Hassam loves researching and writing about all kinds of subjects, including the history of household cleaning products.
What Is Bleach?
Collins Dictionary defines the noun bleach as "a chemical that is used to make cloth white, or to clean things thoroughly and kill germs." As a verb, the word means to "use a chemical to make [something] white or pale in colour." The process of bleaching is now extensively applied in science. It is a process that provides a handy solution to countless industrial activities. It is also used as a common domestic and commercial cleaning product.
According to Dr. Paul May, the bleach you buy at a home goods store is comprised of "a solution of ~3-6% sodium hypochlorite (NaOCl), which is mixed with small amounts of sodium hydroxide, hydrogen peroxide, and calcium hypochlorite."
Bleaching as a Natural Process
We now know that bleaching is a process of whitening or divesting objects from their colours. Through the influence of light or sunlight and in the presence of oxygen and moisture, bleaching is a never-ending and continuous process that occurs naturally in nature.
Sometimes humans utilize "sun bleaching" by placing objects such as clothing outside for extended periods of time. This leads to a fading of the fabric's colours. Humans have also used sun bleaching to naturally lighten their hair.
The way this works is by the sun's UV rays causing "photodegradation." This process involves UV rays penetrating the molecular structures that define a fabric's or head of hair's colour and "opening them up." This stops these structures from being able to absorb particular wavelengths, and they slowly become the same colour as the sun: white.
What Are Some Common Applications of Bleach?
This process constitutes an essential part of treating several articles and commodities in the initial stages. The art of bleaching is typically focused on certain articles, such as textile products. Cotton, linen, silk, wool and other textile fibres are bleached for whitening as an essential step. It is also applied to paper pulp, beeswax and some oils, and other substances, such as wheat flour, petroleum products, oils, fats, straw, hair, feathers and wood.
Bleaching is a rather old process. Prehistoric human beings were also familiar with the effect of the sun on various substances. In fact, even in primitive times, we can find examples of items being exposed to sunlight for purposes of bleaching.
Some of these civilisations were based in Egypt, China, Asia and Europe. The oldest traces can be found in the Egyptian civilisation (around 5000BC). Thus, Egyptians were thought to be experts when it came to applying the whitening power of the sun to bleach objects. They used to discolour their linens by exposing their clothes to sunlight.
Bleach was discovered even before the third millennium BC. The people of that time had adequate knowledge about a solution that could be developed from wood ashes, which, after mixing with water, turned into lye (a substance that is obtained by leaching or removing soluble or other components by percolating a liquid). They knew that the resultant liquid would lighten colours.
They also knew that steeping or soaking things in lye would whiten linen to the extent that if it was allowed to remain dipped for a long period of time, it would completely disintegrate the linen. The whitening process with this lye method is a bit tricky. Additionally, it is cumbersome because it consumes several hours. Furthermore, it warrants extra care as it is pretty strong.
The Dutch and Medieval Bleach
The Dutch are attributed with an important modification they brought about in this sphere in the 11th and 12th century AD. During this time, they emerged as experts on the science of laundering in the entire European community. To soften the harsh effects of lye, they seasoned it with sour milk. They never let anybody in on their secret and, as a result, the process remained a mystery for many years.
Until the mid-18th century, the Dutch dominated and maintained their supremacy in the bleaching trade. Thus, all brown linen, manufactured at the time principally in Scotland, was shipped to Holland for the purpose of bleaching.
The entire course of action, from its despatch to return was a long process—it took about seven to eight months. To achieve results identical to those obtained by using lye, they would soak and sun-dry linen many times. The cumbersome aspect of this was that lye needed up to eight weeks to work properly, not to mention the space that was required for drying the fabric out in the sun.
Harlem, Netherlands: Medieval Hub of Bleaching
Harlem, a city in the western Netherlands was an industrial city best known as a flower-growing centre and distribution point for bulbs, especially tulips. It was also the hub of the bleaching process at the time.
Linen was usually soaked in waste lye for almost a week as the first measure; boiling hot potash lye would usually be poured over that in the next stage. Afterwards, the cloth was usually drawn out, washed and later on placed on wooden containers, filled with buttermilk.
In the vessels, the cloth was allowed to remain dipped for about five to six days. Finally, the cloth was spread on grass, probably in a tenterhook arrangement. During the entire summer, the cloth usually remained exposed to sunshine, while being moist.
