Parabens get a bad rap. Some products proclaim themselves paraben-free. But are they really that bad and isn't the stuff that they prevent (the formation of nasty bacterias) potentially more harmful? What about the alternatives? Do they work and are they safer?

Parabens are preservatives and they are incredibly ubiquitous; you will find them in cosmetics and all manner of hair care products. They are esters of para-hydroxybenzoic acid and common parabens include: methylparaben (which can occur naturally in blueberries), propylparaben, butylparaben. Less common are isobutylparaben, isopropylparaben and benzylparaben.

The fuss started when a 2004 study linked parabens in deodorant to breast cancer. Because parabens mimic human estrogen and it is known that estrogen stimulates cancer, the link seemed plausible. The study has since been discredited and the American Cancer Society has concluded that there is insufficient scientific evidence of parabens increasing breast cancer risk. And a 2005 study said it is "biologically implausible that parabens could increase the risk of any estrogen-mediated endpoint, including effects on the male reproductive tract or breast cancer".

So if parabens are by and large not carcinogenic, what's not to like? Allergies to individual parabens are rare, but there is a high incidence of cross-reaction so a combination of parabens in one product increases the likelihood of a reaction. Many cosmetic and hair products contain up to four or five parabens.

The other reason to avoid parabens is environmental damage. According the Environmental Protection Agency: "the continual introduction of these benzoates (parabens) into sewage systems and directly to recreational waters from the skin leads to the question of risk to aquatic organs." (source) So be nice to fish and use alternatives where possible.

What about the alternatives? Are they any better?

Unfortunately, many other effective preservatives have safety issues. DMDM hydatoin releases formaldehyde. Kathon, a synthetic preservative, was cited as a "major cause of cosmetic allergy" by a study conducted by a Dutch dermatologist. Sodium benzoate produces a carcinogen when it encounters vitamin C and a British study has linked it DNA degeneration.

Safe, but mild, preservatives do exist and they include: phenoxyethanol, potassium sorbate and - as far as I can tell - sodium levulinate and propyl gallate.

UPDATE - 2/28/08 My mother-in-law, Monique (who irritatingly has some rare and amazing wrinkle resistant gene), sent me some clippings from French magazines. I noticed that journalists in France seemed to be  concerned about phenoxyethanol. I did some more research and found out that it is considered to be extremely toxic and concentrations in cosmetics are severely limited in Japan. This is what a company who sells it to laboratories has to say about it:

"Extremely hazardous in case of eye contact (irritant). Very hazardous in case of skin contact (irritant), of ingestion, of inhalation. Inflammation of the eye is characterized by redness, watering, and itching. Skin inflammation is characterized by itching, scaling, reddening, or, occasionally, blistering."

Marta adds: I got pulled up - quite properly - by a reader regarding the quote above. It should be noted that the manufacturer is referring to its raw state at 100% concentrations.

UPDATE - 3/8/08. I have just come across methylisothiazolinoneDeemed safe in Europe, the US and Japan, there is however one study on rats that demonstrated it is a neurotoxin. At best, there is insufficient
data to say that this is safe at this stage.

UPDATE - 6/4/08 The FDA issues a warning on phenoxyethanol

UPDATE - 6/29/16 New study links parabens to birth defects