Japan's Environment Ministry has called on local governments to properly handle activated charcoal used to absorb PFAS chemicals.



The move follows a conclusion by an external expert committee looking into the origin of highly concentrated PFAS detected at a water purification plant in Okayama Prefecture, western Japan, in 2023.



PFAS are organic fluorine compounds, some considered potentially harmful. Activated charcoal is often used to remove them from water.



The experts say it is reasonable to think that used charcoal long left outdoors in an upriver area is the source of the detected chemicals.



The ministry on Wednesday notified prefectures and major cities. It requires proper handling of activated charcoal used to treat water with PFAS levels exceeding the government-designated provisional target.



The notification says absorbed PFAS may be released into the environment if used charcoal is left outdoors for a long time. It requires local authorities to store such charcoal indoors if it is kept for long periods, and to regularly check storage conditions.



It also requires businesses to inform waste processing firms about PFAS inclusion when they dispose of used charcoal. To fully degrade PFAS, the ministry requires processing firms to burn such charcoal at high temperatures in accordance with guidelines set by the ministry.