• What is PFAS?

Per- and polyfluoroalkyl substances (PFAS) are a group of synthetic chemicals. According to the definition by the Organisation for Economic Co-operation and Development (OECD), PFAS are compounds that contain at least one fully fluorinated carbon atom (i.e., a carbon atom bonded to fluorine atoms but not to hydrogen, chlorine, bromine, or iodine). To date, more than 12,000 types of PFAS have been identified.

PFAS are man-made compounds known for their outstanding resistance to heat, acids, bases, corrosion, and stains, making them widely used in both consumer and industrial products. Due to the high stability of certain PFAS structures, they are extremely resistant to degradation in the natural environment and are therefore referred to as "Forever Chemicals."

However, PFAS represent a broad class of substances with varying properties, uses, and potential risks. Not all PFAS exhibit the same level of toxicity or environmental impact.

• This diagram categorizes PFAS into perfluorinated alkyl acids (including PFEAAs), polyfluoroalkyl acids (including PolyFEAAs), precursors to PFAAs, and other miscellaneous PFAS.
• Examples given for sub-types include PFCAs, PFSAs, PFECAs, PFPAs, with highlight on specific chemical groups and their relationships.
• The taxonomy supports regulatory, analytical, and scientific understanding of PFAS varieties and their environmental relevance.

Useful for science education, chemical safety training, and environmental chemistry lessons.

Reference: OECD (2021). Reconciling Terminology of the Universe of Per- and Polyfluoroalkyl Substances: Recommendations and Practical Guidance. Organisation for Economic Co-operation and Development.

• Development of PFAS

In the 1940s, DuPont scientist Roy J. Plunkett synthesized a PFAS compound known as polytetrafluoroethylene (PTFE). Due to its unique hydrophobic and oleophobic properties, DuPont quickly recognized its commercial potential and marketed it widely under the trade name Teflon, applying it to various industrial and consumer products.

As demand for such applications grew, numerous PFAS derivatives were subsequently developed over the following decades. These include perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorohexane sulfonic acid (PFHxS), and more recently, hexafluoropropylene oxide-dimer acid (HFPO-DA, also known as GenX).

The uses of PFAS have since expanded significantly, encompassing a wide range of everyday and industrial products such as non-stick cookware coatings, water-repellent textiles, food packaging, cosmetics, electronics manufacturing processes, and firefighting foams.

• This illustration shows how chemical products in kitchens, cleaning supplies, clothing, food packaging, protective equipment, transport, and household items have proliferated over decades.
• Recent decades emphasize growing awareness of safety and environmental hazards linked to chemicals in common items.
• The growth area highlights diversification of chemical use and the need for more responsible product development and disposal.

Useful for educational purposes to visualize the role and evolution of chemicals in daily life and the need for green chemistry practices.

Reference: Chemical Insights – PFAS Overview

• Common Types of PFAS

Per- and polyfluoroalkyl substances (PFAS) encompass a wide range of chemical structures and classes, depending on the definition applied. They are widely used in both consumer and industrial products, including food packaging, paints, cleaning agents, non-stick coatings, outdoor textiles, and firefighting foams.

In recent years, the Stockholm Convention has reviewed and designated several PFAS as persistent organic pollutants (POPs). Substances currently regulated under the Convention include: Perfluorooctane sulfonic acid (PFOS), Perfluorooctanoic acid (PFOA), Perfluorohexane sulfonic acid (PFHxS), Long-chain perfluorocarboxylic acids (LC-PFCAs).

In addition to these substances listed under the Convention, other commonly found PFAS—often with carbon chain lengths between 4 and 8—include: Perfluorobutanoic acid (PFBA), Perfluorohexanoic acid (PFHxA), Hexafluoropropylene oxide-dimer acid (HFPO-DA, also known as GenX), Perfluorobutanesulfonic acid (PFBS).

Furthermore, several precursor substances, such as fluorotelomer alcohols (FTOHs), are also frequently used in various applications and can degrade into terminal PFAS in the environment.

• This diagram lists major perfluoroalkyl carboxylic acids (e.g., PFOA, PFBA, PFHxA, HFPO-DA), sulfonic acids (e.g., PFOS, PFHxS, PFBS), and acid precursors (fluorotelomer alcohols, FTOHs) under POPs regulations.
• Chemical structures are provided for each regulated substance, which are significant due to their persistence and toxicity in the environment.
• This overview highlights which PFAS are globally regulated and why monitoring and replacement efforts are critical in green chemistry.

Useful for lessons on chemical safety, regulation, green chemistry, and environmental science.

• National Action Plan for the Management of Per- and Polyfluoroalkyl Substances (PFAS)

To prevent environmental harm caused by persistent organic pollutants (POPs), the United Nations established the Stockholm Convention on Persistent Organic Pollutants (hereinafter referred to as "the Convention"). Although Taiwan is not a Party to the Convention, to demonstrate its commitment to POPs control and proactive measures, the Executive Yuan approved the National Implementation Plan for the Stockholm Convention on POPs on July 3, 2008 (Year 97 in the ROC calendar). This plan serves as a concrete basis for inter-ministerial actions related to POPs management. Among the regulated substances under the Convention, per- and polyfluoroalkyl substances (PFAS) are one of the key categories. Relevant government agencies in Taiwan have already referred to the Convention in formulating PFAS-related management measures.

To align with the enhanced PFAS management practices of advanced countries such as the United States, European Union member states, and Japan, Taiwan’s Ministry of Environment, in collaboration with relevant ministries, formulated the Action Plan for the Management of Per- and Polyfluoroalkyl Substances (PFAS) on July 1, 2024 (Year 113 in the ROC calendar). The Plan was formally approved by the Executive Yuan on October 22, 2024. It sets out comprehensive objectives encompassing source control, distribution investigation, international alignment, industrial innovation, and risk communication, thereby enhancing PFAS management through strengthened interagency collaboration and resource integration, while keeping pace with global regulatory trends.

The PFAS Management Action Plan is formulated with reference to relevant provisions of the Stockholm Convention and other international chemical management frameworks. It is grounded in human, biological, and environmental monitoring, as well as risk assessment, and sets forth the following five key objectives:

1. Source Control: Implement upstream controls to reduce or eliminate the use of PFAS.
2. Distribution Monitoring: Monitor and assess the presence of PFAS in the environment, biological media, food, and consumer products.
3. International Alignment: Align with global regulatory trends and engage in international cooperation and exchanges.
4. Industrial Innovation: Encourage industries to voluntarily adopt measures exceeding regulatory requirements or to reduce PFAS use.
5. Risk Communication: Strengthen inter-ministerial collaboration, enhance public education, and improve risk communication.

Download Attachment (PDF)

• The diagram identifies specific ministries handling chemicals regulation, product control, health, import-export, firefighting foam, occupational safety, environment, food/equipment inspection, and environmental education.
• Each colored segment links responsibilities (e.g., food safety, biomonitoring, project review) with a ministry, supporting cross-agency collaboration for chemical management.
• This provides a clear view of the government’s multi-ministry approach to environmental and chemical safety policy.

Ideal for education, public awareness, policy review, and understanding governmental task forces in chemical/environmental management.

Members and Responsibilities of the Inter-Ministerial Task Force under the National Action Plan for the Management of PFAS.