What is the lead dust clearance value for window wells?

What is the lead dust clearance value for window wells?

• A. 800 ug/ft2
• B. 400 ug/ft2
• C. 200 ug/ft2
• D. 1200 ug/ft2

Answer: (B)

The key idea is that lead dust clearance values are surface-specific and used after cleaning or abatement to confirm the area is sufficiently cleaned. For window wells, the standard clearance value is 400 micrograms of lead per square foot (μg/ft2). This means you take wipe samples from representative spots inside the window well, calculate the average lead per square foot, and if that average is at or below 400 μg/ft2, the window well passes cleanup. Window wells can collect dust from indoor spaces and from outdoor dirt tracked in, and they’re harder to clean completely, so this moderate threshold is set to ensure adequate cleaning without being impractically strict. If the measured value is higher than 400 μg/ft2, further cleaning and retesting are required. The other numbers correspond to different surfaces or contexts (such as floors or sills) and aren’t the standard for window wells.

The key idea is that lead dust clearance values are surface-specific and used after cleaning or abatement to confirm the area is sufficiently cleaned. For window wells, the standard clearance value is 400 micrograms of lead per square foot (μg/ft2). This means you take wipe samples from representative spots inside the window well, calculate the average lead per square foot, and if that average is at or below 400 μg/ft2, the window well passes cleanup.

Window wells can collect dust from indoor spaces and from outdoor dirt tracked in, and they’re harder to clean completely, so this moderate threshold is set to ensure adequate cleaning without being impractically strict. If the measured value is higher than 400 μg/ft2, further cleaning and retesting are required.

The other numbers correspond to different surfaces or contexts (such as floors or sills) and aren’t the standard for window wells.