動作分析手法を取り入れた給食調理の二次汚染予防に関する検討

摘要

食中毒原因を調べた報告によれば，食中毒事例の半数以上が二次汚染に起因するといわれるほど，食品衛生管理において二次汚染は大きな問題になっている。二次汚染の根本的な予防を考えると，最終的にはヒトがかかわる調理作業の一つ一つを精査し，どこで二次汚染が起こるのか，あるいは起こり易いのかの実態を明らかにした上で対策を立てる必要性に突き当たる。%Secondary contamination is said to cause more than a half of food poisoning cases and a big problem in food hygiene management. Basic prevention of secondary contamination requires measures to be decided after closely examining each cooking step involving humans and finding out where secondary contamination occurs or how secondary contamination could readily occurs. Hence, we incorporated viewpoints of food hygiene to modify a behavioral analysis called Therblig analysis, which is used in the field of industrial production. We used the modified analysis to perform a behavioral analysis of cooking steps and actions in school lunch preparation in order to find where secondary contamination is apt to occur. In addition, we examined the whole cooking procedure involving food materials, hands and fingers, and machinery and equipments.rnAs a result, we found the followings:rn(1) Secondary contamination was likely to occur in steps taken in sub-hygienic areas of a non-contaminated zone. In other words, considerably contaminated food materials might be handled in a sub-hygienic area, which belongs to a non-contaminated zone. Therefore, it is necessary to recognize that the designation of a work area does not match the contamination level of food materials used in the work area.rn(2) Hands and fingers handling fresh food materials in a sub-hygienic area inevitably touch equipments without being washed. Such actions need to be carefully watched from the viewpoints of the prevention of secondary contamination. Examples of such actions include touching faucets and levers to adjust water flow of tap water, touching knobs to adjust the fire power of a gas range during heating for cooking, touching switch panels of various cooking equipments, and touching the door knob of a refrigerator to take food materials out.rnConsidering the above, the following measures are important for a kitchen and need to be implemented urgently: the preparation of a manual for cleaning the contact points mentioned in (2) to make the practice customary and thorough preparation in advance for efforts to decrease the frequency of touching knobs of a storage chamber. The behavioral analysis sheet devised this time makes it possible to find at a glance how levels of contamination change and which parts of hands and fingers touch equipments. We believe that further improvement of the sheet will lead to its use not only as a tool for hygiene management but also as a tool for hygiene education.