HSE Occupational Health and Industrial Hygiene 2

Question 1

Which OSHA permissible exposure limit (PEL) type represents the maximum concentration a worker can be exposed to for any 15-minute period?

Accepted Answer

Short-term exposure limit (STEL)

Answer

A STEL is the maximum airborne concentration permissible during any 15-minute period, not to be exceeded more than four times per shift.

Question 2

A worker is exposed to a noise level of 95 dBA for 4 hours per day. According to OSHA's permissible noise standard, what is the maximum additional hours of exposure at 90 dBA allowed?

Accepted Answer

2 hours

Answer

At 95 dBA the PEL is 4 hours; at 90 dBA it is 8 hours, so the fraction used is 4/4 = 1.0, meaning no additional 90 dBA exposure is allowed without exceeding the dose.

Question 3

What term describes the process of drawing a contaminant-containing air sample through a collection medium at a known flow rate to measure worker exposure?

Accepted Answer

Active sampling

Answer

Active sampling uses a pump to pull air through a sorbent tube, filter, or impinger at a calibrated flow rate over the sampling period.

Question 4

Which biological monitoring marker is most appropriate for assessing recent benzene exposure in a worker?

Accepted Answer

Urinary trans,trans-muconic acid

Answer

Trans,trans-muconic acid is a specific urinary metabolite of benzene and is the preferred biological exposure index (BEI) for recent benzene exposure.

Question 5

According to the hierarchy of controls, which measure most effectively eliminates an occupational health hazard?

Accepted Answer

Substitution of the hazardous substance

Answer

Substitution removes the hazard entirely by replacing it with a less hazardous material, making it the most effective control below elimination.

(HSE) Certified Health Safety Environment Practice Test

(HSE) Certified Health Safety Environment Practice Test

HSE Occupational Health and Industrial Hygiene 2