PFAS in food and biota: New EFSA limit and new Eurofins method

The necessity to lower the tolerable daily intake values (TDI) for PFAS has been discussed for years in the light of recent research demonstrating adverse and toxic effects also at very low levels. Moreover, the number of epidemiological studies has increased allowing more direct assessment. In Feb 2020 EFSA (EU food safety authority) published a public consultation on their draft scientific opinion. This has now (17 Sep) been followed by the final opinion from the authority.

Proposed limit values for PFAS

Previous TDI limit values have included PFOS (150 ng/kg BW/day) and PFOA (1500 ng/kg BW/day). The new TWI (tolerable weekly intake) value of 4.4 ng/kg BW/week is instead based on the sum of four PFAS (PFOS, PFOA, PFHxS, PFNA). The decision to substitue daily values with weekly was to reflect the accumulative nature of the substances, and the four PFAS were selected considering their comparable blood levels and expected toxicity. The drastically lowered acceptable intake value is derived from observed immune system effects in animals and humans such as lowered antibody and T-cell responses at vaccination. The intake covers both food and water and the Swe Food Agency (SLV; see link) has already informed after the draft opinion that the current drinking water limits might need to be re-assessed.

Eurofins method development

In 2016/17 Eurofins SE restarted PFAS analysis for water and soil with leading limits of quantification (LOQ) and delivery times (TAT). Eurofins now takes the next step and introduces PFAS determination of various food and biota. Given the new, very low, TWI values there was an obvious quest to improve LOQs. The need for better, more sensitive, analytical methods is also called for in EFSA’s report. After intense development work we have been able to achieve significantly lowered LOQs applying customized methods. The new LOQs are for a number of major PFAS 0.01 µg/kg FW including the four given by EFSA in most cases, and can be offered for a range of biotic/food matrices. This LOQ level is frequently 50-100 times less than previously and additional PFAS can be determined at 0.1 µg/kg FW (PFBA 0.3 µg/kg FW), which also is a major improvement. Calculated measurement uncertainty (k=2) is 30%. When analyzing at these low levels the risk of contamination becomes a potential issue and thus preparation (mixing) of food samples is also to be monitored. Please use sample containers provided by Eurofins.

Analytical packages

The new method covers 20 PFAS and is offered in three packages. Depending on the matrix there are two alternatives. One is for matrices such as fish muscle and fruit/berries while the other is for mussels and fish liver. For the latter LOQ is higher for some compounds due to the more complex matrix. Leaves and wood can be analysed with the muscle/fruit method but LOQs may be raised. The optimal sample weight is 50g FW and the minimal 10g FW. Depending on the matrix, sample preparation such as mixing or milling may be required (additional cost). Standard delivery time (TAT) is 10 working days. Express options will be added later on. Please use the PLW codes in the table at ordering since other packs will be available in parallel. The new PFAS packages can be ordered from 8 Oct 2020. Further information will be available in our online catalogue.

Further information (links):

EFSA news
EFSA Journal, scientific opinion
Swedish Food Agency (SLV)

Contact Eurofins experts!

Questions on PFAS can be answered by Patrick van Hees: tel 010-490 8151, e-mail: patrickvanhees@eurofins.se