week 2 summary_may 2012.pdf

NEBOSH IGC Summary – week 2

May 2012 by Dr Osama Abdel-Wahab [email protected]

Element 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



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



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



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



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

- Fall of people - Fall of objects e.g. tools or fluids causing flooding - Collapse of the excavation (Caving) - Overturn of vehicles close to edge - Contact with underground services (electrical cables, gas pipes,

sewage, telephone) - Access and egress (being a confined space: Difficults access &

egress, Hazardous atmospheres - Contamination (sewage, spores) - Type of soil - Removal of soil - Undermining foundations

Precautions & control measures Plan the job using location maps Locate & avoid underground cables e.g. CAT (cable avoidance tools) Issue permit to work Safe digging procedures (follwoing SSOW) Use competent workers – it is PPE e.g. coveralls, helmets & safety shoes Improving evironmental factors such as lighting & ventillation Ensure safe access & egress



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; Gases, 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.g. helmets, reflective vest , steel toe safety shoes Safe access & egress Issue pertmit to work & other legislative documents Site Precautions for children

- Fencing & barriers all around the site - Security guards & patrols - Monitoring the area with CCTV Cameras - Warning signs & Posters - Visit 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 - Remove ladders & prevent access to scaffolds - Lock away hazardous chemicals - Cover holes & excavations - Reduce heights of materials



Element 2: Transport hazards and risk control Hazards of vehicles including fork lift trucks (General)

- Overturning - Overloading - Loss of loads - Collision with pedestrians, buildings or other vehicles - Fire and Explosions

Additional hazards of electric – battery fork lifts

- Hydrogen gas released during battery charging - Inhalation of fumes - Corrosives leading to burns - Electricity problems - Manual handling of battery during recharging - They are quiet (People may not hear them coming)

Procedures to follow when parking fork lift trucks - To be parked in the designated parking area (on a levelled surface not Blocking Walkways or exits) - Switch off engine, lights, radio, etc... - Remove the key & keep it with the responsible person / place. - Put gears (controls) in neutral position. - Apply the handbrake and the wheel chock to prevent rolling away - Forks to be resting on the floor - Mast slightly tilted forward - Surround the forklift with cones & barriers to prevent trips over the Forks. Driver selection Suitable age Medical examination & Routine medical checks at regular intervals Assessment after prolonged absences Competence (KATE, Proper qualifying training & Refresher training)



� 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, proper signs & Floor

marking - Segregation between vehicular route & pedestrian route - Suitable designated parking areas - Proper environmental conditions e.g. adequate lighting & reduced

noise - Avoid sharp or blind bends - Vision panels in doors or transparent doors - Sufficiently wide entrances, gateways & traffic routes - Vision aids e.g. CCTV cameras or mirrors on vehicles & at blind

corners - Setting speed limits for cars e.g. 20 km/h - Designated marked crossing points for pedestrians - FOPS - ROPS - PPE e.g. steel toe safety shoes & High visibility jackets - Driver training & qualification - Using ground guides in reversing (Signallers / Banks men) - Avoid reversing if possible e.g. One-way systems, drive through

parking, circling the vehicles - Reversing alarms (audible & visual) - Refuges & Barriers in loading docks



Element 3:- Musculoskeletal hazards & risk control Ergonomics: The relation & interaction between the work & the worker; how to fit the work to the worker.

In other words, Ergonomics is the study of designing equipment and devices that fit the human body, its movements, and its cognitive abilities.

