Thank you, Brad, for the inquiry.  At this point we know of no at-home water test kit exists that test for THM's (trihalomethanes) or other DBP's (disinfection byproducts).  Testing for those sorts of substances/compounds requires laboratory techniques and equipment.

With that said, companies like National Testing Laboratories offer mail-in water testing services that include tests for THM's. The most basic one we know of is called "Watercheck City-Check Basic" and you can read more about it in the Water Test Kit Store.

Results of testing carried out by National Testing Laboratories typically get emailed to customers about 10 business days after the lab receives samples for analysis.

What are THM's?

The term trihalomethanes describes a class of compounds in the disinfection byproduct family which get created when a disinfectant (example: chlorine in the form of hypochlorous acid) interacts with and/or neutralizes organic contaminants in water.

Scientists and health officials have determined that consuming water with elevated levels of THM's poses a threat to human health and therefore the EPA regulates the amount of THM's that public water supplies may possess.  If a water system's internal testing reveals higher than allowed levels of THM's the water system must immediately remedy the situation and in most cases must also report the failed tests to its customers within a specified period of time.

Filtering THM's Out of Drinking Water

Can home water filters remove or drastically reduce THM's in drinking water?  Yes, some do have that ability.  As an example, several of the home water filters in the Multipure product line have been tested according to NSF/ANSI Standard 53 for the reduction of a number of potentially harmful drinking water contaminants including THM's.

During that testing Multipure’s Drinking Water Systems' Aquaversa, Aquaperform and Aquadome water filter systems effectively reduced concentrations of unwanted contaminants to less than or equal to the permissible contaminant limits for filtered water leaving the systems.

If you'd like to see the full list of potential drinking water contaminants Multipure filters remove or reduce, you can view that information here.

Good afternoon, Stuart, and thank you for your inquiry.

Due to the nature of the testing and low quantities of THM's one could expect to find in drinking water, not simple at-home test kit for THM's exists -- that we know of. Testing for THM's takes place in a laboratory environment.

Companies like National Testing Laboratories offer mail-in water testing services that include testing for THM's and other disinfection byproducts. You can find links to various water testing packages from National Testing Laboratories on the following page:

• 'WaterCheck Water' Test Kits by National Testing Laboratories

FYI: As a general rule it takes about 10 business days to get test results back from NTL (National Testing Labs) and the cost of each testing package depends upon the number of different water quality parameters the kit contains.

OK, so where do THM's come from?

Trihalomethanes (THM's) fall into a classification of drinking water contaminants known as disinfection byproducts, or DBP's.  Contaminants of this nature form when disinfectants such as chlorine get added to water that contains organic matter.

As the chlorine 'goes to work' on the organic matter and sets about breaking it down, as part of the chemical interaction between the organic matter and chlorine disinfection byproducts get created.

Scientists and water experts now believe that prolonged exposure to disinfection byproducts possibly increases people's risk of developing various types of cancers.

What removes or reduces levels of THM's in drinking water?

For information on water filtration systems capable of eliminating harmful levels of THM's, we suggest taking a look at water filtration options that contain Granular Activated Carbon (often abbreviated as GAC).  You can find a number of different filter brands and types on the following sites: FilterWater.Com, FiltersFast.Com and Filter-Drinking-Water.Com.

One particular disinfection byproduct of, trihalomethanes (often abbreviated as THM’s or TTHM’s), has gained enough notoriety that companies like PUR have started certifying some of their products to NSF/ANSI Standards for the reduction of trihalomethanes in drinking water.

Below you will find a list of several PUR water filtration products that have tested and certified to NSF/ANSI Standard 53 (Drinking Water Treatment Units – Health Effects) for the reduction of TTHM’s and other unwanted drinking water contaminants:

• PUR CR-6000 Filtered Water Pitcher
• PUR CR-6000C Filtered Water Pitcher with LED Light
• PUR Faucet Mount Filter 3-Stage – Flavor Options
• PUR Faucet Mount Filter 3-Stage Horizontal Chrome
• PUR Faucet Mount Filter System 3-Stage Chrome

• PUR Faucet Mount Filter System 2-Stage White

For those unfamiliar with how trihalomethanes get into drinking water, they get created when free chlorine molecules attack, neutralize and become entangled with a biological contaminant. That process chain of events converts free chlorine into combined chlorine and in the process disinfection byproducts get created.

