SCCS/1686/25 4 NOAEL rows Safety conclusion

Thiomersal, Thimerosal; Phenylmercuric acetate; Phenylmercuric borate, Unknown

Structured SCCS opinion summary generated from source-matched D1 rows for SCCS/1686/25.

Opinion Number
SCCS/1686/25
NOAEL Rows
4
Substances Covered
3

Substance(s) Covered

Thiomersal Thimerosal; Phenylmercuric acetate; Phenylmercuric borate Unknown

NOAEL Values Extracted from This Opinion

Substance Endpoint Value Study Source
Thiomersal
54-64-8
 NOAEL 1686 NOAEL study
rat
oral
16 weeks
SCCS_vision_codex
{"effect":"SCCS/1686/25 Final version Scientific advice on the safety of Thimerosal (CAS No. 54-64-8, EC No. 200-210-4) and Phenylmercuric salts as preservatives in cosmetic products _________________________________________________________________________________ 19 Table 3.4.4-1: Summary of different, most sensitive toxicological endpoints examined in experimental intermediate-duration oral exposure studies with meHg (after ATSDR 2024). NOAEL/LOAEL in µg Hg/kg bw/day. Species Duratio n NOAEL LOAEL Effect Ref. Rat 14-16 weeks premati ng to PND 21 -- 0.3* Immunodevelopmental: enhanced lympoproliferation in response to mitogens in PND 12 offspring Wild et al. 1997 Rat 14-16 weeks premati ng to PND 21 -- 0.3* Immunodevelopmental: enhanced lympoproliferation in response to mitogens in PND 84 offspring Wild et al. 1997 Rat 14-16 weeks premati ng to PND 21 -- 0.6* Immunodevelopmental: enhanced lympoproliferation in response to mitogens, decreased NK cell","page":19,"pdf":"sccs_o_308.pdf","row_type":"noael_study","study_id":"sccs_o_308_noael_001"}
sccs_o_308.pdf
Thiomersal
54-64-8
 NOAEL 1686 NOAEL study
rat
oral
16 weeks
SCCS_vision_codex
{"effect":"SCCS/1686/25 Final version Scientific advice on the safety of Thimerosal (CAS No. 54-64-8, EC No. 200-210-4) and Phenylmercuric salts as preservatives in cosmetic products _________________________________________________________________________________ 19 Table 3.4.4-1: Summary of different, most sensitive toxicological endpoints examined in experimental intermediate-duration oral exposure studies with meHg (after ATSDR 2024). NOAEL/LOAEL in µg Hg/kg bw/day. Species Duratio n NOAEL LOAEL Effect Ref. Rat 14-16 weeks premati ng to PND 21 -- 0.3* Immunodevelopmental: enhanced lympoproliferation in response to mitogens in PND 12 offspring Wild et al. 1997 Rat 14-16 weeks premati ng to PND 21 -- 0.3* Immunodevelopmental: enhanced lympoproliferation in response to mitogens in PND 84 offspring Wild et al. 1997 Rat 14-16 weeks premati ng to PND 21 -- 0.6* Immunodevelopmental: enhanced lympoproliferation in response to mitogens, decreased NK cell","page":19,"pdf":"sccs_o_308.pdf","row_type":"noael_study","study_id":"sccs_o_308_noael_001"}
sccs_o_308.pdf
Thiomersal
54-64-8
 NOAEL 1686 NOAEL study
rat
oral
16 weeks
SCCS_vision_codex
{"effect":"SCCS/1686/25 Final version Scientific advice on the safety of Thimerosal (CAS No. 54-64-8, EC No. 200-210-4) and Phenylmercuric salts as preservatives in cosmetic products _________________________________________________________________________________ 19 Table 3.4.4-1: Summary of different, most sensitive toxicological endpoints examined in experimental intermediate-duration oral exposure studies with meHg (after ATSDR 2024). NOAEL/LOAEL in µg Hg/kg bw/day. Species Duratio n NOAEL LOAEL Effect Ref. Rat 14-16 weeks premati ng to PND 21 -- 0.3* Immunodevelopmental: enhanced lympoproliferation in response to mitogens in PND 12 offspring Wild et al. 1997 Rat 14-16 weeks premati ng to PND 21 -- 0.3* Immunodevelopmental: enhanced lympoproliferation in response to mitogens in PND 84 offspring Wild et al. 1997 Rat 14-16 weeks premati ng to PND 21 -- 0.6* Immunodevelopmental: enhanced lympoproliferation in response to mitogens, decreased NK cell","page":19,"pdf":"sccs_o_308.pdf","row_type":"noael_study","study_id":"sccs_o_308_noael_001"}
sccs_o_308.pdf
Thiomersal
54-64-8
 NOAEL 1686 NOAEL study
rat
oral
16 weeks
SCCS_vision_codex
{"effect":"SCCS/1686/25 Final version Scientific advice on the safety of Thimerosal (CAS No. 54-64-8, EC No. 200-210-4) and Phenylmercuric salts as preservatives in cosmetic products _________________________________________________________________________________ 19 Table 3.4.4-1: Summary of different, most sensitive toxicological endpoints examined in experimental intermediate-duration oral exposure studies with meHg (after ATSDR 2024). NOAEL/LOAEL in µg Hg/kg bw/day. Species Duratio n NOAEL LOAEL Effect Ref. Rat 14-16 weeks premati ng to PND 21 -- 0.3* Immunodevelopmental: enhanced lympoproliferation in response to mitogens in PND 12 offspring Wild et al. 1997 Rat 14-16 weeks premati ng to PND 21 -- 0.3* Immunodevelopmental: enhanced lympoproliferation in response to mitogens in PND 84 offspring Wild et al. 1997 Rat 14-16 weeks premati ng to PND 21 -- 0.6* Immunodevelopmental: enhanced lympoproliferation in response to mitogens, decreased NK cell","page":19,"pdf":"sccs_o_308.pdf","row_type":"noael_study","study_id":"sccs_o_308_noael_001"}
sccs_o_308.pdf

Safety Conclusion

sccs_opinions
Not safe — not safe as preservatives in eye cosmetic products at currently permitted levels

Key concerns: Renal toxicity (MoS<100 at 0.007%); genotoxicity unresolved; organo-mercury compounds with systemic absorption risk

Opinion date: 2 February 2026

safety_opinions eye area Max 0.007
unknown

Opinion date: 2 February 2026

Source Citation

Primary source https://health.ec.europa.eu/scientific-committees/scientific-committee-consumer-safety-sccs/sccs-opinions_en