Causes of WRULDs Repetitive movements of fingers, hands or arms Twisting movements Squeezing Hammering Pushing, 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.g. 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



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, 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 - it is



Manual Handling Manual Handling Injuries External: Cuts, bruises (Contusions), abrasions, Burns Internal: Fractures, slipped disc (Disc prolapsed), Muscle Sprains, Tendon tears, ligaments tears, joint dislocation, Hernia Activities at risk

- Handling excessive loads - Repetitive handling without adequate breaks or recovery time - Prolonged handling of loads especially if including excessive:

Bending, stooping, twisting & over reaching

Factors affecting the manual handling: Load Weight, Size, Shape Rigidity, Difficulty to grasp Stability (centre of gravity) Sharp edges Hot / cold surface Contents (hazardous or not) Individual Gender Physical capability, energy, Stamina, Height, pregnancy or illness Competence (Manual handling Training, 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. Job rotation / sufficient rest or recovery (breaks) Team lifting Any need for excessive pulling, pushing, twisting, bending & over-reaching. Environment Constraints on posture / Space Floor condition & type of floor surface Level of housekeeping Hot/Cold/ humid conditions or strong wind Environmental factors e.g. Lighting

remember LITE



Hierarchy of control to reduce manual handling injuries: - Avoid manual handling (automate or mechanise the job by using

forklifts, cranes, hoists or conveyors) - Team lifting - Mechanical aids e.g. trolley - Dividing the load into smaller packages (less weight) - Reduce duration & frequency of manual handling tasks - PPE e.g. gloves & safety shoes - it is (manual handling training , etc..) - Follow safe system of work (safe handling technique) �

Kinetic Handling Technique (safe way of lifting a box)

- Assess the load - Check the route - Get as Close as possible to the load with suitable feet position - Ensure secure & firm grip with PPE - Lift the load keeping the back straight & bending only the knees - Keep the Load close to the body while walking - Walk Smoothly avoiding jerky movements - Put down the load then slide into position

Mechanical lifting equipment

- Forklifts - Conveyors - Cranes - Hoists

CONVEYORS

Hazard Control measures & Precautions

Entanglement Guards, No loose clothing Drawing in Pop out rollers, nip guards Sharp edges Edge protection, eliminate edges Items jamming conveyor Adequate design, guards Fall of objects Edge guards, barriers Riding or crossing conveyor Bridges, complete enclosure Impact with objects Helmets Noise Ear plugs Manual handling Mechanical handling & it is Electricity Maintenance & good selection



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)

- Suitable certified crane - Suitable certified, color coded lifting accessories & correct

slinging technique - Competent crane operators & banks men using good means of

communications & agreed signals - Suitable ground conditions (firm levelled surface) - Use of outriggers - Clear pathway avoiding any obstructions - Avoiding overhead services such as power lines - Segregation of working area by barriers & warning signs so one

could walk under the load - Visual & Audible alarms to warn that lifting is taking place - Load to be lifted vertically and to correct height & kept near

ground when travelling - Ensure load is secured, balanced & guided by tag lines - Avoid exceeding of the SWL - Ensure Good visibility with adequate lighting & reduced nosie - Ensure suitable weather conditions and stop the lifting operation

in adverse weather conditons e.g. strong wind - PPE e.g. Gloves, steel toe safety shoes and reflective jackets - When the load is placed on the ground; Release the tension first

to avoid load tackling



Element 4:- Work equipment hazards & risk control Suitability of the work equipment

- Initial integrity - Purpose for use - Place of use

Precautions for maintenance Work

- 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

- Isolation of power source (disconnection & lock out tag out) - Dissipation of stored energy e.g. release stored pressure,

earthing for electricity or leaving the hot surface to cool down - Segregation of the work place by means of barriers & warning

signs Safe means of access - Use suitable PPE e.g. safety shoes, coveralls and safety glasses - Ensure that all workers doing the job are Competent enough - Ensure safe environmental conditions e.g. adequate lighting &

good ventilation - Emergency procedures / SSOW

Mechanical Hazards of Machinery (ENTICE) Entanglement Traps (drawing in – crush / shear) Impact Contact (stab/puncture – cuts – abrasions – burns – etc.) Ejection Draw labelled diagram of each one

Entanglement

Traps (Drawing in)



Traps (Crush / shear) Imapct

Contact (puncture / stab) Contact (cuts)

Contact (abrasions) Ejection



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: - Photocopier and document Shredder Manufacturing / Maintenance Machinery: Bench top grinder and Pedestal drill

