CURRENT PERSPECTIVES ON AEROSOL TOXICITY 277 cases have been reported in teen-agers (4) and either Propellant 12 or a mixture of Propellant 11 and Propellant 12 has been implicated, although not conclusively. Feminine Hygiene Deodorant Sprays Such products have been reported to be no better than frequent bathing to keep the vaginal area free from unpleasant odors (24, 39). Despite this, they have caught on in popularity and are sold widely, probably because many women believe they need them, despite the opinion of some gynecologists to the contrary (40). There are certain formulation differences between vaginal and underarm deodorants, i.e., vaginal deodorants commonly have less alcohol and less perfume-in order to reduce the possibility of irritating the tender vaginal mucous membranes (41). Irritation is more likely to occur with va- ginal than underarm deodorants because the user is more likely to spray the can longer, in that the spray is quite dry and there is little apparent residue. Also, the delivery rates of vaginal deodorants are likely to be higher than underarm deodorants because they are often packaged under substantially higher pressure. Propellant 12 is often used to reduce chilling (41). The Food and Drug Administration has reported that reactions to the vagi- nal spray deodorants are usually due to one or more of the following: in- juries resulting from the high pressure of the propellants primary irritation from the alcohol, antibacterial chemical, or perfume the rapid chilling ef- fects of the propellants on the delicate mucous membranes or skin in this area allergies to the antibacterial chemicals or perfumes (40). Women users have reported irritation of the skin or mucous membranes, vulvitis, weeping derma- titis, chemical burns, and various hypersensitivity reactions, such as prttritis, burning, and edema (7, 40). Some of the special anatomical features of the vaginal area that make it more susceptible to deodorant sprays include the apocrine sweat glands, the thin horny stratum, and the special bacterial flora of the vaginal mucous membranes (24). Hair Sprays Hair sprays have been implicated, in a cause-effect relationship, with the development of ptdmonary granulomatosis (3) and blood dyscrasias (2) in chronic users of such products, possibly due to a hypersensitivity reaction. The resinous ingredients contained in these products have been reported to be the noxious agents. In several reported cases, radiographic examination of the chest showed infiltration of the lung field in users of hair sprays which cleared when the usage of these products was discontinued (3). However, several attempts to duplicate these human findings in rats (42), guinea pigs (43), and dogs (44), exposed to commercial hair spray preparations for as long as two years, failed to demonstrate any pulmonary pathology that could be attributed

278 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS to exposure to these products. The PAS-staining biopsy material, reported by Bergmann et al. (3) to indicate the presence of hair spray resins, was also found in the control animals (44). Furthermore, hematologic studies of dogs exposed to commercial hair sprays for up to 2 years (44) failed to demon- strate the blood dyscrasias (aplastic anemia, thrombocytopenia, and leuko- penia) reported as being compiled from the AMA Department of Drugs Registry on Adverse Drug Reactions by DeNosaquo (2). Further evidence of the safety of commercial hair sprays has been reported in two separate studies of hairdressers in Great Britain. In the first, John (45) studied 146 hairdressers, both men and women, who used hair sprays for be- tween 3 and 5 years. Radiographic examination of these hairdressers, from 14 different salons, failed to demonstrate any pulmonary abnormalities. In a similar study by McLaughlin et al. (46), an X-ray survey of 505 hairdressers in Great Britain was reported. The hair sprays included both shellac-based sprays and sprays containing polyvinylpyrrolidone (PVP). In all groups a significant number of hairdressers had used the sprays for more than 6 years. No abnormal X-ray appearances, suggesting the presence of pulmonary granulomatosis (thesaurosis), were reported, despite the fact that the ma- jority of particles in both types of hair sprays had a diameter of less than i/x and were thus capable of being inhaled. In a study of the particle sizes of hair sprays manufactured in the United States, at least 50% of the hair spray par- ticles had a diameter of 35 ,/x or greater (47), which is larger than the size that is capable of penetrating the lungs to a significant extent. Further studies by Larson (47) also attest to the safety of commercial hair sprays. In this study, no differences in midexpiratory flow rate, measured spirometrically, were found between users of hair sprays and nonusers, in a controlled population of female college students. While the controversy over the safety of hair sprays continues, the bulk of scientific evidence at present indicates that earlier con- cerns over their safety is unfounded. ToxiciTY OF HOUSEHOLD AEROSOLS Because of the diverse nature of the products in this category, and the large number of users in all age groups, the toxicity of these products is of major interest to both the consumer and the aerosol industry. Other than the toxicity of the ingredients in a specific preparation, some of the factors contributing to the toxicity of the household aerosols include the pattern produced by aerosol spray (5) and the cooling action of the propellants (12). If the spray pattern of a product is not well controlled, partic]es intended for application in one place may well penetrate into the eye or impact on the skin. The im- paction of particles from these products, because of the relatively high pres- sure exerted at release, may cause aerosol particles, that would otherwise be harmless, to penetrate the surface of the skin or the cornea of the eye, thus