Butyl- , Ethyl-, Methyl-, Propyl-, These are the big four paraben offenders that also have a body of research behind their side effects in people and the environment.
In personal care formulas Parabens function as an antimocrobial / antifungal to control the growth of yeast, mold, or fungus in a product. Parabens inhibit growth by impairing cellular ability to uptake amino acids and other compounds needed for substrate and energy. Parabens are not effective against bacteria. They all share the same manufacturing process with one variation; the type of alcohol that is used in the chemical reaction. Butyl-, Ethyl-, Methyl-, and Propyl-, Parabens are all obtained through the esterification of p-hydroxybenzoate using the precursor alcohol, in the presence of sulfuric acid. The solution is then neutralized with sodium hydroxide and processed to form a crystalline precipitate that can be incorporated into food, personal care and pharmaceuticals as a preservative, flavor agent, coloring enhancer, fragrance fixative, and antioxidant. While parabens show potent spermicidal activity they are considered to be too toxic for that kind of application. Parabens are approved for use and generally recognized as safe by the FDA in cosmetic preparations at <0.1% concentration and are often combined to increase each others efficacy.
Butyl-, Ethyl-, Methyl-, and Propyl-, Paraben ALL share the qualities listed immediately below
- All parabens are known skin irritants. Exposure often results in mild to severe irritations and inflammation of the skin, this inflammation can show up as redness, dryness, eczema, as well as the worsening of pre existing skin conditions. People can develop severe and intractable sensitivity to all parabens after exposure to just one; this is called cross sensitivity that presents as allergic contact dermatitis. Sensitization and severe dermatitis most frequently occur when parabens are applied to broken skin.
- Parabens all show estrogenic activity – some data suggests that parabens are estrogenic endocrine disruptors. They have been observed to excite existing estrogen based cancerous and pre cancerous cells. They also leave behind metabolites that are biomarkers of estrogen activity in the body of exposed organisms – this goes for everything from us to the fish.
- Parabens do build up in the environment. They are found in almost all water sources – this means ground water, flowing water, drinking water, and wastewater. A single study found that at least one kind of paraben was detected in the urine of 99% of adults in the US, male & female. The hydrophobic (water repelling, won’t mix) properties of each individual paraben vary, however the less hydrophobic ( the more it mixes with water) a paraben is the more toxic it is to the immediate aquatic environment.
Butyl Paraben aka Butyl-4-hydroxybenzoate / BUTYLPARABEN / 94-26-8 / Butyl-p-hydroxybenzoate
- Esterification using butyl alcohol
- Known irritant, unknown sensitizing potential. Confirmed allergy cross sensitivity.
- Butyl Paraben has shown a high propensity for bioaccumulation and has even been detected in supermarket fish.
- In a study between 2003 – 2005 Butyl paraben was detected in 69% of adults tested.
- Greater than 5% concentration will cause contact irritation.
Ethyl Paraben aka Ethyl-4-hydroxybenzoate / ETHYLPARABEN / 120-47-8 / Ethyl-p-hydroxybenzoate
- Esterification using ethyl alcohol
- Recognized phytoestrogen, mild skin irritant, sensitizer
- Ethyl Paraben shows low potential for aquatic/environmental accumulation
- A 2003 – 2005 study found Ethyl Paraben in the urine of 58% of US adults tested.
- Greater than 7% concentration will cause contact irritation
Methyl Paraben aka Methyl-4-hydroxybenzoate / METHYLPARABEN / 99-76-3 / Methyl-p-hydroxybenzoate
- Esterification using methyl alcohol
- Known irritant & sensitizer – Subjects applied methyl paraben to their skin daily for one month- the MP was not metabolized and showed persistent build up in the stratum corneum ( outer skin layer ) /// An in-vitro test using cultured skin showed that methyl paraben decreased cell proliferation, changed cellular morphology, and decreased collagen production /// When exposed to UVB radiation methyl paraben has been shown to increase cellular death & oxidative stress. These findings indicate that methyl paraben may be harmful to skin when exposed to sunlight.
- Methyl Paraben shows definite aquatic accumulation. Testing of groundwater in the UK between 1992 – 2009 found methyl paraben in 44 of 448 groundwater samples or approximately 10%. MP has also been detected in drinking water and wastewater.
- A 2003 – 2005 study found Methyl Paraben in the urine of 99% of US adults tested.
- Greater than 5% concentration will cause irritation.
Propyl Paraben aka Propyl-4-hydroxybenzoate / PROPYLPARABEN / 94-13-3 / 4-hydroxybenzoic acid propyl ester
- Esterification using Propanol
- Known skin irritant, rarely sensitizing. Propyl Paraben is toxic to liver cells and may inhibit or reduce the bodies natural antioxidant functions and responses
- Propyl Paraben has a moderate potential for aquatic accumulation and is often found in groundwater, & drinking water.
- A 2003 – 2005 study found Propyl Paraben in the urine of 96% of US adults tested.
- Greater than 12% concentration will cause irritation
Parabens have documented negative health effects, they are proven to accumulate in our water sources and waterborne food sources. Their link to cancer has not been fully assessed but it is a fact that parabens are frequently found in women who’ve been diagnosed with breast cancer, and in the afflicted tissue. We have been steadily pouring these chemicals into our environment with reckless abandon since the 1920’s. Enough is enough; parabens are bad. They’re bad for your health & your skin, bad for our water & our environment. There is no benefit that could possibly outweigh these grave & proven consequences.
A note should also be made; as it is with Benzyl Alcohol, benzoic acid is a metabolite that results from breakdown of parabens in the body. Benzyl Alcohol has been associated with infant deaths due to the assumed inability of their still developing livers to process benzoic acid. Parabens are readily absorbed through the skin.
Don’t be fooled by this brand name; Optiphen. Get the dirty details in our final installment of Preservatives; A Crash Course.