ACI Environmental & Worker Safety 3 — Questions and Answers
Question 1: Which ANSI standard governs the design and performance requirements for safety footwear used on concrete construction sites?
- ANSI Z41 / ASTM F2413 (Correct answer)
- ANSI Z87.1
- ANSI Z89.1
- ANSI Z359.1
Correct answer: ANSI Z41 / ASTM F2413
ASTM F2413 (previously ANSI Z41) sets the performance requirements for protective footwear including toe impact and compression resistance.
Question 2: What environmental hazard is most commonly created when concrete is poured near a waterway without proper controls?
- pH increase in water causing harm to aquatic life (Correct answer)
- Oxygen depletion from organic decomposition
- Heavy metal contamination
- Radioactive particulate release
Correct answer: pH increase in water causing harm to aquatic life
Cement raises the pH of waterways to toxic levels (11+), which is lethal to fish and other aquatic organisms and violates Clean Water Act provisions.
Question 3: How often must a concrete finisher's N95 respirator be replaced at a minimum during wet concrete grinding operations?
- When it becomes difficult to breathe through or is damaged/soiled (Correct answer)
- Once per week regardless of condition
- Every 30 days
- Only when OSHA inspects the site
Correct answer: When it becomes difficult to breathe through or is damaged/soiled
Respirators should be replaced when breathing resistance increases, structural integrity is compromised, or the facepiece is soiled — per manufacturer guidance and OSHA 29 CFR 1910.134.
Question 4: A spilled Portland cement bag is wetting due to rain on a job site. The primary environmental concern is:
- Runoff reaching storm drains and raising pH of receiving waters (Correct answer)
- Spontaneous combustion of the cement dust
- Release of toxic heavy metals into the soil
- Generation of explosive gases
Correct answer: Runoff reaching storm drains and raising pH of receiving waters
Wet cement generates highly alkaline leachate that can flow into storm drains and harm aquatic ecosystems, violating stormwater permit conditions.
Question 5: Which type of knee pad is most appropriate for prolonged concrete finishing work to prevent bursitis?
- Hard-cap knee pads with cushioned foam or gel interior (Correct answer)
- Cloth knee sleeves
- No knee protection if kneeling is brief
- Standard athletic knee braces
Correct answer: Hard-cap knee pads with cushioned foam or gel interior
Hard-cap knee pads with cushioned interiors distribute pressure and protect against the hardness of concrete slabs, reducing the risk of prepatellar bursitis.
Question 6: What is the minimum safe distance OSHA recommends keeping from the edge of an excavation when operating concrete-pouring equipment?
- The distance depends on excavation depth and soil type, determined by a competent person (Correct answer)
- Always exactly 2 feet from the edge
- Always exactly 5 feet from the edge
- No minimum distance if cones are placed
Correct answer: The distance depends on excavation depth and soil type, determined by a competent person
OSHA requires a competent person to evaluate surcharge loads and set safe setback distances based on specific site conditions including soil classification and excavation depth.
Question 7: When disposing of hardened concrete debris from a finishing site, which agency's regulations primarily govern proper disposal?
- State environmental protection agency under EPA solid waste regulations (Correct answer)
- OSHA only
- ANSI standards board
- Local fire marshal
Correct answer: State environmental protection agency under EPA solid waste regulations
Hardened concrete is generally classified as construction and demolition (C&D) debris regulated under EPA RCRA solid waste rules, enforced by state environmental agencies.
ACI Environmental & Worker Safety 3
Which ANSI standard governs the design and performance requirements for safety footwear used on concrete construction sites?