Did You Know? Perfluorooctanesulfonic acid Has a 19,417x NOAEL Spread Across Sources
Perfluorooctanesulfonic acid shows a same-CAS NOAEL spread across sources for matched species, route, and unit keys.
Perfluorooctanesulfonic acid appears in the NOAEL conflict detector because the same CAS (1763-23-1) has no-observed values that differ by 19,417x across source records.
| Field | Value |
|---|---|
| CAS | 1763-23-1 |
| Species key | rat |
| Route key | oral |
| Comparable unit | mg/kg bw/day |
| Minimum no-observed value | 0.000515 |
| Maximum no-observed value | 10 |
| Sources | ATSDR, ToxValDB |
Why the Spread Matters
The important part is the matching rule. This is not a loose comparison across unrelated studies; the row is normalized to the same CAS, species, route, and unit. That makes the spread a useful signal for anyone reviewing Perfluorooctanesulfonic acid in a cosmetic safety context.
A high spread does not prove that one source is wrong. It says the record needs source-level reading before a single number is reused in a safety narrative. Endpoint type, duration, test article, qualifier, and source corpus can explain why two no-observed values are far apart.
Formulator Takeaway
For Perfluorooctanesulfonic acid, the safe move is to keep the NOAEL attached to its source and study context. The lowest value may be the most conservative point of departure, while the highest value may reflect a different endpoint or study design. A formula review should not flatten the range into a single generic safety number.
The source list below keeps the low-record and high-record handles attached to the page. That is the audit trail for the quick fact: a reader can see which corpus supplied each side of the spread before deciding whether the difference is toxicologically meaningful for a specific product.
That restraint is the point. A large numeric spread is interesting, but it is not a finished safety argument. It becomes useful only when the values stay connected to their endpoints, qualifiers, durations, and source files.
For search readers, the useful answer is not just the biggest number. It is the reason that number should be handled carefully: matched toxicology keys, different source records, and a substance identity that needs source-level review.
Source
- Cross-vertical finding: query5_noael_conflicts.json
- src_corpus: ATSDR; source: ATSDR_toxval_ATSDR_MRLs.xlsx; src_file: Source documentation archived. reference: ATSDR MRLs; row_hash=1b2179bc90ab1b73; source_hash=ToxValhc_2a8139e324630acffd4aee96757f005b; raw_endpoint_type=NOAEL (HED); raw_endpoint_subtype=; raw_value=0.000515; raw_unit=mg/kg/day; method=gavage; effect=developme.
- src_corpus: ATSDR; source: ATSDR_toxval_ATSDR_PFAS_2021.xlsx; src_file: Source documentation archived. reference: ATSDR PFAS 2021; ATSDR TP 2021 PFOS Oral; row_hash=2e0871ea22cef428; source_hash=ToxValhc_93818a7a4a2d7f92f606cf9846cadea8; raw_endpoint_type=NOAEL; raw_endpoint_subtype=; raw_value=10; raw_unit=mg/kg/day; year=2018; fi.