It is remarkable that such a heavily used chemical, with known toxicity, can be so poorly regulated. For example, Procter & Gamble holds a patent which proposes to add 5 milligrams of DBP to each dose of an oral pharmaceutical. A woman of average weight (140 pounds) ingesting this tablet would get a daily dose of DBP that is 80 percent of her current allowable daily dose defined by the RfD. She would get double the dose that would be allowed if the RfD were updated to protect the male fetus from birth defects, assuming no other exposure to DBP in other products.
The Environmental Working Group conducted a web-based analysis to locate consumer products, particularly cosmetics and beauty aids, containing phthalates. We found both dibutyl phthalate (DBP) and diethyl phthalate (DEP) in numerous products, and butylbenzyl phthalate (BBP) in a smaller number of products. Ultimately we limited our search to DBP, because it is a more potent reproductive and developmental toxin than DEP, and is found in a greater number of products than BBP.
Several points became clear during our product search. First, alternatives to phthalates are readily available to industry, as only a fraction of any given type of cosmetic or beauty product contains phthalates.
Second, women have no practical way to choose products that are phthalate-free. Some cosmetics contain ingredient labels on the outside of the product, but the print is so small as to be nearly unreadable, and a typical shopper will not know that "dibutyl phthalate" is the same thing as "butyl ester" or even possibly "plasticizer." Other products, such as more expensive perfumes, contain ingredient labels inside the packaging where they cannot be read until after the product is purchased. We found still other products on store shelves, particularly imported products, that lacked ingredient labels altogether, in direct violation of federal regulations.
Third, with information currently in the public arena, it is nearly impossible to develop anything approaching a comprehensive list of cosmetic and beauty products that contain phthalates. This would require a product-by-product, label-by-label search of every single cosmetic and personal care box and bottle sold in the United States. The results of our analysis only scratch the surface of what will be a daunting task for CDC as they try to define exactly where women of childbearing age are being exposed to phthalates.
As a first step in discovering some of the beauty and personal care products that contain DBP, the Environmental Working Group (EWG) shopped at a local Rite-Aid, surfed the он-лайн store Drugstore.com, and searched the U.S. patent office records for products that contain DBP in the patent application. We found that DBP may be used in a broad range of beauty and personal care products, including shampoos and conditioners, lotions, hair growth formulations, antiperspirants, and sunscreen. It can even be used in gum, candy and pharmaceuticals taken orally.
Our product label searches in electronic and real-world drugstores showed that, for the consumer, the products most easily found that contain DBP are nail enamels and hardeners. In a limited label search of nail products on online drugstore интернет sites, EWG found DBP in a wide variety of name brand items, including Cover Girl and Maybelline nail enamels (Table 3).
The difficulty of compiling comprehensive lists of phthalate-containing cosmetics, from label searches alone, led us to conduct a web-based patent search to discover which companies claimed cosmetic-related inventions that included phthalates as ingredients. As of October 5, 2000, the U.S. Patent and Trademark Office had records of 309 patents related to cosmetics that included DBP as an essential or optional ingredient, or as an ingredient in an example product formulation. Thirty-eight individual companies or inventors hold 105 recent cosmetic-related patents that propose DBP as an additive (Table 4).
In some patents, companies gave information on the percent by weight of DBP proposed to be added to the product. DBP in nail polishes tends to be added at about five percent by weight (for example, Maybelline nail enamel patent 5972095), but DBP in other products ranged up to 20 percent, in a night cream invented by the Japanese company Shiseido (patent number 5891846) (Table 5).
Why the cosmetic industry adds phthalates to their products Multiple chemical properties of DBP make it a useful additive in many types of cosmetics. These properties include its ability to impart flexibility to thin films for mascara and nail polish, its oily texture that makes skin feel soft, and its ability to make lotions penetrate deeper into the skin (Table 6).
DBP as a plasticizer in nail enamel The plasticizing and film-formation properties of DBP make the chemical particularly useful for nail polish. After nail polish is applied, some of the ingredients volatilize and leave behind a film that is the coating over the nail. DBP is one of the ingredients left behind, reducing brittleness and cracking in the polish.
