Government
Saccharin still eludes carcinogen label However, a National Academy of Sciences subcommittee recommends more studies on its safety for human consumption Saccharin cannot be judged a carcinogen on the basis of current information. However, further studies are needed before any determination of its safety for human consumption can be made. These are in essence the conclusions, reached after two and a half years of study by the National Academy of Sciences subcommittee on nonnutritive sweeteners. The inconclusiveness of the subcommittee's findings, contained in a 74page report released earlier this month, means that there will be no changes in saccharin's status quo for some time. The Food and Drug Administration, which requested the $54,500 study in 1972, says it will take several months to evaluate the report's conclusions and recommendations and to delineate exactly what further tests may be needed. The tests themselves could take several more months, especially if long-term feeding studies are necessary. In the meantime, FDA says that saccharin will continue to be marketed under existing limitations. In 1972 FDA removed saccharin from the Generally Recognized as Safe List and froze uses at then-current levels. It recommended that adults consume no more than 1 gram of the substance per day (15 mg per kg body weight per day). That's equivalent to drinking 10 12-ounce cans of diet soda sweetened with saccharin per day. About 4.2 million lb of saccharin were consumed in the U.S. in 1972. About 70% of it went into soft drinks and the rest into coffee, tea, cereal, fruit, cooking, and baking. The NAS report recommends no changes in current use of saccharin. In fact, the report's recommendations are surprisingly similar to those contained in earlier reports, issued by NAS in 1968 and 1970, on the same subject. The latest subcommittee recommends: • Investigation of the question of transplacental carcinogenesis of saccharin and its impurities. • Investigation of the toxicologic significance of impurities in commercial saccharin preparations.
• Comparative studies of the role of stones and parasites in the bladder in the induction of bladder tumors in laboratory animals. • Study of changes in urine composition at high levels of saccharin intake and of the relation of such changes to the induction of bladder stones or calculi. • Epidemiologic studies relating the incidence of cancer with the long-term consumption of saccharin. In its report the subcommittee says the question of possible association of tumors with saccharin consumption is raised only with respect to bladder tumors found in rats in two studies conducted by FDA and the Wisconsin Alumni Research Foundation. In both studies high dietary levels, 5% and 7.5%, of commercial saccharin, containing large and variable mixtures of impurities, were fed. The subcommittee notes that at least one of these impurities, o-toluenesulfonamide, is a possible bladder carcinogen. The report also says that the role of factors known to cause bladder tumors in rats, such as stones and parasites, was not ruled out in either of the two studies. In five
other feeding studies examined by the subcommittee there was no association between saccharin consumption and development of bladder tumors. Nevertheless, the subcommittee recommends that more feeding studies be made with highly purified saccharin, with the impurities alone, and with an artificial mixture of pure saccharin plus impurities before any conclusions as to saccharin's safety are made. The scarcity of epidemiologic studies dealing specifically with saccharin's effects in man are also of concern to the panel. It notes only one study of 100 diabetics, having a mean intake of 0.88 mg of saccharin per kg of body weight per day with duration of intake varying from one to 30 years. Although no tumors of the genitourinary tract have been seen in the group, the panel says that a larger number of subjects would be necessary to draw inferences as to the lack of bladder cancers. Copies of the Academy Report No. PB-238137/AS are available from National Technical Information Service, 5285 Port Royal Rd., Springfield, Va. 22151. Single copies are $4.75 in printed form and $2.25 in microfiche. D
Patent Office to test open applications The U.S. Patent Office, which has been regarded as moving rather slowly in adopting innovations, in at least one instance is moving much faster than Congress is on patent reform. On Jan. 28 the Patent Office will initiate a trial voluntary program in which the public will be free to examine and protest a limited number of patent applications, including some in the chemical field. The program was prompted by legislation before the Senate in the last Congress making opposition or protest proceedings mandatory in all allowed patent applications. The Senate never got around to acting on patent legislation—which has been pending for some eight or nine years—and the proposal died. But the Patent Office is going ahead with its trial program to get at least some preliminary data on its effectiveness and costs. The Patent Office sees several possible benefits accruing from the program. Its underlying purpose is to get the best prior art and other information relevant to the patentability of an application to the patent examiner's attention. The Patent Office thinks this would be helpful in minimizing the more expensive conventional proce-
dures of litigating the question of a patent's validity after it has been issued. The office also believes that the patents should have a more meaningful presumption of validity (that the pat-
Public search room at Patent Office Jan. 20, 1975C&EN
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