In this study, toxicity data were first collected for 184 chemicals from reliable information sources. After a validity check and analysis of these data, reference concentrations (RfC) were determined. The toxicity-weighted release amount (TWR) was then calculated for each chemical by dividing the release amounts by the RfC. Three types of TWR were derived, namely TWR(atm) for human health protection in the atmosphere, TWR(wat) for human health protection in water, and TWR(aq) for aquatic life protection. Thus, TWR could be proposed as a new index for environmental risk management considering both toxicity and release amount. Based on the TWR values, chemicals were ranked according to their potential risk upon release. The ranking results revealed that acrolein, formaldehyde, 1,3-butadiene, and arsenic are among the substances with the greatest risk to human health protection in the atmosphere; acrylonitrile, hydrazine, and pyridine are among those detrimental to human health protection in water; and polyoxyethylene alkyl ether (POAE), n-alkylbenzene sulfonic acid (LAS), and N,N-dimethyldodecylamine N-oxide are those identified as posing a risk to aquatic life protection. Moreover, for higher TWR chemicals, the contribution of each release source has been analyzed and discussed. For example, POAE and LAS are released mainly from households, and therefore efforts to reduce their concentration in the environment should focus on the sewage system. Formaldehyde and 1,3-butadiene are mainly emitted from mobile sources and, therefore, traffic should be evaluated as an important release source of toxic chemicals besides many stationary sources. Acrylonitrile and arsenic are released mainly by a few specific industries, placing the emphasis on the need for responsible care by the individual companies involved.