Monday, May 19, 2008

Apple #318: Bleach

I was doing laundry this past weekend, and I was pouring some color-safe bleach into the washer and I thought, as I often have, "Isn't that phrase, color-safe bleach, a contradiction in terms? How is that possible?" Then just now, I was cleaning my bathroom with cleanser that had bleach added to it, and I was thinking about how handy bleach is. Then I realized, that's it, I have got to find out about this substance called bleach.

Your basic bleach
(Photo from Dr. Tony Kettle's page about research he's doing with bleach-related enzymes)

  • Etymologically speaking, the word comes from an Old English verb that means "to wash" or "to whiten or make pale."
  • Today, the word "bleach" refers to any combination of chemicals that is used to whiten fabrics.
  • That whitening happens by a process of oxidation; that is, the chemical adds oxygen to the stain molecules, the oxygen breaks up the stain molecules, and the stain goes away. The same thing happens to germs or other unpleasant things that could live in the fabric or whatever it is you're bleaching.
  • Some compounds do a better job of bleaching than others.
      • Soda ash, which was made from burned seaweed, worked pretty well at around 300 B.C. and is still used in some industries.

Soda ash, sold commercially and by the looks of it, more recently than 300 B.C. Har har.
(Image from the old Caveman Chemistry site)

      • The Dutch used to soak their fabrics in alkaline solutions and then laid them out in the sun to finish off the bleaching. They then dunked the fabrics in sour milk to get rid of the alkalines. The problem was, the whole thing took weeks.
      • Lye is another bleaching agent. People used to make it by mixing wood ashes with water, or else urine and water, but now lye is made with sodium hydroxide or potassium hydroxide. It is extremely caustic and it can burn you if you touch it. (The word "lye" comes from Old English and Germanic words that mean "to wash.")

Apparently, this woman who works at Dollywood is demonstrating the old-time way of making lye soap. I hope she's got great health insurance.
(Photo from Dollywood)

What modern-day lye looks like
(Photo from Home Brew Biodiesel Genset, about how to convert a diesel generator to run on biodiesel)

      • Ammonia, borax, and plain lemon juice + sunlight are some other substances that can also bleach things for you.
  • Chlorine is another bleaching agent. When you buy a jug of bleach from the grocery store, you're buying chlorine bleach.
      • Chlorine bleach is actually derived from lye (a.k.a. caustic soda or sodium hydroxide).
      • Chlorine bleach is very cheap to manufacture, it removes stains and disinfects fabrics.
      • People also use it to sanitize food service equipment. And folks who are strapped for cash and are unfortunately hooked on intravenous drugs are encouraged to sterilize their needles with bleach.
      • It can also be helpful in killing mold or at the very least, reducing the allergenic properties of most molds.
      • Overall, it's potent stuff.

5-gallon bucket of concentrated chlorine bleach. This is sold to health care facilities. Strong stuff.
(Photo from Sani-Wash)

      • The problem with chlorine bleach is that sometimes it's too potent. Regular, grocery-store bleach not only strips out the color from fabrics in an instant, but it also weakens the fibers. This is why, if you bleach your jeans, they fall apart pretty quickly afterwards.

Oxo Brite and several other oxy- or oxo- cleaners are made of sodium percarbonate, which is soda ash plus oxygen.
(Image from VitaSalus)

  • Another type of bleach is peroxide bleach. This is what's marketed as the color-safe bleach.

Color-safe bleach or peroxide bleach actually contains this: hydrogen peroxide.
(Image from Arista Surgical)

      • Peroxide bleach is not as strong as chlorine bleach, which also means it's not as damaging as chlorine.
      • Because it needs a little extra help to be effective, color-safe bleach (peroxide) works best at removing stains at higher temperatures.
      • It won't strip the color (dye) from your fabrics, but it also won't kill germs or disinfect anything either.
      • All those tooth whiteners use various compounds that essentially release hydrogen peroxide, and that's what is whitening your teeth.
So when people say, "It's got bleach in it," they're actually saying an inaccuracy. Actually some substance causes a bleaching, or whitening effect.

  • I'm sure most of you know this, but please, please do not mix chlorine bleach and ammonia. It will not make a super-powered cleaning formula, it will make straight-up, in your face, war-weapon chlorine gas.
      • When inhaled, first you'll feel it searing your nose and throat -- this is the massive damage happening to the cells lining your nasal passages.
      • Then you'll start to see white spots in your vision. This is the effect of your brain being deprived of oxygen.
      • Then you'll get woozy and pass out, and if your body is not removed from the scene, continued inhalation of chlorine gas can shred your lungs and result in a very painful death.
      • If you have done this, open the windows, get away from the vat of badness you have just mixed, call 911 if necessary.
Okay! So, bleach can be strong stuff. Treat it with respect, and it will be your friend, not your enemy.

Oh, and by the way, here's one last tidbit, just for fun: an obsolete definition of bleach derives from the word black, and means "to blacken."

My copy of the Oxford English Dictionary
How Products are Made, Bleach
Columbia Encyclopedia, Sixth Edition, bleaching, lye
Lace and Linen Classics, A Guide to Laundry Additives
American Chemistry Council, A Sanitary History of Household Bleach
Science Toys, Ingredients, Bleach
Miranda Hitti, "Study: Bleach Cuts Allergy Triggers in Mold," WebMD Medical News
BBC, The Dangers of Mixing Bleach and Ammonia
Xomba, Tell Me Why Can't I Mix Bleach and Ammonia?, How to Treat Chlorine Gas Exposure


  1. Oh, Apple Lady...the things you teach me.
    Things that I had no idea I needed to know.
    But things I'm glad I now know.
    Like how to handle a vat of badness.
    PS - Vat of badness will be a phrase I use daily!

  2. My Nana always told me of making hominy with lye back "on the farm" in Kentucky! But I think you have to rinse it really well so you don't die.

  3. Yes, anonymous, everyone should know how to handle those vats of badness. You never know when you might encounter one.

    And Jarred, according to one site on the subject of using lye to strip the hulls off of hominy to make grits, yes, you do have to do a lot of rinsing. See


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