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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:
key study
Study period:
no data (study completed 01.12.1987)
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: According to the final RAR on SCCPs (EU, 2000), this was a well conducted study, "performed to modern protocols".

Data source

Referenceopen allclose all

Reference Type:
study report
Title:
Unnamed
Year:
1987
Report Date:
1987
Reference Type:
secondary source
Title:
Unnamed
Year:
2000

Materials and methods

Principles of method if other than guideline:
Frequency of mutant colonies assessed in a gene mutation (HPRT) assay with a C10-13 chlorinated paraffin (56% chlorination)
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): Chlorparaffin 56 flϋssig
- Molecular formula (if other than submission substance): CxH(2x-y+2)Cly, where x=10-13 and y=1-13
- Molecular weight (if other than submission substance): 320-500
- Smiles notation (if other than submission substance): no data
- InChl (if other than submission substance): no data
- Substance type: technical product
- Physical state: no data
- Analytical purity: no data
- Impurities (identity and concentrations): no data
- Composition of test material, percentage of components: C10-13 chlorinated paraffin (56% chlorination)
- Isomers composition: no data
- Purity test date: no data
- Lot/batch No.: no data
- Expiration date of the lot/batch: no data
- Stability under test conditions: no data
- Storage condition of test material: no data

Method

Target gene:
hypoxanthine phosphoribosyltransferase (HPRT)
Species / strain
Species / strain / cell type:
Chinese hamster lung fibroblasts (V79)
Details on mammalian cell type (if applicable):
- Type and identity of media: no data- Properly maintained: no data- Periodically checked for Mycoplasma contamination: no data- Periodically checked for karyotype stability: no data- Periodically "cleansed" against high spontaneous background: no data
Additional strain / cell type characteristics:
not specified
Metabolic activation:
with and without
Metabolic activation system:
Aroclor-induced rat liver metabolic activation
Test concentrations with justification for top dose:
0, 5, 10, 15, 20 or 30 µg/ml without S90, 5, 10, 30, 50 or 75 µg/ml with S9
Vehicle / solvent:
no data
Controls
Untreated negative controls:
not specified
Negative solvent / vehicle controls:
not specified
True negative controls:
not specified
Positive controls:
yes
Positive control substance:
not specified
Details on test system and experimental conditions:
METHOD OF APPLICATION: in mediumDURATION- Preincubation period: no data- Exposure duration: no data- Expression time (cells in growth medium): no data- Selection time (if incubation with a selection agent): no data- Fixation time (start of exposure up to fixation or harvest of cells): no dataSELECTION AGENT (mutation assays): 6-thioguanineNUMBER OF REPLICATIONS: two independent experiments performedNUMBER OF CELLS EVALUATED: no dataDETERMINATION OF CYTOTOXICITY - Method: cloning efficiency
Evaluation criteria:
no data
Statistics:
no data

Results and discussion

Test results
Species / strain:
Chinese hamster lung fibroblasts (V79)
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Vehicle controls validity:
not specified
Untreated negative controls validity:
not specified
Positive controls validity:
valid
Additional information on results:
TEST-SPECIFIC CONFOUNDING FACTORS- Effects of pH: no data- Effects of osmolality: no data- Evaporation from medium: no data- Water solubility: soluble up to 750 ug/ml- Precipitation: no data RANGE-FINDING/SCREENING STUDIES: a preliminary study to determine cytotoxicity was conducted to select appropriate dose levels for the main study. The test substance produced a cytotoxic effect from 50 ug/mL with S9 and from 20 ug/mL without S9, up to the limit of solubility (750 ug/mL).COMPARISON WITH HISTORICAL CONTROL DATA: no dataADDITIONAL INFORMATION ON CYTOTOXICITY: cytotoxicity was evident at 20 ug/ml and above without S9 and at 50 ug/ml and above with S9
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):negative C10-13 chlorinated paraffin; 56% chlorinationIn a well-conducted gene mutation (HPRT) study in Chinese hamster V79 cells, Chlorparaffin 56 flϋssig (a C10-13 chlorinated paraffin; 56% chlorination) did not induce a significant, reproducible increase in mutant frequency at doses of up to 75 or 30 µg/ml respectively, with or without a rat liver metabolic activation fraction.
Executive summary:
Chlorparaffin 56 flϋssig (a C10-13 chlorinated paraffin; 56% chlorination) was assessed for its mutagenic potential in mammalian cells using the HPRT assay. After a preliminary study to determine cytotoxicity of the test substance, it was tested at concentrations of up to 75 or 30 µg/ml with or without a rat liver metabolic activation system (S9), respectively, in cultures of Chinese hamster lung fibroblast (V79) cells. Mutants were selected by their resistance to 6-thioguanine. Two independent experiments were conducted. According to an expert review (EU, 2000) on SCCPs, the study was well-conducted and carried out to modern protocols. The test substance did not induce an increase in mutant frequency; cytotoxicity was evident at levels of 50 or 20 µg/ml with or without S9, respectively. In contrast positive control substances (not specified in the available abstract of the report) performed as expected, increasing the mutant frequency, thus demonstrating the validity of the assay. In conclusion, in a gene mutation (HPRT) study in Chinese hamster V79 cells, Chlorparaffin 56 flϋssig did not induce a significant, reproducible increase in mutant frequency at doses of up to 75 or 30 µg/ml respectively, with or without S9.

In view of the similarities in structure and physiochemical properties [between SCCPs and MCCPs], it can be predicted that MCCPs would also be negative in a HPRT study.