The primary purpose of a shower water filter is to remove chlorine from the shower. Chlorine is highly effective in killing bacteria, germs and other microorganisms to make public water supplies safe. But you don't necessarily want chlorine to continue killing living organisms in your lungs, on your skin and on your children's skin and in their lungs. Thus a shower water filter will remove chlorine at the showerhead, before you fill the air in your bathroom with hot chlorinated water mist.
Chlorine is used for water disinfection and for treatment of sewage effluent. Chlorine is also used to disinfect equipment and utensils in beverage and food processing plants, and chlorine is used as an intermediate in the manufacture of a number of organic products such as antifreeze, rubber, cleaning agents, and pharmaceuticals.
When showering with a new shower water filter you will immediately notice:
The chlorine smell is gone
Your hair is softer and more manageable
Your skin feels softer
You use less soap and shampoo
People who use hair coloring will find that it lasts longer
People with sinus or lung impairment will notice that showering no longer irritates them
People with low water pressure experience a decrease in flow
Tall people bump their heads more easily - this filter reduces shower head height by 1½ inches
Most of our customers use drinking water filters or drink bottled water. They understand the potential dangers of drinking contaminated water. But many of them have not been told about or thought about the potential dangers in the shower and the benefits of a shower water filter. When you shower or bathe in warm water, the pores of your skin open up and are more able to absorb chlorine if it is in the water. Also, chlorine-filled steam enters your lungs. People can actually receive more exposure to chlorine during a 5-minute shower than by drinking the same water.
The American Chemical Society estimates that "Householders could receive from 6 to 100 times more of the chemicals by breathing the air around showers, baths, etc. than they would by drinking the water." 1 Chlorine chemically bonds with the proteins in our body's cells. Skin is our body's largest organ and entirely chlorine absorbent. Also, chlorine is vaporized in the shower and inhaled into the lungs where it is transferred directly into the blood system and transported throughout the body.
External symptoms of chlorine exposure are:
dry and irritated skin
damaged, brittle hair and hair loss
redness and burning of the eyes
Unless otherwise noted, the quantitative information on these fact sheets are from "EPA Health Effects Notebook for Hazardous Air Pollutants-Draft", EPA-452/D-95-00, PB95-503579, December 1994."
Acute (short-term) exposure to high levels (>30 ppm) of chlorine in humans results in chest pain, vomiting, toxic pneumonitis, pulmonary edema, and death. At lower level, (< 3 ppm), chlorine is a potent irritant to the eyes, the upper respiratory tract, and lungs.
Limited information is available on the chronic effects of chlorine in humans. Reports from the older literature stated that chronic exposure to concentrations of chlorine of around 5 ppm caused respiratory complaints, corrosion of the teeth, inflammation of the mucous membranes of the nose, and increased susceptibility to tuburculosis.
The Reference Concentration (RfC) and the Reference Dose (RfD) for chlorine are under review by the U.S. Environmental Protection Agency (EPA).
No information is available on the developmental or reproductive effects of chlorine in humans or animals via inhalation exposure. A study reported no adverse effects on growth, lifespan, or fertility in rats exposed to 100 ppm chlorine in their drinking water for their entire lifespan, over seven generations. No information is available on the carcinogenic effects of chlorine in humans from inhalation exposure, and chlorine has not been found to be carcinogenic in oral animal studies. EPA has not classified chlorine for carcinogenicity.
Please Note: The main source of information for this fact sheet is EPA's Drinking Water Criteria Document for Chlorine, Hypochlorous Acid and Hypochlorite Ion. Other secondary sources include the Hazardous Substances Data Bank (HSDB), a database of summaries of peer-reviewed literature, and the Registry of Toxic Effects of Chemical Substances (RTECS), a database of toxic effects that are not peer reviewed.
Chlorine is a potent irritant in humans to the eyes, the upper respiratory tract, and the lungs. Several studies have reported the following effects: 0.014 to 0.054 ppm: tickling of the nose; 0.04 to 0.097 ppm: tickling of the throat; 0.06 to 0.3 ppm; itching of the nose and cough, stinging, or dryness of the nose and throat; 0.35 to 0.72 ppm: burning of the conjunctiva and pain after 15 minutes; above 1.0 ppm: discomfort ranging from ocular and respiratory irritation to coughing, shortness of breath, and headaches.
