A Guide to Contaminants and Water Filtering Shower Heads

It’s no secret that the water coming out of our taps is not fit for consumption without filtering first. So what does this mean for shower water?

Mounting scientific evidence continues to validate growing concerns about shower water quality—highlighting not only the undeniable presence of hazardous chemicals, but also the vital need for water filtering shower heads to protect your health. In this article, we clarify the scope of exactly which contaminants water filtering shower heads can and cannot remove and dive deep into the science behind why filtration media matters. 

Knowing the overall quality of the water where you live is an important first step in understanding the potential risks in your area and what solutions are available to you.

What a free water quality report can tell you

A free water report by zipcode is a quick, straightforward way to gain insight into exactly which contaminants are prevalent in your water. We will take a look at each of these chemicals: how they enter your water, the risks they pose, and what you can do to combat their toxicity.

Free Water Quality Report

Find Out What Exactly Is Lurking In Your Water With Our Free Water Quality Report.
That Way You Can Make The Most Informed Decision On How Reducing These Contaminants.

We’ve separated these pollutants into five main categories:

  • Disinfection by-products (DBPs)
  • Volatile organic compounds (VOCs)
  • Naturally occurring compounds
  • Perfluorinated “forever chemicals” (PFOS, PFOA, PFHPA)
  • Heavy metals

Let’s begin with the contaminant risk most often associated with the water treatment process: disinfection by-products—

What are disinfection by-products (DBPs)?

Disinfection by products in water supply

Disinfection by-products are the unintended result of added disinfectants, typically chlorine or chloramine, reacting to natural matter in the water supply, which in turn creates hazardous substances. 

These chemicals—numbering in the hundreds—remain largely unstudied, with the Environmental Protection Agency (EPA) setting legal limits for only 11 of them. Unfortunately, even these standards were established based on cost and feasibility of the water treatment process rather than considering the toxicity or potential short or long-term effects of DBPs on public health.

The two largest subsets of DBPs, both in number and weight (measured in parts per billion), are haloacetic acids and total trihalomethanes:

Haloacetic acids (HAA9/HAA5)

This group contains 9 different haloacetic acids (HAA9):

  • Dibromoacetic acid
  • Dichloroacetic acid
  • Monobromoacetic acid
  • Monochloroacetic acid
  • Trichloroacetic acid
  • Bromochloroacetic acid
  • Bromodichloroacetic acid
  • Chlorodibromoacetic acid
  • Tribromoacetic acid

Of these, the first 5 are regulated by federal standards (grouped and referred to as HAA5). The last 4, although they pose the same health risks, are not regulated. 

According to the Environmental Working Group (EWG),a non-profit with three decades of research and advocacy in the areas of toxic chemicals and water pollutants, haloacetic acids are:

  • Harmful during pregnancy
  • Cancer causing in laboratory animals
  • Linked to bladder, rectal and colon cancer
  • Known to induce DNA mutation and damage (genotoxic)

Di- and tri-haloacetic acids are on track for inclusion in the National Toxicology Program’s comprehensive Report on Carcinogens

A peer-reviewed scientific study conducted by the EWG found that in 2021 there were at least 241 million people, across all 50 states, found with haloacetic acid levels above recommended health guidelines—a standard that prioritizes cancer risk and fetal harm rather than the cost of water treatment.

Total trihalomethanes (TTHMs)

This group consists of four chemicals: 

  • Chloroform
  • Bromodichloromethane
  • Dibromochloromethane
  • Bromoform

It’s estimated that the drinking water in almost 90% of American households exceeds EWG recommended health guidelines for total trihalomethanes. Of these, there are 410 water providers servicing over half a million people with water containing levels of TTHMs above the set legal limit!

Studies conducted in the U.S. and Europe have shown that TTHMs:

  • Increase the risk of bladder cancer
  • Cause liver, kidney and intestinal tumors in animal studies
  • Increase the risk of miscarriage, birth defects and low birth weight

Volatile organic Compounds (VOCs)

Volatile organic compounds are substances with a high vapor pressure (i.e. they evaporate easily) but have low levels of water solubility. These predominantly human-made chemicals are emitted as gases that, if present in the water supply, enter homes through water pipes and are inhaled or absorbed while using water during bathing and other household activities. 

