Description
Chlorine is a highly corrosive gas with a pungent odor that is derived from natural sources such as salt (sodium chloride) and produced in mass quantities for industrial use. Chlorine is a building block for PVC plastics (vinyl) and for numerous chemicals, including pesticides, refrigerants, anti-knock compounds, and antifreeze. Dissolved in liquid to form sodium hypochlorite, or bleach, it is widely used as a disinfectant, in bleaching, and to purify public water supplies. Another form, hydrochloric acid, may be used in some toilet bowl cleaners.
Household bleach is a weak sodium hypochlorite solution. Household bleach is the most common cleaner accidentally swallowed by children. Children can also be exposed to dangerous gases when cleaners containing bleach are mixed with other cleaning agents, such as ammonia.
Concern about chlorine exposure also arises from its ability to form more toxic byproducts. Chlorine reacts with organic matter in drinking water to produce trihalomethanes, which may cause cancer and possibly developmental effects. A recent study links children’s exposure to one byproduct, nitrogen trichloride, in chlorinated indoor pools to asthma. Chlorine bleaching of paper and the manufacture and incineration of PVC plastic results in the formation of highly toxic dioxins and furans.
Acute toxicity information below is for sodium hypochlorite (bleach).
Health Effects
Immediate Health Effects
- If SWALLOWED, chlorine is Moderately Toxic
- If ABSORBED THROUGH SKIN, chlorine is Not Available
- If INHALED (SNIFFED OR BREATHED IN), chlorine is Not Available
Longterm or Delayed Health Effects
- This chemical is considered an Unclassifiable Carcinogen by the World Health Organization, the U.S. Environmental Protection Agency, or another agency.
- Development Toxicant = Can interfere with normal development of a fetus or child
Other
- Chlorine bleach can cause severe skin and eye irritation or chemical burns to broken skin.
- Possible slight increase in the risk of bladder and rectal cancers in long-time users of chlorinated water supplies.
- Inhaled in high concentrations, can cause respiratory problems including coughing, choking, chest pain, emphysema, and chronic and acute bronchitis. A recent study links children’s exposure to nitrogen trichloride, a chlorination byproduct, at indoor swimming pools to an increased risk in developing asthma.
- Inhalation of chlorine gas can corrode the teeth.
- In laboratory animals, repeated inhalation of chlorine has damaged the liver, kidney, blood, heart, and immune and respiratory systems.
How Exposures Occur
Cleaning Products
- Cleaners containing bleach could be swallowed by children. Clear products may be mistaken for water.
Children can inhale toxic chlorine gases if products containing bleach are mixed with ammonia or cleaners containing acids, such as some toilet bowl and oven cleaners.
Chlorinated Swimming Pool Treatments
- Children can inhale significant amounts of chlorine and chlorination byproducts at levels potentially damaging to their lungs from chlorinator tablets in pools, particularly if they frequently swim in indoor pools, and if high levels of urine or other acidic compounds are present in water.
Exposure to chlorine from a typical swim is roughly the same as occupational chlorine exposures. Chloroform, a trihalomethane, is the volatile byproduct present at highest levels. It is a carcinogen and developmental toxicant, among other things. Exposure to chloroform from a typical swim is equivalent to an entire week’s exposure from drinking and showering . Exposure is best kept at a minimum.
Drinking Water Disinfected with Chlorine
- Children can ingest small amounts of chlorine and its byproducts in drinking water that has been treated with chlorine to kill microbes.
Steam from Showers and Appliances
- Children can inhale chlorine and its byproducts in steam from showers and baths. These toxins can also be absorbed through the skin. Steam from dishwashers using chlorinated water also contains chlorine and byproducts.
Significant Statistics
In 2000, poison control centers in the United States reported that chlorine bleach was implicated in exposures to 18,863 children under the age of six.
The total inhalation exposure of chlorine and chlorine byproducts due to showering, dishwashing and water boiling is comparable to that from dietary exposure.
