CHST Noise Exposure and Hearing Conservation Programs 2

Question 1

Under OSHA's 5 dB exchange rate, what is the permissible exposure duration for a worker exposed to a steady 100 dBA?

Accepted Answer

2 hours

Answer

Using T = 8/2^((L-90)/5), 100 dBA yields 8/2^2 = 2 hours.

Question 2

A noise dosimeter reports a full-shift dose of 200%. What is the equivalent 8-hour TWA?

Accepted Answer

95 dBA

Answer

TWA = 16.61 log10(200/100) + 90 = 95 dBA.

Question 3

Two identical compressors each produce 88 dBA at a worker's position. What is the approximate combined level?

Accepted Answer

91 dBA

Answer

Decibels add logarithmically, so two equal sources increase the level by about 3 dB.

Question 4

A worker spends 4 hours at 95 dBA and 4 hours at 90 dBA. What is the noise dose?

Accepted Answer

150%

Answer

Dose = 100 × (4/4 + 4/8) = 150%.

Question 5

Which OSHA construction standard sets the permissible noise exposure limits shown in Table D-2?

Accepted Answer

29 CFR 1926.52

Answer

29 CFR 1926.52 contains the construction occupational noise exposure limits in Table D-2.

CHST - Construction Health and Safety Technician Practice Test