The EWG recognizes these health risks as being associated with VOCs:

  • Lung, breast and colon cancer
  • Leukemia
  • Hormone disruption
  • Birth defects
  • Harm to the developing fetus and reproductive system
  • Harm to the immune system
  • Harm to the brain and central nervous system
  • Harm to the kidney and liver
  • Tumors in the abdomen, pelvis, nasal cavity and mammary glands

VOCs that threaten water supplies are largely the result of industrial runoff, emissions and improper waste disposal. Common VOC groundwater contaminants include:


Used in industrial solvents since the 1950’s, this VOC is only produced by Dow Chemical in Texas and Ferro Corp. in Louisiana, but has been found in landfills across the country. 

Trichloroethylene (TCE)

For decades, trichloroethylene has been used as a degreaser for metal parts, like steel pipes and engines, and as a common solvent in dry cleaning and carpet cleaning products. Minnesota lawmakers successfully passed the first ban on TCE on June 1, 2023, months after the EPA determined that TCE poses “an unreasonable risk of injury to health”.

Tetrachloroethylene (also known as perchloroethylyne or “perc”)

Similar to TCE, Tetrachloroethylene is a dry cleaning chemical considered by the EPA to be a likey human carcinogen. It enters the water supply as emissions from dry cleaning, automotive and metalworking facilities. 

In total, there are nearly 23 million Americans serviced with water containing potentially harmful amounts of these three VOCs alone.

Wastewater Treatment and Naturally Occurring Contaminants in Water Supply

Naturally occurring compounds

These substances are formed and found in nature, but become toxic when human processes accelerate or increase our exposure to them: 


Nitrate enters water supplies as runoff from fertilizers, manure and wastewater treatment plants. Widespread use of nitrogen-containing fertilizer dramatically increased nitrate pollution, making it one of the most common contaminants in drinking water. 

Exposure to nitrates in drinking water results in greater incidence of colorectal, ovarian, thyroid, kidney and bladder cancers.


Radon, which accounts for almost half of all human radiation exposure, is a radioactive gas emitted by decaying radium in soil and groundwater. 

It is a leading cause of lung cancer, second only to smoking, making it THE leading cause for non-smokers. The EPA estimates that radon in drinking water causes 168 cancer deaths every year: nearly 90 percent of these cases are from lung cancer attributed to breathing radon that is released when water is heated during showering and other household activities.


Our bodies require small amounts of manganese for good health, but excessive amounts target the brain and nervous system—leading to learning, memory and behavior impairment in children. 

It’s estimated that at least 5 million people drink water from public systems above recommended guidelines for manganese levels. Although manganese is naturally occurring and commonly found in both food and water, ongoing research studying the bioavailability of manganese points to water as the main source of manganese toxicity.

A telltale sign of high manganese levels in your water are black, slimy deposits on your faucets and fixtures (quite often confused for black mold). Regularly deep cleaning your shower hose and maintaining a clean shower head are simple, effective ways to reduce your exposure to manganese.

Forever Chemicals Found in Teflon Coating and Non-Stick Pans

Per- and polyfluorinated “forever chemicals” (PFAS, PFOS, PFOA)

Originating from DuPont’s introduction of nonstick coating Teflon in 1946, this family of synthetic chemicals—PFAS for short—has grown to nearly 15,000 and can be found in hundreds of consumer products: from food wrappers and waterproof clothing, to cosmetics and stain resistant carpets and couches.

They are referred to as “forever chemicals” because of their inability to naturally break down in the environment and for their persistence in our bodies: PFAS have been found in breast milk as well as the blood of humans and animals all over the world, including new born babies.

