Palladium sulphate

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Palladium (II) sulphate hydrate was non-mutagenic, when tested either with or without S9, in a guideline bacterial reverse mutation assay (Sarada, 2008).

Link to relevant study records

Reference

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:

21 February 2008 to 13 March 2008

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study (OECD, Japan)

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

Qualifier:

according to guideline

Guideline:

JAPAN: Guidelines for Screening Mutagenicity Testing Of Chemicals

Deviations:

no

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Target gene:

Histidine for S. typhimurium strains; tryptophan for E.coli WP2 uvrA

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

Additional strain / cell type characteristics:

not applicable

Species / strain / cell type:

E. coli WP2 uvr A

Additional strain / cell type characteristics:

not applicable

Metabolic activation:

with and without

Metabolic activation system:

S9, microsomal fraction derived from phenobarbital- and 5,6-benzoflavone-induced rat liver

Test concentrations with justification for top dose:

2.4, 4.9, 10, 20, 39 or 78 μg/plate in tests without S9
10, 20, 39, 78, 156 or 313 μg/plate in tests with S9
(These concentrations were selected after a preliminary test using doses of 1.2, 4.9, 20, 78, 313, 1250 or 5000 μg/plate showed that growth inhibition occurred at and above 78 and 313 μg/plate, respectively without and with S9)

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: dehydrated DMSO
- Justification for choice of solvent/vehicle: at request of sponsor and after solubility tests

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

benzo(a)pyrene

Remarks:

5.0 μg/plate for TA1537, TA98 and TA100 with S9

Positive control substance:

sodium azide

Remarks:

0.5 μg/plate for TA1535 without S9

Positive control substance:

other: 2-aminofluorene

Remarks:

0.01 μg/plate for TA100 and E. coli WP2 uvrA and 0.1 μg/plate for TA98 without S9

Positive control substance:

other: 2-aminoanthracene

Remarks:

2.0 μg/plate for TA1535 and 10 μg/plate for E. coliWP2 uvrA with S9

Positive control substance:

other: ICR-191

Remarks:

1.0 μg/plate for TA1537 without S9

Details on test system and experimental conditions:

METHOD OF APPLICATION: preincubation

DURATION
- Preincubation period: 20 min
- Exposure duration: 48 hr

NUMBER OF REPLICATIONS: plates prepared in triplicate; duplicate studies carried out.

OTHER: The preparations of the test solutions and the study procedures were conducted under lamps with ultraviolet light absorbent filters.

Evaluation criteria:

The test substance was considered to demonstrate mutagenic activity if the number of revertant colonies was at least double that of the spontaneous mutants on the control plates and showed a reproducible dose-response.

Species / strain:

S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

at 78 μg/plate without S9 for all strains and at 156 and 313 μg/plate with S9

Vehicle controls validity:

valid

Positive controls validity:

valid

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

at 78 μg/plate without S9 for all strains and at 156 and 313 μg/plate with S9

Vehicle controls validity:

valid

Positive controls validity:

valid

Additional information on results:

RANGE-FINDING/SCREENING STUDIES: a preliminary test showed cytotoxicity at and above 78 and 313 μg/plate, respectively without and with S9. No increase in mutation frequency was observed with the test substance

COMPARISON WITH HISTORICAL CONTROL DATA: no data given in the report but the frequency of spontaneous revertants are within the ranges given in the literature. Mutation frequency for the positive control substances were reported to be within the historic range

ADDITIONAL INFORMATION ON CYTOTOXICITY:

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Conclusions:

Interpretation of results (migrated information):
negative

Palladium (II) sulphate hydrate did not cause an increase in mutation frequency when tested at up to the limits of cytotoxicity, either with or without S9, in a guideline (GLP) bacterial reverse mutagenicity assay.

Executive summary:

In a OECD Test Guideline 471 study, to GLP, the mutagenic potential of palladium (II) sulphate hydrate was assessed in a reverse mutagenicity assay (Ames test) using the S. typhimurium strains TA1535, TA1537, TA98 and TA100 and E. coli WP2 uvrA.

 

Two independent experiments (each in triplicate) were carried out using the preincubation method, both with and without S9. A preliminary range-finding study had shown the test substance to be cytotoxic at doses at and above 78 and 313 μg/plate, respectively, without and with S9. In consequence these were the top doses tested.

 

Palladium (II) sulphate hydrate did not cause an increase in mutation in these studies, either with or without S9. In contrast, the known mutagens used as positive controls showed the expected mutagenic activity.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Genetic toxicity in vivo

Description of key information

No data identified.

Endpoint conclusion

Endpoint conclusion:

no study available

Mode of Action Analysis / Human Relevance Framework

No data identified.

Additional information

No studies conducted in humans were identified.

 

In an OECD Test Guideline 471 study, to GLP, the mutagenic potential of palladium (II) sulphate hydrate was assessed in a reverse mutagenicity assay (Ames test) using the Salmonella typhimurium strains TA1535, TA1537, TA98 and TA100 and Escherichia coli strain WP2 uvrA. At the limit of cytotoxicity (78 and 313 μg/plate, respectively, without and with S9), palladium (II) sulphate hydrate did not cause an increase in mutation frequency. In contrast, the known mutagens used as positive controls showed the expected mutagenic activity (Sarada, 2008).

Justification for selection of genetic toxicity endpoint
OECD guideline study, to GLP, and the only in vitro genetic toxicity study available.

Justification for classification or non-classification

No evidence of genotoxic activity was seen in a reliable mutagenicity assay in bacterial cells. No studies specifically assessing the mutagenic activity in germ cells were identified. However, the available evidence provides no basis for classifying palladium sulphate for germ cell mutagenicity, according to EU CLP criteria (EC 1272/2008).