How do they make bleach?

Just what it says on the tin: How do they make bleach? The common household bleach often sold under names like “Chlorox”.

And… prior to modern industry, how did they make bleach in the old days? Yes, I know there were alternatives used to modern bleach but I’m not interested in those, I’m interested in how sodium hypochlorite was first made and how.

Bleach is a solution of sodium hypochlorite in water.

It was originally made by passing chlorine gas through a sodium carbonate (washing soda) solution. That didn’t work very efficiently, so a new process was invented using the electrolysis of salt water, which rather neatly produced sodium hydroxide and chlorine, which then react to form bleach.

Wikipedia has details of today’s industrial method:

Bleach is Sodium Hypochorite (generally around 6%) in water. It’s produced electrochemically from brine, which is salt (Sodium Chloride) and water. Wikipedia has a decent article.

Heh, double bogarted… I used to work for a fairly large bleach maker and chemical repackager. And while it is normally produced around 5-6%, we custom ran batches of up to 24% for some customers. I designed testing equipment for Chlorine Institute one summer and ran a month of tests to find new packing material for valving on chlorine cylinders. I now avoid bleach and chlorine products because the smell really bothers me, getting gassed a couple times has a downside :stuck_out_tongue:

Well, thanks for the replies, folks, but the chemical nature of bleach isn’t what I was looking for, exactly (as noted, it’s easy to look that up).

What I was looking for was how they make bleach - do they bubble gas through a big tank of some chemical? Mix various powders and liquids? Apply heat? What?

If, hypothetically, I had a pile of money with which to build a bleach factory what equipment and facilities would I need? How long does it take to make a batch? How to control the concentration?

Also - I’m still interested in the history - what was the first commercial sodium hypochlorite factory, did it use a didn’t method than modern, and what did people do before it was made commercially? Is sodium hypochlorite something a pioneer family could cook up in the back yard like soap, or did they use some other alternative instead?

Zzzz… I’m sorry, were you saying something? :wink:

It was explained: electrolysis of salt water.

Put salt water in big pot. Insert electrodes (ok, actually they’re built-in). Hit the power. TADAAAAAAAAA! Well, ok, that’s the abbreviated version, but it’s what you seem to have missed.

Maybe this answers some of your question: http://www.ehow.com/about_6382595_chlorine-bleach-made_.html

Only because you put it in quotes, it is “Clorox”.

That’s pretty much how salt water pools work: salt water + electrodes = chlorine.

It’s really that simple? Just get a big tank, fill it with the appropriate fluid(s), and add sparks?

Does that mean when lightning strikes the ocean a small amount of bleach is produced?

It seems almost too easy.

on paper main reactions might be simple.

doing it in real life especially on an industrial scale to produce an effective and economic product can be much harder.

It IS kind of easy. That’s why a gallon of bleach costs a little more than the price of the bottle and transportation. :slight_smile:

Here are some leads on the Sykes Bleaching Company, estab in 1792 as well as the Bleachers’ Association Archive.


If I understand correctly, bleach was apparently heavily used in the textile industry, one of the leading sectors of the industrial revolution. Then again, they refer to “Ash” so maybe this is a different type of bleach.

History of dying: http://nuralamsblogs.blogspot.com/2010/10/dyeing-and-chemical-technology-of.html