UNDONE SCIENCE, 3M’s PFAS Ethical Debacle, Part IIa: PFOS Carcinogenicity

A goose perches remotely (near Bend, OR)

In the 2018 peer-reviewed article, “Nonstick Science: Sixty years of research and (in) action on fluorinated compounds,” Richter et al (2018) define UNDONE SCIENCE as “areas of research that are of concern for…members of the public yet are not an area of focus for academic, government or industry researchers often due to deliberate or tacit avoidance.”  The authors continue, “Institutional ignorance….can be intentional as when a company stops studying a topic because they do not want to find further cause for concern.”   Although the Richter et al article focuses primarily on Dupont, a review of 3M documents made public on the Attorney General of Minnesota’s website, demonstrates many ethical lapses at 3M as well.  If you’d like to review the primary data cited here, go to the AG’s website and check out the document numbers I’ve provided in [brackets] below.  Within quotation marks, words italicized inside the parenthesis have been added by me for clarity.

In understanding 3M’s ethical lapses with respect to Undone Science, we have to assume that 3M has shared publicly all of the data describing their historical PFAS research.  Given that the sharing of pertinent  documents was required as part of the litigation in MN, I accept the validity of this assumption.

The most egregious example of Undone Science for PFAS at 3M concerns investigations into the carcinogenicity of PFOS, the compound identified to be widely present in the blood of both production workers and in the general population.  Despite concerning toxicity data in repeat dosing studies in minnows, rats and monkeys, (“FC-95 was the most toxic of the three compounds studied and certainly more toxic than anticipated [1199]”) 3M resisted initiating a standard 2-year carcinogenicity study in rats for PFOS.  A 3M scientist noted the omission: “These short-term tests aren’t intended to measure long term effects like bioaccumlation or chronic toxicity [1372].”

As early as 1978, leaders at 3M discussed the fact that “PFOS is more toxic that previously believed”, concluding, “Since there are no currently accepted short term screens for carcinogenicity it will likely be necessary to access the long term carcinogenic potential of FC95 (PFOS), FC-143 (PFOA) and FM-3422 (Ethyl FOSE alcohol) in long term rodent tests [1168].”  

In 1979, two different 3M toxicologists again pursued permission to move ahead with carcinogenicity studies, the first writing: “Because of the apparent persistence of these fluorochemicals in the body, the most important question remains possible long term effects. Although lifetime rodent studies have limitations in predicting chronic effect (carcinogenesis) for man, they are still considered the most reliable indicators available [1199].”  

The second 3M toxicologist made the case for chronic testing just a few months later: “I believe it is paramount to begin now an assessment of the potential (if any) of long term (carcinogenic) effects for these compounds which are known to persist for a long time in the body and thereby give long term chronic exposure…to delay chronic testing any longer is not warranted. As I indicated before, I think that both the metabolic and chronic toxicity studies are important and must go forward [1212].” 

Despite these pleas from 3M’s own toxicologists, there is no evidence of a carcinogenicity study for PFOS.  

In 1994, fifteen years after the first recommendation to conduct carcinogenicity testing on PFOS, in a Draft Hazard Review for PFOS, the entry under the heading “Chronic Toxicity and Carcinogenicity” reads: “No data found [1418].”  

In the face of data indicating widespread contamination of PFOS in both the blood of their workers and in the general population and with concerning toxicity data in hand, for nearly 20 years, 3M chose to leave the critical characterization of the carcinogenicity potential of PFOS as Undone Science.  No data found.