What ambient air concentration outside containment triggers remediation actions?

What ambient air concentration outside containment triggers remediation actions?

• A. 0.01 f/cc
• B. 0.1 f/cc
• C. 1 f/cc
• D. 0.001 f/cc

Answer: (A)

Evaluating ambient air outside containment uses a very strict action level to protect people outside the workzone. The threshold is 0.01 fibers per cubic centimeter. If measurements outside containment meet or exceed this level, remediation actions must be triggered—such as stopping work, tightening containment, performing additional cleaning, and rechecking air to bring levels back down. This value is chosen to be well below workplace exposure limits, prioritizing public safety rather than worker exposure alone. The higher values listed are not used as outside-containment remediation triggers: 0.1 f/cc is the occupational exposure limit, not an ambient outside-containment action level; 1 f/cc is far too high to prompt remediation; and 0.001 f/cc is more stringent than standard practice for this purpose.

Evaluating ambient air outside containment uses a very strict action level to protect people outside the workzone. The threshold is 0.01 fibers per cubic centimeter. If measurements outside containment meet or exceed this level, remediation actions must be triggered—such as stopping work, tightening containment, performing additional cleaning, and rechecking air to bring levels back down.

This value is chosen to be well below workplace exposure limits, prioritizing public safety rather than worker exposure alone. The higher values listed are not used as outside-containment remediation triggers: 0.1 f/cc is the occupational exposure limit, not an ambient outside-containment action level; 1 f/cc is far too high to prompt remediation; and 0.001 f/cc is more stringent than standard practice for this purpose.