Higher levels of chlorine have resulted in the following effects in humans: 1 to 3 ppm: mild mucous membrane irritation; 30 ppm: chest pain, vomiting, dypsnea, cough; 46 to 60 ppm: toxic pneumonitis and pulmonary edema; 430 ppm: lethal after 30 minutes; 1,000 ppm: fatal within a few minutes.
Chlorine is extremely irritating to the skin and can cause severe burns.
EPA's Office of Air Quality Planning and Standards, for a hazard ranking under Section 112(g) of the Clean Air Act Amendments, considers chlorine to be a "high concern" pollutant based on severe acute toxicity.
Several studies in the older literature reported that chronic exposure to chlorine concentrations of around 5 ppm caused respiratory complaints, corrosion of the teeth, inflammation of the mucous membranes of the nose, and increased susceptibility to tuberculosis in workers.
Animal studies have reported decreased body weight gain, eye and nose irritation, and effects on the respiratory tract, liver, and kidney from chronic inhalation exposure to chlorine.
Other studies have indicated that exposure to chlorine, via inhalation, may alter disease resistance in animals, with higher incidences of emphysema, pneumonia, and tuberculosis reported.
No information is available on the developmental or reproductive effects of chlorine in humans or animals via inhalation exposure.
No adverse effects on growth, lifespan, or fertility were reported in rats exposed to 100 ppm chlorine in their drinking water for their entire lifespan, over seven generations.
Since chlorine is highly reactive, uptake at sites such as the ovaries and testes which are remote from the respiratory tract, is anticipated to be minimal.
No information is available on the carcinogenic effects of chlorine in humans from inhalation exposure.
Several human studies have investigated the relationship between exposure to chlorinated drinking water and cancer. These studies were not designed to assess whether chlorine itself causes cancer, but whether trihalomethanes or other organic compounds occurring in drinking water as a result of chlorination are associated with an increased risk of cancer. These studies show an association between bladder and rectal cancer and chlorination byproducts in drinking water.
Chlorine has not been found to be carcinogenic in animals; no tumors were noted in a study where rats were exposed to 100 ppm chlorine in their drinking water over their lifespan, for 7 generations.
Another study evaluated the potential carcinogenicity of chlorinated drinking water in rats and mice and found no statistically significant increase in tumors that could be related to the chlorinated water.
EPA has not classified chlorine for carcinogenicity.
A new technology filtration media makes effective shower water filters possible. Due to the development of high temperature, catalytic filtration media, shower water filters work on warm to hot water. Carbon is an excellent filtration media when used under the right conditions, such as, in a point-of-use drinking filter. However, carbon drinking water filters are designed to filter tap water under conditions that are much different than found with shower water.
Temperature: The temperature of tap water ranges from 60 - 75 (F). Showering temperatures typically range from 85 - 105 (F). Carbon is a cold-water filter. It is most effective at temperature ranges of 50 - 80 (F). At higher temperatures, carbon becomes ineffective. It will off-load and release contaminants into the water. This shower filtration media was designed for hot water, becoming more efficient as the water temperature increases.
Flow-Rate: The flow-rate of most drinking water filters is less than ½ gallon per minute (GPM). Shower water typically flows at 2.5 GPM (5 times greater). Even using cold water, a minimum of 5 times the amount of carbon would be necessary to filter the shower water.
Volume: Most drinking water filters produce 1-3 gallons per day (GPD). Shower usage ranges from 12.5 to 50 gallons per day (12 times greater). Even with cold water and a 5x larger carbon filter, the filter would have to be an additional 12x larger, or a total of 60x the size of the original tap water filter. Of course, you don't shower in cold water and wouldn't use a 60 lb. shower filter. Instead, the manufacturer invested a great amount of time and energy into developing reliable and realistic catalytic shower filters that filter both free and combined chlorine, dirt, sediment, odors, hydrogen sulfide, iron oxide and more, from your shower water.
