Heat Stress and Hand-Arm Vibration (NIOSH) practice questions for the CSP exam

A safety professional supervising a foundry uses a Botsball (wet globe thermometer) for routine screening. On one afternoon the WGT reading is high and the area is near the action level. The shift lead proposes simply adding 2°C to the reading and treating the result as the final WBGT for all work/rest decisions. Which action best fits the guidance?

1. A.Accept the WGT + 2°C approximation because it is exact for all combinations of humidity, wind and radiant heat
2. B.Subtract 2°C from the WGT reading because the wet sphere overestimates heat load
3. C.Discontinue monitoring because a WGT cannot be used for screening in industry
4. D.Follow the high WGT reading with WBGT or other detailed measurements before making final decisions

A safety professional evaluates a humid, low-airflow bakery workroom. Calculations show the evaporation required for heat balance (Ereq) is 400 W, while the environment can accept at most 500 W of evaporation (Emax). A new supervisor asks what the Ereq/Emax ratio means for the workers' heat strain. Which interpretation is consistent with the guidance?

1. A.Workers can evaporate 80% more sweat than they need, so heat strain is negligible.
2. B.The ratio represents the percentage of metabolic heat that is transferred by radiation.
3. C.The ratio shows that 20% of workers will exceed the recommended core temperature.
4. D.About 80% of the body's skin surface must be wetted with sweat to achieve the needed evaporation, which signals heat strain where evaporation is restricted.

An industrial hygienist wants to use a WGT to predict WBGT at an outdoor loading dock. She has a recently measured relative humidity, wind speed and radiant heat estimate for the dock. A colleague at a different, poorly characterized site has no data on humidity, wind or radiant heat. Based on the guidance, what can be concluded about the predictions at the two sites?

1. A.Prediction within 0.4°C is supported only at the site without environmental data because the wet sphere integrates all factors
2. B.Neither site can be predicted, because WGT cannot correlate with WBGT at all
3. C.Both sites can be predicted equally well, since WGT always predicts WBGT within 0.4°C
4. D.Prediction within about 0.4°C at 90% confidence is supported at the dock with good estimates, but not at the site with limited knowledge of conditions