CIH General Practice 2

Question 1

Which sampling method is most appropriate when a worker's exposure varies significantly throughout the shift?

Accepted Answer

Full-period consecutive sampling

Answer

Full-period consecutive sampling captures the entire shift variability and provides the most representative TWA exposure estimate.

Question 2

The ACGIH TLV-STEL is defined as a concentration that should not be exceeded for more than how many minutes at a time?

Accepted Answer

15 minutes

Answer

The ACGIH TLV-STEL is a 15-minute TWA concentration that should not be exceeded at any time during the workday.

Question 3

A noise survey reveals a worker is exposed to 95 dBA for 4 hours and 90 dBA for 4 hours. Using OSHA's permissible noise formula, what is the dose?

Accepted Answer

125%

Answer

At 95 dBA the limit is 4 hours (4/4=1.0) and at 90 dBA the limit is 8 hours (4/8=0.5); combined dose = 1.0 + 0.5 = 1.5 = 150%.

Question 4

Which administrative control is most effective for reducing cumulative chemical exposure when engineering controls are not feasible?

Accepted Answer

Job rotation among workers

Answer

Job rotation distributes exposure among multiple workers, reducing any single worker's cumulative dose when source elimination is not possible.

Question 5

What does a real-time aerosol monitor measure that a gravimetric filter method does not provide?

Accepted Answer

Continuous time-resolved concentration data

Answer

Real-time aerosol monitors provide continuous, time-stamped concentration readings, allowing identification of peak exposure events during a shift.

CIH - Certified Industrial Hygienist Exam Practice Test