OSHA HAZWOPER 40-Hour (29 CFR 1910.120) course final exam
Chemical hazards (NIOSH Pocket Guide): practice questions
Our HAZWOPER 40-Hour bank has 56 questions on this topic. Here are 5 of them with answers; the full mock exam draws from every topic, like the real one.
Question 1
What is the IDLH for hydrogen sulfide in the Pocket Guide?
- 100 ppm
- 10 ppm
- 300 ppm
- 1,200 ppm
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A. 100 ppm — The Pocket Guide lists hydrogen sulfide IDLH as 100 ppm.
Question 2
What odour does hydrogen sulfide have?
- Rotten eggs
- Bitter almonds
- Fresh mint
- Musty hay
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A. Rotten eggs — The Pocket Guide describes it as a colourless gas with a strong odour of rotten eggs.
Question 3
What is the lower explosive limit of hydrogen sulfide?
- 15%
- 4.0%
- 12.5%
- 1.2%
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B. 4.0% — The Pocket Guide lists LEL 4.0% and UEL 44.0% for hydrogen sulfide.
Question 4
What is the IDLH for nitrogen dioxide?
- 100 ppm
- 1 ppm
- 13 ppm
- 50 ppm
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C. 13 ppm — The Pocket Guide lists nitrogen dioxide IDLH as 13 ppm.
Question 5
What is the IDLH for phosgene?
- 100 ppm
- 2 ppm
- 0.1 ppm
- 20 ppm
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B. 2 ppm — The Pocket Guide lists phosgene IDLH as 2 ppm.