Consumer choice is a powerful thing. Say "jump or I'll spend my cash somewhere else" and you'll set executives scrambling to use one another as makeshift human trampolines. It's for this reason and this reason alone -- at least for the major corporations -- that we're seeing such a proliferation of products cheerily proclaiming that they're BPA-free. Well, parabens are the bisphenol-A of the beauty industry, from the scary headlines to the happy proclamations that beam at you when a product has kicked them to the curb.

But as we mentioned before, parabens aren't the only nasty no-no to avoid. Here are seven other toxic ingredients that regularly hitch a ride on cosmetics and skincare products. Pay heed to these red flags the next time you're out cruising with your shopping cart -- who knows, perhaps some well-dressed man will approach you to ask if Bill from Accounting could perform some aerial acrobatics for your pleasure.

1. Fragrance
Examine the fine print of most personal-care product labels and you're bound to find "fragrance" (or, if you want to get fancy, "parfum") jostling for room with its multisyllabic brethren. Because they're considered trade secrets, fragrances fall into a colossal loophole in federal law that doesn't require companies to disclose the potentially hundreds of chemicals in a single product's olfactory-tickling formula.

This simple term can obscure hinky substances tied to myriad health problems, from allergies to endocrine disruption. In 2002, three-quarters of the 72 products tested by the Environmental Working Group contained phthalates, plasticizer chemicals linked to birth defects, feminization of infant boys, liver and kidney damage, and infertility. None of the products, which included brands like Cover Girl, Pantene, Dove, L'Oréal, and Revlon, had the word "phthalates" listed on their bottles, which is even more insidious.

2. Polyethylene glycol
Polyethylene glycol, better known by its acronym, PEG, isn't a single ingredient but a class of ethylene glycol polymers that moisturize, keep products stable, and enhance the penetration of other ingredients, both good and bad. PEGs are typically followed by a number correlating to how many units of ethylene glycol they comprise, in the form of say PEG-4 or PEG-100; the lower the number, the more easily the compound is absorbed into the skin.

While PEGs can be mild irritants, they're less than desirable primarily because they help traffic funky chemicals across your epidermis, including a slug of impurities they're often contaminated with. According to a report in the International Journal of Toxicology by the Cosmetic Ingredient Review, pollutants found in various PEG compounds include ethylene oxide (used to manufacture mustard gas), 1,4-dioxane, polycyclic aromatic compounds, and heavy metals (lead, iron, cobalt, nickel, cadmium, arsenic).

3. Nanoparticles
Largely untested, these extremely minuscule particles are usually undeclared on product labels, even though they can be absorbed directly into the bloodstream. In addition to bronzers, eye shadows, and lotions, you can also find them lurking in a large number of sunscreens that use micronized particles of zinc oxide and titanium dioxide, which form physical barriers against UV rays. It's on this battlefield that the "nano wars" are at their most feverish.

Although the EWG, after poring over 400 peer-reviewed studies, concluded that the benefits of small-scale zinc and titanium sunscreen ingredients outweighed the potential risks, a recent report by Friends of the Earth, Consumers Union (publisher of Consumer Reports), and International Center for Technology Assessment had a different take. "Consumers must be aware that nanomaterials are being put into sunscreens with very little evidence about their safety and relative efficacy," notes Ian Illuminato, one of the report's co-authors, citing a 2007 Consumer Reports test that the EWG found at odds with its own investigation -- at least for liquid sunscreens.

Powdered sunscreens or sprays, which can be inhaled, are a whole different story, however. The high surface area -- and high reactivity -- of tiny particles of zinc and titanium can provoke inflammatory responses, oxidative stress, and cell damage.

4. Phenoxyethanol
A ubiquitous preservative, even in products touted as "all-natural" or "organic", phenoxyethanol is classified as an irritant by the European Union and a restricted substance in Japanese cosmetics. According to its Material Safety Data Sheet, which refers to 100 percent concentration, phenoxyethanol is not only harmful if inhaled, swallowed or absorbed through the skin, but it can also cause reproductive defects and nervous system damage. In cosmetics, concentrations are typically less than 1 percent, but your exposure to the ingredient could be compounded depending on how often it rears its head in the products you use.

Let's put it this way, if phenoxyethanol is awful enough for the U.S. Food and Drug Administration, which has a spotty record at best when it comes to championing public interest, to put out a consumer alert warning that it can "depress the central nervous system and may cause vomiting and diarrhea" in infants, it's probably wise to steer clear of this bad boy.

5. Triclosan
Triclosan is an antibacterial compound that runs rampant in many cleansers, deodorants and other personal-care products that the U.S. Environmental Protection Agency classifies as a probable human carcinogen. Linked to cancer, developmental defects, and liver and inhalation toxicity, overuse of this hormone-disrupting pesticide -- yes, pesticide -- can also result in strains of drug-resistant superbacteria.

Plus, triclosan tends to bioaccumulate in the fatty tissues of people and animals, which explains why it's been detected in our blood and breast milk. Acutely toxic to several types of aquatic life, triclosan can also degrade into a form of dioxin, a class of known carcinogens. New research also shows that triclosan in tap water can react with residual chlorine from water disinfection to form myriad chlorinated byproducts, including chloroform, a human carcinogen.

6. Petrolatum
Oh, where to begin? This gelatinous substance, also known as petroleum jelly, is derived from crude oil. Its popularity as an emollient largely stems from its extremely low cost. (Vaseline, for instance, is pure petrolatum.) There are cosmetic reasons to eschew the goop: The oily film that sits on the surface of your skin can aggravate acne and slow down cell turnover (read: cause you to prematurely age). But beyond that, petrolatum is also particularly susceptible to contamination by baddie chemicals like 1,4-dioxane, a probable human carcinogen, no thanks to unregulated manufacturing procedures.

In any case, Canada isn't a fan: Beyond the border, Environment Canada classifies the substance as a possible carcinogen, a possible mutagen, and a suspected environmental toxin.

7. Quaternium-15
Considering that quaternium-15 is a known human toxicant, it's astounding that you can find it in "extra-gentle" bubble bath and "extra-sensitive" baby wash. Used as a preservative, quaternium-15 is not cancer-causing in and of itself but breaks down to release formaldehyde, which the EPA classifies as a probable human carcinogen.

Because it's also an allergen, quaternium-15 can cause contact dermatitis in sensitive skin. And if you're allergic to formaldehyde, chances are you're also allergic to quaternium-15.

(By Jasmin Malik Chua, TreeHugger / AlterNet, 01/09/2009)

* Jasmin Malik Chua writes about sustainable fashion and beauty for TreeHugger