2,2-dimethyl-3-phenylpropanol

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Ames test: This study was performed to investigate the potential of the test substance to induce gene mutations according to the plate incorporation test (experiment I) and the pre-incubation test (experiment II) using the Salmonella typhimurium strains TA 1535, TA 1537, TA98, TA 100 and TA 102. The test item did not induce gene mutations by base pair changes or frameshifts in the genome of the strains used. Therefore the test item is considered to be non-mutagenic in this Salmonella typhimurium reverse mutation assay. Chromosom aberration test: The test item dissolved in DMSO, was assessed for its potential to induce structural chromosomal aberrations in human lymphocytes in vitro in two independent experiments. The test item did not induce structural chromosomal aberrations as determined by the chromosome aberration test in human lymphocytes in vitro. Therefore, Muguetalkohol is considered to be non-clastogenic in this chromosome aberration test when tested up to the highest evaluable concentrations. Mouse lymphoma assay: The study was performed to investigate the potential of the test item to induce mutations at the mouse lymphoma thymidine kinase locus using the cell line L5178Y. The test item did not induce mutations in the mouse lymphoma thymidine kinase locus assay using the cell line L5178Y in the absence and presence of metabolic activatio. Therefore, the test substance is considered to be non-mutagenic in this mouse lymphoma assay.

Link to relevant study records

Reference

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: gene mutation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2008-02-15 to 2008-02-27

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP and guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Version / remarks:

1997

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and TA 102

Metabolic activation:

with and without

Metabolic activation system:

Phenobarbital (PB) and β-naphthoflavone (BNF) induced rat liver S-9 mix

Test concentrations with justification for top dose:

3, 10, 33, 100, 333, 1000, 2500 and 5000 µg/plate

Vehicle / solvent:

DMSO and deionised water

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Remarks:

water deionised

True negative controls:

no

Positive controls:

yes

Positive control substance:

sodium azide

Remarks:

TA1535, TA100 without metabolic activation

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 4-nitro-o-phenylene-diamine, 4-NOPD

Remarks:

TA 1537, TA98 without metabolic activation

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Remarks:

water deionised

True negative controls:

no

Positive controls:

yes

Positive control substance:

methylmethanesulfonate

Remarks:

TA102 without metabolic activation

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 2-aminoanthracene

Remarks:

All strains with metabolic activation

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation), preincubation

2 experiments: Preincubation Test and Standard Plate test

DURATION
- Preincubation period: 60 min
- Exposure duration: 48 hours

SELECTION AGENT: Histidine

DETERMINATION OF CYTOTOXICITY
- Method: Cloning efficiency

Evaluation criteria:

Considered as a mutagen if a biologically relevant increase in the number of revertants exceeding the threshold of twice or thrice the colony count of the corresponding solvent control is observed.

A dose dependent increase is considered biologically relevant if the threshold is exceeded at more than one concentration.

An increase exceeding the trehsold at only one concnetration is judged as biologically relevant if reproduced in an independent second experiment.

A dose dependant increase in the number of revertant colonies below the treshold is regarded as an indication of a mutagenic potential if reproduced in an independent second experiment. However, whenever the colony counts remain within the historical range of negative and solvent controls such an increase is not considered biologically relevant.

Species / strain:

S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and TA 102

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

other: negative controls valid, true negative controls not examined

Positive controls validity:

valid

Additional information on results:

Due to contamination of strain TA 1537 in experiment I not data could be obtained and this part was repeated under identical conditions (reported as experiment I). Each concnetration, including the contorls, was tested in triplicate.
No substantial increase in revertant colony numbers of any of the five tester strains was observed following treatment with the test item at any concentration level, neither in the presence nor absence of metabolic activation. There was aalso no tendency of higher mutation rates with increasing concentrations in the range below the generally acknowledged border of biological relevance. Appropriate reference mutagens were used as positive controls. They showed a distinct increase in induced revertant colonies.

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

	TA1535		TA1537		TA98		TA100		TA102
Concentration (µg/Plate)	I	II	I	II	I	II	I	II	I	II
Negative	12	17	15	16	18	31	127	133	438	363
Solvent Control	13	15	17	11	28	31	121	112	463	365
Positive Control	2066	1848	88	124	364	578	2298	2175	4455	1937
3	15	14	15	9	23	31	125	119	386	315
10	11	14	14	11	25	27	132	111	463	365
33	13	13	20	16	21	26	142	114	466	366
100	16	15	15	13	29	27	120	108	464	352
333	16	18	14	10	23	27	110	107	302	265
1000	12	10	9	6	25	9	73	72	91	90
2500	1	2	0	0	0	0	0	0	1	0
5000	0	0	0	0	0	0	0	0	0	0

with S9 Mix
	TA1535		TA1537		TA98		TA100		TA102
Concentration (µg/Plate)	I	II	I	II	I	II	I	II	I	II
Negative	16	20	21	21	35	45	150	133	509	435
Solvent Control	19	20	27	21	30	33	147	129	550	460
Positive Control	329	260	209	151	2292	1340	2969	1619	2938	2448
3	14	16	24	17	30	39	135	118	439	372
10	11	18	20	21	34	35	134	124	506	377
33	15	17	28	18	32	35	123	142	500	398
100	18	19	18	18	34	39	156	129	501	406
333	13	15	24	17	32	41	119	116	385	305
1000	12	4	20	2	27	14	99	6	189	7
2500	1	0	0	0	0	0	7	0	1	0
5000	0	0	0	0	0	0	0	0	0	0

Conclusions:

Interpretation of results (migrated information):
negative

It can be stated that during the described mutagenicity test and under the experimental conditions reported, the test item did not induce gene mutations by base pair changes or frameshifts in the genome of the strains used. Therefore the test item is considered to be non-mutagenic in this Salmonella typhimurium reverse mutation assay.

