What is PFAS?
Per- and polyfluoroalkyl substances (PFAS) are a general term applied to thousands of chemicals manufactured since the 1940’s and can be found in food packaging (microwave popcorn bags, pizza boxes, etc.), stain and water-resistant fabrics, non-stick products, fire-fighting foams, and many other consumer and manufacturing products. They have been widely used for many decades because of their unique surfactant and oil/water repelling qualities. When sampling for PFAS there are several things to consider to help avoid cross-contamination.
Why Should We Care About PFAS?
PFAS are considered an emerging chemical of concern and have been classified as “Forever Chemicals” because they do not easily break down in the environment. PFAS also bioaccumulate in the food chain and can end up in humans primarily due to ingestion of food or water contaminated with the chemicals.
Why is Sampling for PFAS More Complicated?
Due to the low screening level concentrations (ng/L) and prevalence of PFAS in consumer products, false positives are a major concern due to cross-contamination between sampling locations and contamination of samples.
As a result, we have listed five items that are acceptable when it comes to sampling for PFAS.
- HDPE plastic (lab containers, tubing, and other plastic components in pumps, etc.)
- Polypropylene, silicone, stainless steel, nylon, or acetate-containing sampling equipment
- Ballpoint pens
- Ice in LDPE bags may be used, but must be kept in the staging area and should not contact sample media. Samplers must wear gloves when handling ice bags and change after.
- Collected samples may be placed into LDPE bags (e.g., Ziplock®), but should be done so in the staging area. Gloves must be worn and changed.
Additionally, below are four field clothing items that are also acceptable for PFAS sampling.
- Synthetic and natural fibers (e.g., cotton) that are well laundered and not laundered with fabric softener
- PVC, neoprene, or rubber products
- Powderless nitrile gloves
- HDPE products (hard hats, safety glasses, etc.)
There is a lot to consider when preparing for PFAS sampling, so make sure you’re not using restricted items that could cause contamination of your samples.
Questions? Ask our expert, Jason Hoffman!