Chlorine - 100 Years of Safety

No wonder we trust chlorine like we do. It's been used as a pool and spa disinfectant for over a century. Chlorine also is the easiest and most economical way to sanitize your pool and spa. Thanks to chlorine's success, we can dive into a swimming pool or relax in a spa and feel safe from the bacteria that can threaten our health. Using chlorine allows us to enjoy the benefits of a healthy pool and spa environment. The water's clean, so jump in!

A Lifeguard That Protects Against Waterborne Disease

Bacteria, viruses and other microbes exist naturally on most surfaces that are exposed to air, including water. Although many are harmless, some of these contaminants may cause infection and disease. Pools and spas are particularly vulnerable to illness-causing bacteria or germs introduced into the water by swimmers and spa users. The regular and proper use of a chlorine sanitizer in the water will destroy these microorganisms before they have a chance to strike.

The proper use of chlorine sanitizers in your pool or spa kills bacteria and many other disease-causing microbes. This prevents the transmission of a number of common diseases including:

Chlorine: The Universal Choice

Virtually all public pools and 9 out of 10 residential pools are sanitized with chlorine because it is:

  • Dependable - as a primary and residual disinfectant

  • Versatile - as an algaecide, oxidizer, sanitizer

  • Economical - as low-cost, easy-to-use products
  • Although there are other ways to help keep pools and spas safe from waterborne disease - showering before swimming, reducing the number of users, adequate filtration or draining the pool or spa between uses, they don't prevent bather-to-bather transmission. Chlorine-based products do provide this protection.

    The Key Element in Sanitizers

    Chlorine-based sanitizers are the strongest, most effective disinfectants available to consumers. The most popular products for pools and spas come in tablet, granular or liquid form. These sanitizers also leave a beneficial chlorine residual in the water that continues to destroy new bacteria.

    Clean and Safe Pools and Spas

    Chlorine-based sanitizers work to chemically destroy microorganisms. Upon contact with chlorine, billions of bacteria can be rapidly oxidized, along with viruses, fungi and protozoa. And regular chlorination maintains water purity.

    Chlorine Benefits Everyone

    Sanitizing water is just one way chlorine adds to the fun. It is also used to make these popular pool and spa products:

    Chlorine plays an indispensable role in the creation of other products that we use every day - from vinyl, plastic, paint, laundry bleach and film to plumbing, cars, contact lenses and computers. Chlorine keeps tap water clean and is the key to the manufacture of pharmaceuticals. We all depend on chlorine.

    Using Chlorine In Pools & Spas*

    Q. What causes chlorine odor, red eyes, itchy skin and green hair that some people experience while swimming?

    A. These conditions are an indication that the water has not been correctly treated - infrequent shock treatment, not enough chlorine, improper pH, or too much use of copper-based algaecides.
    Q. Are chlorine-based sanitizers safe to use?

    A. Yes. These products are completely safe when used according to EPA-approved package directions. Always read the label on products before using them and never mix any kind of chemicals from different packages.

    Q. What are the proper chlorine levels for my pool?

    A. Keep your pool chlorine levels between 1 and 3 parts per million (ppm).

    Q. Is it different for my spa? And if so, why?

    A. Yes. Keep your spa chlorine levels between 1 and 5 ppm. Spas need more chlorine than pools because of the higher concentration of user wastes.

    Q. What pH level should be maintained with chlorine?

    A. Between 7.2 and 7.6 enhances the activity of chlorine and is comfortable for eyes and skin.

    Q. How often should I test for proper chlorine and pH levels?

    A.Since it is important to retain chlorine levels between 1 and 3 ppm, home pools should be tested at least once daily to ensure an adequate chlorine supply. For public pools, many states require hourly testing.

    Q. What is "shock" treatment?

    A. "Shock" treatment with increased levels of chlorine is an essential part of proper pool and spa care. A chlorine-based shock treatment destroys microorganisms, organic contaminants and chemical by-products. It also leaves a chlorine residual for continued cleaning. Shocking should be done routinely, with frequency ranging from daily for heavily used spas to every other week for lightly used pools. Consult your shock package instructions for proper treatment techniques.

    Quick tip: Your pool service or pool
    product representative will be happy
    to answer any questions you may
    have about the use and storage of
    chlorine-based sanitizers.

    * Answers provided are based on the American National Standard for Residential Inground Swimming Pools, Appendix A, American National Standards Institute/National Spa & Pool Institute, 1995

    Chlorine Chemistry Council

    A business council of the Chemical Manufacturers Association, the Chlorine Chemistry Council (CCC) promotes the continuing, responsible use of chlorine and chlorine-based products. CCC strives to advance the use of accurate science and comparative risk assessment in the public policies that affect chlorine. CCC also researches potential health and environmental effects of chlorine while educating the public on chlorine's health and safety benefits.

    For more information on chlorine and chlorine-based products, contact:

    The Chlorine Chemistry Council
    1300 Wilson Boulevard, Arlington, VA 22209


    Chlorine Chemistry Council
    1 November 1996