The Japanese government recently released a draft policy concerning the treatment of perfluorooctane sulphonic acid (PFOS) and perfluorooctanoic acid (PFOA) in tap water, proposing to reclassify these two chemicals for stricter monitoring under the Water Supply Act. This initiative is in response to global concerns about persistent organic pollutants and aims to enhance the protection of public drinking water safety.
According to the draft, all water suppliers will be required to regularly test for PFOS and PFOA concentrations in water starting from April 2026. Additionally, the policy suggests testing for other PFAS-related chemicals, including Gen X and Perfluorobutanesulfonic acid (PFBS), to comprehensively assess water quality safety.
This policy proposal is based on several years of water sample testing data, which showed that concentrations of PFOS and PFOA in some areas exceeded the government's temporary target of 50 nanograms per liter (ng/l). Notably, from 2020 to 2023, over 10% of testing sites reported PFOS and PFOA levels above this target.
The draft suggests that if test results over three consecutive years consistently show PFOS and PFOA concentrations below one-fifth of the target value, water suppliers may extend the testing frequency from once every three months to every six months or annually. However, if test results indicate that these chemical concentrations reach or exceed one-fifth of the target value (10 ng/l), the testing frequency must be reverted to once every three months.
Furthermore, suppliers who have not yet conducted water quality tests must do so before the implementation of the law. Those exceeding the standards must immediately improve their facilities and advise consumers to avoid drinking tap water until the issue is resolved. The draft also proposes setting a limit of 500 ng/l for "total PFAS" for an additional 30 PFAS chemicals, to reduce exposure risks to the population.
Once approved, this policy draft will be submitted to the Food Safety Commission as stipulated by the Basic Act on Food Safety, to promote the implementation and regulation of the policy.
