On Wed, 23 Jan 2013 11:24:52 -0800, (Dave Platt)
wrote:

Household hydrogen peroxide is only a 3% solution (in water). Even at
that concentration, it's strong enough to "burn" the mouth tissues
somewhat if you use it right out of the bottle. I usually dilute it
1:1 with tap water or mouthwash, so the resulting solution is only
1.5% peroxide.

In higher concentrations, hydrogen peroxide can be distinctly
hazardous (...)

http://retr0bright.wikispaces.com
I've used the process to clean up yellowed plastic with good success,
after making the usual screwups. To get the process to work right,
the H2O2 concentration needs to be about 10%. Too little and it takes
forever. Too much concentration and it bleaches the plastic white
instead of beige or whatever the original color. It also bleaches off
any lettering. This might help:
http://www.h2o2.com/faqs/FaqDetail.aspx?fId=26

For H2O2, I use 35% "food grade" H2O2. For example:
http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=35%25+food+grade+hydrogen+peroxide
Watch out for shipping costs. It requires special handling which can
be expensive. In place of H2O2, I found that commonly available
sodium percarobonate and sodium perborate works fairly well if you
carefully calculate the concentration:
http://www.textfiles.com/uploads/oxiclean.txt
It can be found in Oxy-Boost and hardware store wood bleach in powder
form. The typical formulation is:
http://www.runyoutech.com/htm/FAQ.htm#sodium_perborate_formulations
Sodium Perborate Monohydrate 45%
TAED 15%
Sodium Carbonate 40%
which provides all the necessary TAED catalyst in one package. Oxi
Magic has the TAED, but the rest is alcohol and lye (sodium hydroxide)
which don't do anything useful for the reaction.
http://www.clorox.com/products/clorox-oxi-magic/

As for safety, the ingredients and processes are dangerous and messy.
To get the required UV illumination from the sun, I did my first batch
outside. My deck now looks like a bad case of leprosy due to the
bleach spots from sloppy handling. I also have an old pair of jeans
with matching spots. I always wear safety goggles and nitrile gloves.

I don't plan on doing any more cleanup runs until I can get enough
sunlight for an 8 hr exposure, which means after May 2013. Most of my
HP printers have turned yellow. I'll throw together a web page when
done including my notes on my revised formation.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558