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Hydrogen Peroxide

Your child is foaming at the mouth! Chances are he got into the hydrogen peroxide bottle.  And, chances are he will be perfectly fine…even though all of those bubbles look scary. 

Hydrogen peroxide is a combination of hydrogen and oxygen. (The foam is oxygen bubbles.) It comes in several strengths.

  • Household peroxide is sold in brown bottles in drugstores and supermarkets. It contains 3 percent hydrogen peroxide.

  • Hair bleach is about 6 to 10 percent hydrogen peroxide.

  • “Food grade” hydrogen peroxide is 35 percent. Despite its name, “food grade” hydrogen peroxide should never be taken internally, unless it is extremely dilute.

  • Higher concentrations of hydrogen peroxide, up to 90 percent, are used in industry. 

Children who swallow small amounts of household hydrogen peroxide have few if any problems. The most common symptom is stomach upset and possibly an episode of vomiting. When peroxide is swallowed, it generates oxygen bubbles in the stomach. If there are enough of them, they stretch the stomach out and the child vomits up the foam. Hydrogen peroxide can be mildly irritating, so the child could complain of a bit of mouth soreness and stomach distress. A small drink of water or milk usually is all that’s needed. Hydrogen peroxide is not absorbed from the stomach into the body; once a child’s stomach settles down, no other problems are expected. 

It’s different if someone drinks a large amount of household peroxide. When this happens, it’s usually on purpose. There can be a lot of stomach irritation and even burns that require a trip to the emergency department and possible hospital admission. 

Drinking higher concentrations of hydrogen peroxide can be very dangerous because it can cause tissue burns. “Food grade” hydrogen peroxide is sometimes used as an alternative therapy for a variety of conditions: allergies, arthritis, HIV, diabetes, emphysema, lupus, shingles, warts, and irregular heart rhythms, among many others. (These recommendations are not based on scientific evidence.) Users are instructed to put a few drops of the concentrated hydrogen peroxide into a glass of water. Users often store the hydrogen peroxide in the refrigerator – and that’s the dangerous part of this practice. People mistake the bottle of concentrated hydrogen peroxide for something good to drink. Children and adults who swallowed concentrated hydrogen peroxide suffered severe injury, and in some cases died. 

Hydrogen peroxide and its relative, carbamide peroxide, are used in tooth bleaching materials. These preparations are sold for home use and in dental offices. Because hydrogen peroxide is known to be irritating to tissues, home users must follow directions closely to avoid problems. Tooth sensitivity may occur during treatment along with gum irritation. Anyone who chooses to use a home tooth-bleaching product should first consult with a dental professional. 

During use for any purpose, hydrogen peroxide could splash into the eyes. If this happens, immediately rinse with plenty of running water for fifteen to 20 minutes. Then, call the poison center at 1-800-222-1222

Hydrogen peroxide splashed onto the skin could cause the skin to blanch, or whiten, for a short time. The area might feel tingly for a while, too. Again, rinse with plenty of running water. Skin burns are possible if it was a high concentration of hydrogen peroxide. Call the poison center for advice. 

At one time, hydrogen peroxide was used to disinfect skin wounds. This is no longer recommended, since research has shown that hydrogen peroxide can irritate or damage the cells needed for wound healing. 

Hydrogen peroxide sometimes is still recommended to cause dogs and cats to vomit if they swallow poison. Find out from your vet what the correct dose would be for your pet should vomiting be needed. But, call your vet or the poison center first before causing an animal to vomit. Some substances can be more dangerous to bring up than to leave down. Also, not all animals are capable of vomiting.


Agency for Toxic Substances and Disease Registry.  Medical management guidelines for hydrogen peroxide [Internet].  Atlanta: Centers for Disease Control and Prevention; 2011 Mar 3 [cited 2012 Apr 22]. 20 p.  

American Dental Association Council on Scientific Affairs. Tooth whitening/bleaching: treatment considerations for dentists and their patients [Internet]. Chicago: American Dental Association; 2010 Nov [cited 2012 Apr 22]. 13 p.  

American Society for the Prevention of Cruelty to Animals Animal Poison Control Center. What to do if your pet is poisoned [Internet]. New York: American Society of the Prevention of Cruelty to Animals; [cited 2012 Apr 22]. [Approx 2 screens]

Pritchett S, Green D, Rossos P. Accidental ingestion of 35% hydrogen peroxide. Can J Gastroenterol 2007;21:665-667. 

Wilson JR, Mills JG, Prather ID, Dimitrijevich SD. A toxicity index of skin and wound cleaners used on in vitro fibroblasts and keratinocytes. Adv Skin Wound Care. 2005;18:373:78.

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June 2012, The Poison Post®