The LeadCheck home water analysis test kit is non-toxic, odorless, and recognized by the EPA. When the 3M LC-8S20C detects lead, the swab turns red on contact, giving you clear results in less than 30 seconds. This test kit is easy to to use: simply crush, shake, and swab. In addition, each kit includes test confirmation cards to verify individual test results. This lead test kit is approved for use on various painted surfaces and plastic, but is not approved for tests on plaster or drywall.