Analysis of per- and polyfluoroalkyl substances (PFASs) in water, food and food packaging
PFASs are generally hydrophobic and lipophobic fluorinated compounds, widely used in household and industrial applications:
- stain- and water-resistant coatings for fabrics and carpets
- oil-resistant coatings for paper products approved for food contact (cookie sheets, food paper, fast food packaging, popcorn bags, etc.)
- fire-fighting foams, mining and oil well surfactants, floor polishes and insecticide formulations
Perfluorooctanesulfonic acid (PFOS) and Perfluorooctanoic acid (PFOA) are the best known PFASs and both belong to (per)fluorinated organic surfactants.
These compounds are endocrine disruptors, and there is ever more evidence that they are dangerous to health. For example, PFOA belongs to 2B class according to IARC, meaning that it is undoubtedly carcinogenic to animals and possibly to humans (scientific research on humans is still underway).
The PFAS issue has come to the fore in recent years, because not only are PFASs widespread in the environment, they are also highly persistent since they do not break down when exposed to air, water or sunlight.
Because of chemical stability they can run long distances through the air, thus contaminating sites far away from the production plants and affecting living organisms where they may bioaccumulate (EPA, United States Environmental Protection Agency).
PFASs have especially affected the aquatic environment. In 2013, a PFAS alert was issued in Italy for water contaminated by discharges from industrial plants producing perfluoroalkyl compounds. Attention on the topic is still very high and thorough research has been carried out to assess the risk to human health.
PFAS-related environmental pollution is the main cause of food contamination, which is in turn the main vehicle for human exposure to PFASs.
Major contributors to dietary exposure are:
- fish and other seafood (mainly from fresh water)
- fruit and fruit products (PFOS occurrence)
- meat and meat products (edible offal and liver in particular)
Food may also be contaminated by PFAS migration from food packaging and cookware. Studies have confirmed that PFASs are present in food packaging, especially in packaging used in fast foods that requires oil-resistant coatings.
PFAS contamination in water, food and food packaging causes serious concern among consumers, partly because scientific studies checking for possible adverse effects on health have not been completed yet.
Even though studies are still underway and there is no harmonized legislation, public awareness of PFAS risks have increased worldwide:
- PFOS is included in the list of “persistent organic pollutants” (POP)
- PFOA and its ammonium salt content are among “the substances of very high concern” (SVHC)
- EFSA has published different scientific opinions on per and polyfluoroalkyl substances and recommended to monitor their presence and more thoroughly investigate into the effects of on humans.
Mérieux NutriSciences, a key partner for companies, has developed a LC/ESI-MS/MS method to analyze PFASs in the matrices which may be sources of contamination:
- Food Packaging
Moreover, it continuously works to expand the number of PFASs analyzed, to provide the customers with a comprehensive, accurate and reliable service.
Mérieux NutriSciences analyzes PFASs contained in water by using official 2009 EPA method 537.
At present, there is no harmonized EU legislation on PFASs in water. As a consequence, every Country has adopted its own reference limits set by guide lines or national law. Mérieux NutriSciences performs analyses in compliance with local regulations.
Food and food packaging
As concerns food and food packaging, Mérieux NutriSciences uses specific isotopically-labelled standards for each PFAS analyzed and adopts quantification limits compliant with guide lines and national law.
In food, there is no European harmonized legislation for PFASs, nor official concentration limits. However, 2010 European Recommendation (2010/161/EU) required Member States to provide data for PFASs in food:
- with chromatographic methods
- with LoQ in food: 1 µg/Kg
to which Mérieux NutriSciences is compliant.
Official migration limits have not been established for PFASs contained in food contact material either. EU Framework Regulation 1935/2004 is the only legal reference; as regards limits, art. 3 establishes that packaging materials and articles shall be manufacture so that “they do not transfer their constituents to food in quantities which could endanger human health”. Consequently, monitoring the presence of PFASs in food packaging is pivotal.