What is the federal lead standard used to classify a result as positive in mg/cm2?

• A. 0.5 mg/cm2
• B. 0 mg/cm2
• C. 1.0 mg/cm2
• D. 2.0 mg/cm2

Answer: (C)

The test is asking about the threshold used to decide when a surface wipe sample indicates a lead hazard. In this context, the federal standard for labeling a wipe sample result as positive is a lead mass of 1.0 mg per square centimeter. If a sample yields 1.0 mg/cm2 or higher, it’s considered positive for lead contamination and typically triggers required actions such as remediation or abatement under federal rules. This threshold is set to identify surfaces with a meaningful level of lead dust that poses health risks, especially to children. Results below that level are not classified as positive, though they may still warrant monitoring or follow-up depending on the situation and surface type.