Polyoxyl 40 Stearate
* An emulsifier
* Also known as PEG - 40 Stearate
* Sometimes classified as a PEG - Please read TIA's post on What Is It: PEGs
Polyoxyl 40 Stearate is used in cosmetics and beauty products primarily as a surfactant and emulsifier. It occurs naturally as a white, waxy or flaky substance, according to The Food and Agriculture Organization of the United Nations
notes that Polyoxyl 40 Stearate, as part of the PEG Stearate group, are formed from a naturally fatty acid known as Stearic Acid. The PEG Sterates are used in cosmetics and skin care formulas because they can "clean the skin and hair by helping water to mix with oil and dirt so that they can be rinsed away."
Also known as PEG - 40 Stearate, Polyoxyl 40 Stearate has a molecular weight associated with all PEGs. Its low molecular weight of 40 means that it can penetrate healthy skin, but minimally.
Despite the many fears regarding PEGs, they are seen as an ingredient in a large number of products because of their diverse properties. In a study published in the Toxicology journal
in 2005, entitled "Safety assessment on polyethylene glycols (PEGs) and their derivatives as used in cosmetic products," it was concluded that: "Taking into consideration all available information from related compounds, as well as the mode and mechanism of action, no safety concern with regard to these endpoints could be identified. Based on the available data it is therefore concluded that PEGs of a wide molecular weight range (200 to over 10,000), their ethers (laureths. ceteths, ceteareths, steareths, and oleths), and fatty acid esters (laurates, dilaurates, stearates, distearates) are safe for use in cosmetics."
Polyoxyl 40 Stearate is FDA approved for limited use as a food additive.
Safety Measures/Side Effects:
The Cosmetics Database
found Polyoxyl 40 Stearate (listed as PEG - 40 Stearate) to be a moderate to high hazard ingredient. It notes cancer, developmental and reproductive toxicity, contamination, organ toxicity, and irritation concerns, and has been found to cause tumor formation at moderate doses, and skin irritation in rabbits at very low doses. The MSDS
for Polyoxyl 40 Stearate also notes that it can cause skin and eye irritation, but does say that "repeated or prolonged exposure is not known to aggravate medical condition."
Because Polyoxyl 40 Stearate is classified as a PEG, it can carry with it the concerns associated with all PEGs. According to a study published in the International Journal of Toxicology, PEGs (including Polyoxyl 40 Stearate) can contain harmful impurities, including: Ethylene Oxide, known to increase the incidences of uterine and breast cancers and of leukemia and brain cancer, according to experimental results reported by the National Toxicology Program; 1,4-dioxane, a known carcinogen; PAHs, known to increase the risk of breast cancer; lead; iron; and arsenic (Source
Products and formulas containing Polyoxyl 40 Stearate should not be used on broken or irritated skin. Although PEGs are considered safe for use topically on healthy skin, studies showed that patients suffering from severe burns were treated with PEG-based antimicrobial cream; this treatment resulted in kidney toxicity. "The PEG content of the antimicrobial cream was determined to be the causative agent. However, no evidence of systemic toxicity occurred in studies with intact skin. Because of the observation of kidney effects in burn patients, the CIR Expert Panel qualified their conclusion on the safety of the PEG ingredients to state that cosmetic formulations containing these ingredients should not be used on damaged skin" (CosmeticsInfo.org