However. The Cosmetics Database found PEG 40 Stearate to be a moderate to high hazard ingredient depending on usage. The EWG issues warnings regarding: cancer, developmental and reproductive toxicity, contamination concerns, irritation, and organ system toxicity.
According to a study published in the International Journal of Toxicology, PEGs (including PEG 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 PEG 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).