Trihalomethanes, toxic byproducts of chlorine disinfection of water supplies, may cause more than 10,000 cases of bladder and rectal cancer each year, according to an analysis of more than a dozen peer-reviewed, published, epidemiological studies.
The largest use of chlorine is as a raw material in the production of PVC plastic (vinyl).
Chemical Summary for Chlorine. U.S. Environmental Protection Agency, Office of
Pollution Prevention and Toxics, August 1994.http://www.epa.gov/opptintr/chemfact/s_chlori.txt
In 1995, 98% of U.S.drinking water was purified by chlorine. Water treatment uses only about 5% of the clorine produced nationally each year, however.
Tibbetts, John. “What’s in the Water: The Disinfectant Dilemma,” Environmental
Health Perspectives, Vol. 103, No. 1 (January 1995).http://ehpnet1.niehs.nih.gov/docs/1995/103-1/focus1.html
Solutions
How to detect chlorine
- Cleaning products containing chlorine are sometimes labeled as such, but chlorine can also be identified by its strong, distinct odor.
- Searching for “sodium hypochlorite” or “bleach” in the National Library of Medicine’s Household Products Database will show a list of products that contain it.
How to minimize exposure to chlorine
- Avoid cleaning with chlorine-based products, especially if you or your children have asthma or chronic lung or heart problems. If you do use cleaning products that contain chlorine, wear gloves to avoid direct contact with skin, and provide plenty of ventilation by opening windows. Keep children out of the room!
To prevent the creation of toxic chlorine or chloramine gases, which can damage lungs and cause coughing and choking, never mix chlorine-containing cleansers with other cleaning products, particularly ones containing ammonia or other acidic substances.
- Carbon filters can remove the chlorine and chlorine disinfection byproducts from water. These filters are available for showerheads.
It is extremely important to change filters regularly. Otherwise, the filters will start releasing contaminants back into the water.
- To reduce chlorine and trihalomethanes (THMs) in drinking water:
-Store drinking water in pitchers. About 20% of the THMs will evaporate from the water.
-Drink hot beverages (rather than cold tap water). The THMs and chlorine will evaporate. Cooking also helps reduce THMs intake, but the steam will expose the cook. (Do not use hot water from the tap as hot water leaches lead from pipes.)
Alternatives
- Chlorine-free cleaning products, disinfectants, and laundry bleaches, sometimes made with hydrogen peroxide or sodium perborate. Chlorine-free products are are available at most natural foods stores and by mail order. See also Alternatives to Antibacterials and Disinfectants: Safer Ways to Keep Germs at Bay.
- To prevent the entry of toxic chlorine byproducts into the environment, avoid buying and using PVC (vinyl) plastic products and chlorinated pesticides. Choose recycled and unbleached, or chlorine-free paper products. For more information, go to the Chlorine Free Products Association website.
- Install an ozonator in your swimming pool, hot tub or jacuzzi to reduce the amount of chlorine needed. Many pool supply retail stores have them.
For More information
Books, articles, factsheets and reports
Dickey, Philip. Safer Cleaning Products. Washington Toxics Coalition, May 1998.
http://www.watoxics.org/redirect/PUB_CLEAN.aspx?fromMenu=0&pos=3|0|0&name=PUB_CLEAN
Other government agencies
U.S. Environmental Protection Agency
Office of Ground Water and Drinking Water
Ariel Rios Building
1200 Pennsylvania Avenue, NW
Washington, DC 20460-0003
http://www.epa.gov/safewater/
Nonprofit organizations
Chlorine Free Products Association
19 North Main Street
Algonquin, IL 60102
847-658-6104
http://www.chlorinefreeproducts.org
Greenpeace USA
Toxics Campaign
702 H Street, NW
Washington, DC 20001
800-326-0959
http://www.greenpeaceusa.org/toxics/
Washington Toxics Coalition
4649 Sunnyside Ave N
Suite 540
Seattle, WA 98103
206-632-1545
http://www.watoxics.org
Other websites
Pesticide Action Network Pesticide Database
http://www.pesticideinfo.org
Environmental Defense Chemical Scorecard
http://www.scorecard.org