Agricultural Machinery: - Cylinder mower & trimmer Retail Machinery:- Waste Compactor & Checkout Conveyor Construction Machinery:- Cement Mixer, Circular Saw & petrol chainsaw

Machinery Hierarchy of Controls (FIAT) Fixed guards Interlocking guards, Adjustable guards & Automatic sweep guards. Appliances (Holders / Push Sticks) & Protection devices (Trip device, safety trip wire, photo electric cells, pressure sensitive mats and two hand control system) Training, Information, Instruction, and Supervision (it is) and PPE Fixed Guards:- A physical barrier, kept at its place at all times, has no moving parts, not linked to the machine controls and usually requires a tool to remove it. Advantages Disadvantages

Minimal maintenance Not linked to machine controls Only defeated by deliberate act No protection when removed Visual inspection is enough Full access to dangerous parts

when removed May protect against other hazards e.g. noise, dust, ejection of materials

More difficult to remove: not practical when frequent access required

Tends to be left unfixed when frequent access required

May hamper visibility



Interlocking Guard: - 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 Disadvantages

Allow safe access for feeding materials (frequent opening)

Increase the complexity of the machine

Convenient to use Difficult to test and maintain Less likely to be deliberately defeated

May need a brake or time delay

Speeds up operations 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, 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:- such as holders & push sticks Protection devices:- such as Trip device, safety trip wire, photo electric system, pressure sensitive mat & two hand control device

iT is: on how the machine is operated safely, how & when to be maintained, who is authorized to use it, etc. PPE: such as

- coveralls for chemical splash & entanglement - goggles for ejected material - ear plugs for noise - steel toe safety shoes for crush injuries - hair nets for hair entanglement

� GLOVES should be banned near rotating shafts



Element 5:- 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.g. watches or rings

• Shock electric shock (Electrocution) Factors affecting / influencing severity of electrical shock

- Voltage - Current (amperes) - Time - Conductivity or resistance of the body - Current path through the body - Nature of contact (grip or touch) - Individual factors (age, 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.g. wood

- Call for help - Check ABC - Apply CPR if needed - Treat burns if any - Remain with casualty till emergency services arrive

• Arcing When electricity has sufficient potential to jump across insulating material such as air



• 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.g. 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,

dragged over rough surface, 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 �



Protective systems: Fuse:- A weak link designed to melt, breaking the circuit at excessive currents

Advantages Disadvantages � Cheap and readily available � Does not protect the

individual from shock � Protects equipment � 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.e. break the circuit at excessive current although slightly faster


� Automatically switch or trip under fault conditions

� Does not protect the individual from shock

� No tools to reset

� Not easy to override � No reset until fault cleared � Protects against overload

Earthing:- Electricity will always try reach earth and earthing means providing a path to earth lower than the human body


� May prevent indirect shock by providing a very low resistance path to earth

� Specialist testing and maintenance, professional installation

� Readily identified � Protection defeated if removed



Isolation:- 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)


� Safest option as it eliminates electricity

� May isolate other equipment

� May be physically locked off � May be reconnected unless locked off

� Prevents live fault finding Battery operated tools:- Using battery instead of electrical wires


� Minimal risk during normal use

� Limited battery capacity

� Range not restricted by cable

� Limited power output

� No trailing cable = No tripping hazards or overheating cables

� Precautions need to be followed during mains charging

� Heavier � More expensive

Reduced voltage systems:- By reducing the voltage present system the consequences of electrical shock can be greatly reduced


� Available voltage difference is 55V ac - injury is highly unlikely

� Specialist equipment required for 110 V

� Colour coded cabling system for easy recognition

� Lead from supply to transformer at higher voltages and will need protection with a RCD



Residual Current Device (RCD):- It compares the current flowing into the system with the current flowing out. When the level differs by a preset value the RCD will open rapidly and interrupt the supply


� Rapid and sensitive � May isolate crucial equipment if one RCD covers a number of distribution points, e.g. freezers and computers

� Difficult to defeat � Mechanical device, which could fail

� Easy to use, test and reset � Only protects against earth leakage faults (no overload protection)