This entire course consisted of bucking (steeping or soaking in alkaline lye) and crafting (bleaching on the grass), and needed to be repeated alternately five to six times to achieve the required level of whiteness.
John Roebuck Introduces Diluted Acid
In the 16th century, scientists fancied a new chemical to replace sour milk. John Roebuck, in 1746, began using diluted acid instead of sour milk. He used diluted sulphuric acid in place of sour milk. This was a great improvement that resulted in the application of sulphuric acid in the bleaching process owing to which the entire procedure required only 24 hours and often not more than 12 hours.
Usually, when sour milk was used, six weeks, or even two months, were required, depending on the weather. Consequently, the practice of bleaching was curtailed from eight months to four, which made the trading of linen quite profitable.
In 1774, Swedish chemist Karl Wilhelm Scheele (who is credited with the discovery of oxygen) discovered chlorine which is a highly irritating, green-yellowish gas that belongs to the halogen family. Scheele found that chlorine had the ability to destroy vegetable colours. This discovery motivated French scientist Claude Berthollet to fancy its utility in the bleaching process in 1785.
In experiments carried out during the initial stages, the person involved in it was required to produce chlorine himself. The stuff that needed to be bleached was either exposed to the gas in a chamber or steeped in an aqueous solution. Keeping in view the olfactory effects of chlorine and the health risks it posed, this exercise was met with failure in the beginning.
What Is Chloride of Lime?
In 1792, in the town of Gavel (in Paris), eau de Gavel (water of Gavel) was produced by combining potash solution (one part) with water (eight parts). However, the greatest momentum to the bleaching industry was provided when, in 1799, chloride of lime was introduced by Charles Tennant from Glasgow, the substance we now know as bleaching powder.
What Is Peroxide Bleach?
Peroxide bleach was discovered in the middle of the last century. Although it takes away stains, it lacks the ability to bleach most coloured fabrics. It is considered to be more user-friendly, as it does not cause weakening of the cloth. It also doesn't disinfect and can be safely added to laundry detergents.
Another distinct feature is that it has a longer shelf life in comparison to other types of bleaches. It is more popular in Europe where washing machines are produced with inner heating coils which can increase the water temperature right up to boiling.
Other Uses of Chlorine Bleach
Chlorine bleach has disinfecting qualities and is a powerful germicide. It is useful in disinfecting water, especially in areas where contamination is rampant. In New York City's Croton Reservoir, it was initially used to disinfect drinking water in 1895. In recent times, community health activists have promoted bleach as a low-cost method of disinfecting the needles of intravenous drug users.
Sources and Further Reading
- Sodium Hypochlorite (Bleach) | Paul May, University of Bristol
- What Is Sun Bleaching and How to Use It to Your Advantage | UV Hero
In this article, we take a look at what Sun Bleaching is and some of the different ways that you can take advantage of it. Simply put, when you put something outside and it is exposed to natural sunlight, the colours of the object will begin to fade.
- Sun-Bleached Hair: How to Get It, Steps, Precautions and More | Healthline
Get sun-bleached hair using these easy instructions, plus precautions to take against sun damage and recommendations of ready-made products.
- Bleaching Ground in the Countryside Near Haarlem | Annenberg Learner
- Cleaning Linen the Old Fashioned Way | LinenBeauty
We learned some pretty eye-opening things about cleaning linen the old-school way. Here's what she told us.
- Bleaches | About Cleaning Products
- History of Technology – Chemicals | Britannica
In Britain the growth of the textile industry brought a sudden increase of interest in the chemical industry, because one formidable bottleneck in the production of textiles was the long time that was taken by natural bleaching techniques...
- Claude Louis Berthollet | Google Arts & Culture
Claude Louis Berthollet was a Savoyard-French chemist who became vice president of the French Senate in 1804.
- Charles Tennant (1768-1838) | Graces Guide
Charles Tennant (1768-1838) Scottish chemist and industrialist. He discovered bleaching powder and founded a mighty industrial dynasty.
This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.
