What is the dust wipe clearance level for window wells or troughs?

The dust wipe clearance level for window wells or troughs is set at 100 micrograms per square foot (ug/ft²). This standard is part of the guidelines established for lead hazard assessments, specifically focusing on areas where lead dust may accumulate as a result of lead-based paint deterioration or other sources. The rationale behind this particular clearance level is grounded in health considerations; it aims to ensure that the environment is safe and that any potential exposure to lead is minimized.

A clearance level of 100 ug/ft² is designed to protect vulnerable populations, especially children, who are more susceptible to the harmful effects of lead exposure. Maintaining this threshold aids in determining whether remedial measures were effective. If lead dust levels after cleaning or remediation do not exceed this level, it indicates that the area is reasonably safe for occupants.

Understanding clearance levels is crucial for risk assessors, as it guides their evaluation and recommendations to prevent lead poisoning in residential environments, thereby contributing to public health safety.