Dust clearance limit for window sills is which value?

Dust clearance limit for window sills is which value?

• A. 10 ug/ft2
• B. 40 ug/ft2
• C. 100 ug/ft2
• D. 250 ug/ft2

Answer: (D)

Post-remediation dust clearance uses surface-specific standards for acceptable lead dust levels. For window sills, the allowed dust-lead loading is 250 micrograms per square foot. This higher limit reflects practical cleaning realities: window sills tend to trap more dust and are harder to clean to the lower floor standard. The floor standard is lower (40 μg/ft²) because floors pose a greater risk for ingesting dust and spreading it throughout the space, so they require stricter cleaning. The other numbers aren’t the recognized window-sill standard. So 250 μg/ft² is the correct limit for window sills.

Post-remediation dust clearance uses surface-specific standards for acceptable lead dust levels. For window sills, the allowed dust-lead loading is 250 micrograms per square foot. This higher limit reflects practical cleaning realities: window sills tend to trap more dust and are harder to clean to the lower floor standard. The floor standard is lower (40 μg/ft²) because floors pose a greater risk for ingesting dust and spreading it throughout the space, so they require stricter cleaning. The other numbers aren’t the recognized window-sill standard. So 250 μg/ft² is the correct limit for window sills.