Watch out for these terms:
IPBC, 3-iodo-2-propynyl butylcarbamate, carbamic acid, Glycacil®, and IodoCarb®
However, in 2002, the American FDA concluded that, “According to safety tests, no significant increase in blood levels of lead was seen in trial subjects and the lead was not shown to be absorbed into the body through such use." Therefore, the FDA determined lead acetate to be safe when specific instructions listed on the packaging are followed.
Therefore, you may begin to notice the following on products containing lead acetate: "Caution: Contains lead acetate. For external use only. Keep this product out of children's reach. Do not use on cut or abraded scalp. If skin irritation develops, discontinue use. Do not use to color mustaches, eyelashes, eyebrows, or hair on parts of the body other than the scalp. Do not get in eyes. Follow instructions carefully and wash hands thoroughly after use."
Lanolin is the purified secretory product of the sheep sebaceous gland — or, more plainly sheep sweat. This slightly unpleasant origin has earned the ingredient bad press as a scary ingredient in the past, but it is actually not dangerous if it's purified lanolin. Although lanolin has been known to cause an allergic response in a very small percentage of people, purified lanolin is a clean, healthy product to use. Extensive research by the CIR deemed lanolin to have "low acute toxicity based on available animal data and human experience," and went on to say that lanolin and related lanolin materials are safe for human topical application. This is good news considering its moisturizing benefits.
In hair products, phthalates are used primarily as hair-gelling agents in products. You will notice this by the term “fragrance” in your ingredient list. These phthalates, often simply labeled as "fragrance," are known and praised for making product scents last longer, but they may not be entirely safe.
This is a foaming agent used in hair products to produce the common mousse-like consistency. The National Library of Medicine, HazMap, notes that this ingredient is a human immune system toxicant; moreover, the United States Environmental Protection Agency, Office of Pesticide Programs, says that this ingredient may be a cause of cancer to humans. Although research for the cause of cancer is lacking, it is probably best to steer clear of this ingredient, anyway, especially as it is not essential to the effectiveness of the product. Instead, choose a similar product in a cream base rather than in foam-form.
Amino Methyl Propanol
This active ingredient is used as a pH adjuster that is generally considered safe at levels of concentrations below 2%. Unfortunately, many hair products, especially those requiring a strong pH adjuster (think chemically altering hair straighteners or hair dyes) require concentrations well above 12%, which could cause irritation, speficically affecting the eye area. Because of this possible irritation, some people may wish to to use natural products that temporarily alter the state of their hair rather than products that aim to permanently alter it, since the latter carries a greater risk.
Nitrosamines are formed when certain compounds (typically TEA and DEA) are used with certain preservatives that can break down into nitrates. TEA and DEA are typically used as wetting agents or pH adjusters in cosmetic products. Specifically DEA is used as an emulsifier in shampoos, cleaners, and detergents providing rich later and highly desired consistencies, while TEA is used as fragrance, pH adjuster and emulsifying agent.
Parabens (methyl, butyl, ethyl, propyl)
This sneaky ingredient is used in products as a preservative, yet is rarely labeled correctly.
The easiest way to avoid this ingredient is to use products labeled "paraben-free." Although parabens are typically found in breast cancer tumors, more research is still needed to determine if parabens actually cause breast cancer. Still, many women are choosing to go the paraben-free route and opting for products containing natural preservatives. The downside to natural preservatives is that the they don’t preserve products for very long, so your beauty products will have a shorter shelf life than you're used to.
It's important to make informed decisions about what you put on your hair and body, but in order to do that, you've got to have at least a basic understanding of what ingredients you may want to avoid. Keeping an eye out for the substances listed above is a great start.