Lead, being a toxic metal, can cause various health issues if present in drinking water. Lead enters drinking water through lead pipes, faucets, and fixtures. Certain household fixtures, plumbing pipes, and welding solders made before 1986 may contain lead. According to the United States Environmental Protection Agency (EPA), the maximum allowable concentration of lead in drinking water for an adult is 15 µg/L. Besides this, EPA and CDC declared that there is no safe level of lead in a child’s blood.
So, it’s important to check the lead concentration in your drinking water for safety and health concerns. Lead test strips are the famous options for testing lead in water. In this article, you will get to know about lead test strips, their working, and their accuracy.
Why Test Lead in Drinking Water?
Before talking about lead test strips, let’s clarify why we should test lead, especially in drinking water. Excessive lead exposure to children and adults causes various diseases and disorders.
A little exposure of lead to children is dangerous, and it can lead to fatal disorders and diseases like:
- Hyperactivity and Lower IQ
- Slow growth
- Hearing issues
- Behavior and learning problems
Lead is also harmful to adults and it can cause various problems for them, including:
- Decreased kidney function
- Cardiovascular effects, hypertension
- Reproductive issues both in men and women
According to research conducted in 2016, over 2000 water systems across all fifty states of the U.S had unacceptable levels of lead. Thus, it’s essential to test your drinking water for lead so that you can remove it after testing.
Lead Test Strips
Lead test strips are small paper strips with chemicals to detect lead in water. The lead test strips have a chemical called dithiocarbamates. This chemical reacts with the lead in your water and gives a telltale color change on the surface of test strip paper. The color change indicates the presence of lead in water. Lead test kits are used to check the areas for lead presence quickly.
How Do Lead Test Strips Work?
Using lead test strips to check lead in water is easier than you think. Take a water sample into a container or a glass. Put the lead test strip into the container and hold it there for 10 seconds to two minutes for the chemical to dissolve.
Every lead test strip is made up of three layers. These layers include an indicator layer, leachable dye layer, and backing. If lead is present in water, the indicator layer will change its color. You have to match the color of this layer to the reference chart provided by the manufacturer, along with the test strips. Match the color of the strip with the chart to see the presence of lead in sample water.
Are Lead Test Strips Accurate?
Lead test strips are considered accurate, but they are best for a certain amount of sample and time rather than the long-term water quality test. If you are using lead test strips, you better test every week and month to check whether the results are changing or not. If the water sample contains 15 ppb of lead, the test strips will probably show a positive result.
To get accurate results, you should follow the manufacturer’s instructions about the quantity of sample and time. Use the lead test strips exactly for the time as recommended by the manufacturer, which is mostly 2 seconds. So, the accuracy of these test strips depends on how well and accurately you follow the manufacturers’ instructions.
Limitations of Lead Test Strips
- One of the significant limitations of lead test strips are that it only tells the presence and absence of lead in water, not its quantity. So, lead test kits cannot detect the smaller amounts of dissolved lead as the plumbing contains very little amount of lead solders. Thus, in this case, these test strips can give you a false negative result.
- Another limitation of lead test strips is that the accuracy of the test is compromised if other substances and chemicals such as chlorine are present in the water.
- Moreover, you must use these test strips quickly as they can lose their effectiveness if you do not use them quickly. The chemical reaction starts immediately after putting a lead test strip into the water. So, after its dissolution, the test strip will quickly lose its efficacy.
Other Ways of Testing Lead in Water
Besides using lead test strips, you have a few more options to check the presence of lead in sample water. You can opt for the following methods for lead testing if you do not want to use a lead test strip.
Use Sodium Rhodizonate
A sodium rhodizonate test is performed to check the presence of lead in water. It’s a color reaction indicative, another good option for a quick lead test. You must add a few drops of sodium rhodizonate to your drinking water sample. This chemical reacts with the lead ions in water and creates a reddish-orange color. This test only works best when you allow the solution to sit overnight before you check the results.
You have to wait for a whole night after adding the chemical into the sample solution; otherwise, it will not provide you the accurate results.
The most accurate way of checking lead in water is to perform a lab test. Certified labs perform various tests on sample water, and you can get accurate results. Thus, if you want to check your water’s quality, you better submit your sample at a certified lab and get your results after a day or two.
Lead in drinking water is harmful to humans; thus, it must be detected and removed. Lead water testing kits are used to check the presence of lead in water. The accuracy of these kits depends on how well you follow the manufacturer’s instructions regarding the testing time and sample quantity.