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Toxicological information

Genetic toxicity: in vitro

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Administrative data

Endpoint:
in vitro cytogenicity / chromosome aberration study in mammalian cells
Remarks:
Type of genotoxicity: chromosome aberration
Type of information:
migrated information: read-across based on grouping of substances (category approach)
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
The EU RAR (2005) reports the findings of a number of published tests of cytogenicity / clastogenicity performed with Cr (VI) compounds and incorporates the findings of previous reviews by the UK Health & Safety Executive (HSE; 1989) and the UK Institute of Occupational Health (IOH, 1997). Individual studies are of varying reliability but the overall conclusion (weight of evidence) is considered to be reliable.

Data source

Reference
Reference Type:
review article or handbook
Title:
European Union Risk Assessment Report: chromium trioxide, sodium chromate, sodium dichromate, ammonium dichromate, potassium dichromate
Author:
European Chemicals Bureau
Year:
2005
Bibliographic source:
3rd Priority List; Volume 53

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
The EU RAR summarises the findings of a number of cytogenicity studies performed to various non-standard designs.
GLP compliance:
no
Remarks:
predominantly older published studies
Type of assay:
in vitro mammalian chromosome aberration test

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Type:
Constituent
Type:
Constituent
Details on test material:
No further details are reported.

Method

Target gene:
Not applicable for cytogenicity assays
Species / strain
Species / strain / cell type:
other: various
Metabolic activation:
with and without
Metabolic activation system:
various
Test concentrations with justification for top dose:
Various

Results and discussion

Any other information on results incl. tables

The results of in vitro cytogenicity /clastogenicity / chromosomal aberration tests performed with the water-soluble Cr (VI) compounds in this group are invariably positive.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
positive weight of evidence

The results of several tests performed with water-soluble Cr (VI) compounds indicate that this group of compounds is clastogenic in vitro.
Executive summary:

There is a very large body of evidence indicating that the Cr (VI) ion in solution is directly clastogenic in vitro. This activity was diminished considerably by the presence of reducing agents, in the form of tissue S9 or S12 fractions, gastric juice or reducing agents such as glutathione, ascorbate or sulphite. These all serve to reduce Cr (VI) to Cr (III) outside the cell therefore greatly reducing entry of chromium into the cell.