p-toluidine

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: Comparable to guideline with acceptable restrictions: only 4 strains used, no cytotox. concentration given, no information on GLP

Data source

Reference

Reference 1

Reference Type:

publication

Title:

Salmonella Mutagenicity tests: V. Results from the testing of 311 chemicals

Author:

Zeiger, E. et al.

Year:

1992

Bibliographic source:

Environm Mol Mutagen 19 [21], 2-141.

Reference 2

Reference Type:

secondary source

Title:

p-Toluidine - CAS No: 106-49-0 - SIDS Initial Assessment Report.

Author:

OECD

Year:

2005

Bibliographic source:

UNEP Publications

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

yes

Remarks:

No GLP study. Only four strains were used. Number of replicated trials not reported

GLP compliance:

not specified

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

p-toluidine

EC Number:

203-403-1

EC Name:

p-toluidine

Cas Number:

106-49-0

Molecular formula:

C7H9N

IUPAC Name:

4-methylaniline

Details on test material:

- Name of test material (as cited in study report): p-toluidine hydrochloride
- Analytical purity: 95.7%

Method

Target gene:

his

Species / strain

Species / strain / cell type:

other: Salmonella typhimurium TA97, TA98, TA100, TA1535

Metabolic activation:

with and without

Metabolic activation system:

S9-mix was prepared from Aroclor 1254-induced male Sprague-Dawley rats (RLI) and males Syrian Hamster (HLI) in 10 % and 30 % concentrations.

Test concentrations with justification for top dose:

0, 33, 100, 333, 1000, 2000, 3333 µg/plate in water

Vehicle / solvent:

- Vehicle/solvent used: water

Controls

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: see any other information on the material and methods

Details on test system and experimental conditions:

METHOD OF APPLICATION: preincubation

DURATION
- Preincubation period: 20 min

DETERMINATION OF CYTOTOXICITY
- Method: All chemicals were run initially in a toxicity assay to determine the appropriate dose range for the mutagenicity assay. The toxicity assay was performed using TA100 or the system developed by Waleh et al. 1982. Mutat. Res. 97:247-256. Toxic concentrations were defined as those that produced a descrease in the number of his+ colonies, or a clearing in the density of the background lawn, or both.

Evaluation criteria:

A chemical was judged mutagenic or weakly mutagenic if it produced a reproducible dose-related response over the solvent control, under single metabolic activation condition, in replicate trials. A chemical was judged questionable (?) if the results of individual trials were not reproducible, if increases in his+ revertants did not meet the criteria for a "+W" response, or if only single doses produced increases in his+ revertants in repeat trials. Chemicals were judged nonmutagenic (-) if they did not meet the critearia for a mutagenic or questionable response.

Results and discussion

Test results

Test results 1

Species / strain:

other: Salmonella typhimurium TA97, TA98, TA1535

Metabolic activation:

with and without

Genotoxicity:

negative

Remarks:

see remarks on results including tables and figures

Cytotoxicity / choice of top concentrations:

other: cytotoxicity was determined in preliminary experiments (no further information)

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Test results 2

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with

Genotoxicity:

positive

Cytotoxicity / choice of top concentrations:

other: cytotoxicity was determined in preliminary experiments (no further information)

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Test results 3

Species / strain:

S. typhimurium TA 100

Metabolic activation:

without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

other: cytotoxicity was determined in preliminary experiments (no further information)

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Remarks on result:

other: other: Salmonella typhimurium TA97, TA98, TA100, TA1535

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

Table 1.Mutagenic responses (mean ± SEM; three plates) of Salmonella tester strains to p-toluidine HCl.

 

