The 30-minute Excursion Limit set by OSHA is 1.0 f/cc.

• A. False
• B. 0.3 f/cc
• C. 2.0 f/cc
• D. True

Answer: (D)

The key idea is short-term exposure limits for asbestos. OSHA uses an excursion limit to cap brief spikes in concentration, measured over a specific short window, in addition to the long-term exposure limit. For asbestos, any 30-minute period cannot exceed 1.0 fibers per cubic centimeter (f/cc). This 30-minute excursion limit is separate from the 8-hour time-weighted average PEL of 0.1 f/cc.

So, stating that the 30-minute Excursion Limit is 1.0 f/cc is correct. If a 30-minute reading averages above 1.0 f/cc, action is required to reduce exposure. The numbers 0.3 f/cc and 2.0 f/cc are not the defined excursion limit itself—the first is below the limit, and the second would indicate a violation but does not define the limit.