Scientists’ Statement on the Chemical Definition of PFASs
Bibliographic record
Abstract
RecommendationsT he undersigned are scientists with expertise in per-and polyfluoroalkyl substances (PFASs) and/or the management of chemicals.We assert that the Organization for Economic Co-operation and Development (OECD) definition of PFASs is scientifically grounded, unambiguous, and well suited to identify these chemicals.We are concerned that some individuals and organizations are seeking a redefinition of PFASs endorsed by the International Union of Pure and Applied Chemistry (IUPAC) to exclude certain fluorinated chemical subgroups from the scope of the existing definition.We are concerned that this effort is politically and/or economically, rather than scientifically, motivated.An IUPAC-endorsed and potentially narrower PFAS definition could confer undue legitimacy from the endorsement by a recognized global scientific organization and, thereby, influence regulatory bodies and others to adopt less protective policies.Organofluorine chemicals are used in consumer products and industrial applications to impart oil-, water-, and stainresistance, stability, inertness, and/or other useful properties.The term "PFASs" arose from the need to identify a subgroup of organofluorine chemicals with a common feature, the very stable perfluorinated carbon.There are millions of theoretical PFAS structures, but the much lower number of PFASs actually manufactured and used is estimated to be several thousands.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.032 | 0.067 |
| Meta-epidemiology (narrow) | 0.002 | 0.002 |
| Meta-epidemiology (broad) | 0.002 | 0.003 |
| Bibliometrics | 0.002 | 0.003 |
| Science and technology studies | 0.009 | 0.010 |
| Scholarly communication | 0.010 | 0.009 |
| Open science | 0.005 | 0.006 |
| Research integrity | 0.053 | 0.057 |
| Insufficient payload (model declined to judge) | 0.011 | 0.018 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".