Perfluoroalkylated substances (PFAS)

Known as: Perfluorooctane sulfonate (PFOS), (PFOA) and its salts, Perfluorooctanesulfonic acid and its salts, Perfluorooctane sulfonyl fluoride and its salts (PFOSF)

What are they? The perfluoroalkylated substances are organic chemicals with tensioactive properties classified as persistent organic pollutants (POP) and submitted to specific production and use restrictions according to the Stockholm Convention of 2009 annex B.

Use (purpose): PFAS are frequently used in industrial and domestic applications, such as:

• Stain repellent for fabric and carpets,
• Water repellent impregnation agents for upholstery, fabric and leather 
• Oil resistant agent for paper and cardboard packaging used for food items,
• Fire-fighting foams,
• Tensioactive substances for mining and oil extraction,
• Wooden floor wax,
• Insecticides and pesticides,
• Rubber and plastic compound,
• Part of the shale gas and oil extraction fluids,
• Household and industrial detergents, 
• Metal plating,
• Hydraulic fluids additive,
• Semiconductors, electrical and electronic devices in the colour printers,
• Medical devices,
• Photo mask for Liquid Crystals Displays, anti-reflex and photo-resistant treatments
• Photo industry.

It is not degraded by light, water and biological agents, it is not degraded in environmental conditions. Its elimination requires high temperature incineration. It bioaccumulates in the food chain.

Present status: included in Annex B part 3 of the Stockholm Convention of 2009 with specific derogations for production and use for the above-mentioned purposes with a production decrease schedule and replacement with less polluting technologies.

In Romania: produced and used for a large number of applications according to the above.

Health effects: the half-life in the human organism is of 5.4 years (EFSA, 2008). The chemicals are toxic, carcinogenic and deadly in certain doses. 

Target organs: blood, liver, thyroid, cholinergic effect, it crosses the blood-brain barrier.
In the case of chronic exposure, symptoms are accompanied by changes of the blood parameters, clotting disorders and peripheral irrigation disorders, liver failure, menstrual disorders, adrenal glands disorders, hypothyroidism, endocrine disorders (estradiol) especially in men; thyroid cancer (carcinoma, adenoma, fibroadenoma), breast cancer (carcinoma, adenoma, fibroadenoma), liver tumours, bladder cancer, cancer of the male reproductive organs (prostate and testis). In case of in utero exposure to PFAS, the substances were proven toxic for the embryo development: delayed ossification (sternum and phalanges), cleft palate, reduced birth weight, diffuse oedema or hydrocele, heart defects (ventricular septal defects or enlarged right atrium).

Exposure limits, lethal dose: if inhaled, LD50 for rat is 250 mg/kg body weight. Toxicity studies showed the substances to be lethal in chronic food intake of only a few mg/kg body weight/day.

Contamination sources: 

Occupational: employees of various industrial sectors (electrical and electronic devices, photo shops, extraction industry, chemical industry, industrial fabrics, furniture, automobile industry, textile industry, detergents, etc.) including large industrial laundry facilities employees etc.
Air: household dust and indoor air (offices and homes).
Food: fish from contaminated water bodies, meat and processed meat.

Userful links:

• PFOS, PFAS (EN)
• POP - The National Environmental Protection Agency