It is not easy to come up with a balanced, objective view on potential toxicity of skin care ingredients. Mainstream skin care companies usually assert that whatever ingredients they use are safe. On the other hand, alternative all-natural skin care outfits profess gloom and doom from synthetic ingredients. The majority of independent studies of the subject focus on acute toxicity of high doses or concentrations rather than chronic low-level damage from long-term use of small amounts, a situation far more common in real life.
Considerations regarding potential harm from skin care ingredients:
1. Systemic Toxicity
In regard to a topically applied ingredient, systemic toxicity means that it gets into the bloodstream, travels throughout the body and causes damage in organs other than the skin. It does not appear that any of the common over-the-counter skin care products produce systemic toxicity. However, some topical prescriptions drugs, such as hormonal creams, may have systemic toxicity. It is always best to check with the prescribing physician.
2. Natural vs. Synthetic
Proponents of all-natural skin care believe that any natural substance is more effective than its synthetic analog, and that all synthetic chemicals are toxic. The reality is more complex than that. According to modern science, biological effects of a particular chemical are the same whether it is isolated from natural sources or synthesized in the lab. In theory, that is always true. In reality, depending on whether a substance was derived from natural source or synthesized it may contain different contaminants. Generally, harmful contaminants are more likely in synthetic chemicals, but they do sometimes occur in natural substances as well.
Here, we list a few ingredients which may be capable of causing skin damage with prolonged use:
Sodium Lauryl Sulfate: A lathering agent common in shampoos, toothpaste and cleansers. If exposure is prolonged it is likely to cause skin irritation, dryness and other damages. In fact, sodium lauryl sulfate is sometimes used as a model skin irritant in the experiments where skin protectors are tested.
Mineral oil: These are petroleum derived hydrocarbons used as an inexpensive base in some products. It is known to block skin pores thus causing blackheads. Mineral oil may also interfere with normal perspiration and other skin functions. Mineral oil is commonly found as a base in facial moisturizers, lotions, liquid makeup, makeup remover and body oils.
Synthetic Colors: Whether synthetic colors are completely safe or mildly damaging in the long run, it is unknown. Since they serve no useful purpose, they are best avoided. They are labeled as FD&C or D&C, followed by a color and a number, e.g. FD&C Red No. 6 or D&C Green No. 6. Synthetic colors can be found in a range of personal care such as lotions, shampoo and conditioner, facial creams, shaving creams, and even toothpaste.
Nanoparticles: Nanoparticles are ultra-fine particles that may accumulate in the body, possibly even via topical use, and trigger potentially harmful chemical reactions. As a result, some experts raise concerns about the use of nanoparticles in skin care and cosmetics. Currently, nanoparticles (such as titanium dioxide and zinc oxide nanoparticles) are most commonly used in sunscreens.
Ethanolamines (Monoethanolamine aka MEA, Diethanolamine aka DEA, Triethanolamine aka TEA): These are common pH stabilizers. DEA, an emulsifying agent, is most typically found in products with a creamy consistency such as moisturizers, body washes, and shampoos. DEA and its compounds cause mild to moderate skin and eye irritation. In laboratory experiments, exposure to high doses of these chemicals has been shown to cause liver cancers and precancerous changes in skin and thyroid.
Parabens (e.g. Methyl, Ethyl, Propyl and Butyl Paraben): Often used as preservatives, parabens may release potentially toxic chemicals. Parabens easily penetrate the skin and are suspected of interfering with hormone function (endocrine disruption). In addition, studies indicate that methylparaben applied on the skin reacts with UVB leading to increased skin aging and DNA damage.
Lead and Other Heavy Metals: Heavy metals like lead, arsenic, mercury, aluminum, zinc, chromium and iron are found in a wide variety of personal care products including lipstick, whitening toothpaste, eyeliner and nail color. Exposure to metals has been linked to health concerns including reproductive, organ, immune and nervous system toxicity.
Triclosan: Triclosan, often the active ingredient in antibacterial soaps, body washes, toothpaste etc., can pass through skin and is suspected of interfering with hormone function (endocrine disruption). The European Union classifies triclosan as irritating to the skin and eyes. A study by British researchers found that triclosan has estrogenic and androgenic hormone properties, and exposure could potentially contribute to the development of breast cancer. A joint project of Food & Water Watch and Beyond Pesticides found that bacteria can become cross-resistant to triclosan One study also concludes that, for consumer use, triclosan has no added health benefits over regular soap and water.
Source: smartskincare.com, safecosmetics.org