CAOHC Federal Regulations and Standards 2 — Questions and Answers
Question 1: At what 8-hour TWA noise exposure level must an employer implement a hearing conservation program under OSHA?
- 85 dBA (Correct answer)
- 90 dBA
- 80 dBA
- 95 dBA
Correct answer: 85 dBA
OSHA requires a hearing conservation program for all employees exposed to an 8-hour TWA of 85 dBA or above, known as the action level.
Under 29 CFR 1910.95(c), the action level of 85 dBA TWA triggers hearing conservation program requirements. This is distinct from the 90 dBA permissible exposure limit (PEL).
Question 2: What exchange rate does OSHA use for calculating noise dose?
- 5 dB doubling rate (Correct answer)
- 3 dB doubling rate
- 10 dB doubling rate
- No exchange rate is applied
Correct answer: 5 dB doubling rate
OSHA uses a 5 dB exchange rate, meaning that for every 5 dB increase, the allowable exposure time is halved.
OSHA's 5 dB exchange rate means 90 dBA is allowed for 8 hours, 95 dBA for 4 hours, 100 dBA for 2 hours. This is more lenient than the 3 dB exchange rate recommended by NIOSH.
Question 3: Which OSHA standard specifically addresses occupational noise exposure in general industry?
- 29 CFR 1910.95 (Correct answer)
- 29 CFR 1926.52
- 29 CFR 1904.10
- 29 CFR 1910.1000
Correct answer: 29 CFR 1910.95
29 CFR 1910.95 is the OSHA standard governing occupational noise exposure and hearing conservation programs in general industry.
29 CFR 1910.95 covers all aspects of occupational noise exposure for general industry. The construction industry equivalent is 29 CFR 1926.52.
Question 4: Under OSHA, how must hearing loss be recorded on the OSHA 300 Log?
- When an STS is confirmed and the average hearing level at 2000, 3000, and 4000 Hz reaches 25 dB or more (Correct answer)
- Any time an employee reports difficulty hearing
- Whenever an STS occurs regardless of overall hearing level
- Only when hearing loss results in lost workdays
Correct answer: When an STS is confirmed and the average hearing level at 2000, 3000, and 4000 Hz reaches 25 dB or more
OSHA recording criteria require both a confirmed STS AND an average hearing level of 25 dB HL or more at 2000, 3000, and 4000 Hz.
Per 29 CFR 1904.10, a hearing loss case is recordable when both an STS occurs AND the employee total hearing level averaged at 2000, 3000, and 4000 Hz is 25 dB or more above audiometric zero.
Question 5: What is the maximum permissible exposure limit for noise under OSHA for an 8-hour workday?
- 90 dBA TWA (Correct answer)
- 85 dBA TWA
- 95 dBA TWA
- 100 dBA TWA
Correct answer: 90 dBA TWA
The OSHA PEL for noise is 90 dBA as an 8-hour time-weighted average.
The PEL of 90 dBA TWA is the legally enforceable maximum noise exposure limit. When exceeded, OSHA requires feasible engineering controls and hearing protection.
Question 6: Which federal agency publishes recommended exposure limits for noise that differ from OSHA PEL?
- NIOSH (Correct answer)
- EPA
- MSHA
- FDA
Correct answer: NIOSH
NIOSH recommends an REL of 85 dBA TWA using a 3 dB exchange rate, which is more protective than OSHA.
NIOSH, part of the CDC, conducts research and makes recommendations but does not set enforceable standards. Their REL of 85 dBA with a 3 dB exchange rate is based on equal-energy theory.
CAOHC Federal Regulations and Standards 2
At what 8-hour TWA noise exposure level must an employer implement a hearing conservation program under OSHA?