Data Sources & Methodology
This guide explains the authoritative sources we use and how they map to our Tier system and lists of concern/benign materials.
| Resource | Tier System | Lists of Concern/Benign | How much we know |
|---|---|---|---|
| PubChem |  (Tiers 1 and 2) |
||
| ECHA Harmonized GHS | (Tiers 1 and 2) |
||
| Australia - Safe Work | (Tiers 1 and 2) |
||
| NITE Japan - GHS | (Tiers 1 and 2) |
||
| EPA's ChemInformatics (Safety; GHS) |
(Tiers 1 and 2) |
||
| EPA's ChemInformatics (Hazard) |
(Tiers 2 and 3) |
(lack of data) |
|
| ECHA Industry Self-classified GHS |
(Tier 2 only) |
||
| EPA's CompTox and CTX API |
Clean Water Act Safe Drinking Water Act EPA PFAS 2024 list Hazardous Air Pollutants IARC Carcinogens POPs, etc. |
multiple pieces such as: ToxValDB IRIS PPRTV molecular formula |
|
| SciFinder Chemical Abstract Service |
(Substance class; num refs) |
||
| EPA's TSCA list | (UVCB classification) |
||
| California Prop. 65 | |
||
| The Endocrine Disruption Exchange |
|
Other resources are described in individual chemical profile "Links to Profiles and Data Sheets" sections.
