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Toxicological information

Genetic toxicity: in vitro

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Administrative data

Endpoint:
in vitro gene mutation study in mammalian cells
Remarks:
Type of genotoxicity: gene mutation
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
This study is classified as reliable with restrictions because it is an acceptable, well-documented study report. Read-across justification: Based on the chemical composition, the renewable hydrocarbons produced from raw materials such as fatty acid rich oil like Crude Tall Oil (CTO) or triglyserides, using a hydrotreatment process have similar hydrocarbon fractions and they contain the same critical constituents than fossil diesel fuels. According to the identified hydrocarbon blocks, the typical carbon number ranges and the physicochemical properties, the renewable hydrocarbons with diesel type fractions can be considered as having structural similarities and similar behaviour in contact with water and in the physiological processes than the analogue source substances (fossil diesel fuels). Their irritation properties, skin sensitisation property as well as acute and long-term adverse effects to human health is similar. Therefore, and in order to avoid the unnecessary animal testing, the read-across data from the analogue fossil diesel fuels is used to evaluate skin and eye irritation, the genetic toxicity, carcinogenicity, developmental toxicity and short term and/or long-term toxicological effects of the target substance.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1986

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 476 (In Vitro Mammalian Cell Gene Mutation Test)
GLP compliance:
not specified
Type of assay:
mammalian cell gene mutation assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): API 81-10
- Substance type: Hydrodesulfurized Middle Distillate
- Physical state: Clear yellow liquid

Results and discussion

Test results
Species / strain:
mouse lymphoma L5178Y cells
Metabolic activation:
with and without
Genotoxicity:
positive
Remarks:
weak
Cytotoxicity / choice of top concentrations:
cytotoxicity
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

Read-across justification with data matrices is presented in IUCLID section 13 (Annex I of CSR).

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
positive weakly positive

The study was judged by the authors as producing weak positive findings both in the presence or absence of S9. In view of the positive findings both in the presence and absence of S9, the poor repeatability and the absence of a dose response relationship, this study must be considered unreliable.
Executive summary:

Compositional and physico-chemical data show that Other Gas Oils are very similar to renewable hydrocarbons of wood origin (diesel type fraction). It is considered appropriate, therefore, to read across from the Other Gas Oil data to renewable hydrocarbons of wood origin (diesel type fraction).

In a mouse lymphoma mutagenicity assay, mouse lymphoma cell line, L5178Y, was exposed to the test material, hydrodesulfurised middle distillate in ethanol, in the presence and absence of rat liver S-9 for four hours. In the inactive system (no S-9), the cells were exposed to test material at concentrations ranging from 25 nl/ml to 200 nl/ml and in the active system (with S-9) the cells were exposed to test material at concentrations ranging from 12.5nl/ml to 300 nl/ml. In addition to treated cells, a solvent control group and positive controls consisting of ethylmethane sulfonate for inactive studies (no S-9) and 3-methylcholanthrene (MCA) for active studies (with S-9) were also used to test the efficacy of the mutagenicity assay. This assay was performed in two sets to ensure reproduction of experimental results.

In cells treated with the test material in the absence of S-9, a wide range of toxicities was noted, including high toxicity at higher concentrations (value not specified). Additionally, a repeatable increase in mutant frequency was noted, but this frequency was not dose-dependent. In cells treated with the test material in the presence of S-9 activation, toxicity was again noted at various concentrations (values not specified) along with repeatable increases in mutant frequency. These mutant frequencies, however, were not dose-dependent. Based on these results, the study authors concluded that hydrodesulfurised middle distillate is weakly mutagenic in the mouse lymphoma assay, both in the presence and absence of S-9 activation.

This study received a Klimisch rating of "reliable without restriction" because it closely followed OECD Guideline 476 and appears to be GLP compliant.