Expert: Profile Closed - 12/26/2009

Question
Hello.  I have a question about using 3% hydrogen peroxide to lighten hair.  Is it safe?  I used to go to the salon to get my hair highlighted, but I would get a headache, stiff neck, and other strange symptoms.  It's as if I could feel the chemicals being absorbed throughout my body.  So, as an alternative to highlighting, which contains bleach, ammonia, and other chemicals, I thought it might be safer to use just peroxide.  It worked with good results on my hair, and without the symptoms I get after leaving the salon.  I still had a bit of a headache, but it was tolerable.  I suppose I just may be sensitive to what I put on my scalp, because even lemon juice gives me a headache.  I want to make sure that the peroxide is not carcinogenic or toxic in any way if poured on the scalp.  

I also have a question about the chemicals in hair highlighting.  Because I have had a reaction several times, does that mean that I am allergic to these chemicals, or that they are toxic in some way?  I certainly do not want to be doing any damage to my body.  

Thank you for reading my post, and thanks in advance to your response.  

Answer
Hi there, and thank you for your question.

Before I give my answer, I should say I'm in no way a hair stylist or anything like that, so I would always advise checking with a professional before actually carrying out any procedure. I will do my best to give you the background info you requested though.

Firstly, there are many pages on the web which suggest that using Hydrogen Peroxide at 3% is a safe method of lightening hair, though it should be recognized that these sites don't take account of any individual sensitivity you may have. An example of such a site is:

http://www.wikihow.com/Bleach-Your-Hair-With-Hydrogen-Peroxide

However, the key to your question is in the process you are carrying out; whether in a salon or at home, you are using strong oxidizing chemicals to alter the chemical nature of the color in your natural hair. Chemicals strong enough to do this nearly always have the potential to do harm to other parts of your body.

In general, I would regard coloring dyes as more potentially dangerous, as some dye molecules found in generally available hair dyes have been proven to induce cancers in laboratory animals. Whilst there is no conclusive link to human cancers, obviously it is a bit concerning that such compounds are in use.

Bleaching and lightening compounds in general use are not yet associated with any long-term health risks, but are well-known as potentially causing short-term damage and skin irritation.

The pattern of damage you describe suggest that your body may be either becoming sensitive to the chemicals used in hair lighteners, or that your skin is particularly sensitive to the chemicals used, in which case switching to a dilute hydrogen peroxide solution would be a better option if you did want to lighten hair.

The bottom line, though, is that chemicals that are powerful enough to alter hair color will always have the potential to damage skin and cause other effects; the safety data sheet for dilute hydrogen peroxide lists even the 3% solution as harmful and irritant. That is not so say that using hydrogen peroxide is necessarily unsafe - indeed, millions of people use it every week in a variety of products, including hair bleaches - , but there is no guarantee that in an individual case, such as yours, hydrogen peroxide will be safe.

I asked a colleague about your question, and he agreed, but also added that he had seen newspaper reports suggesting that using hydrogen peroxide by itself doesn't generally produce such good or even coloring; again, this will not apply to everyone, but is worth bearing in mind.

Hope that has been useful; in summary, most hair-lightening products are considered safe enough to use that the government approves them. However, the process of hair lightening necessarily uses harsh chemicals, and a person such as you who has already experienced problems in response to such chemicals could react unexpectedly to any compound used, including dilute hydrogen peroxide.

I am sorry I couldn't be of more practical help, but as I say, with my short hair, my experience of hair-styling is minimal! I would suggest that your next step is to discuss the matter with your doctor, or seek a stylist's advice, before deciding on your course of action. The information I have given you is chemically correct, but I realize it doesn't go that far towards solving your problem. Sorry!   Thanks again for your question, have a happy holiday!