How to Read Lead Test Results for Paint

The EPA established limits for lead in paint in 1978.

There are two systems for testing the lead content of paint: X-ray fluorescence (XRF) and laboratory testing through the National Lead Laboratory Accreditation Program. If your test results were delivered on-site at the time of testing, XRF testing was most likely used. If the test results came later, it was probably laboratory testing.

1. If XRF testing was used, a lead content of 1 mg per square centimeter of painted surface is defined as leaded paint.

2. If your XRF test results were inconclusive, it may be because of materials below the paint. It is possible to retest by removing some surface paint and establishing a reading of the material underneath as a base reading.

3. If laboratory testing was used, determine whether your test results are being reported as a percentage or in terms of milligrams per square centimeter.

4. If the laboratory test results are reported as milligrams per square meter, a lead content of 1 mg per square centimeter is considered leaded paint.

5. If the laboratory test results are reported as a percentage, results of 0.5 percent lead constitute leaded paint.

Tip

Be sure that your paint is tested by a certified lead-based paint professional, a certified inspector or a certified risk assessor.

Warning

At the moment, there are no lead test kits recognized by the Environmental Protection Agency as being free from reporting both false positive and false negative results.

If your house was built before 1978, there is a higher chance of having lead content in the paint, as it was not until 1978 that the EPA established limits for lead in paint.

Even if your test results are negative, it does not mean that there is no lead in the paint. It simply means that the paint does not contain enough lead to be classified as leaded paint. Homeowners should still be cautious about paint flakes, chips and dust.