Experimental use of chlorine in drinking water began in the 1890's to combat water-borne diseases such as Cholera and Typhoid. Chlorine quickly gained wide acceptance because of the low cost and high efficiency it had in killing just about everything hazardous in the drinking water. The use of chlorine allowed population centers to appear and thrive without any epidemic outbreaks. Today however, we know more about chlorine and why it is so important to remove it from our water before we drink it, cook with it, or shower in it. Chlorine is a known poison and the safety of drinking this poison over a long-term period is highly uncertain. We now know that chlorine reacts with water-borne decaying organic matter like leaves, bark, sediment, etc. to create a family of other chlorinated organic compounds, which may be highly toxic.
The major expansion of worldwide production of chlorine in the mid-20th century followed discovery of a multitude of diverse and beneficial applications. Some (e.g. the pesticide DDT and PCBs, widely used as lubricants and coolants in electrical equipment) were originally praised as major health or industrial advances, but later aroused environmental concerns and are now banned.
“Taking long hot showers is a health risk, according to research presented last week in Anaheim, California, at a meeting of the American Chemical Society. Showers, and to a lesser extent baths, lead to greater exposure to toxic chemicals contained in water supplies than does drinking the water. The chemicals evaporate out of the water and are inhaled. They can also spread through the house and be inhaled by others. House holders can receive 6 to 100 times more of the chemical by breathing the air around showers and bath than they would by drinking the water.” NEW SCIENTIST 18 September 1986 1
“Conservative calculations indicate that taking a shower exposes you to the equivalent of consuming an additional two liters of chlorinated water each day. Inhalation and skin absorption of chloroform and chlorine by-products is greatest in the shower, where these gases are vaporized.” THE WATER YOU DRINK: HOW SAFE IS IT? 2
“The National Academy of Sciences estimate that 200 to 1000 people die in the United States each year from cancers caused by ingesting the contaminants in water. The major health threat posed by these pollutants is far more likely to be from their inhalation as air pollutants. The reason that emissions are high is that because water droplets dispersed by the shower head have a larger surface-to-value ratio than water streaming into the bath.” SCIENCE NEWS, Vol. 130 3
“A Professor of Water Chemistry at the University of Pittsburgh claims that exposure to vaporized chemicals in the water supplies through showering, bathing, and inhalation is 100 times greater than through drinking water.”
“As chlorine is added to kill pathogenic microorganisms, the highly reactive chlorine combines with fatty acids and carbon fragments to form a variety of toxic compounds, which comprise about 30% of the chlorination by – products.”
“Epidemiological studies suggest a link between ingestion of toxic chemicals in the water and elevated cancer mortality risks.” THE NADER REPORT – TROUBLED WATERS ON TAP 4
“Showering is suspected as the primary cause of elevated levels of chloroform in nearly every home because of the chlorine in the water.” ENVIRONMENTAL PROTECTION AGENCY 5
“While the purity of our drinking water is of primary importance, contaminants and chlorine byproducts also enter our bodies through the skin via the water in which we bathe. Also, our lungs absorb toxic fumes from the gaseous chlorine byproducts that are released in a steamy shower. Chlorine in shower water can strip protein from our hair and skin causing dry, irritated eyes, itchy skin, and dandruff.” WATER: THE ULTIMATE CURE 6
“The total inhalation exposure (summation of the three scenarios; shower, pre- and post-cooking activities and cooking) was found to be comparable with that for direct ingestion, indicating that inhalation is an important pathway for THM exposure from drinking water.” SCI TOTAL ENVIRON-Jan 31, 2000 7
“As a result, entry by inhalation route is as important as entry by ingestion route when conducting exposure analyses of contamination from volatile organic compounds such as TCE.” TOXICAL IND HEALTH- Mar-April 1996 8
