long chain alkyl thio carbamide metal complex

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

10 April 2003 to 7 May 2003

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2003

Report date:

2003

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 (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Test material form:

liquid: viscous

Details on test material:

Batch: MRD-02-375
Expiry date: Feb 2008
Viscous black liquid

Method

Target gene:

histidine locus (S. typimurium strains), tryptophan locus (E. coli)

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 pKM 101

Additional strain / cell type characteristics:

not applicable

Metabolic activation:

with and without

Metabolic activation system:

post-mitochondrial fraction derived from Aroclor 1254-induced rat liver (S-9 mix).

Test concentrations with justification for top dose:

Range-finding study: 0, 5, 15, 50, 150, 500, 1500 and 5000 µg/plate
Study 2: 0, 50, 150, 500, 1500 and 5000 µg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: hexane
- Justification for choice of solvent/vehicle: due to the insolubility of the test substance in more commonly used solvents

Controls

Controls 1

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

sodium azide

Remarks:

without S9 Migrated to IUCLID6: 0.5 ug/plate (TA 1535 and TA100)

Controls 2

Positive controls:

yes

Positive control substance:

9-aminoacridine

Remarks:

without S9 Migrated to IUCLID6: 50 ug/plate (TA1537)

Controls 3

Positive controls:

yes

Positive control substance:

2-nitrofluorene

Remarks:

without S9 Migrated to IUCLID6: 1 ug/plate (TA98)

Controls 4

Positive controls:

yes

Positive control substance:

other: 2-(2-Furyl)-3-(5-nitro-2-furyl)acrylamide; 0.05 ug/plate (WP2 uvrA, pKM101)

Remarks:

without S9

Controls 5

Positive controls:

yes

Positive control substance:

other: 2-aminoanthracene; 2 ug/plate (TA1535), 10 ug/plate (WP2 uvrA pKM101)

Remarks:

with S9

Controls 6

Positive controls:

yes

Positive control substance:

benzo(a)pyrene

Remarks:

with S9 Migrated to IUCLID6: 5 ug/plate (TA1537, TA98, TA100)

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation)
DURATION
- Preincubation period: none
- Exposure duration: 72 hr


NUMBER OF REPLICATIONS: 3 plates prepared per concentration, two independent studies were carried out

NUMBER OF CELLS EVALUATED: 10(8)/plate

DETERMINATION OF CYTOTOXICITY
- Method: relative total growth (background lawn)

Evaluation criteria:

Considered positive if there was a reproducible increase in revertants of an least twice (three times for TA1535 and TA1537) the vehicle controls.

Statistics:

No statistical analysis was performed where the test gave a clear positive or negative result

Results and discussion

Test results

Test results 1

Key result

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Remarks:

There is historical control data on the vehicle, therefore untreated control not necessary in accordance with the OECD TG 471.

True negative controls validity:

not examined

Positive controls validity:

valid

Test results 2

Key result

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Remarks:

There is historical control data on the vehicle, therefore untreated control not necessary in accordance with the OECD TG 471.

True negative controls validity:

not examined

Positive controls validity:

valid

Test results 3

Key result

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Remarks:

There is historical control data on the vehicle, therefore untreated control not necessary in accordance with the OECD TG 471.

True negative controls validity:

not examined

Positive controls validity:

valid

Test results 4

Key result

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Remarks:

There is historical control data on the vehicle, therefore untreated control not necessary in accordance with the OECD TG 471.

True negative controls validity:

not examined

Positive controls validity:

valid

Test results 5

Key result

Species / strain:

E. coli WP2 uvr A pKM 101

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Remarks:

There is historical control data on the vehicle, therefore untreated control not necessary in accordance with the OECD TG 471.

True negative controls validity:

not examined

Positive controls validity:

valid

Additional information on results:

RANGE-FINDING/SCREENING STUDIES: the first study was a range-finding study

COMPARISON WITH HISTORICAL CONTROL DATA: historical control data was included in the report for the bacterial strains used, the combined data for solvent controls, and for the positive controls

Remarks on result:

other: No mutagenic potential

Any other information on results incl. tables

The concurrent positive controls demonstrated the sensitivity of the assay and the metabolising activity of the liver preparations.

Applicant's summary and conclusion

Conclusions:

Interpretation of results: negative

In a GLP study conducted according to OECD guideline 471, test material MRD-02-375 (EC# 457-320-2) showed no mutagenic potential in an assay for reverse mutation in bacterial strains, at up to 5 mg/plate with and without S9.

Executive summary:

In a GLP study conducted according to OECD guideline 471, the mutagenic potential of test material MRD-02 -375 (EC#457-320-2) was assessed in a bacterial mutation assay (Ames test).

Up to 5000 micrograms/plate of the test substance (dissolved in hexane) was incubated with S. typhimurium strains TA1535, TA1537, TA98 and TA100 and E. coli strain WP2 uvrA pKM101 in a plate incorporation assay, both with an without a rat liver activation fraction (S9). After 72 hr incubation the revertant colonies were counted using an automated colony counter. Two independent assays were carried out with triplicate plates being prepared for each concentration.

No increases in revertant colonies were observed with the test material compared to the vehicle controls. No cytotoxicity was observed as shown by the presence of a confluent background lawn. The positive control substances showed the expected increases in mutant frequency, indicating the effective performance of the assay.

In conclusion, EC# 457 -320 -2 showed no mutagenic potential in an assay for reverse mutation in bacterial strains, at up to 5 mg/plate with and without S9.