CHST Health Hazards and PPE 4 — Questions and Answers
Question 1: A worker is sandblasting a structure coated with lead paint. Which combination of respiratory protection is MOST appropriate?
- Half-face air-purifying respirator with P100 filters
- Supplied-air respirator (SAR) in pressure-demand mode (Correct answer)
- Powered air-purifying respirator (PAPR) with organic vapor cartridges
- N95 disposable filtering facepiece
Correct answer: Supplied-air respirator (SAR) in pressure-demand mode
Supplied-air respirators in pressure-demand mode provide the highest protection factor required for abrasive blasting operations involving lead-containing coatings.
Question 2: According to OSHA's heat illness prevention standard, which environmental condition triggers mandatory acclimatization protocols for new workers?
- Heat index above 80°F (27°C)
- Heat index above 91°F (33°C) (Correct answer)
- Ambient temperature above 85°F (29°C)
- Wet bulb globe temperature above 78°F (26°C)
Correct answer: Heat index above 91°F (33°C)
OSHA guidance recommends acclimatization protocols when the heat index exceeds 91°F, with new workers limited to 20% of normal workload on day one.
Question 3: Which type of hearing protection provides the highest Noise Reduction Rating (NRR) typically available for construction workers?
- Foam earplugs with NRR 33 (Correct answer)
- Earmuffs with NRR 31
- Canal caps with NRR 28
- Custom-molded earplugs with NRR 26
Correct answer: Foam earplugs with NRR 33
Foam earplugs have the highest NRR ratings available (up to 33 dB) among common hearing protection devices.
Question 4: A construction worker develops redness, itching, and blistering after contact with uncured epoxy resin. This reaction is BEST classified as:
- Irritant contact dermatitis
- Allergic contact dermatitis (Correct answer)
- Chemical burn
- Photodermatitis
Correct answer: Allergic contact dermatitis
Epoxy resin reactions that involve immune sensitization and occur after repeated exposures are classified as allergic contact dermatitis.
Question 5: What is the OSHA permissible exposure limit (PEL) for respirable crystalline silica in construction?
- 0.025 mg/m³ as an 8-hour TWA (Correct answer)
- 0.05 mg/m³ as an 8-hour TWA
- 0.1 mg/m³ as an 8-hour TWA
- 0.25 mg/m³ as an 8-hour TWA
Correct answer: 0.025 mg/m³ as an 8-hour TWA
OSHA's silica standard for construction (29 CFR 1926.1153) sets the PEL at 50 micrograms per cubic meter (0.025 mg/m³ respirable) as an 8-hour TWA.
Question 6: When inspecting a full-body harness after a fall arrest event, the CORRECT action is:
- Re-inspect and return to service if no visible damage is found
- Replace only the lanyard and re-certify the harness
- Remove from service immediately and destroy or mark unusable (Correct answer)
- Send to manufacturer for inspection before reuse
Correct answer: Remove from service immediately and destroy or mark unusable
Any fall arrest equipment subjected to a fall event must be immediately removed from service and destroyed or clearly marked as unusable, regardless of visible damage.
Question 7: A contractor is working in a confined space with an oxygen-deficient atmosphere. Which of the following oxygen concentrations is defined by OSHA as immediately dangerous to life or health (IDLH)?
- Below 19.5%
- Below 18%
- Below 16% (Correct answer)
- Below 10%
Correct answer: Below 16%
OSHA defines an IDLH atmosphere for oxygen deficiency as below 16%, while below 19.5% is considered oxygen-deficient requiring continuous monitoring.
CHST Health Hazards and PPE 4
A worker is sandblasting a structure coated with lead paint.
Which combination of respiratory protection is MOST appropriate?