How to Test for Lead Paint

Testing for lead paint.
credit: McClendon Hardware
You can conduct a fairly reliable lead check with a store-bought test pen.

Lead paint is a household hazard that continues to exist in American homes despite the fact that its use was outlawed in 1978. Homes built before that time are likely to have at least one coat of lead paint, although it may be covered by one or several coats of newer paint. Add to that the facts that countries like Japan and Vietnam continue to use lead paint on products they sell in foreign markets and that some 40 countries worldwide, including such major exporters as China, Taiwan and the Philippines, still use lead as an additive in paint products.

Lead is toxic, and ingesting it even in small quantities is dangerous, especially for children. If you live in a house built before 1978 or if you have furniture that originated in a country that allows the use of lead paint, your health and that of your family depends on removing any lead-based paint that could end up in your food or in the mouth of a curious toddler. And to remove it, you have to find it.

Testing for lead is something you can do yourself with a store-bought kit, but in some cases, it's better to collect a sample of suspect paint or dust and send it to a professional lab for testing. If you opt for lab testing, it's important to follow the recommended procedure for collecting a sample to ensure a reliable test.

Lead: the Poisonous Pigment

Dutch Boy lead paint.
credit: Clay Point Associates, Inc.
At one time, the presence of lead in a paint product was a desired feature.

Element number 82 in the periodic table, lead is a soft, bluish metal that exists in small amounts in the earth's crust. Artists and painters have used lead carbonate for centuries as a pigment because of its highly opaque, scintillating white color, and they have also used lead tetroxide, which makes paint bright red.

Lead resists corrosion, improves paint durability and acts as a drying agent, so it's no wonder that paint manufacturers in the U.S. began adding it to their products in the 1800s. This practice continued until lead use was limited by Congress in 1971 and finally curtailed by the Consumer Product Safety Commission in 1976. A complete prohibition of lead in household paint took effect in 1978.

The prohibition came into effect because of the growing appreciation of the adverse health effects of lead. It's a neurotoxin that produces a number of symptoms in adults, including headaches, joint and muscle pain, and problems with memory and concentration. Children and pregnant women are particularly vulnerable to lead poisoning. Children can experience learning and developmental disorders, hearing loss and seizures. Pregnant women may give birth prematurely, and the newborns may weigh less than normal and experience slowed growth.

Using Lead Test Swabs

Home lead test kit.
credit: Protective Products
Testing swabs turn red in the presence of lead.

The EPA recommends only two home lead test products on its web page: LeadCheck from 3M and D-Lead from Klean Strip. As of 2018, the production of the D-Lead Paint Test Kit has been discontinued, so LeadCheck is the only EPA-approved option currently available. A package of eight single-use LeadCheck swabs costs a little over $20.

Before you use a LeadCheck swab, it's important to expose all the layers of paint on the surface you're testing. The top layers may not contain lead, but the older ones underneath might. When testing on wood, make a cut through the paint with a utility knife all the way to the wood to remove a small piece of paint and expose the wood. When testing on drywall, hold the knife at a 5-degree angle and cut a circular section about the size of a nickel. Be sure to cut all the way down to the drywall, but try not to cut through the drywall paper. Gypsum could interfere with the testing chemicals in the swab.

Each swab is attached to a pair of sealed ampoules enclosed by a cardboard tube.

  1. Squeeze the cardboard tube and crush the ampoules. You'll hear the sound of glass breaking.
  2. Shake the tube to mix the chemicals. The swab is now activated. It only remains activated for 90 seconds, so be sure the test area is ready.
  3. Squeeze slowly and firmly until a little of the mixture appears on the swab.
  4. Rub the swab on the test area and keep rubbing for about 30 seconds, then stop. If the test area or the swab itself turns pink or red, lead is present.
  5. Deposit a drop of the mixture on one of the dots on the confirmation card dots that comes with the test kit. It should immediately turn red. If the swab or test area didn't turn pink or red, this procedure confirms that the chemicals are working and that lead isn't present.

Each swab is good for only one test, so you need a new one for each additional area to be tested. Be sure to clean the knife blade with alcohol to prevent cross-contamination before you begin preparing another test area.

You should wear latex gloves when conducting these tests. After all tests are complete, deposit the used swabs in one of the gloves, stuff that glove into the other one, and throw everything away.

Collecting a Sample for a Lab Test

Lab test kit for lead.
credit: Green Depot
Lab testing is more accurate if all you have is dust or a pile of paint chips.

You may prefer to send a sample to a lab for testing. Lab tests are more accurate, especially when you suspect lead in a sample of dust or paint chips that have fallen onto the floor. You can buy a lab test kit at any building supply outlet for less than $20. It comes complete with instructions, but here's a quick rundown of the procedure:

  1. Put on the gloves that come with the test kit. If you're taking a paint sample, clean dust and dirt off the test area. If you're collecting a dust sample, no cleaning is required.
  2. Collect a paint sample by cutting through all the layers of paint down to the substrate and removing enough paint chips to fill a tablespoon.
  3. Collect a dust sample by using the wipe that comes with the kit. Rub the wipe lightly to ensure you actually collect dust and don't simply push it around.
  4. After you collect the sample, fold the wipe in half so that the soiled side is inside the fold. Rub the clean side of the wipe along the surface again in the perpendicular direction. Fold the wipe again.
  5. Deposit the paint chips or the wipe in the plastic bag supplied with the kit, seal it and put it in the postage-paid mailing envelope supplied. Include a check or money order for the testing fee and mail the envelope.