What is the lead dust clearance value for outside concrete?

What is the lead dust clearance value for outside concrete?

• A. 800 ug/ft2
• B. 400 ug/ft2
• C. 600 ug/ft2
• D. 1200 ug/ft2

Answer: (A)

After cleanup, clearance testing uses surface-specific dust thresholds. For exterior concrete, the allowable lead dust level on a wipe sample is 800 micrograms per square foot. This value reflects outdoor conditions while still protecting people from exposure on a surface that can be touched or tracked indoors. If all exterior concrete wipe samples are at or below 800 μg/ft2, clearance is achieved; if any sample exceeds it, further cleaning and re-testing are needed. The other numbers don’t apply to outside concrete in this clearance context, as they correspond to different surfaces or scenarios.

After cleanup, clearance testing uses surface-specific dust thresholds. For exterior concrete, the allowable lead dust level on a wipe sample is 800 micrograms per square foot. This value reflects outdoor conditions while still protecting people from exposure on a surface that can be touched or tracked indoors. If all exterior concrete wipe samples are at or below 800 μg/ft2, clearance is achieved; if any sample exceeds it, further cleaning and re-testing are needed. The other numbers don’t apply to outside concrete in this clearance context, as they correspond to different surfaces or scenarios.