Bleach

Bleach is a chemical product primarily used as a cleaning and disinfecting agent. It is a strong oxidizing agent and is commonly made up of sodium hypochlorite (NaClO) or calcium hypochlorite (Ca(ClO)₂) as the active ingredient.

Bleach is known for its ability to remove stains, whiten fabrics, and kill bacteria, viruses, and other microorganisms. It is commonly used in households for laundry purposes, as well as for cleaning and sanitizing surfaces, such as kitchen counters, bathroom fixtures, and floors.

Both natural and synthetic pigments usually possess highly complex molecules, the color property often being due to only a part of the molecule. Bleaches usually attack only that small part, yielding another substance similar in chemical structure but colorless.　

By Adina Firestone - Wikipedia Commons

Sunlight is the oldest known bleaching agent. The ancient Hebrews and Egyptians dipped their fabrics in water and set them out in the sun to bleach.

"Grass bleaching" or "lawn bleaching" was a traditional method used to whiten cotton and linen fabrics before the advent of chemical bleaching agents. Grass bleaching involved laying the fabrics on grassy lawns and exposing them to direct sunlight while periodically sprinkling or dampening them with water.

The moisture from the grass and periodic watering would help to keep them damp, aiding in the bleaching process.

The exact duration of grass bleaching varied depending on factors such as weather conditions, fabric thickness, and desired whiteness. It could take several days or even weeks of exposure to sunlight and regular moistening to achieve the desired level of bleaching.

Before modern bleach formulations, various substances were used for bleaching purposes. For example, sour milk, lemon juice, and even urine were historically employed as natural bleaching agents.

During the time of King Louis XIV of France and Queen Elizabeth I of England, people bleached their hair with lye (sodium hydroxide). Understandably, that caused their hair to fall out, so wigs started appearing.

Bleaching powder was introduced in 1799 by the Scottish chemist Charles Tennant. It was easier and safer to use on fabrics than the chlorine gas it replaced.

Grass bleaching was a labor-intensive and time-consuming process. It was gradually replaced by the development of chemical bleaching agents, such as chlorine bleach, which provided a more efficient and predictable method of whitening fabrics.

By the early 20th century, chemical bleaching was more popular than grass bleaching because it was faster and more efficient. However, in recent years, there has been a growing interest in natural and sustainable methods of bleaching fabrics. This has led to a resurgence in the use of grass bleaching.

Bleach can be effective in removing certain stains, such as those caused by coffee, tea, or grass. However, it is important to follow the instructions and precautions provided on the bleach packaging and to test it on a small, inconspicuous area before treating the stain.

Household bleach is the recommended chemical to decontaminate people exposed to the anthrax virus, by the U.S. F.D.A.

Bleach is a potent chemical and should be used with care. It should be kept out of reach of children and pets. When using bleach, proper ventilation is recommended, and it should not be mixed with other cleaning products, particularly those containing ammonia, as it can produce toxic gases.

Source Inventors.about.com