� Cannot be reset with a fault on the circuit

Double Insulation:- Covering live parts by two separated layers of insulation


� Two layers of insulation prevent user contact with any live parts

� Physical damage may defeat double insulation

� No earth required � No earth provided in double insulation extension leads, therefore defeats protection if used with equipment that requires an earth



Element 6:- 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, cutting, etc. Mechanical heat (Sparks/friction) PLUS causes of electrical fires page 19 Flash point:- The temperature at which gas & vapour will ignite momentarily by an external source of ignition e.g. spark Fire point:- The temperature at which gas & vapour will sustain a flame when ignited by an external source of ignition e.g. spark Auto-Ignition (Self ignition):- The temperature at which gas & vapour will ignite without any external source of ignition. Methods of Heat Transfer Direct burning:- The flame and a combustible fuel are in direct contact and the fuel heats up and eventually ignites. Radiation:- Heat is radiated through the air causing heating of a materials at a distance from the fire. Conduction: Heat travels within solid material from the hot part to cooler part Convection:- Hot air current rises up to replace cooler air , causing the build up of hot and unburned gases under ceilings etc. and allows fire to spread from one room to another.



Classes of fire A Carbonaceous material (Combustible solids) EXAMPLE: Wood & paper B Flammable liquids EXAMPLE: Alcohol & Petrol C Flammable gases EXAMPLE: Butane, methane & propane D Metals EXAMPLE: Aluminium & Magnesium F 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 �� Water, Dry powder or Aqueous Film Forming Foam (AFFF)

For class B �� Dry powder, AFFF or CO2 For class C �� Dry powder or CO2 For class D �� Special powder or dry sand For class F �� Wet chemicals For Electrical �� Dry powder or CO2

� Wet Chemicals (potassium acetate, carbonate, or citrate) extinguishes the fire

by forming a soapy foam blanket over the burning oil and by cooling the oil.

� 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



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. - Fire marshals to guide the employees during the evacuation - Suitable means of fire fighting such as water sprinklers, whose

reels and fire extinguishers - Unobstructed means of escape with reasonable travel distances,

fire doors, exit signs, Emergency lighting & illuminating signs - Assembly points (Muster points) - Regular drills & practices on evacuation

Precautions to ensure safe evacuation in the event of fire

- Adequate fire detection equipments e.g. smoke detectors - Good means of raising alarms (visual & audible) - Automatic contact with the emergency services & fire department - Roll calls - Safe evacuation plan. - Special consideration for disabled people, pregnant women, etc. - Regular drills & practices on evacuation - Unobstructed means of escape with reasonable travel distances

fire doors, exit signs, Emergency lighting & illuminating signs - Muster point / assembly point (clearly identified & proper location) - Closing the windows & fire doors after leaving - Adequate fire fighting equipment such as: Fire extinguishers,

sprinklers, hose reels - Fire marshals & fire wardens helping in the above



Element 7:- Chemical & biological health hazards & risk control Respiratory defences (Body defences against dust)

- The hair in the nose acting as a filter to purify the air from the dust particles

- wetness of the nose (mucus) so the dust would stick to it & will be trapped and will go no further inside the lung

- The change of direction to the larynx so the dust particles in the air would stick to the nasal wall

- Sneezing and coughing which would expel the dust outside the respiratory system

- Turbulent motion of the air in the nose and the centrifugal force which will throw the dust to the sides sticking to the mucus

- 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

- The immunity system of the body: White Blood Cells (WBC) in the alveoli

- Fibrosis of the lung: isolating the affected non-functioning part from the rest of the healthy lung

- Tears and blinking of the eyes (not part of the respiratory defences)

Digestive defences (Body defences against ingested substances)

- Digestive juices & enzymes, the useful bacteria and the strong acid (HCL) which will destroy the harmful substances inside the stomach.

- Vomiting & diarrhoea which get rid of the toxins and the harmful substance out of the body.

- Smell & taste protecting the person from eating or drinking harmful substances or bad food.