	TA 100														TA 1535
DOSE	NA (-)		NA (-)		10% HLI (?)		30% HLI (+)		30% HLI (+w)		10% RLI (?)		30% RLI (-)		NA (-)		10% HLI (-)		30% HLI (-)		10% RLI (-)		30% RLI (-)
µg/PLATE	MEAN	SEM	MEAN	SEM	MEAN	SEM	MEAN	SEM	MEAN	SEM	MEAN	SEM	MEAN	SEM	MEAN	SEM	MEAN	SEM	MEAN	SEM	MEAN	SEM	MEAN	SEM
0	132	7.8	107	8.1	113	6.2	122	0.7	110	10.4	114	5.8	143	1.5	39	2.0	15	2.2	10	3.3	17	3.5	13	2.0
33	142	8.3			120	7.8					131	5.2					12	0.9			13	2.1
100	133	3.5	123	4.7	128	4.0	134	0.3	139	5.1	135	4.9	130	2.5	28	5.9	9	2.0	14	1.9	9	2.8	13	1.5
333	135	8.4	103	7.0	154	3.7	164	5.8	147	9.6	153	12.6	145	3.2	30	2.0	12	1.9	16	2.9	14	0.9	16	2.1
1000	137	5.1	122	6.0	146	4.4	219	23.4	158	9.5	157	3.3	155	14.2	32	2.3	16	2.5	18	1.9	13	2.2	15	1.8
2000	137s	6.2	116s	11.1	178s	8.2	239s	10.3	197s	19.0	157s	5.4	156s	9.3	33	5.4	15s	0.9	17	1.2	10s	2.5	17	2.3
3333			111s	7.3			256s	6.9	191s	10.7			156s	8.6	17s	3.5			17s	2.7			11s	1.5
POS	1441	49.7	1516	49.8	1622	18.3	993	9.9	1952	66.7	1577	21.7	525	16.3	1131	12.1	149	9.0	288	16.7	133	7.0	134	9.5

 

 

Table 2.Mutagenic responses (mean ± SEM; three plates) of Salmonella tester strains to p-toluidine HCl

 

 

 

	TA97										TA98
DOSE	NA (-)		10% HLI (?)		30% HLI (-)		10% RLI (-)		30% RLI (-)		NA (-)		10% HLI (-)		30% HLI (-)		10% RLI (-)		30% RLI (-)
µg/PLATE	MEAN	SEM	MEAN	SEM	MEAN	SEM	MEAN	SEM	MEAN	SEM	MEAN	SEM	MEAN	SEM	MEAN	SEM	MEAN	SEM	MEAN	SEM
0	138	4.3	110	6.6	194	12.8	135	4.2	233	6.4	17	3.5	30	3.9	29	2.2	39	2.2	40	1.7
33			140	12.2			157	4.3					37	3.9			40	1.7
100	131	0.3	172	3.0	205	8.7	146	10.2	227	17.2	15	1.5	35	4.1	28	1.5	43	3.5	34	2.6
333	127	7.2	148	1.5	212	12.7	151	6.3	220	14.6	16	5.7	36	1.2	40	1.7	44	1.2	36	4.7
1000	133s	3.5	135	8.3	200	5.8	173	5.0	193	3.9	19	2.6	38	5.0	44	7.7	38	2.8	47	5.2
2000	122s	2.0	144s	7.5	209s	8.9	166s	6.7	218s	8.8	15	0.9	38	1.5	45s	3.1	41	2.9	35	0.9
3333	99s	5.7			194s	2.6			184s	6.4	13s	1.2			46s	3.6			40s	4.4
POS	1257	33.7	1011	75.0	840	31.0	1087	30.4	477	11.8	1112	32.0	1930	44.6	1251	7.4	1571	43.9	443	22.0

 

HLI =Aroclor1254-induced hamster liver S9

RLI =Aroclor1254-induced rat liver S9;

s = slight clearing of background lawn (colonies not counted)

+ = mutagenic

+W= weakly mutagenic

? = questionable response;

- =non mutagenic

 

POS: positive control

 

 

 

 

Negative results were noted in all strains with and without metabolic activation except TA100 in the presence of hamster liver S9-mix.
The positive controls were functional.
Overall conclusion: weak positive

 

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
positive with metabolic activation in Salmonella typhimurium strain TA100
negative without metabolic activation in Salmonella typhimurium strain TA100
negative in Salmonella typhimurium strains TA97, 98 and 1535

Executive summary:

Zeiger (1992)

The Ames test was conducted with a method similar to OECD guideline 471 with deviations (only four strains were used. Positive controls were used, but the name of the substances were not mentioned)

p-toluidine in concentrations ranging between 0 and 3333 µg/plate using Salmonella typhimurium TA97, TA98 and TA1535 without metabolic activation and in the presence of hamster or rat liver S9-mix was found not mutagenic. Salmonella typhimurium TA100 was tested negative without metabolic activation and in the presence of rat liver S9-mix but was positive in the presence of hamster liver S9-mix. Concurrent positive controls were always functional.