How to Test for Lead Paint in Your Home

Older homes have a lot going for them, including charm that newly built homes just can't compete with, but they are also likely to have lead paint on the walls and woodwork. According to data from the Environmental Protection Agency (EPA), there is a 24 percent chance that a house built between 1960 and 1978 — the year lead-based paint was banned — has lead paint, and the chances go up with age. It's 69 percent in houses built between 1940 and 1959 and a whopping 87 percent in houses built before 1940. These are numbers with serious repercussions for you and your family, especially children, who are more susceptible to lead poisoning than adults.

You can deal with lead paint in more than one way. You can encapsulate it as you do asbestos by covering it with a material that won't allow the lead to escape, or you can remove the lead paint altogether. First, though, you have to know it's there, and you can do that with a DIY store-bought lead test kit. Most kits give reliable results quickly as long as you use them correctly and in accordance with the manufacturer's instructions.

People have been using the soft, malleable metal known as lead (atomic symbol Pb, atomic number 82) for millennia, and although there have been glimmers of recognition of the harm it does in the human body, most have been blissfully unaware because it wasn't until the mid-20th century that the danger came to be fully appreciated. Ancient civilizations used lead-based cookware, preferring it to iron because of lead's ability to resist corrosion and because of the slightly sweet taste of litharge, the oxide that forms on lead surfaces. The Romans made their water pipes from lead, and scholars believe it may have been the infertility caused by lead ingestion that was responsible for the fall of the Roman empire.

What our forebears didn't know was that lead, which has no useful purpose in the human body and doesn't form compounds that allow it to be expelled, collects in organs, such as the stomach, kidneys and brain. It causes a variety of diseases, including colic — a combination of abdominal distress, nausea and fever — and brain disorders, such as forgetfulness, depression and irritability. Prolonged lead exposure can cause high blood pressure, heart disease, kidney disease and infertility. These effects can be magnified in children, who may develop ailments of the central nervous system and suffer such symptoms as clumsiness, agitation and drowsiness, which progress to vomiting, stupor and convulsions as lead concentrations increase.

Because lead exposure in children can lead to learning disabilities as well as sickness, the Centers for Disease Control and Prevention (CDC) warns that there is no safe lower limit for lead accumulation. Although the CDC defines acceptable levels as those below 5 micrograms per decaliter, the underlying message is clear: Children should never ingest lead in any quantity ... period.

Prior to 1978, it was common practice to add lead to paint for color and durability and to accelerate drying. Lead found its way into paint primarily as a pigment, either as lead (II) antimonate (Naples yellow), lead tetroxide (red lead), lead II carbonate (white lead — formerly used as "white face" cosmetic), lead chromate (yellow — still used for road markings) and lead molybdate (orange-red). Lead pigments tend to be very bright, which is why they have been so popular.

Lead paint is safe as long as it stays on the painted surface, and no one comes in contact with it, but as any type of paint ages, it tends to dry out and flake off, and the resulting lead dust can accumulate on the floor or, when flaking off exterior surfaces, in the soil, and that's where it poses even more danger. The dust can become airborne, but even if it doesn't, curious toddlers playing indoors or outdoors can ingest it. Toddlers can also pull the odd paint chip off peeling surfaces and put it in their mouth, and they can also mouth windowsills, interior woodwork and toys that have been painted with lead paint.

Although it's possible to encapsulate lead paint with an appropriate primer, conventional paints and primers are unsuitable and allow the lead to leach to the surface. For this reason, older homes that have several coats of paint with only the bottom one containing lead are still hazardous, and they become more so when the paint ages and begins chipping. This is why it's so important to test for lead paint and to take remedial measures if you find it.

While virtually every test kit you can buy online or at a hardware store can give almost instant results, some are prone to false positives for certain types of paint, so which kit you choose matters. After conducting its own tests, the EPA recommends just three of the many products available, and one of these is available only to residents of Massachusetts. The two widely available EPA-recommended kits are D-Lead and 3M LeadCheck, and they are different. LeadCheck is rhodizonate-based and turns red when it detects lead, so it can yield a false positive on red and pink paint, whereas D-Lead is sulfide-based and turns dark, so it can yield a false positive with dark-colored paints.

You can get reliable results using tests from other manufacturers, but to be on the safe side, you should test with both a rhodizonate- and sulfide-based kit. There are other testing methods, such as using X-ray fluorescence, but they must be undertaken by qualified technicians.

It's important to read the directions on the test kit and follow them exactly. The method for using a product such as LeadCheck, which uses swabs for testing, is different than that for using one such as D-Lead, which requires you to mix a solution that includes a sample of the paint to be tested. When testing a surface with multiple layers of paint, you'll want a sample that includes all the coats, including — and especially — the one on the bottom, which is the one most likely to contain lead.

If a test confirms lead on painted surfaces in your home, lead may also be present elsewhere, including in the soil or the drinking water, so it's prudent to call a professional lead risk assessor to evaluate the hazard. The assessor will recommend an abatement strategy, which may include encapsulation or even a remodel to remove and replace all lead-painted surfaces. Since no amount of lead is safe for young children, it's important for each child to have a blood test so that a lead remediation strategy, such as chelation therapy, can be undertaken for children with high blood levels.