What are the EPA clearance standards for lead dust on floors?

• A. < 10 µg/ft²
• B. < 50 µg/ft²
• C. < 1 µg/ft²
• D. < 100 µg/ft²

Answer: (A)

After abatement or renovation, the level used to judge whether a floor is clean enough is a dust-lead clearance standard. For floors, the pass threshold is 10 micrograms of lead per square foot. This means that wipe samples taken from floor surfaces must show lead levels at or below 10 µg/ft² to achieve clearance. If any sample exceeds that, additional cleaning is required and the area must be re-tested until all samples meet the standard. This relatively strict floor limit is chosen to reduce the amount of lead dust that children could ingested through hand-to-mouth activity. Other surfaces have different clearance thresholds, but for floor dust, the 10 µg/ft² standard is the key pass level.