At the end of October the CPSC released a statement that:
“Many of the tests performed using the kits did not detect lead when it was there (false negatives); some indicated lead was present when it was not (false positives). Of 104 total test results, more than half (56) were false negatives, and two were false positives. None of the kits consistently detected lead in products if the lead was covered with a non-leaded coating. Based on the study consumers should not use lead test kits to evaluate consumer products for potential lead hazards.”
Yesterday, Health Canada issued a warning claiming the same thing.
Health Canada’s product safety laboratory evaluated a number of the kits, which typically are swab-based systems that tests for lead using a chemical that reacts with lead, changing colour if lead is present.
The home tests have been available for some time from specialty shops, but have more recently been available on the Internet and in hardware and general merchandise stores, where they sell for between about $8 and $19.
Tests done by Health Canada showed results may be affected by pigment in the product being tested.
Unfortunately, neither association released the names of the tests they believed to be inaccurate. I guess it is safe to say that purchasing any of these tests would not be a good idea.