微量有害物質のリスクを指標とした製品のライフ・サイクル・アセスメントに関する研究

Abstract

In the high advanced-technological society, toxic chemicals are build in the consumers' goods, which result in chemicals release into the environment and accumulated potential risk. In order to predict the impacts, the authors construct Life Cycle Ranking System (LCRS) for product life cycle. In this paper, the GaAs which is compound semiconductor and phosphoric ester which is flame retarding chemicals are estimated. LCRS evaluate the magnitude of potential risk relatively by means of multipling the degree of chemicals release in the environment through each product life cycle step and magnitude of chemical hazard per unit exposure. The difficulty of political alternatives in the stages of production, recovery of disused goods, seperation and disposal of toxicant chemicals is evaluted as social cost by ranking. The result of assessment shows that rise of collecting rate brings rise of potential risk of GaAs in the case of recovery system of the electric household durable goods for only the circulation of resources. Separating GaAs from production certainly decreases chemical risk and increases difficult of the stage of production, separation and disposal. It is found that the difference between decrease of the amount of phosphoric ester used in the consumer's good and the amount of release into environment by recycle of plastic makes chemical risk decreased and the extention of kind of reused parts composed in consumer's goods increases difficulty of thestage of production.