Kris Hansen's PFAS Journal

Applying my experiences as a 3M scientist to illustrate industries' efforts to manufacture doubt about global PFAS contamination.

Jun 24, 2025

Who I am, why I’m writing, what I’m referencing

Shortly after starting at 3M as a new PhD chemist in 1996, I found myself in the midst of that company’s reckoning with their role in the public health crises precipitated by their global PFAS contamination. It’s been just over a year since Sharon Lerner shared her story via Propublica and The New Yorker about my experiences working as a 3M chemist during that tense and intense period . Lerner’s article was over a year in the writing. As she wrote and researched, we spent many hours reviewing data and documents and analyzing my time working in the 3M Environmental Lab between 1996-2001. In working with Lerner, I took the opportunity to closely examine the public record of 3M’s history with PFAS for the first time.

Seeing what was recorded in the public documents made it evident to me what was not. I found that my own experiences in 3M’s Environmental Lab were endemic of 3M’s long history of suppressing data and manufacturing doubt at the cost of public- and environmental health.

I’m sharing my thoughts and experiences for several reasons. First, as a resident of the eastern Twin Cities of Minnesota, I live in a front-line PFAS contaminated community. Our drinking water supply has been compromised by 3M landfills and one of 3M’s PFAS manufacturing facilities. The neighborhood I grew up in is downstream of a 3M landfill that leached PFAS into ground water and into local lakes. Near my home is Tartan High School, a downstream community with “cancer clusters” of young people that many suspect occurred due PFAS exposure from another 3M landfill [e.g. LINK, LINK]. My own children went to an elementary- and middle school in neighborhoods with drinking water contaminated by 3M’s landfills. I want to illustrate how industry manufactures doubt so that other communities can be better protected from unknowingly exposing children and families to industrial toxins.

Second, communities that want to clean up PFAS-contaminated drinking water face a huge economic investment. My community (several cities with a collective population around 150,000 in 2018) settled with 3M for $850,000,000 in 2018, primarily to serve that goal. The settlement money is projected to run out in 2027, and the job of building and maintaining the needed water treatment infrastructure is still incomplete. Many other communities will not have such resources to work with. I hope that talking about my own experiences and highlighting relevant, publicly-available historical documents around industries’ knowledge of and response to PFAS contamination will be useful to communities looking to recoup some of the costs associated with cleaning up PFAS contamination of their drinking water and natural resources.

Finally, I hope to make contributions to those who study the ways US corporations manufacture doubt about the public health and environmental safety of their products. Understanding these patterns is important so that we, as scientists, employees, consumers, and community members can identify when we are being manipulated, misled, or deceived.

My account will reference publicly-available documents and my personal experiences working at 3M, specifically in the Environmental Lab at 3M between 1996-2001. My professional bio is available at Savanna Science Consulting, savannsci.com, and a summary of my PFAS-related work at 3M is provided below.

Thanks to the work of Lori Swanson and her team at the Minnesota Attorney General’s Office and that of the Forever Pollution / Forever Lobbying Project, there are many 3M-PFAS and Dupont-PFAS documents in the public domain. The documents made public in 2018 as part of the settlement between 3M and the State of MN can be found on the MN Attorney General’s website HERE. When I cite one of these documents, I will note the document number (e.g. #2534 or #1145). The 3M and Dupont documents collected and archived by the Forever Pollution/Forever Lobbying Projects can be found HERE or HERE. When I cite one of these documents, I will include the hyperlink to the specific document (e.g. LINK or LINK). These documents complement my personal experiences working at 3M developing methods and analyzing samples for 3M and also, on occasion, for Dupont. Despite significant searching, I have not been able to find many of the documents I remember authoring while at 3M. Perhaps they will turn up.

I am so grateful to those who have worked to assemble these documents and make them available to the public. They give us a peek behind the closed doors of some of the biggest, wealthiest companies in the world whose products populate almost every aspect of our lives. Without access to these internal documents, consumers, communities and families have only the information the company chooses to share. Full access to this information, shared and unshared, is critical for communities affected by PFAS pollution and contemplating the investment necessary to mitigate the damage.

A summary of my work at 3M

I was hired by 3M in 1996 as a Chemistry Post-doc in 3M’s Environmental Lab. Later, my Post-doc was converted to a full-time position of Sr Analytical Chemist. I left 3M’s Environmental Lab at the beginning of 2001 for a “sabbatical” in another part of the company and formally left the 3M Environmental Lab in March 2002.

Between late 1997 and 2001 in 3M’s Environmental Lab, I was working on the global PFOS contamination issue; I reported to Mr. Jim Johnson. Mr. Johnson abruptly left 3M near the end of 1997 at which point I began reporting to the Technical Director in the Environmental Lab, Mr. Dale Bacon.

