At this time, EPA does not recognize LeadCheck swabs for testing plaster and drywall for lead in RRP-eligible projects (though the swabs are the only currently recognized swabs for testing for lead paint in houses built prior to 1978).
While inexpensive LeadCheck swabs are recognized for testing for lead paint on wood, such as window frames and sills, determining the presence or absence of lead in plaster and drywall applications now requires a third-party test, which can get expensive.
Without the third-party test to verify there is NO lead in the plaster or drywall of older homes undergoing renovation, a professional company must comply with RRP lead-safe work practices.
However, LeadCheck announced that EPA recognition for testing drywall and plaster with its swabs will occur within a few weeks.
See here how to test for lead on stucco and drywall, or watch the video below.