The Wonders of Common Bleach

bleach light switch surfaceThe story of bleach reaches back more than 200 years to the rule of Louis XVI.  The very same year the final king of France ascended to the throne, the powerful bleaching abilities of chorine were discovered. Depholgisticated salt spirit, the early name for the yet to be understood chlorine gas, proved dangerous and unstable but less than a decade later it was discovered that this gas could be dissolved in a solution of potash lye to create a stable and more effective way to make use of this new bleaching compound.  This revolutionary experiment created hypochlorous acid and after further refinement of production methods to use caustic soda in place of potash lye, the sodium hypochlorite solution that we know as bleach was created.  This new stable, cheap, and effective chlorine solution became the go to for industrial bleaching and later disinfection.

In its couple hundred-year history bleach has become an important tool in the worldwide battle against many illnesses.  Accepted throughout the developing world as a safe and effective means to nearly eliminating diseases like cholera and typhoid, bleach’s power as a disinfectant has saved untold numbers of people from terrible deaths since its introduction.  The discovery of bleach’s disinfecting properties may be as important to the health of the world population as antibiotics.

The hypochlorite solutions broad range of capabilities lays in the unique chemistry taking place.  General cleaning is characterized as the use of a surfactant (soap) to break down the biofilm network formed as bacteria grow on a surface.  This results in bacteria being lifted from their hold on the surface allowing them to be carried away in the wash water or on your cleaning tool. Without breaking down this biofilm layer on a surface it will provide shelter to any germs protected below making efforts to sanitize ineffective.  Germs maybe dislodged at this point, but they are still viable, and some are likely to settle into a new home.  When it comes to control of communicable disease its not only important to lift the germs from a surface but also to inactivate them.

cleaning kitThe strong oxidizing capabilities of bleach are key to its success in killing germs.  Upon contact with fats or proteins that make up the cell bodies of germs the active ions in the bleach solution react destroying cell functions and deactivating the cell. This direct attack to the structure of cells makes it effective across the complete range of micro-organisms including bacteria, viruses, fungi, and spores. Given long contact times bleach can completely sterilize even at low concentrations and at a low price.  The list of disinfectants able to reliably destroy germs at the rate blech does is very short. Many other common disinfectants will achieve the desired germ kill rate but leave behind the toughest of viruses and fungal spores as these disinfectants lack the ability to kill a complete spectrum of organisms.  Some other disinfectants with peroxide or ammonium bases, though effective, lack stability over time and is not as reliable when spread of disease is the key concern.  It is for this reason that bleach products are still a top choice for disinfection in health care settings.

Perhaps the most stubborn of micro-organism are those that cause odours.  Theses organic molecules that cause odour are oxidized and neutralized effectively removing the cause of the odour.  Interestingly there has been some recent research demonstrating a curious chemical reaction that takes place when bleach meets our bodies sweat.  Those familiar with the unruly odour of a busy gym may reach for a bleach solution recognizing its ability to end these odours and their causes but this combination releases chlorine from the bleach solution into the air.  Though perhaps not the solution to every problem, bleach is one of the only products available to a consumer that will eliminate the odour and kill the organisms that cause it adding yet another wonder to the list.  

Bleach white laundry dryingThough there are a few other options for high-level disinfects with this broad-spectrum killing power most are not well suited to cloth fabrics.  Disinfectants like iodine are very effective at inactivating germs but are not well suited to cloth applications because of their pigments.  Bleach has the ultimate set of properties for laundry use.  As hypochlorite in the wash water meets organic stains in fabrics it reacts with the proteins, fats, and carbohydrates in the same way these parts in cells are inactivated while disinfecting or fighting odour.  These organic pieces that react are then lifted from the fabric quite often restoring stained surfaces to their original appearance.  With a global move to conserve energy more people than ever are washing laundry in cold water inevitably leading to the deterioration of the fabric’s whiteness.  This provides yet another perfect application for bleach as its’ low temperature reactivity will remain effective brightening whites, removing stains, and killing germs even at low temperatures. 

As you can see, bleach has earned its place as a top cleaning agent around the world for good reason. Its low cost, high effectiveness and complete kill spectrum make it the most reliable option in many industries.  It plays an integral role in our food supply, healthcare, recreation and water supply, putting to use all its varied abilities and controlling unwanted micro-organic life.

Like any other reactive chemical, it is important to know how to use bleach safely.  This means doing your research to be sure you are using the correct strength and the surface you are using it on will not be damaged.  With such a range of applications, from toothpastes safe enough to be in your mouth to lab strength that will quickly burn your skin, hypochlorite solution can come in many concentrations.  Be sure to read safety data sheets or containers to more fully understand how to safely use these solutions.


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