When Mr. Johnson left 3M at the end of 1997, around the time I developed a method for PFOS in sera, I formed a team of researchers in the Environmental Lab. We were known as FACT, Fluorine Analytical Chemistry Team. I was the leader of FACT. This team of 3M employees and contracted scientists was about 6 to 15 scientists and technicians before being broken up in 1999.

In addition to carrying out research around PFAS contamination and routes of exposure, the FACT analyzed samples for several 3M groups including 1) 3M Toxicology (e.g. PFAS characterization in tissue samples collected in support of tox studies conducted on rats, monkeys and mice including sera, liver, plasma, placenta and mild curd), 2) 3M Manufacturing Facilities (e.g. characterization of various samples originating at or near 3M manufacturing facilities including waste water, sludge, tars, surface wipes), 3) Environmental Samples (e.g. characterization of blood from non-occupationally exposed humans, wildlife, surface water, drinking water and animal feed), and 4) Product Exposure (e.g. characterization of PFAS transfer from PFAS-coated packaging to food and degradation of PFAS-coated textiles from 3M and Dupont). I had a central role in developing methods and collecting data to support these areas and to identify and characterize the global contamination associated with PFAS compounds. By early 1999, my team and I had characterized over a dozen different PFAS chemicals present in blood from the non-occupationally exposed population.

My team developed methods for and primarily used HPSE (high pressure solvent extraction), HPLC-MSMS, High Resolution HPLC-MS, GCMS, GCECD, GCFID and Total Organic Fluorine and Absorbable Organic Fluorine to support characterization of a variety of samples.

In my role, I problem solved with 3M scientists and engineers engaged in the challenges and questions sparked by my work “discovering” global PFOS contamination including with members of the Medical Division (epidemiology and toxicology) and Plant Engineering (Decatur, Antwerp, Cottage Grove), as well as with Environmental Scientists, Product Responsibility Managers and 3M Management/Executive Management. We even analyzed samples for Dupont on occasion.

In addition to leading the technical and organizational aspects of the FACT, I was the Environmental Lab’s technical expert on PFAS methods (especially mass spectrometry, but also HPLC-MSMS, GCMS, SCF and HPS Extraction, Organic Fluorine), leading the transfer of analytical methods to outside contract labs (e.g. Exygen, Centre, Battelle, Northwest Bioanalytical) and suggesting new equipment/capabilities for the Environmental Lab to purchase. I supported researchers in several disciplines within 3M and my group completed method development activities and analysis for at least one academic researcher, providing the majority of PFAS-specific data published in several of his publications. I authored numerous reports (GLP and non-GLP) and was the primary author on the 2 publications my Environmental Lab-led team was allowed to submit for publication in peer-reviewed journals. I had responsibility for collection of data and for authoring the analytical method sections of manuscripts in toxicology and epidemiology studies published by 3M, and for manuscripts relating to PFAS in wildlife samples authored by 3M-engaged academics.

I did not participate in PFOS-related discussions with the US EPA although data collected by me and my group were frequently included in TSCA §8(e) submissions/additions. On more than one occasion, I met with 3M executives in meetings I understood to be in preparation for their discussions with EPA or FDA. I did numerous presentations to 3M leadership, including to the CEO (Mr. Desimone), and to various 3M teams, describing what we had learned about PFAS and how we had learned it.

I was not a decision maker in 3M’s PFAS response nor was I a member of any of the myriad senior-level “special teams” that were formed in response to the global contamination by 3M’s PFOS and other fluorochemicals. However, between 1997-2001, as the technical lead most central to the development of methods and collection of data associated with PFAS compounds in humans, animals, 3M waste streams and the environment, I was in a unique position to review and evaluate many different dimensions of PFAS exposure. My technical partnerships with toxicologists, epidemiologists, industrial engineers, and product responsibility liaisons allowed me to engage in cross-functional technical discussions with other experts and to connect information across disciplines, using data from one area to help answer questions in another. I had an understanding of the limits of the sample preparation methods and analytical technologies in general and of our methods specifically. I authored at least one report in the 1990s positing a theory for “root cause” of PFAS exposure to humans and the environment.

Scientifically, I am qualified to evaluate and discuss the analytical capabilities necessary to support the kinds of data and conclusions my work developed in the late 1990s. As a 3M scientist central to the “discovery” and characterization of an environmental crisis within that corporation, I have first hand experience with instances of "manufacturing doubt,” both inside and outside the corporation. I hope to use this forum to share my experiences, expertise and analysis about corporate efforts to manufacture doubt around one of the most significant and widespread industrial pollutants of our time [LINK], [LINK].

What to expect

I’m hoping to publish approximately weekly.

How can you help me?

Please share this with people interested in PFAS and public health. I dont have a social media presence but I have a powerful network of friends and professionals I know can help share my message. Specifically, I’d like to reach communities who are dealing with PFAS contamination. So please spread the word!

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