alkaline colourless gas with a pungent odour. • Organic Solvents These dissolve other substances & are also used as cleaning & degreasing agents. throat. eyes. headaches. lungs. Affecting the lungs increasing the rate of respiration and high levels depress the rate of respiration leading to unconsciousness and even death • Carbon Monoxide CO More toxic than CO2. Affecting the brain & the nervous system casuing acute lead poisoning Resulting in nausea. nasal passages. boilers. May 2012 by Dr Osama Abdel-Wahab DR47241@yahoo. Affecting the skin. nausea. Affecting the skin. • Lead A heavy.g. inflammation of the lungs and in the large concentrations can cause blindness and fluid in the lungs (emphysema) Eye protection and respiratory protection are essential. Affecting the eyes & the respiratory system casuing severe irritation. vehicle exhausts Affecting the lungs & the blood casuing headache. eyes & the lungs.com Page 34 . dermatitis. Leading to eye irritation. Effects may be headaches. Found where incomplete combustion occurs e. soft and easily worked metal. They are volatile & evaporate quickly at room temperature so their vapours can be breathed easily. nervous problems and in severe cases causing death. • Asbestos Affecting the lungs causing Asbestosis (Lung cancer) • Carbon Dioxide CO2 Colourless and odourless gas which is heavier than air. Can enter body by eating contaminated food or by breathing fumes or dust. Colourless and odourless and tasteless gas. drowsiness. Substitution e.Damping down the dust by spraying water .Vaccuming instead of sweeping .NEBOSH IGC Summary – week 2 • Isocyanates Organic compounds widely used in industry for products such as spray painting of vehicles and production of polyurethane rubbers and foams.Extractor fans & Local exhaust ventilation (LEV) .Visual signs of dust in the air or deposited on surfaces or clothes .Bringing pre-formed components .g. bronchitis.Results of monitoring using dust lamps or smoke tube . sneezing.Maintenance problems e.Elimination of dusty operation (outsourcing) . granite & glass Affecting the lungs as breathing silica could lead to serious lung disease “silicosis” • Dust Affecting the respiratory system causing asthma.Enclosure of the dusty operation or machines . granules or paste instead of powders . Dust Identification: .g. Affecting the nasal passages.Poor visibility or excessive tears & blinking of the eyes .respiratory problems: coughing.it is May 2012 by Dr Osama Abdel-Wahab DR47241@yahoo. • Silica Found in sand. abnormal blocking of filters Control measures for dust: . breathing difficulty .Respiratory protective equipment e. throat & the lungs leading to lung Inflammation & asthma.Reduce duration & frequency of the dusty operations .Medical check up & Health survillance with medical treatment for any health problem .Reduce duration & frequency of exposure to dust .Reduce number of workers exposed to dust . dust mask .g. emphysema and conditions such as asbestosis or Silicosis if the dust contains asbestos or silica.com Page 35 . good hygiene & housekeeping Legionella (Legionnaire’s disease) Bacterial infection transmitted to humann by inhaling airborne bacteria found in water sources such as air conditioning systems.Ingestion . swimming pools.com Page 36 . biocide treatment and effective cleaning and maintenance. it is. disinfection. meningitis & Jaundice. Routes of entry into the body (Biological agents) . covering damaged skin. river water. Pneumonia & difficulty in breathing Fatal in 20% of the cases. Hepatitis A. malaise & jaundice. Precautions & Control measures: Temperature control and monitoring. Pneumonia. coughing & headache). Precautions & Control measures: Vaccination. sneezing. water sports. etc. nausea. Those at greatest risk are smokers or old people with chest problems. Symptoms: Flu like symptoms (Fever. B and C Viral inflammation of the liver caused by viral infection transmitted through ingesting food contaminated with faeces (hepatitis A) Or by blood & body fluids (hepatitis B & C) Symptoms: Inflammation of the liver.NEBOSH IGC Summary – week 2 Biological Agents Leptospirosis (Weil’s disease) Bacterial infection transmitted to humans by ingesting contaminated rat urine. stagnant water etc. Fatal in 20% of the cases (Attacks the kidneys & liver) Precautions & Control measures: pest control. coughing & headache). sewers. fever. Avoiding sharp implements. sneezing. avoiding stagnation & avoiding “dead legs” in pipe work. Symptoms: Flu like symptoms (Fever.Injection May 2012 by Dr Osama Abdel-Wahab
[email protected] entry (open wounds) . The most common source is in construction sites. cooling towers. Proper disposal of contaminated waste and good hygiene practices.Inhalation . it is. Store different types of waste separately .Select appropriate containers .Choosing a Suitable location .Sufficient storage area .Protect waste from the elements .Never store incompatible waste together .Avoid contamination of general waste with hazardous materials May 2012 by Dr Osama Abdel-Wahab