What harm can trihalomethanes in drinking water cause?

Four different trihalomethanes can form as a result of chlorination: Chloroform, Bromodichloromethane, Dibromochloromethane, and Bromoform. The United States Environmental Protection has found that excessive exposure to these compounds has resulted laboratory rats developing cancer.

While many scientists may disagree on the exactly how much exposure to each compound constitutes overexposure, we think it wise to keep tabs on your local water treatment system’s track record of trihalomethane level management (data available in annual reports) and if deemed necessary, install an NSF certified water treatment system capable of reducing trhalomethane levels.

I have 2 questions that I am not finding answers to on this blog. I could be overlooking the answers. 1) is there a home test kit for THM’s and HAA5? 2) I purchased some property & I would like to test a pond on the property for contaminates other than the drinking water quality home test kit variables such as fossil fuel/petroleum contamination and other pollutants.

For those who do not know, THM’s stands for trihalomethanes and HAA5 stands for haloacetic acid. Both compounds fall in the category of disinfection byproducts, or chemical products created when a disinfectant acts on a contaminant in water. In recent years health officials have determined that exposure to these compounds can increase a person’s risk of developing cancer.

With regard to KC’s question about THM and HAA5 test kits, we do not know of any at-home drinking water test kits for these compounds. Testing for disinfection byproduct levels requires a laboratory environment.

If you wish to test for these two compounds you will have to use a kit that you mail into a certified drinking water testing laboratory such as National Testing Laboratories. Within about (2) two weeks after receiving your water they will issue a lab report telling you all sorts of interesting things about your water — including how many disinfection byproducts your water contains, if it has any at all.

National Testing Laboratories offers several different testing options, but their most popular water testing option provides sample submitters with analysis of their water for a total of 83 different water quality parameters:

• Bacteria (presence/absence for coliform and E.coli),
• (19) heavy metals and minerals,
• (6) other inorganic chemicals,
• (5) physical characteristics,
• (4) trihalomethanes and
• (47) volatile organic chemicals.

Worried about other things such as pesticides, herbicides and PCB’s? National Testing Laboratories offers a water testing option that includes all of the above tests plus an an additional check for (20) pesticides, herbicides and PCB’s. They gave it a really long name, WaterCheck with Pesticides Laboratory Analysis Water Testing Kit, and it test for a total of 97 different water quality parameters.

“Expectant mothers can expose themselves to the higher risk by drinking the water, swimming in chlorinated water, taking a bath or shower, or even by standing close to a boiling kettle, say researchers.

The finding, based on an analysis of nearly 400,000 infants, is the first that links by-products of water chlorination – chemicals known as trihalomethanes, or THMs – to three specific birth defects.

Exposure to high levels of THMs substantially increased the risk of holes in the heart, cleft palate and anencephalus, which results in the absence of a major portion of the brain, skull, and scalp.” ( source )

Most water systems chlorinate the water they provide in an effort to eliminate parasites and bacteria in drinking water which could lead to waterborne ailments and illnesses.

Not sure if your water contains THMs? Maybe the next few statements will help:

• Public water supplies that use free chlorine as their primary disinfectant (instead of chloramines) may contain THMs. The compounds form when free chlorine molecules lock horns with a biological contaminant during the disinfection process.
• Public water supplies that use chloramines as their primary disinfectant (instead of free chlorine) typically do not contain THMs. However it should be noted that these water systems do periodically ‘burn’ their water lines with free chlorine in an effort to get rid of any biofilm that has formed and THMs do result from those ‘burn’ sessions.

Still unsure as to whether or not your drinking water may contain THMs? You have three options:

1. Call your local water authority and ask them if they use free chlorine as the primary disinfectant or chloramines. If so, then your water most likely contains chloramines.
2. Have your water tested by a certified water testing professional.
3. Use reliable drinking water test kits for both free chlorine AND total chlorine.