Executive summary:

This study was performed to investigate the potential of the test substance to induce gene mutations according to the plate incorporation test (experiment I) and the pre-incubation test (experiment II) using the Salmonella typhimurium strains TA 1535, TA 1537, TA98, TA 100 and TA 102. The assay was performed in two independent experiments both with and without liver microsomal activation. Due to contamination of strain TA 1537 in experiment I no data could be obtained and this part was repeated under identical conditions (reported as experiment I) Each concentration, including the controls was tested in triplicate. The test item was tested at the following concentrations:

3, 10, 33, 100, 33, 1000, 2500 and 5000 µg/plate.

Reduced background growth was observed in all strains with and without metabolic activation in both experiments.

Toxic effects, evident as reduction of the number of revertants (below the indicaiton factor of 0.5) were observed with and without metabolic activation in all strains used in both experiments. No substantial increase inrevertant colony numbers of any of the five tester strains was observed following treatment with the test item at any dose level, neither in the presence nor absence of metabolic activation (S9 -Mix). There was also no tendency of higher mutaiton rates with increasing concentrations in the range below the generally acknowledged border of biological relevance. Appropriate reference mutagens were used as positive controls and showed a distinct increase of induced revertant colonies.

The test item did not induce gene mutations by base pair changes or frameshifts in the genome of the strains used. Therefore the test item is considered to be non-mutagenic in this Salmonella typhimurium reverse mutation assay.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Additional information

Additional information from genetic toxicity in vitro:

Ames test

A study was performed to investigate the potential of the test substance to induce gene mutations according to the plate incorporation test (experiment I) and the pre-incubation test (experiment II) using the Salmonella typhimurium strains TA 1535, TA 1537, TA98, TA 100 and TA 102. The assay was performed in two independent experiments both with and without liver microsomal activation. Due to contamination of strain TA 1537 in experiment I no data could be obtained and this part was repeated under identical conditions (reported as experiment I). Each concentration, including the controls was tested in triplicate. The test item was tested at the following concentrations:

3, 10, 33, 100, 33, 1000, 2500 and 5000 µg/plate.

Reduced background growth was observed in all strains with and without metabolic activation in both experiments. Toxic effects, evident as reduction of the number of revertants (below the indicaiton factor of 0.5) were observed with and without metabolic activation in all strains used in both experiments.Appropriate reference mutagens were used as positive controls and showed a distinct increase of induced revertant colonies. The test item did not induce gene mutations by base pair changes or frameshifts in the genome of the strains used. Therefore the test item is considered to be non-mutagenic in this Salmonella typhimurium reverse mutation assay.

Chromosome aberration test

The test item, dissolved in DMSO, was assessed for its potential to induce structural chromosomal aberrations in human lymphocytes in vitro in two independent experiments. In each experimental group two parallel cultures were analysed. Per culture 100 metaphase plates were scored for structural chromosomal aberrations. In this study, either with or without metabolic activation no clastogenicity was observed at the concentrations evaluated. However, a dose-dependent increase of chromosomal aberrations could be observed in Experiment I in the presence of S9 mix after pulse treatment (1.0, 1.5, 2.5 % aberrant cells, excluding gaps). The values were within the range of the laboratory’s historical control data (0.0 – 4.0 % aberrant cells, excluding gaps) and considered as biologically irrelevant. No relevant increase in the frequencies of polyploid metaphases was found after treatment with the test item as compared to the frequencies of the controls. Appropriate mutagens were used as positive controls. They induced statistically significant increases (p < 0.05) in cells with structural chromosome aberrations.

Mouse lymphoma assay

The study was performed to investigate the potential of the test item to induce mutations at the mouse lymphoma thymidine kinase locus using the cell line L5178Y. The assay was performed in two independent experiments, using two parallel cultures each. The first main experiment was performed with and without liver microsomal activation and a treatment period of 4 h. The second experiment was performed with a treatment period of 24 hours in the absence of metabolic activation and 4 hours in the presence of metabolic activation. The concentration range of both main experiments was limited by cytotoxic effects of the test item. No substantial and reproducible dose dependent increase in mutant colony numbers was observed in both main experiments. No relevant shift of the ratio of small versus large colonies was observed up to the maximum concentration of the test item. Appropriate reference mutagens were used as positive controls and showed a distinct increase in induced mutant colonies, indicating that the tests were sensitive and valid.

Conclusion: Three OECD guideline studies were performed determining the genetic toxicity of the test item in an Ames test, one Chromosome aberration test and one Mouse lymphoma assay. No genetic toxicity was observed in all three studies.

Justification for selection of genetic toxicity endpoint
GLP and guideline study

Justification for classification or non-classification

Classification, Labelling, and Packaging Regulation (EC) No 1272/2008

The available experimental test data are reliable and suitable for classification purposes under Regulation (EC) No 1272/2008. As a result the test substance is not considered to be classified for genetic toxicity under Regulation (EC) No 1272/2008.