Taiwan Strengthens Drinking Water Safety with New PFAS and Emerging Contaminant Guidelines

On 9 September 2025, Taiwan’s Ministry of Environment (MEO) announced that nationwide drinking water tests for PFAS (per- and polyfluoroalkyl substances) are in compliance with national limits. At the same time, the ministry issued guideline values for six additional emerging contaminants to strengthen water quality management. The new substances include germanium, thallium, boron, microcystin-LR, DEHP (a plasticizer), and the total sum of 20 PFAS compounds.

Previous PFAS Regulation Efforts

In November 2024, Taiwan revised its drinking water quality standards to include PFAS limits, becoming one of the first countries in Asia to adopt such measures. Under the updated standards, PFOA + PFOS must not exceed 50 ng/L and PFOS + PFHxS must not exceed 70 ng/L. Since the start of 2025, testing has been conducted at 130 large-scale water treatment plants, covering 91% of the national water supply, with all results meeting the standards.

Test Results Confirm Compliance Nationwide

Analysis shows that:

• For PFOA + PFOS, over 96% of samples were either undetected or at less than one quarter of the standard. Only isolated cases in central Taiwan reaching about half the limit.
• For PFOS + PFHxS, 98% of samples fell below a quarter of the limit, confirming that PFAS levels in drinking water are generally safe nationwide.
• Observed patters also show surface water sources tending to have lower PFAS concentration than groundwater, and that the northern, southern, and eastern regions exhibit particularly low concentrations.

Rolling Updates in Line with International Trends

According to the Ministry, guideline values for emerging contaminants will be continuously updated, following expert consultation and international trends such as the EU Drinking Water Directive.

The newly introduced guideline for ‘total PFAS (20 compounds)’ is 100 ng/L. Local environmental agencies and water utilities have been instructed to integrate these new values into their monitoring regimes.

The Ministry also noted that future updates will follow international developments, with the National Environmental Research Institute enhancing testing methods and capacity, including total organofluorine screening techniques, to ensure Taiwan’s drinking water remains safe and aligned with global standards.