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Ask Dr. Laundry

Ask Dr. Laundry

Bleach 101

By Dr. Laundry February 9, 2010

Q. My husband, who loves bleach, sent me your video the other day because I think bleach is bad for the environment. I listened to it and thought, “Wow, I must have been wrong all this time. Bleach isn’t bad for the environment; it is just salt.” But, having been raised to trust but verify, I did further research. This is what I found:

Making and transporting chlorine, which is toxic, are both dangerous processes. Greenpeace reports that despite tight controls, organochlorines are occasionally produced during chlorine manufacture, and Clorox, which buys the chlorine to make its bleach, readily admits that a serious transport accident in the late 1970s caused a total overhaul of its handling systems. [I am glad the transportation system was overhauled, but the company is buying chlorine, which undermines your video.]

Bleach itself breaks down mainly into salt, oxygen and water when it is released into the environment, but small amounts of AOX, or “adsorbable organic halides,” are also released. They are known to be toxic to shellfish and other marine and aquatic organisms. The Nordic Ministers Conference, made up of environmental ministers from Norway, Sweden and other Nordic countries, lists bleach as one of a number of substances considered dangerous to the environment. Scorecard, the hazards ranking system developed by Environmental Defense in the U.S., ranks bleach as a high risk environmentally and a slight to moderate risk in the workplace.

Ordinary table salt (sodium chloride, NaCl) is half chlorine, and a simple electrochemical reaction with salt water produces chlorine gas easily. That same reaction produces sodium hydroxide (NaOH), and by mixing chlorine gas with sodium hydroxide you create sodium hypochlorite (NaOCl). When you buy a gallon of bleach at the grocery store, what you are buying is the chemical sodium hypochlorite mixed with water in a 5.25-percent solution.

I find this information undermines your arguments that bleach is safe for the environment and thus consider your video and ad campaign misleading.

A. Thanks for your inquiry and I’m glad your husband loves bleach. I admire your research but am a little confused about the way parts of it have been interpreted or are incomplete.

Let’s try and address each one:

  • Yes, Clorox does buy liquid chlorine gas to produce our bleach. We do this as the easiest way to make the sodium hypochlorite active, NaOCl. The chlorine gas comes from the electrolysis of salt water. Then, we bubble the chlorine gas through a solution of water and caustic to make the dilute household liquid bleach solution (5-7% sodium hypochlorite active). There is no free chlorine in the product after this reaction is completed and the reaction is carried out in a closed, sealed container. As for the Greenpeace reference, I’d need to know what “…organochlorines are occasionally produced during chlorine manufacture” (frequency and amount) really means, as this probably is something that might occur, and they can’t prove it happens. It’s theoretically possible, but consistent proof probably doesn’t exist. If this were happening on a frequent basis, manufacturers definitely would/have addressed the issue.

  • Yes, Clorox did overhaul the chlorine gas handling system, but not as a result of an accident at our facilities. This was done to insure that transporting and handling chlorine gas at our facility would be as safe as possible for our employees and the surrounding community. In addition, we shared this world class technology for free with our suppliers and other manufacturers to minimize the risk of an accident occurring anywhere.

  • After use in household cleaning or laundry, sodium hypochlorite breaks down into 95-98% salt and water. The remaining 3-5% is easily handled/removed by either sewage treatment or a septic tank where it degrades like starting soil. Further, no liquid bleach enters the environment as it reacts with organic loads in pipes and is consumed long before it reaches sewage treatment.

  • While the Nordic Ministers Report and even the Environmental Defense lists may have bleach on their list, one should note that Europeans (especially Northern Europe) historically have always had a negative bent toward bleach. A large amount of their “fear” is based on chlorine reactions in manufacturing processes like paper mills, and these industrial situations involve entirely different chemistry than using sodium hypochlorite for laundry and household cleaning. There have also been several studies published in Southern Europe that are in direct opposition to their Northern brothers position, and are based on household usage (I can send references if you like). Finally, we are registered with the United States EPA and meet all their rigid standards for efficacy and safety.

  • Table salt is sodium chloride, not sodium chlorine. Actually, sodium chloride contains 60% chlorine (35/58 Mol Wt). I wouldn’t recommend that you try “..the simple electrochemical reaction of salt and water,” as you would find this isn’t as easy as you have written. The chemical reaction to produce table salt starts with two very reactive materials,sodium and chlorine, neither of which you would want to handle, but these are changed into a chemical composition that one can put on food, run through your body, and can be found in the ocean. The new/final product has completely different properties than the starting materials, which is usually true of most chemical reactions. This also holds true for sodium hypochlorite, because at the end of the day, after reacting with stains and soils, it will be mostly salt and water. It is a very reactive chemical which quickly and effectively breaks down stains and soils into smaller parts that allow them to be more easily removed from surfaces and fibers, strips away body oils, sweat and dead skin flakes from underwear and bedding, and kills bacteria, viruses and mold/mildew so that MSRA, HIV, H1N1 and a host of other bad guys will be less of a problem for mankind. And finally, whenever there is a natural disaster, one of the first requests from folks on the front line is for cases of Clorox® Regular-Bleach to treat drinking water and prevent the spread of cholera and other debilitating diseases. They know that when used as directed, liquid bleach is safe and effective.

  • So when you purchase a bottle of Clorox® Regular-Bleach at the grocery or Target, you are buying a solution of at least 6% sodium hypochlorite with a little sodium hydroxide and sodium carbonate to help buffer the solution and help maintain the product performance for up to a year. Under normal usage, it will quickly break down to 95-98% salt and water, and any remaining bleach will quickly react with components in your sewer or septic tank line.

So I don’t think that I have been misleading in the videos or blog material. I’m proud of the science behind Clorox® Regular-Bleach, and feel that it provides the consumer with the most cost-effective cleaning and disinfectant product on the market while doing so safely and without damaging the environment.