Skin defences

- Sweating: Cooling down the skin and killing harmful organisms - Keratin: Forming the protective hard layer of the skin - Melanin: responsible for the pigmentation of the skin, more

melanin makes the skin darker providing more protection from the sun and ultra violet light

- Sebum: the oily substance secreted by the skin to prevent it from dryness

- Hair: protecting and filtering the skin - Sensory serves: the sense of touch in the skin - Blisters, rash and inflammation to fight any infection of the skin



Other defences - Tears & Blinking of the eye - Pain - Hormones e.g. Adrenalin

Types of Dermatitis:

1- Irritant / Contact 2- Allergic / Sensitive

Symptoms: - Irritation of the skin, Inflammation, Blisters, rash, swelling, redness, hotness, Dryness and cracking of skin, 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.g. gloves and coveralls Barrier creams Extractor fans & LEV it is Dose-response relationship All substances are poisons; there is none which is not a poison; The right dose differentiates a poison and a remedy. 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, Lead � brain & nervous system Ammonia � eyes, skin & lungs Organic solvents � liver, 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



� 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, it is usually reversible.

EXAMPLE: Alcohol intoxication due to consuming large amount of alcohol in short time.

� 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. Occupational Hygiene & Health hazards

1- Identification of health hazards 2- Measurement of health hazards 3- Assessment of health hazards 4- Control of health hazards

1- Identification of health hazards:

• Forms of chemical agents: - Dust: Total inhalable & Respirable dust (0.5 – 7.0 micron) - Fume - Mist - Smoke - Vapour

• Forms of biological agents: - Fungi - Bacteria - Viruses

Routes of entry into the body (chemical agents)

- Inhalation - Ingestion - Direct entry (open wounds) - Injection - Absorption



Classification of Hazardous Substances Irritant: Non-corrosive substances which through immediate, prolonged or repeated contact with skin or mucous membrane may cause inflammation (Dermatitis) Example: Petrol, cement, 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, inhaled or penetrated the skin may cause damage to health (cause diseases – ill health) Example: Petrol, 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. Example: Bromine & Benzene Teratogenic: Substances which cause harmful effects to the embryo (baby) inside the uterus of the pregnant woman. Example: Drugs & medications



Material Safety Data sheet (MSDS) = Information on hazard data sheet

1- Identification of the substance & Manufacturers’ information 2- Composition & information on ingredients 3- Hazard identification 4- First aid measures 5- Fire fighting measures 6- Accidental release measures 7- Handling & Storage 8- Exposure control & Personal protection 9- Physical & Chemical properties 10- Stability & Reactivity 11- Toxicological information 12- Ecological information 13- Disposal consideration 14- Transport information 15- Regulatory information 16- 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- Measurement of health hazards: THREE survey techniques:-

1) Initial appraisal: Gathering information such as OEL, details of the substances used, people affected, types of hazards, risks, and precautions; from different sources such as MSDS, manuals, experts, etc.

2) Basic survey:

� Qualitative observations: Smoke tube & Dust lamp

� Quantitative observations: Stain tube detector (Grab sampler)



Diagram of Chemical stain tube detector (Grab Sampler)

Advantages Disadvantages Low cost Inaccurate Takes little time Positioning of tube affects reading Immediate result Only a snap shot

Little training needed Inefficient Information during spillage Chemical use only Good for coarse indication 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- Assessment of health hazards: Risk assessment (5 STEPS AS USUAL)

1 2 3 5 10 20

Glass tube Direction of flow

Fused tip Pre-layer Fused tip

Porous granules, e.g. silica gel,chemical reagent Scale

divisions

READ

1 2 3 5 10 20

Scale



4- Control of health hazards: Eliminate: remove the substance, or avoid the activity or process e.g. 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.g. 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, job

rotation, adequate breaks, good levels of Hygiene and housekeeping & providing the needed it is

PPE:

- Respiratory protection such as breathing apparatus to protect from chlorine or ammonia

- Hand & skin protection such as gloves to protect from detergents or solvents

- Eye protection such as goggles to protect from corrosives or ammonia

- Protective clothing such as chemical splash suits to protect from acids & biological agents

