Disodium tetrachloropalladate

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:

10 October 2002 to 25 October 2002

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study (OECD, EEC), to GLP, on closely-related surrogate

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2002

Report date:

2002

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)

Deviations:

no

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Dihydrogen tetrachloropalladate(2-)

EC Number:

241-047-9

EC Name:

Dihydrogen tetrachloropalladate(2-)

Cas Number:

16970-55-1

IUPAC Name:

Dihydrogen tetrachloropalladate

Test material form:

other: liquid

Details on test material:

- Name of test material (as cited in study report): dihydrogen tetrachloropalladate (II)-solution
- Substance type: brown liquid
- Physical state: liquid
- Analytical purity: 99.95%
- Impurities (identity and concentrations): no data
- Composition of test material, percentage of components: 47% (w/v) of dihydrogen tetrachloropalladate(II) in the solution
- Isomers composition:
- Purity test date: no data
- Lot/batch No.: 4515932529
- Expiration date of the lot/batch: 12 September 2003
- Stability under test conditions: reported as stable in water for at least 96 hr
- Storage condition of test material: at room temperature in dark; stable

Method

Target gene:

Histidine

Species / strain

Species / strain 1

Species / strain / cell type:

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

Additional strain / cell type characteristics:

not applicable

Species / strain 2

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 Aroclor 1254-induced rat liver. The S9 mix contained 5% (v/v) S9 fraction in the first two studies and 10% (v/v) in the third study.

Test concentrations with justification for top dose:

Study 1:
3, 10, 33, 100, 333, 1000, 3300 and 5000 μg/plate for TA100 and WP2 uvrA.

Study 2:
3, 10, 33, 100, 200 and 333 μg/plate for TA15335, TA1537 and TA98.

Study 3:
3, 10, 33, 100 and 200 μg/plate for TA15335, TA1537 and TA98 without S9;
10, 33, 100, 200 and 333 μg/plate for TA15335, TA1537 and TA98 with S9;
10, 33, 100, 200 and333 μg/plate for TA100 and WP2 uvrA with or without S9.

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: water
- Justification for choice of solvent/vehicle: no data

Controls

Controls 1

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

methylmethanesulfonate

Remarks:

650 μg/plate for TA100 without S9

Controls 2

Positive control substance:

sodium azide

Remarks:

5 μg/plate for TA1535 without S9

Controls 3

Positive control substance:

4-nitroquinoline-N-oxide

Remarks:

10 μg/plate for WP2 uvrA without S9

Controls 4

Positive control substance:

9-aminoacridine

Remarks:

60 μg/plate for TA1537 without S9

Controls 5

Positive control substance:

other: daunomycin

Remarks:

4 μg/plate for TA98 without S9

Controls 6

Positive control substance:

other: 2-aminoanthracene

Remarks:

With 5% S9: 1 μg/plate for TA1535, TA98 and TA100; 2.5 μg/plate for TA1537; 5 μg/plate for WP2 uvrA. With 10% S9: 2.5 μg/plate for TA1535, TA1537, TA98 and TA100; 10 μg/plate for WP2 uvrA

Details on test system and experimental conditions:

METHOD OF APPLICATION: in medium; in agar (plate incorporation)

DURATION
- Exposure duration: 48 hr

NUMBER OF REPLICATIONS: Plating done in triplicate. Each bacterial strain tested in two independent studies

DETERMINATION OF CYTOTOXICITY
- Method: relative total growth

Evaluation criteria:

The test substance was considered to be mutagenic if the number of revertant colonies was at least twice that of the spontaneous revertants and reproducible in at least one independently repeated experiment. However any mean plate count of less than 20 revertants was considered to be not significant.

Results and discussion

Test results

Test results 1

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not specified

True negative controls validity:

not specified

Positive controls validity:

valid

Test results 2

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not specified

True negative controls validity:

not specified

Positive controls validity:

valid

Test results 3

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not specified

True negative controls validity:

not specified

Positive controls validity:

valid

Test results 4

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not specified

True negative controls validity:

not specified

Positive controls validity:

valid

Test results 5

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not specified

True negative controls validity:

not specified

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation: no

RANGE-FINDING/SCREENING STUDIES: yes. In the range-finding study, dihydrogen tetrachloropalladate (II)-solution was tested (in triplicate) at up to 5 mg/plate, in the presence or absence of a 5% rat liver metabolic activiation (S9) system. Cytotoxicity was seen at concentrations of 0.33 mg/plate and above.

COMPARISON WITH HISTORICAL CONTROL DATA: yes and acceptable minimum and maximum numbers of spontaneous revertants and revertants induced by the positive controls given in the report.

Remarks on result:

no mutagenic potential (based on QSAR/QSPR prediction)

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative

In an OECD Test Guideline 471 study, to GLP, dihydrogen tetrachloropalladate (solution) failed to induce an increase in mutation frequency in four S. typhimurium strains or in E. coli WP2 uvrA, either with or without S9, when tested at up to the limits of cytotoxicity.

Executive summary:

The mutagenic potential of dihydrogen tetrachloropalladate (solution) was assessed in a reverse mutagenicity assay, conducted according to OECD Test Guideline 471 and to GLP. The test substance was assessed in four Salmonella typhimurium strains (TA1535, TA1537, TA98 and TA100) and in Escherichia coli WP2 uvrA, in an attempt to detect both base-pair substitution and frameshift mutations.

In the range-finding study, dihydrogen tetrachloropalladate was tested (in triplicate) at up to 5 mg/plate, in the presence or absence of a 5% rat liver metabolic activation (S9) system. Cytotoxicity was seen at concentrations of 0.33 mg/plate and above. In Salmonella strains TA1535, TA1537 and TA98, cytotoxicity was observed at doses of 0.2 and 0.33 mg/plate, without or with a 5% rat liver S9 respectively. In an independent repeat study using all five strains, but this time without or with a 10% S9 fraction in the S9 mix, cytotoxicity was again seen at 0.2 and 0.33 mg/plate respectively.

Dihydrogen tetrachloropalladate (solution) did not cause an increase in mutation frequency, either with or without metabolic S9 activation, when compared to the spontaneous mutation frequency. In contrast, the known mutagens used as positive controls showed the expected mutagenic activity.