Hydrogen peroxide is a first aid staple in many households, routinely used to disinfect small wounds. Bottles of it are readily available at drug stores, with the compound formulated for home use vended in dilute form of 3% to 10%.

Hydrogen peroxide also finds application as an antiseptic gargle, a clothes and hair bleach, and an aid to ear wax removal. A paste of hydrogen peroxide and baking soda is used as a tooth scrub, and hydrogen peroxide is the major component of any number of tooth-whitening products.

Higher concentrations (30% or greater) of hydrogen peroxide are used in industry as a bleach for textiles and paper, as a component of rocket fuels, and for producing foam rubber and organic chemicals. Hydrogen peroxide in these strengths is dangerous for the untrained to handle or come into contact with. Spills of industrial-strength peroxide in transit have resulted in freeway and rail line closures, because at such concentrations hydrogen peroxide presents an imminent danger of fire and explosion, and inhalation of its fumes can send people to the hospital.

While some of the peroxide-related tips enumerated in the following example above have previously appeared on other Internet-circulated lists, this particular compilation seems to have begun its on-line life in January 2006:

I would like to tell you of the benefits of that plain little O’l bottle of 3% peroxide you can get for under $1.00 at any drug store. My husband has been in the medical field for over 36 years, and most doctors don’t tell you about peroxide, or they would lose thousands of dollars. 1. Take one capful (the little white cap that comes with the bottle) and hold in your mouth for 10 minutes daily, then spit it out. (I do it when I bathe or shower.) No more canker sores and your teeth will be whiter without expensive pastes. Use it instead of mouthwash. 2. Let your toothbrushes soak in a cup peroxide to keep them free of germs. 3. Clean your counters, table tops with peroxide to kill germs and leave a fresh smell. Simply put a little on your dishrag when you wipe, or spray it on the counters. 4. After rinsing off your wooden cutting board, pour peroxide on it to kill salmonella and other bacteria. 5. I had fungus on my feet for years – until I sprayed a 50/50 mixture of peroxide and water on them (especially the toes) every night and let dry. 6. Soak any infections or cuts in 3% peroxide for five to ten minutes several times a day. My husband has seen gangrene that would not heal with any medicine, but was healed by soaking in peroxide. 7. Put two capfuls into a douche to prevent yeast infections. I had chronic yeast infections until I tried this once or twice a week. 8. Fill a spray bottle with a 50/50 mixture of peroxide and water and keep it in every bathroom to disinfect without harming your septic system like bleach or most other disinfectants will. 9. Tilt your head back and spray into nostrils with your 50/50 mixture whenever you have a cold, plugged sinus. It will bubble and help to kill the bacteria. Hold for a few minutes then blow your nose into tissue. 10. If you have a terrible toothache and can not get to a dentist right away, put a capful of 3% peroxide into your mouth and hold it for ten minutes several times a day. The pain will lessen greatly. 11. And of course, if you like a natural look to your hair, spray the 50/50 solution on your wet hair after a shower and comb it through. You will not have the peroxide burnt blonde hair like the hair dye packages, but more natural highlights if your hair is a light brown, faddish, or dirty blonde. It also lightens gradually so it’s not a drastic change. 12. Put half a bottle of peroxide in your bath to help rid boils, fungus, or other skin infections. 13. You can also add a cup of peroxide instead of bleach to a load of whites in your laundry to whiten them. If there is blood on clothing, pour directly on the soiled spot. Let it sit for a minute, then rub it and rinse with cold water. Repeat if necessary. I could go on and on. It is a little brown bottle no home should be without! With prices of most necessities rising, I’m glad there’s a way to save tons of money in such a simple, healthy manner.

As to how good its advice is, the best that can be said is that some of the items are accurate, while others are unproved and possibly unprovable. In the main, however, one would likely not suffer much ill effect by following the list’s recommendations.

The two possible exceptions to the “no ill effects” pronouncement are the tips that involve putting hydrogen peroxide into direct contact with mucous membranes: spraying it into the nose to clear plugged sinuses or combat colds, and adding it to a douche to prevent yeast infections. While we don’t know if such suggestions work as touted, given the Centers for Disease Control’s statement that “When used for household disinfectant purposes (3% to 5%), [hydrogen peroxide] is mildly irritating to the skin and mucous membranes,” we’d have to advise that trying out either tip might not be such a good idea.

Of the list’s suggestions that can be vetted, no less an authority on germs than Dr. Philip Tierno advocates pouring hydrogen peroxide or mouthwash over toothbrushes after every use. Hydrogen peroxide has also long been touted as an effective remover of bloodstains, but people do need to be reminded that it is also a bleach and so might lift out the color of the item being cleaned along with the stain. Disinfecting countertops and cutting boards with hydrogen peroxide can also be handy as the liquid does combat a number of household nasties, but the 3% dilution hydrogen peroxide is commonly sold at won’t be the “sudden death to all germs” answer that this list of tips presents it as.

As for killing foot fungus, putting the run on boils, curing canker sores, or cleaning out infections, it is not known if hydrogen peroxide is effective for these purposes. Soaking an infected wound in hydrogen peroxide several times throughout the day for five or ten minutes at a crack is probably not a good idea, though, because the solution can damage tissue if left in contact with skin for any length of time.

Two additional health-related uses for hydrogen peroxide should also be examined, even though neither of them was mentioned in this list of tips: injecting and swallowing hydrogen peroxide. While such treatments do have their advocates (who in turn claim such dosings will cure everything from AIDS to cancer), both uses amount to quackery. The proponents of “oxygen therapy” assert they are boosting the body’s ability to destroy disease-causing cells, but there is no medical proof to support such use. Moreover, according to the American Cancer Society (ACS), both such uses are dangerous.

Hydrogen peroxide can be harmful if swallowed. Drinking the concentrated solutions sold in some health food stores (35%, or “food grade” hydrogen peroxide) can cause vomiting, severe burns of the throat and stomach, and even death. Direct skin contact or breathing the vapors of hydrogen peroxide can also be harmful. Hydrogen peroxide injections can have dangerous side effects. High blood levels of hydrogen peroxide can create oxygen bubbles that block blood flow and cause gangrene and death. Destruction of blood cells has also been reported after intravenous injection of hydrogen peroxide.

The ACS also notes “The medical literature contains several accounts of patient deaths attributed directly to oxygen therapy.”

One such case was the 14 March 2004 death of Katherine Bibeau of South Carolina. The coroner who handled the case attributed her death to the intravenous infusion of hydrogen peroxide Ms. Bibeau had been receiving as a treatment for her multiple sclerosis. Hydrogen peroxide destroys blood platelets, the cells that coagulate to stop bleeding, and puts oxygen into the bloodstream that can form bubbles which stop the flow of blood to organs, said Clay Nichols, the pathologist on the case.

As to what to make of the numerous claims asserted of the hydrogen peroxide, in the main, most external uses of household-strength hydrogen peroxide are relatively harmless (if not necessarily helpful), but internal use should be shunned. Gargle with it, wipe wounds with it, foam the wax out of your ears with it, bleach your hair and your clothes with it, but don’t drink it or let someone shoot it into your veins.