A ranar 2 ga Nuwamba, Babban Ofishin Ma'aikatar Ilimin Halitta da Muhalli ya ba da "Sanarwa akan Bugawa da Rarraba" Cikakken Jerin Kare Muhalli (2021 Edition)" (Babban Wasika na Ofishin Muhalli [2021] No. 495).A cikin "Comprehensive List of Environmental Protection (2021 Edition)", blue gawayi/coke/pitch (sai dai tarkon kwalta ta amfani da yanayi, vacuum ko amospheric da injin ci gaba da distillation tafiyar matakai) a cikin coking (lambar masana'antu 2520) a cikin ƙarfe na gargajiya da ƙarfe masana'antu, Karfe Rolled (ma'aikata code 3130) chromium-plated karfe takardar (sai trivalent chromium electroplating tsari) / launi mai rufi farantin (sai dai chromium-free launi shafi tsari) kayayyakin, ferroalloy smelting (masana'antu code 3150) karfe manganese / karfe silicon / karfe chromium kayayyakin , Jerin samfurori da aka samar ta hanyar tsarin galvanizing mai zafi a cikin karfe (lambar masana'antu 3208) sune samfurori "ƙazanta sosai";baƙin ƙarfe-yin (lambar masana'antu 3210) da ƙarfe-yin (lambar masana'antu 3220) kayayyakin ba a rarraba su a matsayin "samfurin ƙazanta" da "haɗarin muhalli" "samfurin.