JillB.. on October 18, 2019:
While reading the Bible Mark 9:1-3 Jesus took Peter James & John with him & led them up a high mountain, - There he was tranfigured before them. His clothes became a dazzling white, whiter than anyone in the world could bleach them... My thoughts were WOW! they were bleaching in the time of Christ. I didn't realize that process had been around that long. So I looked it up and came across this article with was very informitive. Duh! I didn't know but now I do. Thanks
Lisa on March 21, 2018:
I think you made a mistake " It also don't disinfect and can be safely added in laundry detergents." Hydrogen peroxide is used as a disinfectant.
DJ on October 19, 2017:
I read this out of curiosity because I was reading about what God required the Hebrews to do if something had mildew on it. If it was spreading mildew, it had to be burned. I know that bleach will kill mildew and was curious if they could have produced bleach back then. Sounds like it would have been a very long process to have done then so burning was probably the fastest way to keep the mildew from spreading. I was a painting contractor and when encountering mildew I would use a bleach and water solution to get rid of it before painting. If you paint over mildew it will just bleed through unless you kill it with bleach or some other chemical. Very informative article. Thanks for writing it.
shartina on June 19, 2017:
Wow! Informative for such a short article. Exactly what I was looking for the evolution with dates and locations. Even descriptive ingredients and methods used at that time frame.
Wonder Ladybug on March 19, 2017:
I think this was really helpful when i used a summary out of this i had got a 100. My teacher was so proud of me also i was the only one who trumed in a report on bleach. They also had some instering facts. When my teavher read this she was so proud her head was about to blow of the top of her head she was so amxed about what I talked about in my summary. Not to mention butI kind of used a few.senteves out of the information that was given on bleach. Some sentences that i wantef to use I used them in my very on sentence. If you are looking at my comment right now you should read the information thatis given on bleach if you havn't already havan't read it. If you have to do a report on bleach you do you a short/or long summary out of this information. If you have a teacher thatalways want his/her work done right and not baby work I think this the information that you need right now because you will make a good grade on your work only of you give a good and noce neat work and no no baby mess tjat you have to do. So all I am saying is this was instering information on bleach.
madeyson on April 17, 2012:
I am doing a project on bleach
Thomas Mulrooney from Burnley, Lancashire, UK on March 21, 2012:
Who would have thought that a HubPage about the history of bleach could actually be interesting? Well, you managed it!
Thanks for the interesting read :-)
Hannah on February 23, 2012:
Came here out of personal interest as to the history of bleach. Really liked this!
Annie D. on January 23, 2012:
thanks! Very informative.
michael on November 14, 2011:
im doing a science fair on bleach exposure to oxygen affecting is bleaching properties.
sasha on November 14, 2011:
i am doing a project on bleach
penelope on August 16, 2011:
hi, im doing a project on bleach ( chemical) but my profeeser wants me to present the bleach made by the french, but i cant seem to find anything to do with project!
please help me with more info!
David Eggers on November 03, 2010:
Bleach is still sold in the US because people there have the common sense not to drink it.
d on April 09, 2010:
Needed to know the history of bleach....thanxs for the info.....very informative.
josee on February 22, 2010:
im doing my science fair on bleach sorry if i splet things wrong and thank you for helping me this really help me a lot and u did said a lot of things that i needed help on so thank u so much!!!!!!!!!!!!!!!!!!!! PS: T
mallory on January 29, 2010:
im doing a project on bleach and ur article was very usful thanks
s on January 17, 2010:
good article. needed to find out if bleach had ammonia in it as i use it to clean up cat accidents and ammonia is bad as it encourages more "accidents"! Thanks for the good information.
A. on January 13, 2010:
Thank you so much. Very informative and well written. Always good to read something from someone this well educated!
June on July 18, 2009:
Bleach is sold in Western Europe
Detox Homes on May 20, 2009:
That's because we have not known about the dangers associated with it. And also because it is a rather quick and convienent product. There are now many in the population that are begining to become more informed!
mike hart on January 15, 2009:
bleach is a caustic chemical and banned in western europe. Why is it still used so widely in the U.S.?
Eileen Hughes from Northam Western Australia on June 21, 2008:
Really interesting and informative. Its amazing how they worked on the fabrics way back in history. I use bleach a lot around the home for disinfecting the yard after dogs piddle and put a tiny bit in the birds water to keep it cleaner. Less algae.
Thanks for that. It was great.