1,3-dichloro-5-isocyanatobenzene

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

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: only 4 strains used - well documented and scientifically acceptable

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1995

Report date:

1995

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Principles of method if other than guideline:

The mutagenic potential of 3, 5-Dichlorphenylisocyanate was examined in the salmonella microsome test according to the plate incorporation and preincubation methode Bacteria of four histidine-auxotrophic Salmonella typhimurium LT2 mutant strains (TA 98, TA 100, TA 1535, and TA 1537) were exposed to doses up to 5000 µg per plate.

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

1,3-dichloro-5-isocyanatobenzene

EC Number:

252-276-9

EC Name:

1,3-dichloro-5-isocyanatobenzene

Cas Number:

34893-92-0

Molecular formula:

C7H3Cl2NO

IUPAC Name:

1,3-dichloro-5-isocyanatobenzene

Details on test material:

content: 99.7 %

Method

Target gene:

Ames assay: detection of base pair substitutions and frameshift mutations

Species / strain

Species / strain / cell type:

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

Additional strain / cell type characteristics:

not specified

Metabolic activation:

with and without

Metabolic activation system:

S9 mix

Test concentrations with justification for top dose:

(1) 0, 5000, 1000, 200, 40, 8 µg/plate dissolved in EDGE
(2) 0, 0.32, 1.00, 3.20, 10.0, 32, 100 µg/plate dissolved in EDGE

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

yes

Positive controls:

yes

Positive control substance:

other: sodium azide, nitrofurantoin, 4-nitro-1,2-phenylene diamine, 2-aminoanthracene

Details on test system and experimental conditions:

salmonella typhimurium strains (TA 98, Ta 100, TA 1535 and TA 1537) were used

Results and discussion

Test results

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:

doses up to 3.2 µg/plate did not cause bacteriotoxic effects. bacteriotoxic effects at higher doses yet doses up to 200 µg/plate could partially be used for assessment purposes

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

doses up to and including 3.2 µg/plate did not cause any bacteriotoxic effects when the plate incorporation method was used: total bacteria counts remained unchanged and no growth inhibition was observed. the substance revealed strong bacteriotoxic effects at higher doses yet doses up to 200 µg/plate could still partially be used for assessment purposes

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

Doses up to and including 3.2 µg per plate did not cause any bacteriotoxic effects when the plate incorporation method was used: Total bacteria counts remained unchanged and no growth inhibition was observed. The substance revealed strong bacteriotoxic effects at higher doses yet doses up to 200 µg per plate could still partially be used for assessment purposes.

After preincubation, bacteriotoxic effects were detected for the dose of 3.2 µg/plate and for higher doses.

.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative

Executive summary:

method: Ames test according OECD 471, the mutagenic potential of 3,5-Dichlorphenylisocyanate was examined in the salmonella microsome test according to the plate incorporation and preincubation methode Bacteria of four histidine-auxotrophic Salmonella typhimurium LT2 mutant strains (TA 98, TA 100, TA 1535, and TA 1537) were exposed to doses up to 5000 µg per plate.

result: negative, there was no evidence for mutagenic effects of 3,5-Dichlorphenylisocyanate with and without S9 mix. A biologically relevant increase of the mutant count over control levels was not observed. Therefore, 3,5-Dichlorphenylisocyanate was considered

to be non-mutagenic with and without S9 mix in the Salmonella/microsome test.