Risk assessmentindependent cross-checkfull text checked I-FSH-19 in-depth review
EFSA: PFOS and PFOA (2018)
Risk to human health related to the presence of perfluorooctane sulfonic acid and perfluorooctanoic acid in food.
Overview
EFSA Panel on Contaminants in the Food Chain (CONTAM) et al.. EFSA J 2018 · PMID 32625773 · DOI 10.2903/j.efsa.2018.5194
Fish and seafood were important dietary sources of PFOS and PFOA; many Europeans exceeded EFSA's 2018 weekly limits (13 and 6 ng/kg).
Does the study support the specific claim? Unclear · Methodological quality: high
Plain-language summary
Study explained simply
- What did the researchers want to find out?
Set safe intake.
- How was the study done?
EFSA risk assessment (BMD and PBPK modelling; EU occurrence data).
- How many people, animals or samples were studied?
20,019 results.
- What was actually found?
TWIs 13 (PFOS) and 6 (PFOA) ng/kg bw/week; high consumers exceed PFOS TWI up to 13-fold; fish meat contributed up to 79% of PFOS lower-bound exposure in the elderly.
- What do the results mean in everyday life?
Fish contributes PFAS.
- What are the study's limitations?
Superseded (2020); most data below detection; 62% from Germany.
- What does it say about Elawady's specific claim?
Context.
- Do the results apply to Germany and Europe?
High.
- What can explicitly not be concluded from this study?
Farmed vs wild differences; individual health risk.
Scientific in-depth review
1. Full reference
- Authors
- EFSA Panel on Contaminants in the Food Chain (CONTAM) et al.
- Journal
- EFSA J
- Year
- 2018
- Identifier
- PMID 32625773 DOI 10.2903/j.efsa.2018.5194
- Verification
- verified – PubMed efetch 2026-10-25
- Retracted
- no
- Corrections
- none
- Extent checked
- full text
- Conflicts of interest and funding
EFSA scientific opinion requested by the European Commission; CONTAM Panel and working group under EFSA declarations-of-interest policy; no specific conflicts reported in the full text
2. Research question
Risks of PFOS/PFOA in food
3. Study design and population
- Study design
- Risk assessment – EFSA CONTAM Panel scientific opinion (mandate from the European Commission): hazard characterisation from human epidemiological studies with benchmark dose and PBPK modelling, plus dietary exposure assessment from EU occurrence data
- Population
EU population
- Country
EU
- Period
Occurrence samples collected 2000-2015 (majority after 2007), data received to end of October 2016; opinion 2018
- Sample size
21,411 initial results (16 European countries; Germany 62%); 20,019 in final dataset (PFOS 10,191; PFOA 9,828); left-censored 74% (PFOS) and 91% (PFOA)
4. Methods and endpoints
- Exposure / intervention
PFOS and PFOA in food and drinking water
- Comparator
TWIs: 13 ng/kg bw per week (PFOS), 6 ng/kg bw per week (PFOA)
- Endpoints
Critical effects: increased serum total cholesterol (adults; PFOS and PFOA) and reduced antibody response to vaccination in children (PFOS); also birth weight and ALT considered
- Statistical methods
BMD modelling (BMDL5: PFOS 21-25 ng/mL plasma; PFOA 9.2-9.4 ng/mL), PBPK conversion to intake (PFOS 1.8, PFOA 0.8 ng/kg bw per day), lower- and upper-bound exposure
5. Actual results
- Results
TWI 13 ng/kg bw/week (PFOS) and 6 ng/kg bw/week (PFOA). PFOS mean LB exposure 1.3-20.9, P95 3.5-165.9 ng/kg bw/week (TWI exceeded up to 1.6-fold at mean and 13-fold at P95 LB); PFOA mean LB 1.5-18.3, P95 3.4-37.6 (up to 3- and 6-fold). Fish and other seafood an important contributor for both; 'fish meat' had the highest contribution to overall PFOS LB mean exposure among seafood subgroups (up to 79% in the elderly). Fish meat mean PFOS LB-UB 2.2-2.8 ug/kg (max UB 211); fish offal 4.51 ug/kg; highest in barbel, perch, anchovy, roach, bream. No farmed-vs-wild comparison.
- Absolute risks
not reported (exposure vs TWI)
- Authors' conclusion
A considerable proportion of the European population exceeds the TWIs for PFOS and PFOA, which is of concern; the exposure assessment is highly uncertain, with true exposure considered closer to lower-bound estimates.
6. Strengths
- Health-based guidance values derived from human data
- Large EU dataset; explicit uncertainty discussion
7. Weaknesses
- High left-censoring and insensitive methods; large LB-UB gap
- Data dominated by Germany (62%)
- Causality of cholesterol association debated (observational studies)
- Superseded in 2020 by the group TWI of 4.4 ng/kg bw/week (I-FSH-18)
- No farmed vs wild fish comparison
8. Risk of bias
- Orienting tool
- No standard tool fits (regulatory risk assessment); structured judgement of validity threats
- Type of assessment
- structured assessment based on the full text by a single reviewer (no formal double review)
- Full formal assessment
- no
- Overall risk of bias
- some concerns
- Rationale
Single-reviewer structured judgement based on the full text; not formal (needs two independent reviewers). Changed from not_assessable to some_concerns.
| Domain | Judgement | Rationale |
|---|---|---|
| Hazard characterisation | some concerns | Critical effects from observational human studies (possible confounding, reverse causation for cholesterol); BMD/PBPK assumptions documented. |
| Occurrence data representativeness | some concerns | 62% from Germany; high left-censoring. |
| Exposure modelling | some concerns | Large LB-UB differences; LB judged closer to truth. |
| Transparency and process | low | Full documentation of data cleaning and uncertainties. |
Full-text review (25 October 2026): Added data cleaning (21,411 to 20,019 results; left-censoring 74%/91%), BMDLs and PBPK intakes, exposure ranges and exceedance factors, fish-meat contribution (up to 79% in the elderly) and levels; noted no farmed-vs-wild comparison; bias overall changed from not_assessable to some_concerns.
9. Assessment of the statistical interpretation
10. Relevance to the specific claim
Context (fish as PFAS source).
11. Independent contrary findings
12. Transferability to Germany and Europe
High.
13. Overall methodological judgement
Superseded by the 2020 opinion (I-FSH-18) but confirms that fish meat is a major dietary source of PFOS in Europe and that intake often exceeds health-based values; it does not distinguish farmed and wild fish.
| Multidimensional assessment | |
|---|---|
| Authenticity of the source | verified |
| Methodological quality | high |
| Risk of bias | some concerns |
| Precision of results | not applicable |
| Directness | indirect |
| Reproducibility | unknown |
| Consistency with the overall evidence | unknown |
| Regional transferability | high |
| Adequacy of the interpretation (by the archive) | not applicable |