Environmental & Worker Safety Flashcards
7 cards from real ACI practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Environmental & Worker Safety flashcards as text
Which OSHA standard requires construction employers to provide a written silica exposure control plan?
Answer: 29 CFR 1926.1153
29 CFR 1926.1153 is OSHA's Respirable Crystalline Silica standard for construction, which mandates a written exposure control plan and Table 1 compliance.
A concrete finisher experiences sudden chest tightness and difficulty breathing after grinding without dust controls. What condition should be suspected?
Answer: Acute silicosis or reactive airways response from silica overexposure
Acute silicosis can develop from short-term high-intensity silica exposure and presents with rapid-onset respiratory distress requiring immediate medical attention.
What class of hard hat is required when a concrete finisher works near energized overhead electrical lines?
Answer: Class E (Electrical) rated for 20,000 volts
Class E hard hats are tested to withstand 20,000 volts and are required when workers may be exposed to high-voltage electrical hazards overhead.
What is the recommended wet-bulb globe temperature (WBGT) threshold above which mandatory rest breaks should be introduced for outdoor concrete work?
Answer: Above 28°C (82°F) WBGT with increasing frequency above 31°C
NIOSH and ACGIH guidelines recommend instituting rest-in-shade schedules when WBGT exceeds 28°C, with more frequent breaks as it climbs above 31°C.
Which chemical component of Portland cement is primarily responsible for causing allergic contact dermatitis in concrete finishers?
Answer: Hexavalent chromium (Cr VI)
Hexavalent chromium naturally present in cement is a sensitizer that causes allergic contact dermatitis, a chronic occupational skin disease among concrete workers.
What does the Globally Harmonized System (GHS) pictogram showing a flame over a circle indicate on a concrete admixture label?
Answer: Oxidizer that can intensify fire
The flame-over-circle GHS pictogram specifically identifies oxidizers — chemicals that can increase the intensity of a fire — distinct from the plain flame symbol for flammables.
Under EPA's National Pollutant Discharge Elimination System (NPDES), construction sites disturbing one or more acres must have which document in place?
Answer: A Stormwater Pollution Prevention Plan (SWPPP)
NPDES Construction General Permits require a SWPPP that identifies pollutant sources (like concrete washout) and best management practices to control stormwater runoff.