今年化工系统开始对生产中化学物质进行登记管理,由于化学毒物的种类繁多,毒性数据复杂,涉及的面比较广,所以只是试点,逐步推广。今将实施化工毒物登记制度过程中遇到的若干问题逐一认识、学习,现将化学物质的毒性分级提出来讨论。早在四十年代,有人就将毒物的致死量与毒性之间关系阐明了,所谓致死量,主要是用LD_(50)半致死量为客观指标,通过大鼠口服,吸入,家兔经皮等动物试验,估测毒物对人的可能致死量、以此将化学毒物划分为剧毒、高毒、中毒、低毒、实际上无毒、无毒等六级。近五十年的发展过程,基本上逆循这一分级原则,但是趋于更科学合理,更加 This year, the chemical industry started to register and manage chemical substances in production. Due to the wide range of chemical poisons, complicated toxicity data and relatively wide coverage, it is only a pilot project and gradually promoted. The implementation of the chemical poisoning registration system in the process of some of the problems encountered one by one understanding, learning, now toxic substances in the classification presented to discuss. As early as the forties, some people explained the relationship between the lethal dose and the toxicity of poison. The so-called lethal dose mainly used the LD 50 half-dead dose as an objective indicator. It was orally administered to rats and inhaled through the skin of rabbits Such as animal experiments to assess the possible lethal dose of poison on humans, in order to be divided into toxic chemicals poisonous, highly toxic, poisoning, low toxicity, in fact non-toxic, non-toxic and other six. The development process in the past 50 years basically reversed this grading principle but tended to be more scientific and rational and even more