Even more significant to Nielsen is the paucity of scientific data on exposure and long-term health effects of the various ingredients that appear at extremely low levels. Some enforced limits do exist, especially in the case of the metals lead, arsenic, cadmium, mercury and antimony, which are restricted to set measures of parts per million. In the absence of direct evidence to justify their elimination, agents like TEA or dioxane continue to appear in marketed goods, although Health Canada does publish this fact on a Cosmetic Ingredient Hotlist. “As far as I am aware, very little or no research has been carried out to determine the effect of persistent low doses of substances in products like cosmetics,” says Nielsen. That shortcoming was revealed in a report on metals in cosmetics, which drew a great deal of media attention early in 2011. Issued by an interest group called Environmental Defence, the report offered up case studies of the amount of particular metals that particular individuals would find in their daily cosmetic regime. A comprehensive bibliography was intended to support the assertion that these ingredients posed a clear health hazard. However, more than one-third of the 71 entries on this list consist of links to American and Canadian government websites, while others refer to mass media reports. Even where references to peer-reviewed scientific journal articles occur, many of them only describe analytical techniques that might be used to study low-level exposure to cosmetic ingredients, rather than documenting any cases of such exposure. In fact, no more than a handful of articles actually deal with such cases, and even these may not be immediately applicable to the circumstances of cosmetics users in North America. For instance, several articles deal exclusively with the use of surma, an antimony-based eye shadow that is traditionally used on children in North Africa and the Middle East. Schwarcz, for his part, insists that cosmetic firms have a vested interest in ensuring that their wares do not harm the health of customers. Despite a popular perception that leaving industries to police their own standards is the equivalent of letting the fox guard the henhouse, he maintains that companies are sensitive to the concerns voiced by observers like Malkan and Deacon. In the U.S., for example, members of an industry trade association known as the Personal Care Products Council have been conducting this kind of research since 1976, using procedures developed with the Food and Drug Administration and the Consumer Federation of America. The results of this collaboration, known as the Cosmetic Ingredient Review, include safety assessments that are published in the International Journal of Toxicology. Nevertheless, industry critics could well remain unsatisfied by this organization’s track record. By the time California was introducing its legislation in 2006, for example, one account of this development noted that the Cosmetics Ingredient Review had considered 1,286 agents over the previous 30 years and just nine of them had been formally removed from use in products. In the meantime, even more tantalizing aspects of this debate are emerging. Schwarcz puts forward a proposition that is likely to prove to be even more unsatisfactory to critics of the cosmetics industry: small quantities of toxic agents might actually benefit human health. Dubbed hormesis, this idea has been championed in the peer-reviewed scientific literature by University of Massachusetts toxicologist Edward Calabrese. Not surprisingly, his work has generated some lively
debate. “It does make biological sense,” observes Schwarcz. “When an organism is attacked by poisons, it responds by unleashing a variety of molecules, mostly enzymes, which attempt to repair the damage. If the amount of toxin is minute, there may be an overreaction, with more defense chemicals being churned out than needed, leaving an excess to deal with the molecular insults of everyday life. It may yet turn out that the apocalyptics who warn us of the perils of exposure to parts per trillion of toxic chemicals are on the wrong track.” Along with the emergence of this new perspective on chemical exposures, Nielsen sees the very definition of “lowlevel” moving to an entirely different plane. She suggests that a host of new problems could be posed by the growing use of agents that are being manipulated at the nanometre scale. And if little has been revealed about the impact of conventional chemical use over the past few decades, even less is known about the health effects that might ensue from recently launched nanotechnological methods. Nielsen has conducted surveys on consumers’ knowledge and concerns about nanotechnology. The results of these surveys reveal the public’s suspicion and skepticism toward the use of nano-scale materials in cosmetics. For her, this attitude is an extension of the disappointment she has heard individuals express when they learn about the limitations of Canada’s regulations on cosmetics. “Most consumers believe that the government looks at every product before it is sold,” she explains. “Most believe that their interests are being looked after. They will react with disbelief, however, when told that no safety assessment is carried out on cosmetics before they are allowed to be sold.”
october 2011 CAnadian Chemical News 17