4-methylanisole

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Based on the summaries from 4 Ames test, as well as in vivo the test item is not genotoxic.

Link to relevant study records

Reference

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1980

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

yes

Remarks:

in the first mutation test, data was provided for 4 bacterial strains only (due to contamination in the 5th strain).

GLP compliance:

not specified

Remarks:

test performed prior to the GLP criteria

Type of assay:

bacterial reverse mutation assay

Target gene:

Histidine operon

Species / strain / cell type:

other: Salmonella typhimurium strains TA100, TA1535, TA1538, TA98 and TA1537

Metabolic activation:

with and without

Metabolic activation system:

S9-mix

Test concentrations with justification for top dose:

- First mutation test: 10, 1, 0.1, 0.01 µl/plate
- Repeat test: 0.1, 0.01, 0.001, 0.0001 µl/plate

Vehicle / solvent:

DMSO

Untreated negative controls:

not specified

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: -S9: TA 1535/100 sodium azide (5µg/plate); -S9: TA 1537/1538/98 4-nitro-o-phenylenediamine (500µg/plate); +S9: TA 1535/98/100 2-amino-anthracene (2 µg/plate); +S9: TA 1537 Neutral red (10 µg/plate); +S9: TA 1538 2-acetyl-aminofluorene (20 µg/plate)

Details on test system and experimental conditions:

DETERMINATION OF CYTOTOXICITY
- Method: other: Bacteriostatic test assessing zone of inhibition; assessment of bacterial lawn

Key result

Species / strain:

other: Salmonella typhimurium strains TA100, TA1535, TA1538, TA98 and TA1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

other: >= 1 µl /plate

Vehicle controls validity:

valid

Untreated negative controls validity:

not specified

Positive controls validity:

valid

Remarks on result:

other: all strains/cell types tested

Table 1: Maximum revertants/plate and corresponding test concentrations in the1st mutation test:
Strain	Tested compound	Maximum revertants/plate [corresponding dose unit in µg/plate]
		without S9-mix	with S9-mix
S. typhimurium TA1535	vehicle control	16	15
	Test substance	15 [0.1]	14 [0.1]
	Positive Control	721	408
S. typhimurium TA1537	vehicle control	7	7
	Test substance	7 [0.01]	7 [0.1]
	Positive Control	115	141
S. typhimurium TA1538	vehicle control	15	15
	Test substance	16 [0.1]	15 [0.01]
	Positive Control	529	448
S. typhimurium TA98	vehicle control	34	36
	Test substance	36 [0.1]	36 [0.1]
	Positive Control	1111	617
S. typhimurium TA100	vehicle control	contamination	contamination
	Test substance	contamination	contamination
	Positive Control	contamination	contamination
Table 2: Maximum revertants/plate and corresponding test concentrations in therepeat test:
Strain	Tested compound	Maximum revertants/plate [corresponding dose unit in µg/plate]
		without S9-mix	with S9-mix
S. typhimurium TA1535	vehicle control	16	12
	Test substance	18 [0.0001]	14 [0.0001]
	Positive Control	926	178
S. typhimurium TA1537	vehicle control	8	10
	Test substance	10 [0.0001]	10 [0.001]
	Positive Control	136	65
S. typhimurium TA1538	vehicle control	15	13
	Test substance	13 [0.0001]	19 [0.0001]
	Positive Control	1158	183
S. typhimurium TA98	vehicle control	39	31
	Test substance	42 [0.001]	32 [0.0001]
	Positive Control	1600	contaminated
S. typhimurium TA100	vehicle control	86	68
	Test substance	92 [0.0001]	71 [0.0001]
	Positive Control	644	contaminated

Conclusions:

Under the experimental conditions of the test, there was no evidence of mutagenic potential of p-methylanisol.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Genetic toxicity in vivo

Description of key information

Based on the 2 in vivo studies, one UDS and one micronucleus, the test item is not genotoxic.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Additional information

In the key study similar to OECD TG 471, different ranges of 4-methylanisol concentrations (i.e. 0.01, 0.1, 1 and 10 µl/plate or 0.0001, 0.001, 0.01, 0.1 µl/plate in DMSO) were tested in an Ames test and no mutagenic potential in the Salmonella strains TA1535, TA1537, TA1538, TA98 and TA100 with/without metabolic activation was shown (Givaudan ULR/59/791049). Toxicity to bacteria was found as absence or incomplete formation of the background bacterial lawn from 1 µl/plate onward.

In a supportive study, 4-methylanisol was found negative in an Ames test at concentrations of 0.1, 0.5, 1, 2.5, 5, 10, 25 and 50 µl/plate using Salmonella strain TA1535, TA1537, TA1538, TA98 and TA100 with/without metabolic activation (Lorillard1984).

In a supportive study, 4-methylanisol was reported to be negative in an Ames test using Salmonella typhimurium strain TA 1535, TA 1537, TA 98 and TA 100 with/without metabolic activation, at a single test substance concentration, i.e. 366.5 µg/plate (Florin1980).

In vitro gene mutation of 4-methylanisol in bacteria was tested in a further Ames test specified as plate incorporation assay, being reported as short database summary. 4 -methylanisol was found negative, using Salmonella strain TA1535, TA1537, TA1538, TA98 and TA100 with/without metabolic activation (Heck1989A). The test substance concentration of 50000 µg/plate was reported as highest concentration tested.

 

Taken together, 4-methylanisol is not mutagenic in bacteria with or without metabolic activiation.

 

Justification for classification or non-classification

The present data on genetic toxicity do not fulfill the criteria laid down in 67/548/EEC and regulation (EU) 1272/2008 and therefore, a non-classification is warranted.