CHST CHST - Construction Health and Safety Technician Health Hazards and PPE Questions and Answers 3 — Questions and Answers
Question 1: A construction worker is grinding metal indoors without ventilation. Which combination of PPE is MOST critical to prevent both respiratory and eye hazards?
- Safety glasses and a surgical mask
- A face shield and an N95 respirator
- Goggles and a PAPR with HEPA filter (Correct answer)
- Welding helmet and a dust mask
Correct answer: Goggles and a PAPR with HEPA filter
Goggles provide better splash and particle protection than glasses, and a PAPR with HEPA filter offers powered air-purifying respiratory protection against metal dust in a poorly ventilated space.
Question 2: Under OSHA 29 CFR 1926.62, what is the action level for lead exposure that triggers medical surveillance requirements?
- 10 µg/m³ as an 8-hour TWA
- 30 µg/m³ as an 8-hour TWA (Correct answer)
- 50 µg/m³ as an 8-hour TWA
- 100 µg/m³ as an 8-hour TWA
Correct answer: 30 µg/m³ as an 8-hour TWA
The OSHA action level for lead in construction is 30 µg/m³ as an 8-hour TWA, which requires medical surveillance, biological monitoring, and training.
Question 3: What is the primary purpose of a supplied-air respirator (SAR) compared to an air-purifying respirator (APR)?
- SARs are lighter and easier to wear for extended periods
- SARs provide breathing air independent of the ambient atmosphere (Correct answer)
- SARs filter contaminants more efficiently than APRs
- SARs are required only when IDLH conditions are suspected
Correct answer: SARs provide breathing air independent of the ambient atmosphere
Supplied-air respirators deliver clean breathing air from an external source, making them suitable for oxygen-deficient or IDLH atmospheres where APRs cannot provide adequate protection.
Question 4: A worker develops contact dermatitis after repeated exposure to Portland cement. What is the PRIMARY causative agent?
- Calcium silicate dust causing abrasive irritation
- Hexavalent chromium acting as a sensitizer (Correct answer)
- Calcium oxide causing pH-neutral reaction
- Silicon dioxide triggering an allergic response
Correct answer: Hexavalent chromium acting as a sensitizer
Hexavalent chromium (Cr VI) present in Portland cement is a known skin sensitizer that causes allergic contact dermatitis with repeated exposure.
Question 5: During confined-space entry on a construction site, the atmosphere tests at 19.0% oxygen. How should this be classified?
- Normal — no action required since it is close to 20.9%
- Oxygen-deficient — entry requires supplied-air or SCBA (Correct answer)
- Slightly low — a half-face APR with OV cartridge is sufficient
- Oxygen-enriched — fire risk is the primary concern
Correct answer: Oxygen-deficient — entry requires supplied-air or SCBA
OSHA defines an oxygen-deficient atmosphere as less than 19.5% O₂; at 19.0% the space requires supplied-air or SCBA for entry.
Question 6: Which type of glove material provides the BEST protection against ketone solvents commonly found on construction sites?
- Latex rubber
- Natural rubber
- Butyl rubber (Correct answer)
- Polyvinyl chloride (PVC)
Correct answer: Butyl rubber
Butyl rubber gloves offer superior resistance to ketones and other polar solvents, outperforming latex, natural rubber, and PVC for these chemicals.
Question 7: A safety technician is reviewing heat stress controls for roofers working in July. Which engineering control has the highest hierarchy priority?
- Providing personal cooling vests for each worker
- Scheduling heavy work during cooler morning hours
- Installing shade structures over the work area (Correct answer)
- Requiring workers to drink 1 cup of water every 20 minutes
Correct answer: Installing shade structures over the work area
Installing shade structures is an engineering control, which ranks higher in the hierarchy of controls than administrative (scheduling) or PPE (cooling vests, hydration) measures.
CHST CHST - Construction Health and Safety Technician Health Hazards and PPE Questions and Answers 3
A construction worker is grinding metal indoors without ventilation.
Which combination of PPE is MOST critical to prevent both respiratory and eye hazards?