Lead is a toxic metal that can cause illness and even death. Lead poisoning has been linked to brain damage, learning disabilities, and hearing problems in children. Adults who are exposed to high levels of lead over time could experience kidney disease, high blood pressure, and reproductive problems.
However, the only way to know if you have lead in your tap water is by using home drinking water test kits such as those offered by Varify or other brands.
Let’s explore what these kits do, and find out how accurate they are.
What are lead test strips?
Lead test strips for water are small paper strips that include a special chemical that detects lead in your drinking water.
These kits use chemicals called dithiocarbamates that react with the presence of lead in your water supply to create a telltale color change on the strip’s paper surface so you’ll know immediately whether or not there’s any danger.
Why test for lead in your drinking water?
If your home was built before the 1986 Safe Drinking Water Act then you could have lead service lines and lead pipes. Lead is also found in brass or chrome-plated faucets, some solder and outdoor faucets, and in the solder of older homes.
A 2016 investigation by USA today identified over 2000 water systems across all fifty states that had unacceptable levels of lead [1]
This is concerning because of the findings of studies conducted on animals and humans which were published between 1989 and 2014 by a research team led by Bruce Lanphear[2] at Simon Fraser University, British Columbia.
In these studies, they found that even small amounts of lead exposure in children contribute to lower intelligence, behavioral problems, and impaired development [3].
Exposure to lead in drinking water can also be a concern for adults. For example, the EPA says that adults who drink water containing very high levels of lead over a long period could experience lead poisoning symptoms such as joint pain, memory problems, and increased blood pressure.
Studies have found that people who have been exposed to drinking water with high levels of lead are more likely to die from heart disease than those without exposure.
How do lead test kit strips work?
Lead test kit strips for water are very easy to use, with simple testing procedures.
You simply collect a water sample, insert the test strip into the container, and wait between 10 seconds to two minutes for it to dissolve.
The test strip is made up of three layers: an indicator layer, leachable dye layer, and backing.
If there is lead in your water, the indicator layer on the test strip will change color.
Check the color against the chart that the manufacturer has provided.
Are lead test strips accurate?
Lead test strips are said to be very accurate. But they’re best for a snapshot in time rather than a long-term test of your water quality. So ideally, you’d want to make multiple tests over weeks or months to make sure the results aren’t changing.
For the most accurate results, use the testing strip for exactly the amount of time recommended by the test kit manufacturer. Vitality recommends just two seconds.
The accuracy of these tests depends on how well you follow the manufacturer’s directions for test times and quantities, what substances are in the sample being tested, and what other materials may be contaminating the sample.
As these test kits are inexpensive and quick, we recommend doing a couple of tests at a time to check that the results are accurate.
How much lead is too much?
EPA standards set the legal limit for lead in drinking water at 15 parts per billion. But no amount of lead is considered safe and there’s no known level of exposure to lead that is completely without risk.
If you’re concerned about the amount of lead in your water, consider a countertop RO system from our best-of list here.
Limitations of water test kit strips for lead
One of the limitations of lead test strips is that they only indicate the presence or absence of lead, not how much.
They are generally not that effective for detecting smaller amounts of dissolved lead, such as if your plumbing contains very small levels of lead solder.
The test kit may give you a false negative result.
The accuracy of the test strips also decreases if there are other substances or chemicals in your water, such as chlorine.
Another limitation of lead test strips is that you have to use them very quickly. If not used immediately, they lose their effectiveness because the chemical reaction begins breaking down almost immediately after being dissolved into water.
Other ways to detect the presence of lead in your home’s drinking water
You can add a few drops of sodium rhodizonate to your drinking water. Sodium rhodizonate is a chemical that reacts with lead ions in water to create a reddish-orange color. This DIY test works best if you allow the solution to sit overnight before checking for the reaction.
The downside of this method is that there’s no way to tell if you’ll get a positive result until you add the solution and allow it to sit overnight, although the longer it sits the easier it will be for you to detect.
You can also use more in-depth at-home test kits such as Tap Score, which is available from Amazon, Home Depot, or other hardware stores.
Another way to test for lead in your drinking water is through a professional service that is experienced in water testing.
You can hire an independent lab to do the water testing for you, but it will cost more than using at-home tests kits. There are plenty of professionals who offer home kits that are just as accurate as those used by independent labs.
