2,4,6-trinitrotoluene

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

As far as in vitro studies, the substance is a potential mutagen and further in vivo testing is necessary.

Link to relevant study records

Reference

Reference 1

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: genome mutation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1 Feb 1975 - 28 Feb 1978

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Qualifier:

equivalent or similar to guideline

Guideline:

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

GLP compliance:

no

Remarks:

The studies were conducted in 1978, before implemenation of OECD Guidelines (1981) and EU Guidelines (1988) as well as GLP principles. The studies were probably conducted according to TSCA guidelines.

Type of assay:

bacterial reverse mutation assay

Specific details on test material used for the study:

Test material was dissolved in DMSO at different concentrations.

Species / strain / cell type:

S. typhimurium TA 1538

Species / strain / cell type:

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

Details on mammalian cell type (if applicable):

The S-9 fraction from rat liver prepared according to the procedure of Ames Test.

Metabolic activation:

with

Metabolic activation system:

The microsomal activation system used for mutagenic assay contained per ml: S-9 fraction (0.08 ml), NADP (4 uM), glucose-6-phosphate (5 uM), KCl (33 uM), MgCl2 (8 uM), and sodium phosphate buffer (100 uM), pH 7.4.The system was prepared fresh daily.

Test concentrations with justification for top dose:

1000, 300, 100, 30 and 10 ug/plate (0.1 ml)

Details on test system and experimental conditions:

all strains/cell types tested

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with

Genotoxicity:

positive

Remarks:

300 ug/plate

Cytotoxicity / choice of top concentrations:

not determined

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with

Genotoxicity:

positive

Remarks:

10 ug/plate of TNT

Cytotoxicity / choice of top concentrations:

not determined

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with

Genotoxicity:

positive

Remarks:

10 ug/plate of TNT

Cytotoxicity / choice of top concentrations:

not determined

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with

Genotoxicity:

positive

Remarks:

300 ug/plate

Cytotoxicity / choice of top concentrations:

not determined

Species / strain:

S. typhimurium TA 1538

Metabolic activation:

with

Genotoxicity:

positive

Remarks:

10 ug/plate of TNT

Cytotoxicity / choice of top concentrations:

not determined

Remarks on result:

other: Potential mutagen.

TNT exhibited significant increase in the number of revertants at 10 and 30 ug/plate.It produced both base-pair substitution and frame-shift mutations. As little as 10 ug/plate of TNT was mutagenic in the TA-98, TA-1538 and TA-1537 strains. When 30 ug/plate were used, TNT was positive in four test strains; at 300 ug/plate, TNT was positive in all five tester strains.

 

Conclusion: Potential mutagen.

Conclusions:

Potential mutagen. Further testing is necessary.

Reference 2

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:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Holston Army Ammunition Plant (Kingston, TN, USA)

Species / strain / cell type:

S. typhimurium TA 98

Species / strain / cell type:

S. typhimurium TA 100

Metabolic activation:

with and without

Metabolic activation system:

S9

Test concentrations with justification for top dose:

Five dose levels of each compound were prepared.

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO

Positive controls:

yes

Positive control substance:

sodium azide

Remarks:

for strain TA100

Positive controls:

yes

Positive control substance:

other: 2,4,7-trinitro-9-fluorenone

Remarks:

for strain TA98

Positive controls:

yes

Positive control substance:

benzo(a)pyrene

Remarks:

to check activity of the S9 in each series of tests with each bacterial strain.

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

not applicable

Genotoxicity:

not determined

Cytotoxicity / choice of top concentrations:

not determined

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

not applicable

Genotoxicity:

not determined

Cytotoxicity / choice of top concentrations:

not determined

Species / strain:

E. coli WP2

Metabolic activation:

not applicable

Genotoxicity:

not determined

Cytotoxicity / choice of top concentrations:

not determined

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with

Genotoxicity:

negative

Remarks:

exhibiting no mutagenicity

Cytotoxicity / choice of top concentrations:

not determined

Species / strain:

S. typhimurium TA 100

Metabolic activation:

without

Genotoxicity:

negative

Remarks:

exhibiting no mutagenicity

Cytotoxicity / choice of top concentrations:

not determined

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with

Genotoxicity:

positive

Remarks:

slightlu mutagenic

Cytotoxicity / choice of top concentrations:

not determined

Species / strain:

S. typhimurium TA 98

Metabolic activation:

without

Genotoxicity:

positive

Remarks:

slightlu mutagenic

Cytotoxicity / choice of top concentrations:

not determined

Not mutagenic in strain TA 100; slightly mutagenic in strain TA 98. Further testing is necessary.

Conclusions:

Not mutagenic in strain TA 100; slightly mutagenic in strain TA 98. Further testing is necessary.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (positive)

Genetic toxicity in vivo

Description of key information

Negative response observed for TNT in the liver assay indicates that it is unlikely to be rat hepatocarcinogen.

Link to relevant study records

Reference

Endpoint:

in vivo mammalian cell study: DNA damage and/or repair

Remarks:

Type of genotoxicity: DNA damage and/or repair

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 486 (Unscheduled DNA Synthesis (UDS) Test with Mammalian Liver Cells in vivo)

Qualifier:

according to guideline

Guideline:

EU Method B.39 (Unscheduled DNA Synthesis (UDS) Test with Mammalian Liver Cells In Vivo)

GLP compliance:

yes

Type of assay:

unscheduled DNA synthesis

Species:

rat

Strain:

other: Alderley Park (AP) or Fischer 344 (F344)

Sex:

male

Route of administration:

oral: gavage

Duration of treatment / exposure:

12 hours

Frequency of treatment:

adminitered once

Dose / conc.:

100 mg/kg bw/day (actual dose received)

Dose / conc.:

200 mg/kg bw/day (actual dose received)

Dose / conc.:

500 mg/kg bw/day (actual dose received)

Dose / conc.:

1 000 mg/kg bw/day (actual dose received)

No. of animals per sex per dose:

2, 3 or 5 animals per dose

Control animals:

yes

Tissues and cell types examined:

Liver, blood.

Key result

Sex:

male

Genotoxicity:

negative

Toxicity:

no effects

TNT was inactive in each strain. Urine of the TNT-treated animals esd bright red due to the presence of TNT (in an acid medium) and their blood contained elevated levels of methaemoglobin. Nonetheless, hepatocyte, morphology was normal and showed no evidence of toxic picnosis.

Conclusions:

Interpretation of results: negative.
Negative response observed for TNT in the liver assay indicates that it is unlikely to be rat hepatocarcinogen. Nonetheless, high levels, of methaemoglobin were observed in the TNT-trerated rats and their urine was coloured red. These facts, together with the known toxicities of this agent suggest a possible carcinogenic hazard to the haemopoetic and urinary tissue of animals exposed chronically to it at toxic dose-levels.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Additional information

Additional information from genetic toxicity in vivo:

Justification for selection of genetic toxicity endpoint
In vivo study is supposed to be more relevant.

Justification for classification or non-classification

In vivo data available for TNT confirms negative responses which is sufficient for no classification of TNT as mutagenic.