Thaum Lub Kaum Ib Hlis 2, Lub Chaw Haujlwm Saib Xyuas Kev Noj Qab Haus Huv thiab Ib Cheeb Tsam tau tshaj tawm "Daim Ntawv Ceeb Toom Txog Kev Luam Ntawv thiab Tshaj Tawm "Cov Ntawv Teev Npe ntawm Kev Tiv Thaiv Ib puag ncig (2021 Edition)" (Environmental Office Comprehensive Letter [2021] No. 495).Nyob rau hauv "Cov Ntawv Qhia Txog Kev Tiv Thaiv Ib Cheeb Tsam (2021 Edition)," xiav charcoal / coke / pitch (tshwj tsis yog rau tar distillation siv atmospheric, nqus los yog atmospheric thiab nqus cov txheej txheem txuas ntxiv distillation) hauv coking (kev lag luam code 2520) hauv cov tsoos hlau thiab hlau. Kev lag luam, steel Rolled (kev lag luam code 3130) chromium-plated steel ntawv (tshwj tsis yog trivalent chromium electroplating txheej txheem) / xim-coated phaj (tshwj tsis yog chromium-dawb xim txheej txheej txheem) cov khoom, ferroalloy smelting (kev lag luam code 3150) hlau manganese / hlau silicon / Cov khoom siv hlau chromium, Cov khoom lag luam ua los ntawm cov txheej txheem kub-dip galvanizing hauv cov hlau (kev lag luam code 3208) yog cov khoom "muaj kuab heev";hlau-ua (kev lag luam code 3210) thiab steel-making (kev lag luam code 3220) cov khoom tsis raug cais raws li "muaj kuab paug heev" thiab "siab ib puag ncig txaus ntshai" "cov khoom.