Triammonium hexachlororhodate

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: gene mutation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

not stated

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Not to current international guidelines, but scientifically acceptable

Data source

Reference

Reference Type:

publication

Title:

Cyto- and genotoxic effects of coordination complexes of platinum, palladium and rhodium in vitro

Author:

Bunger J. et al.

Year:

1996

Bibliographic source:

International Archives of Environmental Health, 69, 33-38

Materials and methods

Test guideline

Guideline:

other: Revised test protocol of Maron and Ames (1983)

Version / remarks:

The study differed principally from OECD TG471 in that only four bacterial strains were tested. The recommended strain TA1535 was ommitted.

Principles of method if other than guideline:

Bacterial reverse mutation assay. The study differed principally from OECD TG471 in that only four bacterial strains were tested. The recommended strain TA1535 was ommitted.

GLP compliance:

not specified

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Reference substance 001

Cas Number:

15336-18-2

Details on test material:

Ammonium hexachlororhodate (CAS 15336-18-2)

Method

Species / strain

Species / strain / cell type:

S. typhimurium, other: TA97a, TA98, TA100 and TA102

Metabolic activation:

with and without

Metabolic activation system:

Sprague-Dawley rat liver, Induced with Phenobarbital and beta-naphthoflavone

Test concentrations with justification for top dose:

The test substance was dissolved in distilled water and diluted to 5-500 ug/plate [probably 10, 50, 100 or 500 ug/plate] in all four tester strains , in the absence or presence of (4% and 10%) S9. The number of revertant colonies on the plates were recorded after 48 hours of incubation in the dark at 37degC.

Controls

Controls 1

Negative solvent / vehicle controls:

yes

Remarks:

Distilled water

Positive controls:

yes

Positive control substance:

methylmethanesulfonate

Controls 2

Positive controls:

yes

Positive control substance:

other: 2-aminofluorene

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation)

DURATION
- Exposure duration: 48 hr in dark

NUMBER OF REPLICATIONS: Tests done in duplicate and repeated at least three times

Evaluation criteria:

For the test substance to be considered mutagenic, a two-fold (or more) increase in the mean revertant numbers must be observed in the plates containing the test substanced compared to the spontaneous reversion rate.

Results and discussion

Test results

Test results 1

Species / strain:

S. typhimurium, other: TA97a, TA98, TA100 and TA102

Metabolic activation:

with

Genotoxicity:

positive

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Test results 2

Species / strain:

S. typhimurium, other: TA97a, TA98 and TA102

Metabolic activation:

without

Genotoxicity:

positive

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Test results 3

Species / strain:

S. typhimurium, other: TA100

Metabolic activation:

without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Additional information on results:

The test substance caused a 2- to 10-fold increase in revertants in all four tester strains (compared with spontaneous reversion rates), in the presence of S9. In the absence of S9, a 2- to 10-fold increase in reversion rates was seen in three tester strains, whereas in TA100 there was no evidence of a mutagenic effect. "The increase in reverse mutation rates in the samples that tested positive was dosage-dependent".

Any other information on results incl. tables

High doses of the metal compounds proved toxic to the tester strains", resulting in a thinning of the background bacterial lawn. Although no actual data were provided for ammonium hexachlororhodate, the minimum toxic dose for the rhodium salts was apparently 500 ug/plate.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
positive

Ammonium hexachlororhodate was mutagenic in a bacterial reverse mutation assay using Salmonella typhimurium strains TA97a, TA98, TA100 and TA102 when tested in the presence and absence of a rat liver metabolic activation system.

Executive summary:

In a bacterial reverse mutation assay,similar to OECD Test Guideline 471, ammonium hexachlororhodate was tested for mutagenic activity using Salmonella typhimurium strains TA97a, TA98, TA100 and TA102 in both the presence and absence of a metabolic activation system derived from phenobarbital and beta-naphthoflavone induced rat livers (S9). (The recommended strain TA1535 was omitted.) A mutagenic effect was seen in all four strains in the presence of metabolic activation and in all but strain TA100 in its absence.

 

In conclusion, the test substance was mutagenic in Salmonella typhimurium, in the presence and absence of metabolic activation.