Control

Anticipation

Recognition

Evaluation

toxic

irritant

allergic

carcinogenic

mutagenic

teratogenic

number of EXISTING cases of a disease

RR = IR in exposed groups/IR in nonexposed groups

RR<1 = good

bias

confounding

chance

causality

Strength of association

Dose-response effect

Time sequence

Consistency

Biologic coherence

SF = failure producing load/ allowable stress

allowance for unknowns related to materials, assembly, or use

tensile

compression

shear

torsion

bending

bearing

impact

fatigue

1) injury

2) accident

3) unsafe conditions/acts

4) undesirable traits

5) social environment

environmental climate

work demands 

clothing

exothermic reaction that expands rapidly to unreacted material by conduction, convection, and radiation.

Combustion zone<330m/s

Doesn't product rapid increase in pressure to induce explosion

exothermic reaction, shock wave in material to propogate reaction

Reaction zone expands v >> 330m/s

Results in explosion

Px = Ptot (% gasx)

1. understudy

2. draft documentation

3. notice of intended changes (NIE)

4. TLV/BEI and adopted documentation

5. withdraw for consideration

1. proper partial pressure of oxygen in breathing gases

2. control contaminant gases and particles

3. select proper breathing gases for depths where nitrogen narcosis is a risk

1. ignition sensitivity

2. explosion severity

3. explosibility index- product of ignition sensitivity and explosion severity.

Enactment

Enforcement

Engineering

Education

Pre-exposure- primary prevention

During exposure- reduce injury

Post-exposure - prevent death/disability

excessive water loss from sweating and inadequate circulation

fatigue, nausea, headache, giddy, cold clammy skin

move to cooler location

muscle cramps during or following exertion in hot envirornment

Excessive loss of body salts from sweating

replace fluids and essential salts

reduced performance of sensorimotor, mental, and vigilance tasks when exposed to heat.

reduced work effort, reduced clothing, seeking cooler conditions

acclimatization and training help this

may faint as result of redistribution of blood to peripheral tissue, reducting the blood flow to brain

move to cooler location, lie down

blood vessels vasodiolate- get wider to dump heat into atmosphere

failure of thermal regulatory mechanism

termination of sweating

hot/dry skin

body temp rises

mental confusiong, loss of consciousness, colvulsions, coma, fatal

immediate and rapid cooling

mild form of heat stroke

partial failure of sweating

small blister eruptions

prickly sensation

sweat glands plugged, so sweat retained causing inflammation

keep skin dry, avoid heat exposure

% of body surface area affected

body part affected

type: thermal, electrical, chemical

exposure to cold temp, moist skin, and inactivity

vasoconstriction in feet/legs cause:

pale appearance

numbness

swelling and pain

itching and painful reddening of skin

caused by congestion of capillaries when exposed to cold

immune system reaction

exposure to cold causes histamine release

itchy, red blotches in skin

swelling of tissue, vomiting, rapid heart rate, difficulty breating may result

freezing of tissue

damage = function of depth of frozen tissue

white/gray yellow skin color

may or may not be painful

lowering of core body temp

shivering

numbness, disorientation, confusion, amnesia, impairment of judgement, unconsciousness, muscular rigidity, ventricular fibrillation, respiratory arrest, death

air temp

humidity

mean radiant temp

air speed

body temp

conductors= allow electrions to flow

insulators = inhibit flow

function of material

R= resistivity * current = current / conductivity

P = I^2 * R

energy lost to resistance changes to HEAT ENERGY

current flows through air between 2 conductors that are not in direct contact.

Arc function of voltage bt conductors, conductivity of medium, and distance between conductors

energized equipment

radiated energy

lighting/computer/sensor failure

limit current that can flow through a circuit or device.

fuses- I exceeds some limit value, fuse heats above melting point and separates, stopping current flow 

circuit breakers- switch that opens when current passing through exceeds some limit

lockouts

interlocks- switch intended to prvent access to energized/dangerous location

thermal & overspeed cutouts- cut pour when the temperature approaches certain limit (hairdryer)

2 bodies have a conductor between them to equalize charge

Controls static charge buildup

atmospheric oxygen

pure oxygen

fluorine

chlorine

nitrogen tetroxide

peroxides

halogens

nitrates

nitrites

strong acids

Heat

Fuel

Oxygen

Chain Reaction

garbage, cotton, wood shavings, oily rags

store under water/earth, limit height of piles, break piles to release heat, monitor temp at bottom of pile, coat surface with air sealent

carbon monoxide, carbon dioxide

hydrogen sulfide, hydrogen cyanide, hydrogen chloride

nitrogen dioxide

sulfur dioxide

ammonia, acrolein, phosgene

A- wood, paper, organic

B- liquids

C- electrical

D- metals

Isolation

Cooling combustibles

reaction inhibition

water

gas extinguishants (CO2, nitrogen, foams)

Fixed automatic- sprinklers

portable- fire extinguisher

mobile- roll on wheels

To prevent injury & illness in workers

Limited to workplaces with more than 10 employees

1. assumption of risk

2. contributory negligence

3. fellow servant rule- employer attempts to show that a fellow employee was negligent and caused injury of worker.

Temporary total- completely unable to work for a period of time

Temp partial- are able to work at a less demanding job during injury. Return after recovery to normal.

Perm partial- perm reduction of work capability, but still employed

Perm total- no longer able to work.