Home Lead Test Kits Are Unreliable

The Consumer Product Safety Commission (CPSC) announced on October 22 that test kits used to test for lead on products in a consumer's home are highly unreliable. Based on tests performed by the CPSC, consumers should not use such test kits as they lead to false readings.

The CPSC used test kits, which are commonly available for consumers. Tests were performed on paints and other products, which the testers knew contained varied levels of lead. According to the CPSC, these test kits detected many false negatives or positives. Thus, the test kits either falsely detected lead, even though the product did not contain lead; or the test kits falsely indicated that no lead was present, when the product did in fact contain lead. The CPSC conducted a total of 104 tests. 56 of the tests turned out to be false negatives, indicating the product was lead-free, when in fact it did contain lead. Only two showed false positives. Furthermore, if the product contained a non-leaded coating, the kits were inconsistent in the lead detection.

The CPSC used two types of test kits, which are usually used by consumers to test for lead hazards in their homes. These two types of kits use chemical reactions of rhodizonate ion and sulfide ion as a base. The maximum lead level regulatorily set by the CPSC for household paint is 0.06%. Generally, these test kits are developed to find higher lead levels than the one set by the CPSC. Consequently, the CPSC test results show these kits are not reliable to detect low lead levels in paint or other materials, not even levels slightly above the level set by the CPSC as safe. Furthermore, the kits effectiveness can be hampered by influences from iron, tin, or dirt in or on the product. Additionally, test kit results are reflected by color changes, which, if paint is tested, can be distorted by the color in the paint, making it difficult to interpret the result.

The CPSC also tested x-ray fluorescence (SRF) to screen for lead. Of the thirteen samples, twelve test results were correct. Therefore, this type of test is much more reliable. However, since this type of test is not available to the general public, and requires training before it can be properly used, it might be of better use for professional inspectors than consumers.

Based on their test results the CPSC advises consumers not to use these at-home lead test kits. Consumers worried about a possible lead hazard in a product in their house should have it professionally tested. A test performed by a trained professional will provide accurate results.

For more information, consumers can check with the CPSC on the website at www.cpsc.gov. If there is suspicion of a high level lead exposure, consumers are advised to immediately contact their physician for evaluation.professional will provide accurate results.