Why is Chlorine (bleach) dangerous?
by Kristiana Anderson
Around 1900, Herbert Dow, the founder of Dow Chemical, split common salt to make commercially valuable sodium hydroxide. In the process, an unwanted byproduct was released: the highly toxic green gas, free chlorine. Mr. Dow, a chemistry teacher, soon began combining chlorine with other elements, thus creating "chlorine chemistry," which gave rise to solvents, pesticides and many other useful but toxic chlorinated compounds.
One characteristic of chlorinated chemicals is the strength of the bond created between chlorine and other elements. While this bond makes chlorine a valuable element for chemists when building new compounds, it is also one of the keys to understanding why chlorine is so dangerous. Once formed, chlorinated compounds are very persistent in the environment and difficult to break down. Today there are about 15,000 of them in commercial use.
Chlorinated hydrocarbons like polychlorinated biphenyls (PCBs) were used in electrical transformers in place of petroleum oils, which often were flammable. Perchloroethylene ("Perc") was used extensively as a degreaser for cleaning dirty automobile parts and dirty clothes ("dry" cleaning) and was not flammable like other similar solvents.
In 1939, DDT was introduced as an insecticide to kill the mosquitoes that caused malaria, thus stopping the spread of this insidious disease. When Rachel Carson wrote Silent Spring, she accurately predicted the environmental devastation that DDT in particular, and the chlorinated hydrocarbons in general, would bring. In the 1970s, chlorinated hydrocarbons would be identified as suspected carcinogens and implicated at Love Canal and Times Beach, turning these communities into hazardous waste sites.
During the 1980s, a growing body of evidence suggested chlorinated hydrocarbons were harmful not only to fish and birds, but to mammals (including humans). Volatile organic halides, (VOXs), like chloroform and trichloroethane, were found to be carcinogenic in small animals. And, through the 1990s, evidence continued to accumulate that chlorinated hydrocarbons may disrupt human reproduction as they disrupted reproduction in birds and fish, and play a role in dramatic increases in breast and testicular cancer, the 50% decline in male sperm counts, and a host of other developmental disorders.
What is Chlorine?
Residing at number 17 on the Periodic Table of the Elements, chlorine is a toxic, yellow-green gas that's one of today's most heavily used chemical agents. Because it is highly reactive and is rarely found in its pure form, chlorine is manufactured by passing an electrical current through salt water or melted salt. The electricity splits the salt molecules apart and creates chlorine.
As consumers, we're most familiar with chlorine's role as a bleaching agent for paper, and as an ingredient in household cleaners. When immersed in a concentrated bath of chlorine, the natural colors of things like cotton fibers and wood pulp disappear, leaving behind a bright white surface on which any dye or ink can be applied. We see chlorine's ability to bleach out color firsthand in our washing machines, where we use it to remove stains and dirt in our laundry, and brighten whites.
Why is it Dangerous?
The widespread use of chlorine is causing far-flung and extremely serious risks to our health and the health of the environment. Unfortunately, this damage isn't easy to see at first glance.
Only researchers using special tools and methods can observe it. Because the harmful effects of chlorine are hidden from direct view, we haven't had any reason to stop and think about the possibility that using it could be dangerous.
After all, chlorine is so common it's sold in every supermarket in the country. True enough, but the evidence scientists have gathered seems to tell us that it shouldn't be. Far from being America's household helper, and industry's best chemical friend, chlorine is something we should stop using right now.
In fact, on October 27, 1993, the American Public Health Association unanimously passed a resolution urging American industry to stop using chlorine.
Organochlorines and the Environment
Organochlorines are a large class of organic chemicals, or carbon-based substances, that contain one or more chlorine atoms. Some organochlorines, like dioxins, are unintentional by-products of industrial processes that use chlorine. But most are created on purpose. Some 11,000 different organochlorine compounds are currently manufactured around the world, and they can be found in everything from plastics and pesticides to refrigerants and solvents. So many organochlorines are used for so many purposes, in fact, that of the 40 million global tons of chlorine produced each year, 75% is used to make these chlorinated chemicals.
When chlorine is combined with carbon-based molecules, the resulting materials display a wealth of useful traits. They are usually highly reactive, which means they easily combine with other molecules to create still more new compounds (a valuable characteristic to chemists who use many organochlorines as stepping stones to creating other materials). Organochlorines are also generally extremely stable which means they have a long, sturdy life. And they are easily able to dissolve in oils which makes them excellent candidates for industrial solvents, cleaners, and surface coatings.
Yet as useful as organochlorines are, it's also a fact that they are the single most hazardous classes of compounds ever created. Scientists have found that exposure to organochlorines can create a wide variety of health problems including cancer, hormonal disruption, reproductive and developmental disorders, neurological problems, immune system dysfunction, and other serious conditions. Complicating this problem is the fact that organochlorines can often cause these effects at levels hundreds of thousands of times lower than the levels required by most other poisons. Some organochlorines, like dioxins, are so hazardous that they affect human health at levels measured in parts per trillion, an amount equivalent to a single drop in a train of tank cars 10 miles long.
When this extreme toxicity is factored in with the organochlorine properties considered so useful by the chemical industry, the problem becomes clear. Because chlorine is highly reactive, its use often creates new and unforeseen toxins when released into the environment. Because organochlorines are extremely stable, they can remain to trouble us for a long timeup to 2,500 years in some cases. And because they readily dissolve into oils, they are able to easily enter and accumulate in human and animal fatty tissues. Further complicating the picture is the fact that organochlorines are highly efficient environmental travelers. They've been found in regions as remote as Midway Island and the Arctic, places thousands of miles from the nearest source.
Chlorine and Household Products
Chlorine is a common ingredient in many household cleaners. It appears in countless formulas either by itself as a bleaching or sanitizing agent, or as part of another chemical compound. Other names for this chemical include hypochlorite, sodium hypochlorite, sodium dichloroisocyanurat e, hydrogen chloride, and hydrochloric acid. Because it is such an effective cleaning and disinfecting agent, and because it is found in so many products, many people are surprised to learn that the presence of chlorine in the cleaners we use actually represents a serious household hazard and one of the biggest stumbling blocks to the creation of a healthy home.
Chlorine is a poisonous toxin that at high enough concentrations can cause permanent physical damage and even death. At low concentrations, chlorine is corrosive and a strong irritant to the lungs and mucous membranes.
When chlorine is present as a part of another chemical in a product's formula, that chemical is almost always a member of a family of compounds called organochlorines, a separate class of extremely hazardous materials capable of unpleasant surprises all their own.
In addition to such direct hazards, both chlorine and the organochlorines that contain it can readily combine themselves with other materials present in the home and environment to form new toxic substances. For example, when chlorine reacts with naturally occurring organic matter and/or certain other chemicals, carcinogens known as trihalomethanes are often created. And we've all heard the admonition never to mix chlorine (or products that contain chlorine) with ammonia because the resulting chemical reaction will create a poisonous gas.
The use of chlorine in household cleaning products is more troubling still because many such products are designed specifically to be sprayed into the air and applied to surfaces in the home. These actions spread chlorine throughout the house and often leave widespread areas - sometimes far beyond the original area that was being cleaned - contaminated by residues of varying concentrations.
These suggestions can keep your home and family safe from the hazards of chlorine: ..:namespace prefix = o ns = "" />
Never use any cleaning product that you suspect of containing chlorine or that has the term 'chlor' in any ingredient. Substitute biodegradable, natural ingredient-based alternatives instead.
Be particularly wary of scouring powders, dishwasher detergent, disinfecting agents, toilet cleaners, and tub & tile cleaners. The majority of the products in these categories contain chlorine.