ASP ASP Hazardous Materials and Chemical Safety 2

Question 1

What does the acronym TLV-TWA stand for in occupational exposure guidelines?

Accepted Answer

Threshold Limit Value - Time-Weighted Average

Answer

TLV-TWA (Threshold Limit Value - Time-Weighted Average) is the ACGIH-recommended airborne concentration for a normal 8-hour workday, 40-hour workweek.

Question 2

Using OSHA's 5 dB exchange rate, at what noise level is the maximum permissible exposure time reduced to 1 hour?

Accepted Answer

105 dBA

Answer

Starting from 90 dBA at 8 hours, each 5 dB increase halves exposure time: 95=4 hr, 100=2 hr, 105=1 hr.

Question 3

What is OSHA's permissible exposure limit for respirable crystalline silica (as quartz) in general industry?

Accepted Answer

50 µg/m³ as an 8-hour TWA

Answer

OSHA's 2016 silica rule set the PEL at 50 µg/m³ as an 8-hour TWA for general industry, a significant reduction from the prior limit.

Question 4

A Short-Term Exposure Limit (STEL) is defined as a time-weighted average concentration not to be exceeded over what maximum duration?

Accepted Answer

15 minutes

Answer

STEL is a 15-minute TWA concentration that should not be exceeded during any part of the workday.

Question 5

What is OSHA's permissible exposure limit (PEL) for carbon monoxide (CO) in general industry?

Accepted Answer

50 ppm TWA

Answer

OSHA's PEL for CO in general industry is 50 ppm as an 8-hour TWA per 29 CFR 1910.1000.

(ASP) Associate Safety Professional Practice Test

(ASP) Associate Safety Professional Practice Test

ASP ASP Hazardous Materials and Chemical Safety 2