I. Soc. Cosmet. Chem., 25, 271-281 (May 1974) Current Perspectives on Aerosol Toxicity CHARLES O'CONNOR WARD, Ph.D.* Presented May 4, 1973, Seminar, Cincinnati, Ohio Synopsis-The TOXICITY of cosmetic, household, or personal product AEROSOLS is primarily the result of either deliberate abuse or allergic reactions to one or more of the ingredients. Hair sprays, antiperspirants, deodorants, and feminine hygiene sprays, among others, have been reported to produce toxic reactions in some users. A review of the pub- lished experimental and clinical data does not substantiate the contention that, when used as directed, they are hazardous. It is true, for instance, that the fiuorocarbon PROPEL- LANTS, in experimental situations, can sensitize the myocardium to catecholamine-in- duced arrhythmias and thus produce a situation detrimental to the user, but not in the amounts to which the consumer is ordinarily exposed. The differences between toxicity, the inherent ability to produce undesirable alterations in biological tissue, and HAZARD, the likelihood that toxicity will occur, may explain the case for aerosol products. The potential for toxicity of properly packaged cosmetic, household, and personal product aerosols is present the hazard is small under conditions of normal use. INTRODUCTION As with any other type of packaging or delivery system for cosmetics, drugs, or household products, aerosols have characteristics that are uniquely their own. In general, they are safe, convenient, easy to manipulate, and, for the most part, economical to use. In addition to these advantages, however, this particular method of packaging and delivery is somewhat harder to con- trol once the contents have been liberated from the container. Foams, paints, and cosmetic powders are easily seen and handled but many drug and liquid cosmetic formulations, such as deodorants and hair sprays, are hard to see once released and often the respect that other aerosol products are given by the consumer is not accorded these items. Individuals often have a difficult time relating to a substance that, because of its small particle size, is difficult to see thus, the potential hazards, includ- ing warning labels, are often ignored. This can be illustrated in the case of a *St. John's University, College of Pharmacy and Allied Health Professions, Jamaica, N.Y. 11439. 271

9,72 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS hypothetical man who sprays an entire can of an aerosol insecticide into a small room and then, without opening any windows, goes to sleep in the room rising later he finds manifestations of a contact allergy. Yet he probably would not have treated a can of gasoline that way, despite the relatively innocuous nature of the chemicals in the can of gasoline. TYPES OF AEROSOL TOXICITY Toxic reactions to aerosols have been reported in the literature for several categories of products: cosmetics, such as hair sprays (1-3) and deodorants (1, 4, 5) perfumes (6) personal products such as feminine hygiene deodor- ant sprays (7, 8) and household products, such as spray paints (9), insecti- cides (10), aerosolized vegetable oils (11), and room deodorizers (5, 9). Medicinal aerosols have also been reported to produce some of the same toxic effects, but they will not be discussed in this paper. The types of toxicity reported can be broken down into two main categories, those due to the propellants and those due to the active or inert ingredients in the formula- tions. Propellant toxicity can result either from the refrigerant properties of the propellants (freezing of tissues or local anesthesia) or from the chemical na- ture of the propellants and the biological responses they elicit (12). Many of the reported cases of aerosol toxicity are likely due to toxic reac- tions to the active or inert ingredients in the formulation, rather than to the propellants. Allergic reactions are among the more COlnmon forms of toxic responses to cosmetic aerosols. It has been estimated that approximately 10% of the population as a whole has some type of allergic disease (6) or has suf- fered an allergic response to some foreign substance during their lifetime and it is a well-accepted medical fact that people who are allergic to one sub- stance, or have an allergic disease such as asthma or hay fever, are prone to be allergic to other products as well-especially upon repeated exposure. The incidence of persons allergic to cosmetic products, on the other hand, is probably between 2 and 3%, when verified by a patch test (6). In the data compiled by one cosmetic company who markets a broad range of products, only 448 reactions were reported in 114 million units sold (6). In an earlier reference, the incidence of allergic skin reactions to lanolin was 1.14% in an unscreened sample of users. (Lanolin is widely used in cosmetic formulations for its unique cmollient and emulsification properties.) On the other hand, when a controlled sample with no history of allergic skin disease was tested, no allergic reactions to lanolin were reported (13). Recent refinements and improvements in the purification of the lanolin used in cosmetic products have eliminated lanolin allergy as a significant problem. Reactions to perfume oils, a ubiquitous ingredient in cosmetic aerosol products, are almost entirely due to an allergic or hypersensitive response, rather than due to primary irritation (6). There are more than 5000 odiferous substances in general use