per- and polyfluoroalkyl substances
Let an agent explain what PFAS are and where they are used, relay health and environmental findings from agencies with attribution, relay regulatory status and limits by jurisdiction, and route personal exposure questions to health authorities and clinicians.
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
written by Claude from model knowledge without web access - no source was read, every claim is a lead to verify
Researched by: Claude
Purpose and description
Let an agent explain what PFAS are and where they are used, relay health and environmental findings from agencies with attribution, relay regulatory status and limits by jurisdiction, and route personal exposure questions to health authorities and clinicians.
A large class of synthetic organofluorine chemicals containing fully or partly fluorinated carbon chains, including PFOA, PFOS and thousands of related substances, used since the 1940s in non-stick coatings, water and stain repellents, firefighting foams and industrial processes; PFAS are extremely persistent in the environment, accumulate in people and wildlife, are linked by health agencies to effects such as raised cholesterol, immune and developmental effects and some cancers, and are increasingly restricted.
What it is for: Historically, water, oil and stain resistance and firefighting; now largely being phased out.
It can be explain the class and its uses; relay health and environmental findings; relay regulatory status and limits; route personal exposure questions.
Distinguishing features
Extreme persistence
Water and oil repellency
Bioaccumulation
Wide regulatory action
What it looks like
Not visible as a class; present in coatings, foams, textiles, water and blood at trace levels.
Physical character
number of substances: over 10000 count - by OECD definition
carbon-fluorine bond energy: about 485 kJ/mol - source of persistence
How it is recognised
Fluorinated carbon chains, synthetic
Persistent and bioaccumulative
Fluoropolymers such as PTFE are PFAS by most definitions; other organofluorines such as some medicines are not
Related models
is a kind of - in registry terms
is a kind of - in registry terms
is regulated by - for PFOS, PFOA and PFHxS
is found in - as a contaminant
In practice
Families and kinds
perfluoroalkyl acids such as PFOA and PFOS
shorter-chain replacements such as GenX chemicals
fluorotelomers
fluoropolymers such as PTFE
PFAS in firefighting foams
precursors and degradation products
Identifiers
CAS numbers per substance
OECD PFAS definition 2021 structural definition
Standards and regulation
Stockholm Convention listings
EU REACH restriction proposals and drinking water limits
US EPA drinking water standards and reporting rules
National limits in food, water and products
Failure modes and hazards
Persistent contamination of water and soil
Human health effects identified by agencies
Regrettable substitution with similar chemicals
Agents giving personal medical advice
Where this came from
wikidata · CC0 1.0
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 4 bundles · 8 layers · 8 findings · 16 questions.
Understand What PFAS are.
Definition.
Definition
Definition and uses.
Definition
Definition.
- What are PFAS, and where have they been used? definition
- Is the substance a PFAS by the relevant definition? boundary
Kinds
Kinds.
Kinds
Kinds.
- What subclasses exist, and how do long-chain and short-chain PFAS differ? definition
- Which entry fits the specific substance? action
Impact Health and environment.
Attribution.
Health
Health findings.
Health
Health.
- What do health agencies conclude about PFAS exposure effects, with attribution and dates? provenance
- Is the user asking about their own exposure, which needs a health authority or clinician? boundary
Environment
Environmental fate.
Environment
Environment.
- How do PFAS move through water, soil and food chains, and where is contamination found? provenance
- Which sources are cited? provenance
Regulate Regulation and limits.
Regulation.
Limits
Limits and standards.
Limits
Limits.
- What limits apply in drinking water, food and products by jurisdiction? provenance
- Is the information current? boundary
Phase-out
Restrictions and phase-out.
Phaseout
Phaseout.
- Which PFAS are restricted or being phased out, and what debates surround broad restrictions, with positions attributed? provenance
- Is the presentation neutral? boundary
Manage Remediation and alternatives.
Practice.
Remediation
Treatment and cleanup.
Remediation
Remediation.
- How are PFAS removed from water and destroyed, and what are the limits of current methods? provenance
- Which entry fits water treatment? action
Alternatives
Alternatives.
Alternatives
Alternatives.
- What alternatives exist for coatings, textiles and foams, and how are they assessed? provenance
- Which references are standard? provenance
What the second pass must settle
- Should PFOA and PFOS be separate primary entries?
- How should regulatory limits be linked by jurisdiction?
- How should the evolving scientific assessments be recorded with dates?