PFOA and PFOS are two of the most studied chemicals in the PFAS family. The EWG cites numerous studies as linking these and several other closely related PFAS chemicals to: 

  • Testicular, kidney, liver and pancreatic cancer
  • Reproductive problems
  • Weakened childhood immunity
  • Low birth weight
  • Endocrine disruption
  • Increased cholesterol
  • Weight gain in children and dieting adults

You can limit your exposure to PFAS by opting for cast iron or stainless steel cookware, and avoiding stain-resistant coatings like Scotchgard and clothing made with GORE-TEX. 

Heavy Metal Contamination in Water Supplies

Heavy metals

The disturbing history of heavy metal contamination in the American water and food supply has been well documented for decades, but the battle to lower the federal limit to a level that protects health is far from over:


Radium is a soluble, radioactive element commonly found in groundwater that naturally occurs in very low levels in almost all rocks and soil. Radium releases radioactive particles at elevated concentrations due to activities associated with oil and gas extraction, such as drilling and hydraulic fracturing (“fracking”).

Risks associated with radium include:

  • Bone cancer
  • Tumors in the lungs and other organs
  • Damage to the skin and blood
  • Leukemia

Even though the EPA has set a guideline for zero radioactive elements in drinking water, over 40% of Americans are serviced with water that not only contains these elements, but at levels that exceed EWG health guidelines.

Hexavalent Chromium (Chromium-6)

This cancer-causing contaminant, which gained widespread attention from the film ‘Erin Brockovich’, occurs naturally in some areas, but industrial pollution is the number one contributor to its presence in water supplies. In addition to being carcinogenic, prolonged exposure to chromium-6 in drinking water can also cause liver damage and harm to the reproductive system.

Despite widespread testing, which found chromium-6 in the water supply of more than two-thirds of Americans, pressure from the industries responsible for chromium-6 contamination continue to stall the EPA’s safety review—effectively preventing the agency from setting a national standard.


A naturally occurring mineral, arsenic accumulates in water supplies by leaching from rocks into groundwater that is then used for drinking or irrigation. Arsenic contamination is further compounded by arsenic pollution from mining waste, metal production, coal power plants and the burning of fossil fuels.

Both the EPA and World Health Organization have identified arsenic as a "known human carcinogen" with the following health concerns:

  • Cancer
  • Harm to the central nervous system
  • Harm to the brain and nervous system
  • Skin lesions
  • Change to the heart and blood vessels (cardiovascular disease)
  • Increase in the risk of heart disease, stroke and diabetes

The risks are especially severe for pregnant women, young children and individuals who smoke.

Filtration solutions for water contaminants

Higher-end countertop and whole-house ion exchange, reverse osmosis and activated carbon filtration systems are recommended for reducing or removing many of these chemicals. Unfortunately, these options are expensive, and whole-house systems are rarely feasible or permitted for the 34% of individuals who rent their homes. 

KDF 55 and Calcium Sulfite Shower Head Water Filter from HammerHead Showers

KDF 55 and Calcium Sulfite Shower Head Water Filter from HammerHead Showers

Even though water filtering shower heads cannot remove the chemicals listed above

(despite how some companies might advertise them), they are extremely effective at preventing the compounding effects of toxicity from chlorine, lead, mercury and bacteria. Investing in a tested, durable shower head water filter—like the one we developed at HammerHead Showers—is an actionable step you can take towards protecting yourself from harmful shower water contaminants.  

Read on to discover more about these small but powerful devices and why they are a vital investment for your health:

The importance of water filtering shower heads

Water filtering shower heads remove or neutralize harmful impurities in your shower water before it sprays out of the shower head, preventing contaminants from being absorbed into your skin or vaporized and inhaled (our definitive guide on shower water filters will answer all of your questions, including everything to know before buying one!).

While there are countless options to choose from, filters containing KDF 55 and calcium sulfite stand apart as the only shower water filters that are science-backed, thoroughly tested and proven to provide consistent results:  

Kinetic Degradation Fluxion (KDF) filtration media consist of high-purity zinc and copper granules that initiate a redox process (short for reduction-oxidation: simply put, a transfer of electrons between compounds). Through this exchange of electrons, KDF entirely removes some harmful contaminants while converting others into harmless substances.