[email protected] quantities of waste to a minimum .NEBOSH IGC Summary – week 2 Precautions for safe storage of waste .com Page 37 .Protection form adverse weather conditions .Labelled & individual containers .Ensure storage area is well secured . e.com Page 38 .NEBOSH IGC Summary – week 2 Element 8:.Damping .Frequency in Hz .Isolation . 83 dB is double the intensity of 80 dB Health effects of noise Acute Stress.Measuring the loudness / amplitude of the sound waves measured in decibel (dB) Safe limit is 80 dB Rule of 3 Every 3 dB increases means doubling the intensity i. measured in cycles per second or Hertz (Hz) Human range is 20 Hz – 20 KHz Intensity:. increased heart rate and insomnia Temporary threshold shift Temporary tinnitus Trauma e.Use of PPE .Measuring the pitch / tone of the sound waves.Distance between the source of noise & the person exposed to it .Improving the design of the machine . Burst eardrum Blast deafness Chronic Permanent threshold shift (Noise Induced Hearing Loss) Permanent tinnitus Presbycusis Factors affecting the risk from Noise .Duration & frequency of exposure to noise .Physical & psychological hazards Noise: is any unwanted sound Frequency:. Irritability.g.Proper maintenance May 2012 by Dr Osama Abdel-Wahab DR47241@yahoo. nervousness .Loudness in dB .The nature of the place Noise control measures / precautions Source: Eliminate or reduce the noise from the source by . Reduce the duration & frequency of exposure to the noise .Reduce the force exerted & the strength of grip with work equipment .it is on the nature of risks May 2012 by Dr Osama Abdel-Wahab
[email protected] Page 39 .Automate or mechanise the job to elimination the use of vibrating tools .PPE such as ear plugs & ear muffs Hand-Arm Vibration Health Effects Acute: Numbness & Tingling in the hands and extremities Chronic: .Low temperature .Select ergonomically designed equipment .Force exerted .Select the suitable tool with low vibration .NEBOSH IGC Summary – week 2 Path: Prevent/reduce transmission of noise through air or structures by using .Reduction in manual dexterity .Increase the distance between the worker & the source of noise .Screens and barriers .Swollen painful joints .Use PPE such as Gloves and heated pads .Silencer The Person: . age & health condition Control Measures for hand-arm vibration .it is .Frequency of the vibrating tools ( in Hz) .Proper maintenance of equipment .Duration & frequency of exposure .Absorption .Health surveillance & treatment of any medical problem .Permanent Numbness & Tingling .Reduce the degree of vibration as much as possible .Reduction in the sensation of touch Risk Factors .g.Individual factors e.Reduce the duration of exposure to the vibration .Enclosure .Blanching of the fingers (Vibration White Fingers) . Acclimatisation . big freezers & open air during winter) Lowered heart rate Hypothermia Shivering Confusion & Loss of concentration Frost bite Increased risk of strains & sprains Risk factors .Health surveillance & medical checkup .Temperature control .NEBOSH IGC Summary – week 2 Work in Hot & Cold environment Physiological effects of heat Stress (in foundries.Reduce duration & frequency of exposure .PPE e.Source of heat / cold temperature Control measures .Duration & frequency of exposure .it is May 2012 by Dr Osama Abdel-Wahab DR47241@yahoo. insulating clothes .Hot / cold drinks .Body activity & health condition .com Page 40 . food preparation area.Ambient temperature & weather conditions .Type & amount of clothes . glass works & laundries) Skin burns Cataracts Dehydration Heat cramps Raised heart rate Headaches Confusion & Loss of concentration Vomiting Fainting Sun stroke & Heat stroke Physiological effects of cold Stress (cold stores.g. g. erythema & cataract Death May 2012 by Dr Osama Abdel-Wahab DR47241@yahoo. eye protection • Skin creams Ionising Radiation Type Alpha Beta Gamma X-Ray Use in Industry Smoke detectors & anti static devices Thickness testing & sterilisation of material Non-Destructive Testing & Radio therapy NDT & Radio diagnosis Health effects of ionizing radiation Acute health effects (high dose) Erythema (Reddening of the skin) Radiation sickness (Nausea & Vomiting) Hair loss Diarrhoea Death Chronic health effects (small dose) Carcinogenic effect (Cancer) Mutagenic effect (Hereditary defects) Teratogenic effect Sterility .com Page 41 . e. Bar code readers Food preparation. Signal transmission Welding Radar and communications Health effects of non-ionizing radiation Burns Erythema (Reddening of the skin) Cataract Arc eye Retinal burn Temporary sterility Risk factors & Control measures of non-ionizing radiation: • Duration & frequency of exposure • Distance between the source & the worker • Shielding • it is • Proper maintenance & inspection of equipment (source) • PPE.NEBOSH IGC Summary – week 2 Radiation Non-Ionising Type Infrared Lasers Microwaves Ultra-violet Radio waves Use in Industry Heating and brazing Cutting. it is .Correct disposal of radioactive materials . Schools.com Page 42 .half life of the radioactive material . policemen & enforcement officers Control measures . safe precautions for lone workers . coded locked doors & physical barriers .it is: on absorbing anger.Checking visitors’ credentials (IDs) . wide counters.Proper shielding (Lead or thick concrete) .Avoid Lone working.NEBOSH IGC Summary – week 2 Risk factors & Control measures ofionizing radiation .Using suitable PPE e.Welcoming environment & nice decor .Zero tolerance of aggressive behaviour May 2012 by Dr Osama Abdel-Wahab DR47241@yahoo. Health care