PFOS Testing

1. PFOS Introduction

PFOS stands for perfluorooctane sulphonate, an acronym derived from perfluorooctane sulphonate. It consists of a fully fluorinated anion from perfluorinated sulfonic acids. The term "perfluorinated" is often used to describe substances in which all hydrogen atoms in the carbon chain are replaced by fluorine. PFOS has become a representative term for various derivatives of perfluorooctane sulfonic acid and polymers containing these derivatives. When PFOS is detected in the environment, it typically exists in a degraded form. Substances that can decompose into PFOS are referred to as PFOS-related compounds. According to the U.S. Chemical Abstracts Registry, 96 different fluorinated organic compounds can release PFOS into the environment through degradation, and these are classified as PFOS-related substances.

It is reported that PFOS is one of the most persistent organic pollutants. It exhibits both hydrophobic and oleophobic properties and has a wide range of applications. PFOS can be absorbed by organisms through inhalation and ingestion, with the majority binding to plasma proteins in the blood, while the remainder accumulates in the liver and muscle tissues of animals. Animal experiments have shown that a PFOS concentration of 2 milligrams per kilogram of body weight can lead to death.

2. PFOS Applications

PFOS-related chemicals are used in various products, primarily in three application areas:

(1) PFOS-related chemicals used in surface treatment provide stain resistance, oil resistance, and water repellency for personal clothing, home furnishings, and automotive interiors.

(2) PFOS-related chemicals used in paper protection, as part of the pulp molding process, ensure oil and water resistance for paper and cardboard.

(3) PFOS-related chemicals in the category of performance chemicals are widely used in specialized industrial, commercial, and consumer fields. This category includes various PFOS salts that are commercialized as final products.

Historically, PFOS, its salts, and precursors have also been used in other applications, such as carpet and fabric treatments, upholstery, food packaging, mosquito repellents, oil, soil and grease resistance, surfactants in specialized applications like firefighting foam, aviation hydraulic fluids, and mist suppression in metal plating.

3. Items Potentially Containing PFOS in the Electronics Manufacturing Industry

Liquids such as: detergents, cleaning solutions, etching solutions, various treatment agents, insulating oils

Coatings and sprays such as: PC steel plates, powder coatings, pigments, dyes

Inks and printed materials such as: electrodes, resistors

Surface treatment agents and treated surfaces such as: electroplated products, plating materials, anti-reflective materials, protective films

Molded products and materials such as: printed circuit boards, ceramic substrates, resins, sliding materials, gaskets

Solder-related items such as: fluxes, solder pastes

Auxiliary materials for processes such as: greases, release agents, sealing materials, lubricants, adhesives

4. PFOS Hazards:

PFOS and its derivatives enter the body through inhalation, drinking water, and food intake and are difficult to excrete, ultimately accumulating in the blood, liver, kidneys, and brain of humans and other organisms. PFOS exhibits hepatotoxicity, affecting fat metabolism; it reduces sperm count and increases abnormal sperm in experimental animals; it increases peroxidation products in multiple organs, causing oxidative damage and directly or indirectly harming genetic material. PFOS disrupts the balance of excitatory and inhibitory amino acids in the central nervous system, making animals more excitable and irritable; it delays the growth and development of young animals, affecting memory and the establishment of conditioned reflexes; it reduces serum thyroid hormone levels. Extensive research has found that PFOS possesses various toxicities, including genotoxicity, male reproductive toxicity, neurotoxicity, developmental toxicity, and endocrine disruption, making it a systemic multi-organ environmental pollutant.

(1) Persistence

(2) Bioaccumulation

(3) Toxicity

(4) Long-range environmental transport capability

5. Restriction Directives

On December 27, 2006, the European Parliament and the Council jointly issued Directive 2006/122/EC on the restriction of the marketing and use of perfluorooctane sulfonic acid (PFOS). The draft was passed by the European Parliament on October 30, 2006, with 632 votes in favor and 10 against. It was finally approved by the Council on December 12, 2006, and officially published and came into effect on December 27, 2006.

The EU will strictly restrict the use of PFOS. The European Parliament collectively voted on the final amendment to the EU Dangerous Substances Directive (76/769/EEC) before it was incorporated into the new Chemicals Regulation (REACH). Member states will have 18 months to transpose the directive into national law (i.e., by June 27, 2008). In December 2002, at the 34th Joint Meeting of the Chemicals Committee of the OECD, PFOS was defined as a substance that persists in the environment, is bioaccumulative, and harmful to humans. The REACH Regulation designates PFOS as a key chemical requiring prior authorization for use due to its status as a well-known persistent organic pollutant.

6. Limit Requirements

Directive 2006/122/EC stipulates that preparations containing PFOS as a component must not be sold if the concentration or mass is equal to or exceeds 0.005%. For textiles or other coated materials, sales are prohibited if the amount of PFOS in the coating material is equal to or exceeds 1 μg/m2. If PFOS is used in semi-finished products at a concentration or mass equal to or exceeding 0.1%, the semi-finished products and components are also banned from sale. The scope of the restriction includes all products to which PFOS has been intentionally added, including specific components and surface coatings, such as textiles. However, the restriction applies only to new products; products already in use or on the second-hand market are not restricted.

7. Exemptions

(1) Photoresists or anti-reflective coatings for photolithographic processes;

(2) Photographic coatings applied to films, papers, or printing plates;

(3) Anti-misting agents for non-decorative hexavalent chromium electroplating or wetting agents in controlled electroplating systems;

(4) Hydraulic fluids.