Because lead in soldered plumbing joints can contaminate drinking water, codes now require solder containing less than 0.2% lead for domestic water lines. But this regulation hasn't been in place long and old plumbing can be a hazard. Plumbing joints can be checked for the presence of lead with LeadCheck For Solder. A test kit contains ten single-test swabs, which are each covered by a cardboard sleeve. Inside each sleeve are two glass vials containing a twopart test solution. To test a solder joint, the vials are crushed, turning the cotton swab yellow. When wiped over a solder joint, the solution will change to pink if any lead is present. A ten-pack LeadCheck kit costs about $30. For more