What must the dust samples for window wells be less than to pass?

To pass the lead dust clearance criteria for window wells, the dust samples must be less than 400 µg/ft². This standard is based on regulations that mandate safe levels of lead dust in residential environments, specifically in areas where children may be exposed.

Meeting this threshold is crucial because lead exposure can have harmful health effects, particularly on young children. Therefore, maintaining dust levels below the specified amount helps ensure a safe living environment. The established limit of 400 µg/ft² serves as a protective measure to prevent lead poisoning and its associated risks.

In context, other potential thresholds, such as 250 µg/ft² or 350 µg/ft², do not align with the regulatory framework outlining safe lead dust levels in window wells, which supports the need for the 400 µg/ft² benchmark.