HSE Occupational Health and Industrial Hygiene 5

Question 1

Which ACGIH exposure limit category represents a concentration that should not be exceeded even instantaneously?

Accepted Answer

Ceiling (C)

Answer

The ACGIH Ceiling (C) value is the concentration that should never be exceeded at any time during the workday, regardless of how brief the exposure.

Question 2

A new chemical process introduces hydrogen sulfide gas. Workers report detecting a rotten egg odor during startup, then losing the ability to smell it. What phenomenon explains this?

Accepted Answer

Olfactory fatigue (odor paralysis)

Answer

Hydrogen sulfide rapidly paralyzes the olfactory nerve at concentrations above about 100 ppm, causing workers to lose the warning signal precisely when danger is greatest.

Question 3

Under OSHA's hearing conservation program (29 CFR 1910.95), at what action level must employers enroll workers in annual audiometric testing?

Accepted Answer

85 dBA TWA

Answer

OSHA requires employers to implement a hearing conservation program, including audiometric testing, when worker noise exposure reaches or exceeds an 85 dBA 8-hour TWA action level.

Question 4

Which type of air-purifying respirator provides protection against both particulates and organic vapors simultaneously?

Accepted Answer

Combination cartridge respirator

Answer

Combination cartridges contain both a particulate filter and a sorbent bed for organic vapors, providing dual protection in environments with both hazard types.

Question 5

A company's industrial hygienist conducts exposure monitoring and finds results consistently below 50% of the PEL. Under OSHA guidelines, what is the minimum recommended reassessment interval?

Accepted Answer

Every year or when process changes occur

Answer

Industry guidance recommends annual reassessment or whenever process, material, or control changes could affect exposure, even when results are well below the PEL.

(HSE) Certified Health Safety Environment Practice Test

(HSE) Certified Health Safety Environment Practice Test

HSE Occupational Health and Industrial Hygiene 5