professionals. Representing authority e.Duration & frequency of exposure .Good means of Communication & alarm systems . recording and investigating violent incidents .Distance between the radioactive material & the people .Good hygiene practices .g. how to recognise aggressive behaviour & how to deal with it wisely . radiation suit .Providing information on delays .Proper queue management .g.Regular removal of cash from the workplace .Reporting.Security officers & CCTV cameras .Safe & secure design of workplace e.Monitoring exposure using film badges & Geiger counters Violence at work Verbal abuse / threats AND Physical attacks Internal AND external violence Occupations at risk Taxi drivers . Cash transactions Delivery/collection of money.g. sexual harassment. prevention of career development. work planning. race or disability. Demands: workload too high or too low. new technology. Control: how much control the person has in the way they do their work. 3. 5. shift work and unsocial hours. extremes of temperature and / or humidity. family commitments. threats or verbal abuse e. draughty conditions.com Page 43 . the conflict of different job demands such as working for more than one manager. pain killers & tobacco Insomnia (Poor sleep patterns) Causes of stress: 1. illness. and Environment: inadequate lighting.NEBOSH IGC Summary – week 2 Stress Physical Effects Headaches Dizziness Aching neck and shoulders Skin rash Prone to infections Raised heart rate & Increased blood pressure Diabetes Heart disease Stomach & mouth ulcers Psychological effects Increased anxiety Reduced concentration Irritability & nervousness Panic attacks & Sudden mood changes Inability to cope Reduced work output / performance Increased use of alcohol. 4. e. problems with glare. cramped or untidy working conditions. malicious gossip. e.g. inadequate welfare facilities and poor weather conditions for those working outside.g. financial worries. communication. and working hours. staff support systems. inadequate ventilation. fear of redundancy. being unclear about roles. unjustified picking of faults. Individual: skills not matched to the task. responsibilities and expectations. e. unclear job description. Role: job insecurity. conflicting roles. repeated shouting and swearing. 8.g. & discrimination due to gender. consultation. high noise and vibration levels. Relationships between employees: physical violence. 7. security problems. Change: how organisational change is managed and communicated in the organisation. use of acquired skills. repetitive or monotonous work. inadequate training. and exposure to violence and bullying. excessive overtime. redundancies.g. May 2012 by Dr Osama Abdel-Wahab DR47241@yahoo. e. restructuring. and fair and open feedback on the work and role. drugs. Culture of the organisation: how it approaches work-related stress. 6. 2.g. and unclear objectives. sickness absence / ill-health trends.NEBOSH IGC Summary – week 2 Identification of Stress Stress within the organisation may be identified by: • • • • • • informal observation & conversation with workers & supervisors.com Page 44 . reduced productivity of the employees High staff turnover. performance appraisal with an opportunity for open discussion of problems. monitoring of attendance records and conducting ‘return to work’ interviews. The end of week 2 GOOD LUCK Please Turn Over May 2012 by Dr Osama Abdel-Wahab DR47241@yahoo. ONLY a NEW question should be on a new separate page) The number of the question must be mentioned in the box at the top of the page All answers must be Specific . answer in the form of list Don’t cross any answer as there’s no negative marking As much as possible. 6 mark = 6 points etc.NEBOSH IGC Summary – week 2 Examination rules & tips - - Each question MUST be answered on a separate page (subsections of the same question should be answered in the same page. Action Verbs in exam questions: o Explain. Give a clear account of. don’t waste your time Read the question 3 times carefully before starting the answer If you run out of time . so the exam will be 2 & half hours instead of 2 hours but ONLY if you bring a non-technical bilingual dictionary (regular book not electronic one) Nothing else is alowed as it’s a closed book exam Time of the exam is enough but just enough . Structure your answer into separate headings e. complete & meaningful sentences The handwriting should be CLEAR enough Use the regular blue pen & in the drawings use a pencil In General: 8 mark question = 8 points answer. external & internal / short term & long term etc.com Page 45 . If your mother tongue is not English (according to the nationality registered in the exam) you will be given extra 30 minutes.g. or reasons for o List / Identify / Give / state : Select & name: Provide without explanation nor details o Define: Provide a generally recognised or accepted definition PLUS an appropriate example o Sketch: Draw a labelled diagram (using a pencil) May 2012 by Dr Osama Abdel-Wahab DR47241@yahoo. In General: the answer of 8 mark question should be about half a side of A4 page and the answer of 20 mark question should be about one side & half of A4 pages The exam starts at 9:00 am SHARP Bring your passport or ID The exam is 2 hours . Describe or Outline: Give a detailed word picture .