Sulfates present in drywall (gypsum) and plaster dust can interfere with
3Mô LeadCheckô Swabs color development. It is possible with a minimum
amount of care to accurately test for lead paint on plaster surfaces with
3Mô LeadCheckô Swabs.
1. With a clean utility knife, make a nickel sized half circle cut at a
low angle (about 5 degrees) cutting down to the bare drywall (gypsum) and
plaster core to expose all layers of paint. Make the cut as seen in figure
2. Fold down the semicircular flap with the knife blade so that it forms a
3. Using an activated 3Mô LeadCheckô Swab, hold the swab above the cut
allowing the 3Mô LeadCheckô reagent to flow into the pocket making sure
that the liquid contacts all layers of paint both in the cut itself and
the peeled back flap. Carefully rub the swab around the periphery of the
peeled back flap, taking care not to contact the drywall (gypsum) or
plaster. Only rub the swab on all layers of paint found on the flap. Do
not rub the swab in the pocket.
4. If lead is present, a pink or red color will develop along the edges of
the cut, flap, or swab tip usually within 30 seconds.
5. If no pink or red color develops, immediately confirm the negative
result by squeezing a drop of the 3Mô LeadCheckô reagent onto one of the
confirmation card dots. It should turn red immediately.
3Mô LeadCheckô Swab Demo on
Painted Drywall and Plaster