- Barrier creams

Discipline



Labelled diagram of Local Exhaust Ventilation (LEV)

LEV becomes inefficient because of:- - Failure of operators to use it properly - Lack of proper maintenance - Unauthorised modifications - Incorrect settings - Hood damaged or not well positioned - Blocked / damaged ducts - Full / damaged dust collection bags - Blocked / damaged filter - Wear & tear of fan blades - Increased contaminant level - Poor design of the LEV (inadequate capacity) Checks / inspection: opposite of above



Examples of chemical agents (hazardous substances) & Target Organs

• Ammonia Strongly corrosive alkaline colourless gas with a pungent odour. Affecting the skin, eyes & the lungs. Leading to eye irritation, dermatitis, 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.

• Asbestos Affecting the lungs causing Asbestosis (Lung cancer)

• Carbon Dioxide CO2 Colourless and odourless gas which is heavier than air. 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, Colourless and odourless and tasteless gas. Found where incomplete combustion occurs e.g. boilers, vehicle exhausts Affecting the lungs & the blood casuing headache, drowsiness, flushed “pink” appearance and ultimately asphyxiation and death

• Chlorine A greenish toxic gas with a pungent smell. Affecting the eyes & the respiratory system casuing severe irritation.

• Lead A heavy, soft and easily worked metal. Can enter body by eating contaminated food or by breathing fumes or dust. Affecting the brain & the nervous system casuing acute lead poisoning Resulting in nausea, headaches, nervous problems and in severe cases causing death.

• Organic Solvents These dissolve other substances & are also used as cleaning & degreasing agents. They are volatile & evaporate quickly at room temperature so their vapours can be breathed easily. Affecting the skin, nasal passages, throat, lungs, eyes, & the liver. Effects may be headaches, nausea, dizziness & loss of consciousness and in extreme cases leading to death.



• Isocyanates Organic compounds widely used in industry for products such as spray painting of vehicles and production of polyurethane rubbers and foams. Affecting the nasal passages, throat & the lungs leading to lung Inflammation & asthma.

• Silica Found in sand, granite & glass Affecting the lungs as breathing silica could lead to serious lung disease “silicosis”

• Dust Affecting the respiratory system causing asthma, bronchitis, emphysema and conditions such as asbestosis or Silicosis if the dust contains asbestos or silica. Dust Identification:

- Visual signs of dust in the air or deposited on surfaces or clothes - Results of monitoring using dust lamps or smoke tube - Poor visibility or excessive tears & blinking of the eyes - respiratory problems: coughing, sneezing, breathing difficulty - Maintenance problems e.g. abnormal blocking of filters

Control measures for dust:

- Elimination of dusty operation (outsourcing) - Bringing pre-formed components - Substitution e.g. granules or paste instead of powders - Enclosure of the dusty operation or machines - Extractor fans & Local exhaust ventilation (LEV) - Vaccuming instead of sweeping - Damping down the dust by spraying water - Reduce duration & frequency of exposure to dust - Reduce duration & frequency of the dusty operations - Reduce number of workers exposed to dust - Respiratory protective equipment e.g. dust mask - Medical check up & Health survillance with medical treatment for

any health problem - it is



Biological Agents Leptospirosis (Weil’s disease) Bacterial infection transmitted to humans by ingesting contaminated rat urine. The most common source is in construction sites, water sports, river water, swimming pools, sewers, etc. Symptoms: Flu like symptoms (Fever, sneezing, coughing & headache), Pneumonia, meningitis & Jaundice. Fatal in 20% of the cases (Attacks the kidneys & liver) Precautions & Control measures: pest control, covering damaged skin, it is, 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, cooling towers, stagnant water etc. Symptoms: Flu like symptoms (Fever, sneezing, coughing & headache), Pneumonia & difficulty in breathing Fatal in 20% of the cases. Those at greatest risk are smokers or old people with chest problems. Precautions & Control measures: Temperature control and monitoring, avoiding stagnation & avoiding “dead legs” in pipe work, biocide treatment and effective cleaning and maintenance. Hepatitis A, 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, fever, nausea, malaise & jaundice. Precautions & Control measures: Vaccination, disinfection, it is, Avoiding sharp implements, Proper disposal of contaminated waste and good hygiene practices.