Calcium sulfite is a compound that efficiently converts chlorine into nontoxic chloride ions in less than one second. It is often used in conjunction with KDF to enhance and prolong the life of the filter cartridge.


KDF and Calcium Sulfite Shower Head Water Filter from HammerHead Showers

Common contaminants targeted by water filtering shower heads

KDF and calcium sulfite filters are specially designed to tackle these invisible threats in shower water:


Of all the hazardous chemicals found in drinking water, there is one whose ubiquitous presence makes it an all but guaranteed contaminant for anyone drinking from a public water supply: chlorine. 

The function of chlorine in killing waterborne pathogens in drinking water is necessary, but prolonged exposure to this harsh chemical can contribute to or worsen:

  • Skin conditions like psoriasis, acne and eczema 
  • Dry scalp and skin
  • Brittle hair and nails
  • Asthma and other respiratory issues

Shower water is particularly dangerous because higher water temperatures vaporize chlorine, producing noxious chlorine fumes that we breathe in— exacerbated even further by less than ideal ventilation in many bathrooms.

Both KDF and calcium sulfite are highly efficient at converting chlorine to harmless water-soluble chloride ions.


As we saw with the tragic crisis in Flint, Michigan, this potent neurotoxin continues to affect communities across the United States nearly 40 years after being banned. Lead is known to impair intellectual development and concentration in children and is especially damaging up to age 6.

When passed through a KDF filter, soluble lead is converted into insoluble lead atoms which attach themselves to the filtration media and remain trapped inside the cartridge.


Mercury—an industrial, mining waste and coal-fired power plant pollutant—is another neurotoxin still found at levels above recommended guidelines in water supplies servicing at least 13,000 people, despite its widely known devastating health effects. Health concerns include:

  • Harm to the brain and nervous system
  • Harm to fetal growth and child development
  • Harm to the kidney
  • Harm to the immune system

Similar to lead, the zinc and copper granules found inside of KDF filters bond with mercury: effectively trapping and removing it from your shower water.

Bacteria, algae and fungi

Recent studies indicate that some pathogens found in shower water and on shower heads are becoming resistant to chlorine. These and many other types of bacteria, algae and fungi are known to accumulate in shower heads and hoses, becoming a slimy layer of concentrated biofilm that can be particularly harmful for individuals with weak or compromised immune systems.

KDF’s redox process creates a hostile environment for microbes, killing some on contact while rendering others harmless by destroying microbial cell walls or damaging the cell itself. 

A quality shower head water filter that uses efficient filtration media is a one-stop solution for combatting these contaminants—reducing the impact of water impurities on your health and elevating your shower experience at the same time.

Our top pick for water filtering shower heads 

When it comes to water filtering shower heads, these three considerations will make the difference between purchasing a quality product with genuine filtration capabilities or a well-marketed gimmick:

  1. Filtration media type
  2. Amount of filtration media 
  3. Housing material


Our All Metal Universal Shower Head Filter Attachment packs in 450 grams of chlorine-killing KDF 55 and calcium sulfite. More filtration media means more surface area and longer contact time for eliminating the maximum amount of contaminants. Unlike most plastic filters you find on the market, we use a lead-free brass housing to ensure you can replace the internal cartridge for years to come without breaks, cracks or needing replacements.

Take the first step in protecting your health TODAY

Faced with so many potential dangers, it's normal to feel powerless, overwhelmed, and not know where to begin.

Our advice: Focus on what you can control and start small—every little change adds up to make a big difference. It's our hope that the practice of using a water filtering shower head becomes as commonly associated with detoxifying the body as drinking and cooking with filtered water, sufficiently hydrating to promote healthy liver function and eating antioxidant-rich foods.

At The Shower Head Store, we prioritize using materials like brass and stainless steel that are SAFE and built to last. Purchasing our products means saying NO to fast fashion and all of the harmful industrial processes that go along with it: upgrade your shower experience and become part of the solution today!

Free Water Quality Report

Find Out What Exactly Is Lurking In Your Water With Our Free Water Quality Report.
That Way You Can Make The Most Informed Decision On How Reducing These Contaminants.

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