Glycerol

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

The mutagencity potential of glycerin was examined in two separate Ames tests. The test material was negative as tested in the Ames test.

The test material was evaluated in the Chinese hamster ovary assay with and without metabolic activation. The test material did not meet the criteria set for a positive response set by the author of the report and was considered to be negative by the author.

The test material was evaluated in the Chinese hamster ovary Sister Chromatid Exchange assay with and without metabolic activation. The test material did not induce a mutagenic response in the Chinese hamster ovary SCE assay with and without metabolic activation.

The test material was evaluated in the Unscheduled DNA Synthesis assay. The test material did not induce a mutagenic response in the Unscheduled DNA Synthesis assay using rat hepatocytes.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Genetic toxicity in vivo

Description of key information

Although an in vivo mutagenicity study has not been conducted, given the lack of a mutagenic response in in vitro studies, the lack of a carcinogenic response in a chronic tox/carcinogenicity study and that glycerol is considered one of the primordial biomolecules, there is no reason to expect that glycerol would be mutagenic.

Additional information

In the available evaluations performed by official bodies (OECD 2002, EFSA 2017) a number of additional genotoxicity toxicity studies were evaluated and summarised. The overall conclusion was that there is no in-vitro or in-vivo data that indicates glycerol to have a genotoxic potential.

EFSA conclusion: Glycerol did not show any genotoxic activity in different in vitro assays, which include negative results in the bacterial reverse mutation assay (Ames test), in chromosome aberration assays and in studies on DNA damage in mammalian cells. Questionable results obtained in a HGPRT gene mutation assay did not show a dose–response effect and were therefore judged of no biological significance. A lack of valid in vivo genotoxicity data was not of concern since clear negative findings were observed in in vitro assays. On this basis, the Panel considered that glycerol as a food additive did not raise concern with respect to genotoxicity.

OECD conclusion: There are no structural alerts (expert judgement) which raise concern for the inherent mutagenic potential of glycerol. In vitro, glycerol was negative (with and without metabolic activation) in Ames tests and did not induce chromosomal effects in mammalian cells. The responses seen in a limited gene mutation study in mammalian cells are of uncertain biological relevance as the doses were not maximised. Only two in vivo studies are available. A negative result was observed in a chromosome aberration test, and an increase (not statistically significant) in post implantation loss was seen in a rat dominant lethal assay. However, for both assays, the limited details reported and absence of a positive control, mean no reliable conclusions can be drawn from the in vivo data.

Thus, overall, there is no in vitro or in vivo data that indicates glycerol to have a genotoxic potential.

There was no new relevant information identified up to and including 2021 (most recent literature research).

Re-evaluation of glycerol (E 422) as a food additive, EFSA Journal 2017;15(3):4720

Glycerol, CAS Number 56-81-5, OECD SIDS Initial Assessment Report For SIAM 14 Paris, France, 26-28 March 2002

 

Justification for classification or non-classification

There is no justification for classification based on data from available studies.