Routes of entry into the body (Biological agents)

- Inhalation - Ingestion - Direct entry (open wounds) - Injection



Precautions for safe storage of waste - Choosing a Suitable location - Sufficient storage area - Labelled & individual containers - Ensure storage area is well secured - Store different types of waste separately - Never store incompatible waste together - Select appropriate containers - Keep quantities of waste to a minimum - Protect waste from the elements - Protection form adverse weather conditions - Avoid contamination of general waste with hazardous materials



Element 8:- Physical & psychological hazards

Noise: is any unwanted sound

Frequency:- Measuring the pitch / tone of the sound waves, measured in cycles per second or Hertz (Hz) Human range is 20 Hz – 20 KHz Intensity:- 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.e. 83 dB is double the intensity of 80 dB Health effects of noise

Acute Chronic

Stress, Irritability, nervousness , increased heart rate and insomnia

Temporary threshold shift Permanent threshold shift (Noise Induced Hearing Loss)

Temporary tinnitus Permanent tinnitus Trauma e.g. Burst eardrum Presbycusis

Blast deafness Factors affecting the risk from Noise

- Frequency in Hz - Loudness in dB - Duration & frequency of exposure to noise - Use of PPE - Distance between the source of noise & the person exposed to it - The nature of the place

Noise control measures / precautions Source: Eliminate or reduce the noise from the source by

- Improving the design of the machine - Damping - Isolation - Proper maintenance



Path: Prevent/reduce transmission of noise through air or structures by using

- Screens and barriers - Enclosure - Absorption - Silencer

The Person:

- Increase the distance between the worker & the source of noise - Reduce the duration & frequency of exposure to the noise - it is - PPE such as ear plugs & ear muffs

Hand-Arm Vibration Health Effects Acute: Numbness & Tingling in the hands and extremities Chronic: - Permanent Numbness & Tingling

- Blanching of the fingers (Vibration White Fingers) - Swollen painful joints - Reduction in manual dexterity - Reduction in the sensation of touch Risk Factors

- Frequency of the vibrating tools ( in Hz) - Force exerted - Duration & frequency of exposure - Low temperature - Individual factors e.g. age & health condition

Control Measures for hand-arm vibration

- Automate or mechanise the job to elimination the use of vibrating tools

- Select the suitable tool with low vibration - Reduce the degree of vibration as much as possible - Select ergonomically designed equipment - Proper maintenance of equipment - Reduce the force exerted & the strength of grip with work

equipment - Reduce the duration of exposure to the vibration - Health surveillance & treatment of any medical problem - Use PPE such as Gloves and heated pads - it is on the nature of risks



Work in Hot & Cold environment Physiological effects of heat Stress (in foundries, 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, food preparation area, big freezers & open air during winter) Lowered heart rate Hypothermia Shivering Confusion & Loss of concentration Frost bite Increased risk of strains & sprains Risk factors - Body activity & health condition - Type & amount of clothes - Duration & frequency of exposure - Ambient temperature & weather conditions - Source of heat / cold temperature Control measures - Acclimatisation - Health surveillance & medical checkup - Hot / cold drinks - Reduce duration & frequency of exposure - Temperature control - PPE e.g. insulating clothes - it is



Radiation

Non-Ionising Type Use in Industry

Infrared Heating and brazing Lasers Cutting, Bar code readers Microwaves Food preparation, Signal transmission Ultra-violet Welding

Radio waves 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, e.g. eye protection • Skin creams

Ionising Radiation

Type Use in Industry Alpha Smoke detectors & anti static devices Beta Thickness testing & sterilisation of material

Gamma Non-Destructive Testing & Radio therapy

X-Ray NDT & Radio diagnosis

Health effects of ionizing radiation Acute health effects (high dose) Chronic health effects (small dose) Erythema (Reddening of the skin) Carcinogenic effect (Cancer) Radiation sickness (Nausea & Vomiting)

