FDA releases new PFAS testing method, results from sample testing

The U.S. Food and Drug Administration (FDA) is making available a scientifically validated method for testing for 16 types of per- and polyfluoroalkyl substances (PFAS) in a variety of food groups. The FDA continues to lead national efforts to estimate overall dietary exposure to PFAS and this is an important step in furthering collaboration between the FDA and states in assessing the safety of human and animal food from specific areas potentially affected by environmental contamination.

The FDA has also shared final results from its limited food sample testing in three surveys released in June, based on the application of the validated method, which established a method detection limit (MDL) for each food group tested. These three surveys included a general sampling of foods collected as part of FDA’s Total Diet Study (TDS), as well as a survey of produce and a survey of dairy products, both from specific areas affected by PFAS environmental contamination.

The final results show reductions in the number of positive samples compared to the FDA’s initial results. These reductions stem in part from the application of the newly established MDL, the level at which PFAS can be reliably measured over repeated testing. In the initial testing, the agency reported very low levels of certain PFAS chemicals in certain foods and as it validated the method and finalized the results, some of those concentrations are below the MDL and therefore are no longer reported as having detectable levels of PFAS.

Total Diet Study: The final results confirm and strengthen the FDA’s initial finding that the specific PFAS chemicals it tested for were not detected in most of the food samples that had been collected in 2017 as part the FDA’s Total Diet Study. TDS is a sample of foods representative of the broad range of foods that the average consumer might eat and that are not associated with known environmental contamination.

Initially, the FDA reported that certain PFAS chemicals were detected (although in many cases at very low levels) in 14 out of 91 samples. The new results show detectable levels of certain PFAS chemicals in only two of 91 samples.

In addition, the final results include updated data for a single chocolate cake sample and a single chocolate milk sample tested as part of the sampling of foods from the TDS. With additional research, the FDA was able to determine that chocolate appears to produce false positives in the method, affecting results for both foods. Though initially the chocolate cake sample showed a high value for one type of PFAS, the agency has determined that there is no detectable PFAS in either chocolate-containing food. To prevent similar types of false positives, the analytical method now includes an additional step in the procedures to confirm measurements are accurate.

Produce Survey: For the survey of 20 produce samples from a specific geographic area affected by environmental PFAS contamination, the number of samples with a detectable level of at least one PFAS has gone down from 19 to 16 samples. The concentrations of the PFAS chemicals found in the 16 produce samples were so low that the FDA affirms its determination that these substances, at the levels found in the samples, are not a human health concern.

Dairy Survey: For the survey of dairy samples analyzed from two farms with PFAS contamination of groundwater, the final results indicate that the milk samples that were previously determined to be a health concern still had high levels of at least one PFAS, with its conclusions unchanged. All milk samples that were determined to be a potential human health concern were discarded and did not enter the food supply.

The FDA is currently analyzing additional TDS samples to increase its baseline knowledge of PFAS occurrence in foods and expects to release those results later this year.

Press release