214 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS structural and histological differences, the problems of transport across the skin and metabolism within the skin, and the unique differences of the human in response to irritation and sensitization. These differences will continue to plague us in our efforts to extrapolate animal skin test data to the most likely effects in man. We are all familiar with words descriptive of our economy, such as "depression," "recession," "gold fever" and "inflation." Inflation, however, is a truism that will continue to stalk us, profoundly accelerating the cost of our safety testing, particularly when it relates to human panelists. Gasoline shortages and prices have created a very real problem involving the transportation costs of panelists getting to and from a testing facility. This suggests that the testing laboratory which is located within a convenient and economical mass-transportation system, or one which is located near a large population of young people, will grow and survive the torments of inflation. In the future, consumer groups and regulatory agencies will continue to impose greater responsibilities on manufacturers of cosmetics, toiletries, and topical drugs to assure the safety of newly marketed products. The end results for the manufacturer will be more and more testing, with very specific protocols for meaningful studies, as well as greater expenditures of time and monies. The domino effect, culminating in a higher cost of final product to the consumer, can only fan the fires of inflation. HUMAN SAFETY TESTS THAT WILL PERSEVERE SKIN IRRITATION During the past decade, the twenty-one-day cumulative irritancy test has been used very successfully for assessing and ranking the mildly irritating potential of new products (2,3). It will continue to be used. Low-irritancy and high-irritancy controls-- products that have been found repeatedly to give low and high irritation scores, respectively--should always be included in this test. It is also important that these controls be your own products, whose formulations are known. Admittedly, patches can shift or fold on panelists' backs, or a panel can be comprised of one or two individuals with jittery skin, akin to those subjects with twitchy lungs or hyper-irritable airways so conducive to bronchospasm, or high temperature and humidity can dilute the test product under the occlusive patch or provoke an annoying and confusing tape dermatitis. Nevertheless, reliable testing facilities, with well-trained personnel augmented by careful and experienced monitors, can make the twenty- one-day cumulative irritancy test a useful and reproducible procedure. There are researchers and dermatologists, however, that regard the patch test, wherein a product is presented to the skin under a dressing, as an archaic procedure, deserving a decent burial. The Duhring Chamber-Scarification Test has received notoriety as a means of circumventing many of the disadvantages of patch testing (4). Certainly, this type of test is capable of detecting subtle differences in irritation potential of toilet soaps (5). Unfortunately, the procedure is profoundly influenced by meteorological conditions, and testing, at least in the Northeast, is best performed only in the winter months. Immediate and temporary burning or stinging, purely subjective responses without the subsequent development of redness, scaling or edema, can create a perplexing and annoying problem. This is particularly true if you happen to be the individual charged

SAFETY TESTING IN THE EIGHTIES 215 with the responsibility of safety testing your company's new products, as well as the official correspondent to consumer complainants. Kligman's Facial Sting Test (6), conducted in an environmental chamber with carefully preselected facial stingers, or an exaggerated usage test, can be helpful in discovering which new facial products may have a potential for eliciting temporary burning or stinging. Possibly special panels of subjects, who have active atopic dermatitis, or xerotic skin, or seborrheic dermatitis, should be used with this type of problem. CONTACT SENSITIZATION Over the years, the human tests for predicting contact sensitization potential have undergone significant evolution. Our testing has progressed from the Schwartz-Peck Test (7), with a single induction patch followed by a challenge application 10 to 14 days later, to multiple induction applications, also followed by a subsequent challenge in 10 to 21 days (Draize-Shelanski Repeat Insult Procedure) (8,9). The sample sizes for this latter test have ranged from 50 to 200 subjects. Proponents of this test procedure find solace in increasing the panel size in an effort to improve the statistical inference of the test results and their relationship to the population-at-large. One satisfactorily completed sensitization test of this type, however, even if it involves 200 panelists, cannot be equated to the real world, where millions of consumers may be exposed to a specific product. Moreover, patch test conditions are vastly different from normal use conditions. The Maximization Test (10,11) is particularly useful for evaluating the sensitization potential of certain products, particularly colognes and perfumes, which characteristi- cally are simple formulations with relatively high fragrance loads and containing few other ingredients. If the original test results suggest that the product may be a sensitizer, the testing should always be repeated with new panelists. It must he understood at the outset that the Maximization Test does not directly assess the safety of a product in actual use--except when the results of testing are negative. The Maximization Test, conducted and interpreted properly, is here to stay for the 1980's. Of course, there are those who may have moral and ethical reservations about the Maximization Test, and the possibility of inducing allergic contact sensitization for an indefinite period of time. If sensitization is produced, it does not persist for a full lifetime. It wanes with time--a cardinal feature of cell-mediated, delayed hypersensitiv- ity. Secondly, it does not necessarily follow that induction of contact sensitization, via the Maximization Test, will mean that the positively reacting panelist will become a positively reacting consumer. The customary usage of most cosmetic products is vastly different than this particular testing procedure, where optimal, artificial conditions have set the stage for enhanced penetration. A few caveats should be mentioned about the Maximization Test. The total fragranc• load in any group of four test samples should not exceed a concentration of 20-25%. Fragrance oils are complex formulations. Therefore, there is always the possibility of common ingredients--at significant levels--in different fragrances. The spillover effect (12), or phenomenon coined para-allergy (11), where reactions become intensified as a result of strong allergic patch test reactions elsewhere, should also be recognized. This problem, understandably, calls for retesting with different panelists and a different group of test products.