If ambient air counts go above 0.01 f/cc outside the containment, what action should the site supervisor take?

• A. Stop removal, mist air with amended water, cleanup all debris, locate and repair containment breach
• B. Continue removal and monitor the air
• C. Increase ventilation and resume removal
• D. Evacuate the building and halt all operations

Answer: (A)

When ambient air outside containment shows fibers above 0.01 f/cc, the immediate priority is to halt removal and stop further release. This threshold indicates fibers are escaping the controlled area, so stopping work prevents additional exposure. The next steps focus on containment and cleanup: mist the area with amended water to suppress dust, thoroughly clean up debris to remove potential sources of re-entrainment, and locate and repair the containment breach to restore a closed environment. Once the breach is fixed, air monitoring should confirm that levels outside containment have returned to acceptable limits before resuming removal. Continuing work or simply increasing ventilation could spread fibers and worsen exposure, and evacuating the building is reserved for more severe or imminent hazards.