What is the lead dust clearance limit for window sills?

What is the lead dust clearance limit for window sills?

• A. 40 ug/ft2
• B. 100 ug/ft2
• C. 250 ug/ft2
• D. 150 ug/ft2

Answer: (C)

Lead dust clearance testing uses wipe samples to measure how much lead remains on surfaces after abatement, and the acceptable amount depends on the surface type. For interior window sills, the clearance limit is 250 micrograms of lead per square foot (µg/ft²). This higher number compared with floors reflects how window sills tend to collect and hold dust differently and can be harder to clean completely, while floors are more directly cleaned and walked on, making a stricter standard appropriate. In practice, after cleanup you’d collect wipe samples from representative window sills and compare the results to 250 µg/ft²; if results exceed this limit, you re-clean and retest until they meet the standard.

Lead dust clearance testing uses wipe samples to measure how much lead remains on surfaces after abatement, and the acceptable amount depends on the surface type. For interior window sills, the clearance limit is 250 micrograms of lead per square foot (µg/ft²). This higher number compared with floors reflects how window sills tend to collect and hold dust differently and can be harder to clean completely, while floors are more directly cleaned and walked on, making a stricter standard appropriate. In practice, after cleanup you’d collect wipe samples from representative window sills and compare the results to 250 µg/ft²; if results exceed this limit, you re-clean and retest until they meet the standard.