If the DBP stayed intact in the polish, women might absorb negligible amounts of the chemical into their bodies. But a group of scientists in Hamburg, Germany showed that water-soluble components of the polish, like DBP, are dissolved out of the polish each time they contact water, a conclusion they reached after measuring the leaching of DBP from nail polish that had dried for three days. In fact, one of the reasons nail polish eventually chips is that it becomes brittle as DBP is leached out of the film. This means that every time a woman washes her hands, DBP is washed out of her nail polish and contacts her skin. The scientists conclude that "water-soluble components... attain the skin during extensive but transient contact." Therefore, a woman wearing nail polish not only can absorb DBP through her nail, but also has multiple opportunities to absorb DBP directly through her skin.
Since the 1940's scientists have known that nail polish contains allergenic ingredients (Sainio et al 1997). Some companies are beginning to study formulations of nail polish that have reduced quantities of DBP, because of concerns over allergic reactions. The well-known French cosmetics company L'Or?al, in patent number 5,676,935, claims "Nowadays, it is preferable to use plasticizers other than phthalates in varnishes for reasons of allergy..." In fact, allergic responses to DBP can be severe. In a 1999 case study published in the journal Dermatology, the authors describe a case of anaphylactic shock, a severe allergic reaction, in a patient exposed to DBP in the coating of an oral pharmaceutical (Gall et al 1999).
The ability of DBP to cause allergic reactions means that the chemical can induce a state of hypersensitivity in the immune system. Environmental antigens such as DBP can cause the immune system to respond to chemical exposures with immunological reactions that are harmful, varying from hives to life-threatening responses such as anaphylactic shock, where low blood pressure and breathing difficulties can result in death.
L'Or?al USA is still using DBP in their nail products - for example, in their Maybelline Express Finish Fast-Dry, Ultimate Wear, and Salon Finish nail enamels that EWG found on the shelves of a Rite-Aid drugstore in Washington DC, in September 2000. Even DBP's well-recognized effects on the immune system have not been enough to change manufacturers' practices.
DBP as a "penetration enhancer" Both Elizabeth Arden Company (New York, New York) and Chesebrough Ponds (Greenwich, Connecticut) hold patents for cosmetics in which DBP is proposed as a penetration enhancer.
Elizabeth Arden proposes DBP as an additive to skin care products, where DBP is used to get more of the product deeper into the skin: "improving [the product's] delivery through the stratum corneum to its site of action in the epidermis." Similarly, Chesebrough Ponds proposes that DBP can be added to a hair growth formulation for men to help the formulation penetrate deeper into the scalp to the site of action at the hair follicles.
Research from the chemical giant Zeneca gives more evidence that DBP acts as a penetration enhancer. Their work shows that when DBP is added to products for the skin, allergic reactions are more severe (in this case, to ingredients other than DBP). The scientists postulate that the enhanced allergic reactions stem from DBP's ability to deliver the chemicals deeper into the skin (Dearman et al 1996).
The use of DBP as a penetration enhancer stands in direct contrast to CERHR's assertion that "Dermal contact with products containing DBP is possible, but absorption through the skin is most likely minimal." The Center cites a study of DBP migration through rat skin. CDC, on the other hand, upon discovering high levels of DBP in women of childbearing age, postulates that dermal absorption is playing a role: "Dermal absorption also occurs at a significant rate for phthalates with short side chains such as ...DBP...," citing the same rat study as evidence (Blount et al 2000).
Regardless of how various government agencies are interpreting the dermal absorption study in rats, industry continues to use DBP specifically for its ability to absorb deep into the skin.
DBP as a humectant and emollient DBP is listed as a humectant or emollient in patents from Procter & Gamble Company (Cincinnati, OH), Lever Brothers Company Inc (New York, NY), Colgate Palmolive Company (New York, NY), Kraft General Foods (Northfield, IL), Anheuser-Busch, Incorporated (St Louis, MO) and four other companies. Humectants are skin moisturizers; emollients soften the skin. Information in patents from these major companies indicate that DBP is added to skin care products because its oily texture gives the impression that the skin itself is soft and moisturized, when in fact it is the DBP residue that makes the skin feel this way.
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