noun
priority substance; substance requiring priority action
Technical term used in environmental regulation and chemical management to designate substances that need urgent assessment or control.
環境省は優先取組物質のリストを公表した。
The Ministry of the Environment published a list of priority substances.
この化学物質は優先取組物質に指定されている。
This chemical substance is designated as a priority substance.
Compound of 優先 (priority), 取組 (effort, initiative), and 物質 (substance). The term likely originated in Japanese environmental policy as a translation of 'priority substance'.