Which lead kit you should use depends on paint color. If you're color-blind, don't use a kit that turns pink or red. Also note that lead test kits use one of two chemicals--sodium sulfide or rhodizonate--to detect lead by color change. Consider buying one of each type to test paint of all colors.
Here's how to keep yourself and your family safe.
Start with a blood test. All children should be screened at ages 1 and 2, according to the Environmental Protection Agency. Recent renovations or major repairs to a building built before 1978 could disturb older paint and are more reason to test children's blood lead levels. The federal Centers for Disease Control and Prevention defines elevated lead levels as 10 micrograms per deciliter (mcg/dL) of blood. But Consumer Reports believes that the CDC should lower that amount to 5 mcg/dL because research suggests even low levels may be harmful.
Find the lead. If a child tests negative for lead and you live in a house built before 1978, you might still want to know whether any painted surfaces contain lead, as remodeling and even sanding could release it.
Rhodizonate-based lead kits can yield false positives on red or pink paint; sulfide-based kits can yield false negatives or positives on dark paint. For more reliable results, use one of each type of kit. Follow instructions exactly and ensure that every layer of paint is exposed. Depending on the kit, you can test several areas for less than $100.
Your home might not be the only source of lead. Children can be exposed to lead if they attend day care in a pre-1978 building. Toys can be another source, as we reported in New worries over lead, for which we tested some lead kits on dishes, toys, and other household objects. Toys have lower lead limits than pre-1978 house paint. You'll find photos and descriptions of recalled products on the website of the Consumer Product Safety Commission, where you can also sign up to get e-mail notification of product recalls.
Call a pro for prompt action. If your child tests positive for lead, the quickest route to detection and stabilization is to find a certified lead inspector or risk assessor. Starting in 2010, contractors renovating pre-1978 buildings must have certification. Your regional EPA office has data on certified professionals; or you can find more information at epa.gov/lead/pubs/renovation.htm. Some homeowners are eligible for government-insured loans to help defray costs.
Another option is to hire a trained XRF (X-ray fluorescence) technician to screen for lead. Or you can send samples to a lab instead. If you choose to do that, be aware that the results are measured on a different scale: parts per million, not milligrams per square centimeter. An XRF gun isn't the best choice for some surfaces. And if you get positive results, you should follow up with a lab test. XRF screening costs about $500 for an average home. Lab testing of paint chips can cost $85 per sample.
Consumers Union, the advocacy arm of Consumer Reports, believes there are probably no safe levels of lead, especially for children. If your child and home test positive for lead and you've eliminated other sources, consider remediation.