A recent article published on Lab Manager opened with a pertinent question that bears repeating here: “How do you study the effects of exposure to PFAS when it is in everything?!”
Per- and polyfluoroalkyl substances (PFAS) are in the air we breathe, the food we eat, the water we drink, the carpet we walk on, and the objects we handle every day. And, yes, PFAS contamination finds its way into laboratory environments, too.
The challenges of maintaining a clean lab for PFAS testing
Prevalence in produced goods
PFAS chemicals have been widely used in consumer products for approximately 70 years. This wide usage impacts lab equipment and supplies. Like everything else, lab tools and supplies are forged from various materials—and some of those materials probably contain PFAS, even if they’re not intended to contain PFAS.
Misinformation regarding “PFAS-safe” equipment
There’s a notion out there that the inherent properties of polypropylene and high-density polyethylene (HDPE) materials protect a lab environment from PFAS contamination. Unfortunately, we’ve found that not to be the case in all situations. Depending on the levels of detection and list of PFAS analytes being examined, a supply assumed to be PFAS-free may not be.
Insufficient supply checks and processes
Well-intentioned labs can unknowingly let PFAS compounds slip through their supply checks undetected. For example, this situation can occur when blank testing is used to check for a laundry list of PFAS compounds—save for the one PFAS compound hiding in a supply material. All is well until that one hiding compound becomes one the lab needs to analyze when it didn’t need to do so prior.
And while the right lab processes can get help get rid of a particular PFAS compound, some compounds are difficult (if not outright impossible) to eliminate. When a lab lacks the proper procedures for eliminating or accounting for PFAS compounds, it is bound to experience cross-contamination.
Measuring the concentration levels of different compounds
A lab must be able to test for various PFAS compounds at specific concentrations, encompassing a wide range of granularity. As an example of just how granular these detection capabilities need to be, let’s look at the EPA’s recently proposed limits on the maximum concentration levels of certain PFAS compounds found in drinking water.
Two PFAS have proposed limits of four parts per trillion (or nanograms per liter). The lab must be able to reliably quantify the concentration of these PFAS at about one-third of the minimum level required, which, in this case, is also four parts per trillion. All told, then, the total detectable amount allowed in a quarter of a liter sample (the usual sample size) is 0.33 nanograms.
Simply put: The larger the set of PFAS compounds a lab must test for and the lower the required detection limits, the harder it is to maintain a sufficiently clean lab.
How to maintain a clean lab for PFAS testing
Never use a lab supply or tool without testing it
This is the Golden Rule at our labs. Every object introduced into your lab environment should have already been tested and cleared of PFAS across a spectrum of compounds.
Put the proper processes in place
PFAS contamination can occur when preparing and analyzing samples. By codifying and mandating procedures, such as cleaning the lids of your manifolds and rinsing out labware before use, you can minimize or eliminate the risk of PFAS contamination.
Practice an overabundance of caution with your samples
Even when you’re told that an arriving sample has a low level of detectable PFAS, do your own testing on a small scale to confirm. And never assume a sample is clean unless you know where the sample is coming from and review its data collected by other labs.
Be mindful of your instrumentation
When mishandled, low-level samples can still contaminate your instruments and trigger a false PFAS detection. Most procedures for preparing a sample concentrate its level of PFAS contaminants. You will see this concentration happen with solid-phase extraction (SPE), for example. And by the time the sample is ready, its PFAS concentration could have accumulated from a few hundred per trillion to somewhere in the part per billion range, which could be a problem, depending on what those contaminants are.
Partner with PFAS testing experts
At Enthalpy, we practice what we preach—meaning we follow every possible safeguard and exercise an overabundance of caution in our labs to mitigate PFAS cross-contamination during our analyses. To learn more about our PFAS testing services and the steps we follow to ensure clean lab environments, send us a message.
Bryan Vining
Laboratory Director
Dr. Bryan Vining is the laboratory director for Enthalpy Analytical Ultratrace in Wilmington, NC. Bryan is a 23-year veteran of the laboratory industry. He started his career as a product specialist and later worked in various lab roles before joining Enthalpy Analytical, LLC in 2016. Bryan has deep experience in the application of isotope dilution technology to the measurement of persistent organic pollutants, such as PFAS, at very low (ultratrace) levels in the environment. He has contributed to the revision of multiple EPA methods that use isotope dilution technology. Bryan graduated with a B.A. in Chemistry from Huntingdon College, before proceeding to get a Ph.D. from Florida State University and an M.B.A. from the University of North Carolina Chapel Hill.
