When multiple layers of non-leaded coatings are present over lead paint, what does this most significantly affect?

The presence of multiple layers of non-leaded coatings over lead paint most significantly affects bulk paint chip samples reported in percentage weight. When assessing painted surfaces that may contain lead, the layers of non-leaded paint can create a barrier that influences the sample's overall composition.

In a bulk paint chip sample, the analysis typically determines the lead concentration by measuring the portion of lead relative to the total weight of the paint sample. If non-leaded layers are present, they dilute the concentration of lead in the sample collected because the results are averaged over the entire chip. Consequently, you might underestimate the true lead content of the underlying lead paint due to the presence of these non-leaded layers.

This is crucial for risk assessors to understand, as it directly impacts the evaluation of lead hazards in a property. Proper interpretation of these samples is essential for determining the presence of lead and making informed decisions on remediation and safety measures.