HAZMAT Flashcards
HAZMAT
Name 5 Hazardous Atmospheres
- Flammable environments including gases e.g. Acetylene, LPG, petrol, ethanol, acetone and flammable dusts
- Oxygen enriched environments (>23.5%) - aid in combustion e.g. clothing
- Low oxygen environments (<19.5%) - leads to unconsciousness and death
- Toxic chemical contaminants and irritants e.g carbon monoxide (CO), sulphur dioxide (SO2), ammonia (NH3) and oxides of nitrogen (NOx)
- High temperature environments - Burn airways and lungs causing pulmonary oedema
- Radioactive environments - Medical facilities or radioactive good transported 7 Particulates - dust or aerosols created from processing flour, coffee grounds, coal, plastics and metals.
What are the 3 Airborne contaminants. Give a definition of each and 3 examples
- Gases - substances that are too volatile to exist as a liquid or solid at typical air temperature/pressure examples - Hydrogen, Helium, Methane, acetylene, propane and nitrogen dioxide
- Vapours - evaporative product of volatile liquids)examples - acetone, petrol, benzene, styrene and ethanol
- Aerosols - very small solid particles or liquid droplets dispersed in a gas stream (usually the atomsphere)examples flour, coal, plastics and metals.
What are the units of Measurements?
- Volume Percent (v/v%) - percentage concentration of a gas or vapour in air. - measures Oxygen levels1% v/v = 10,000 ppm
- Parts per million (ppm) - measures toxicity
- Percent of LEL (% of LEL) - measures flammability
Acceptable Oxygen levels (lower and higher levels)?
19.5 to 23.5
Explain Lower Explosive Limit (lel)
Lowest concentration level for a gas or vapour to burn or explode if an ignition source is present. Below this concentration limit, the gas or vapour is too lean to burn.
5% low alarm, 10% high alarm, LEL is a percentage of a percentage
Explain Upper Explosive Limit (uel)
Upper Explosive Limit. Highest concentration level for a gas or vapour to burn or explode if an ignition source is present. Above this, the gas or vapour is too rich to burn in that environment.
What is flammable range?
Is the concentration range of a gas or vapour (expressed a Vol% in air) that will burn or explode if an ignition source is present.
Anything in between the lel and uel is flammable range.
What does ES stand for?
Exposure Standards - this indicates safe airborne concentrations or chemicals in occupational environments Such concentrations should neither impair the health nor cause undue discomfort, consistent both long and short term exposure.
What is TWA?
Time-weighted average - Limit you can be exposed to in a working week. Average concentration a worker can be repeatedly exposed to based on an 8 hour working day over a 5 day working week without adverse effect
What is STEL?
Short-Term Exposure Limit - is the concentration to which workers can be exposed for up to 15 minutes at a time, max 4 times per day with at least 1 hour break between exposures without adverse effect.
What is PLV
Peak Limitation Values - substances considered highly hazardous as they may induce acute toxic or irritant effects.If the value is exceeded, then the atmosphere is considered occupationally unacceptable.
What is IDLH?
Immediate Danger to Life and Health ‘An atmospheric concentration of substance that poses immediate threat to life, would cause irreversible or delayed adverse health effects OR prevent the individual from escaping from the dangerous atmosphere.’
Acute vs Chronic Toxicity - difference between the two?
Acute - Sufficiently poisonous that single large dose is likely to severely impair health or even lead to death
Chronic - cause long term health damage, typically from repeated exposure to low concentration levels
Micro Rae 4 Head Test Table
O2 - Oxygen / v/v% =19.5% -23.5%
CO -Carbon Monoxide / PPM = 30-50
H2S -Hydrogen Sulphide / PPM = 10-20
LEL -Flammability / % of LEL = 5%-10%
difference between a bump test vs a calibrated test
Bump test - the monitor is working and reacting as expected
Calibrated test - performed to ensure the monitor is accurate
Draw up a technical corridor Decontamination
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