“Although ingestion is commonly considered to be the primary source of exposure to chloroform from tap water, inhalation and skin absorption exposure concentrations were found to be even higher.” SCI TOTAL ENVIRON- 11 Jul. 1998 9
“However, other exposure routes, such as dermal absorption and inhalation, may be important components of an individual’s total exposure to drinking water disinfection by-products.” “The results from this study indicate that household activities such as bathing and showering are important routes for human exposure to THMs.” EXOP ANAL ENVIRON EPIDEMIOL- Jul-Aug. 2000 10
“Recently, showers have been suspected to be an important source of indoor exposure to volatile organic compounds (VOC).” “Since estimates of chloroform risk from domestic water use for the three exposure routes—ingestion, inhalation and dermal—are similar, all routes must be used to calculate the total risk when making policy decisions regarding the quality of the municipal water supply.” RISK ANAL-Dec 1990 11
“On one hand, chlorination has freed civilization from the constant dangers of waterborne epidemics. On the other hand in the mid –70s scientists discovered that chlorination could create carcinogens in water. 80% of the population drinks chlorinated water. There was a higher incidence of cancer of the esophagus, rectum, breast and larynx and of Hodgkin’s Disease among those drinking chlorinated surface waters. Volatile organics can evaporate from water in a shower or bath. Conservative calculations indicate that inhalation exposures can be as significant as exposure from drinking the water, that is, one can be exposed to just as much by inhalation during a shower as be drinking 2 liters of water a day. People who shower frequently could be exposed through ingestion, inhalation and/or dermal absorption.” IS YOUR WATER SAFE TO DRINK? 12
“Skin absorption of contaminant has been underestimated and ingestion may not constitute the sole or even primary route of exposure.” AMERICAN JOURNAL OF PUBLIC HEALTH, Vol. 74-1984 13
“The cause of arteriosclerosis and resulting heart attaches and strokes in none other than the ubiquitous chlorine in our drinking water.” CORONARIES / CHOLESTEROL / CHLORINE 14
“Chlorine gas was despicably used during WW1. When the war was over, the use of chlorine was diverted to poisoning germs in our drinking water. The combination of chlorine (when in drinking water) and animals fats results in arteriosclerosis, heart attacks, and death.” WATER CAN UNDERMINE YOUR HEALTH 15
Information on Chlorine hazards is obtained from the Environmental Protection Agency (EPA) at http://www.epa.gov/ttnatw01/hlthef/chlorine.html, and is published with permission.
Anderson, I., “Showers pose a risk to health”, New Scientist, 1986 Aug. 18.
Archer, Jonn. The Water you drink: How Safe is it? Pure Water Press, 1996.
Raloff, J., Toxic showers and baths, Science News; 130:190.
Duff, Conacher and Assoc. “The Nader Report-Troubled waters on tap”, 1988 Jan. Center for Study of Responsive Law. Wallace, L., Environmental Protection Agency.
Meyerowitz, Steve. Water: The Ultimate Cure. Book Publishing Company, 2000.
Lin T.F. & Hoang S.W., “Inhalation exposure to THMs from drinking water in south Taiwan”. Sci Total Environ, 2000 Jan 31; 246(1).
Maslia, M.L., Aral, M.M., Williams, R.C., et al., “Use of computational models to reconstruct and predict trichloroethylene exposure”. Toxical Ind Health, 1996 Mar-April; 12(2): 139-52.
Kuo, H.W., Chiang, T.F., Lo, I.I., et al. “Estimates of cancer risks from chloroform exposure during showering in Taiwan”. Sci Total Environ, 1998 Jul 11; 218(1):1-7.
Backer, L.C., Ashley, D.L., Bonin, M.A., et al. “Household exposures to drinking water disinfection by-products: whole blood trihalomethane levels”. Exop Anal Environ Epidemiol, 2000 Jul-Aug; 10(4): 321-6.
Jo,W.K., Weisel, C.P., Lioy, P.J., “Chloroform exposure and the health risk associated with multiple uses of chlorinated tap water”. Risk Anal, 1990 Dec; 10(4): 581-5.
Gabler, R., Is your water safe to drink?, Consumer Reports Book, 1987.
Brown, H., “The role of skin absorption as a route of exposure for volatile organic compounds (VOCs) in drinking water”, Amer Jour Pub Health, 1984 May; 74.
Price, J. M., “Coronaries/Cholesterol/Chlorine”, Jove Book, Alta Enterprises, 1969.
Walker, N.W., “Water can undermine your health”, Norwalk Press, 1974.