Mutagenic effect (Hereditary defects)

Hair loss Teratogenic effect Diarrhoea Sterility , erythema & cataract Death Death



Risk factors & Control measures ofionizing radiation - Duration & frequency of exposure - Distance between the radioactive material & the people - Proper shielding (Lead or thick concrete) - Using suitable PPE e.g. radiation suit - Correct disposal of radioactive materials - half life of the radioactive material - Good hygiene practices - it is - 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 , Health care professionals, Schools, Cash transactions Delivery/collection of money, Representing authority e.g. policemen & enforcement officers Control measures

- it is: on absorbing anger, how to recognise aggressive behaviour & how to deal with it wisely

- Providing information on delays - Proper queue management - Welcoming environment & nice decor - Checking visitors’ credentials (IDs) - Safe & secure design of workplace e.g. wide counters, coded

locked doors & physical barriers - Security officers & CCTV cameras - Good means of Communication & alarm systems - Regular removal of cash from the workplace - Avoid Lone working; safe precautions for lone workers - Reporting, recording and investigating violent incidents - Zero tolerance of aggressive behaviour



Stress

Physical Effects Psychological effects Headaches Increased anxiety Dizziness Reduced concentration Aching neck and shoulders Irritability & nervousness

Skin rash Panic attacks & Sudden mood changes Prone to infections Inability to cope Raised heart rate & Increased blood pressure

Reduced work output / performance

Diabetes Increased use of alcohol, drugs, pain killers & tobacco

Heart disease Insomnia (Poor sleep patterns) Stomach & mouth ulcers

Causes of stress: 1. Culture of the organisation: how it approaches work-related

stress, e.g. communication, consultation, staff support systems, and working hours;

2. Demands: workload too high or too low, shift work and unsocial hours, excessive overtime, and exposure to violence and bullying;

3. Control: how much control the person has in the way they do their work, e.g. work planning, use of acquired skills, repetitive or monotonous work;

4. Relationships between employees: physical violence, threats or verbal abuse e.g. repeated shouting and swearing, malicious gossip; unjustified picking of faults, prevention of career development; sexual harassment; & discrimination due to gender, race or disability;

5. Change: how organisational change is managed and communicated in the organisation, e.g. new technology, restructuring, redundancies, and unclear objectives;

6. Role: job insecurity, fear of redundancy, being unclear about roles, responsibilities and expectations, conflicting roles, e.g. the conflict of different job demands such as working for more than one manager;

7. Individual: skills not matched to the task, inadequate training, unclear job description, and fair and open feedback on the work and role, illness, financial worries, family commitments; and

8. Environment: inadequate lighting, problems with glare, cramped or untidy working conditions, security problems, extremes of temperature and / or humidity, inadequate ventilation, draughty conditions, high noise and vibration levels, inadequate welfare facilities and poor weather conditions for those working outside.



Identification of Stress

Stress within the organisation may be identified by: • informal observation & conversation with workers & supervisors; • performance appraisal with an opportunity for open discussion of

problems; • monitoring of attendance records and conducting ‘return to work’

interviews; • sickness absence / ill-health trends; • reduced productivity of the employees • High staff turnover.

The end of week 2

G O O D L U C K Please Turn Over ��



Examination rules & tips

- Each question MUST be answered on a separate page (sub-sections of the same question should be answered in the same page, 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 , 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, 6 mark = 6 points

etc. - 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 ; If your mother tongue is not English

(according to the nationality registered in the exam) you will be given extra 30 minutes, 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 , don’t waste your time

� Read the question 3 times carefully before starting the answer � If you run out of time , answer in the form of list � Don’t cross any answer as there’s no negative marking � As much as possible; Structure your answer into separate

headings e.g. external & internal / short term & long term etc. Action Verbs in exam questions:

o Explain, Describe or Outline: Give a detailed word picture ; Give a clear account of, 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)

week 2 summary_may 2012.pdf

Documents