2-methyl-m-phenylene diisocyanate

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: Data is from peer reviewed journal

Data source

Reference

Reference Type:

publication

Title:

Chemical behavior of seven aromatic diisocyanates (toluenediisocyanates and diphenyl methane diisocyanates/ under in vitro conditions in relationship to their results in the Salmonella/microsome test

Author:

K. Seel , U. Walber a, B. Herbold b, R. Kopp

Year:

1999

Bibliographic source:

Mutation Research 438, 109–123

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: Similar to OECD 471

Principles of method if other than guideline:

Salmonella/microsome test was performed on 2, 6 Toluene diisocyanate chemical to know its mutagenic effect.

GLP compliance:

not specified

Type of assay:

bacterial gene mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

2-methyl-m-phenylene diisocyanate

EC Number:

202-039-0

EC Name:

2-methyl-m-phenylene diisocyanate

Cas Number:

91-08-7

Molecular formula:

C9H6N2O2

IUPAC Name:

1,3-diisocyanato-2-methylbenzene

Details on test material:

- Name of test material: 2,6 Toluene diisocyanate
- Molecular formula: C9H6N2O2
- Molecular weight: 174.1584 g/mol
- Substance type: Organic
- Physical state: No data
- Purity: No data available
- Impurities (identity and concentrations): No data available

Method

Target gene:

Histidine

Species / strain

Species / strain / cell type:

S. typhimurium, other: Salmonella typhimurium LT2 mutants TA 1535, TA 100, TA 1537 and TA 98

Details on mammalian cell type (if applicable):

Not applicable

Additional strain / cell type characteristics:

not specified

Metabolic activation:

with and without

Metabolic activation system:

S9 fraction was obtained from Aroclor 1254 500 mgrkg in corn oil, single intraperitoneal injection, 5 days prior to sacrifice. induced male Sprague–Daw- ley rats

Test concentrations with justification for top dose:

0,150,300,600,1200,2400 and 4800µg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: Ethyleneglycoldimethylether (EGDE)
- Justification for choice of solvent/vehicle: No data

Controls

Untreated negative controls:

not specified

Negative solvent / vehicle controls:

yes

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

other: 2-aminoanthracene with S9 metabolic activation system

Remarks:

No data on control chemical available

Details on test system and experimental conditions:

Details on test system and conditions
METHOD OF APPLICATION: in agar (plate incorporation)

DURATION
- Preincubation period: No data available
- Exposure duration: 48 hrs
- Expression time (cells in growth medium): 48 hrs
- Selection time (if incubation with a selection agent): No data available
- Fixation time (start of exposure up to fixation or harvest of cells): No data available

SELECTION AGENT (mutation assays): No data available
SPINDLE INHIBITOR (cytogenetic assays): No data available
STAIN (for cytogenetic assays): No data available

NUMBER OF REPLICATIONS: Duplicate. Three plates were used for each concentration and each strain.

NUMBER OF CELLS EVALUATED: No data available

DETERMINATION OF CYTOTOXICITY The toxicity of the substance was assessed as a gross appraisal of background growth on mutant plates and/or as a marked and dose-dependent reduction in the mutant count.

OTHER EXAMINATIONS:
- Determination of polyploidy: No data available
- Determination of endoreplication: No data available
- Other:

OTHER: No data available

Evaluation criteria:

A reproducible and dose-related increase in mutant counts of at least one strain is considered to be a positive result. For TA 98, this increase should be about twice that of negative controls, whereas for TA 1537 at least a threefold increase is required.

Statistics:

No data available.

Results and discussion

Test results

Test results 1

Species / strain:

S. typhimurium, other: TA 1535, TA 100, TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

valid

Untreated negative controls validity:

not specified

Positive controls validity:

valid

Test results 2

Species / strain:

S. typhimurium TA 98

Metabolic activation:

without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

valid

Untreated negative controls validity:

not specified

Positive controls validity:

valid

Test results 3

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with

Genotoxicity:

negative

Remarks:

upto 150 µg/plate for 10% S9 mix and upto 300 µg/plate for 30% S9 mix

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

valid

Untreated negative controls validity:

not specified

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Effects of pH: No data
- Effects of osmolality: No data
- Evaporation from medium: No data
- Water solubility: No data
- Precipitation: Yes, observed
- Other confounding effects: No data

RANGE-FINDING/SCREENING STUDIES: No data

COMPARISON WITH HISTORICAL CONTROL DATA: No data

ADDITIONAL INFORMATION ON CYTOTOXICITY: No data

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

Table: Result of 2,6 TDI dissolved in EDGE and metabolic activation

Strain S9, µg/plate	TA1537		TA98
	10% S9	30% S9	10% S9	30% S9
0	12	14	47	45
150	13	21	67	57
300	13	16	87*	61
600	15	15p	130*	73*
1200	7p	10p	166*p	97*p
2400	7p	9p	128*p	82*p
4800	P	P	P	P
2-Aminianthracene	360*	66*	1538*	618*

*: Mutagenic effect

p: precipitation

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative With and without Salmonella typhimurium TA 1535, TA 100, TA 1537
negative without metabolic activation Salmonella typhimurium strain TA98
negative with metabolic activation Salmonella typhimurium strain TA98; upto 150 µg/plate for 10% S9 mix and upto 300 µg/plate for 30% S9 mix

2, 6 Toluene diisocyanate is negative for the strains TA 1535, TA1537 and TA100 with and without S9 activation system and negative for Salmonella typhimurium strain TA98 upto 150 µg/plate for 10% S9 mix and upto 300 µg/plate for 30% S9 mix. Hence 2, 6 Toluene diisocyanate is not likely to classify as a gene mutant in vitro.

Executive summary:

Salmonella/microsome test was performed on 2, 6 Toluene diisocyanate to determine its mutagenic effect in the bacterial tester strains TA1535, TA1537, TA100 and TA98 of Salmonella typhimurium LT2 mutants. Plate incorporation method was performed and the reversion count was made after 48hrs incubation period.

2, 6 Toluene diisocyanate is negative for the strains TA 1535, TA1537 and TA100 with and without S9 activation system and negative for Salmonella typhimurium strain TA98 upto 150 µg/plate for 10% S9 mix and upto 300 µg/plate for 30% S9 mix. Hence 2, 6 Toluene diisocyanate is not likely to classify as a gene mutant in vitro.