(4-nonylphenoxy)acetic acid

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

Study period:

May 4, 1984 - May 17, 1984

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Non-guideline study performed under QAU surveillance. No E. coli WP2/TA 102 included in the test, but with sufficient details and acceptable for assessment.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1984

Report date:

1984

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

other: the method described by AMES et al. (AMES et al., 1973; AMES et al., 1975)

Test guideline 2

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

yes

Remarks:

no E.coli WP2/TA 102 strain included

GLP compliance:

no

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

(4-nonylphenoxy)acetic acid

EC Number:

221-486-2

EC Name:

(4-nonylphenoxy)acetic acid

Cas Number:

3115-49-9

Molecular formula:

C17H26O3

IUPAC Name:

2-(4-nonylphenoxy)acetic acid

Details on test material:

- Analytical purity: Commercial grade

Method

Target gene:

his

Species / strain

Species / strain / cell type:

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

Metabolic activation:

with and without

Metabolic activation system:

Aroclor 1254 induced S9 fraction of rat liver

Test concentrations with justification for top dose:

20, 80, 320, 1280 and 5120 µg/0.1 ml in both experiment I and II

Vehicle / solvent:

- Solvent used: acetone

Controls

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: see "details on test system and conditions"

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation)

DURATION
- Exposure duration: 48 hours at 37 +/- 1.5 °C in darkness.

NUMBER OF REPLICATIONS: 3 Petri dishes were prepared per strain and per group. In order to confirm the result, the experiment was repeated once.

DETERMINATION OF CYTOTOXICITY
- Method: growth of background lawn

POSITIVE CONTROLS:
- without S9 mix:
TA98: daunorubicin-HCl, 5 and 10 µg/0.1 ml phosphate buffer
TA 100: 4-nitroquinoline-N-oxide, 0.125 and 0.25 µg/0.1 ml phosphate buffer
TA 1535: N-methyl-N'-nitro-N-nitrosoguanidine, 3 and 5 µg/0.1 ml phosphate buffer
TA 1537: 9(5)aminoacridine hydrochloride monohydrate, 50 and 100 µg/0.1 ml DMSO
- with S9 mix:
TA 100: 2-aminoanthracene, 5 µg/0.l ml DMSO.
TA 1535: cyclo-phosphamide, 250 µg/0.1 ml phosphate buffer

Evaluation criteria:

The test substance is generally considered to be non-mutagenic if the colony count in relation to the negative control is not doubled at any concentration.

Statistics:

When the colonies had been counted, the arithmetic mean was calculated.

Results and discussion

Test results

Species / strain:

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

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

A growth-inhibiting effect was observed at the upper concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation: At the concentrations of 1280 and 5120 µg/0.l ml the substance precipitated in soft agar


ADDITIONAL INFORMATION ON CYTOTOXICITY: A growth-inhibiting effect of the compound was observed in the experiments without microsomal activation at the upper concentrations. In the experiments with microsomal activation this effect was less pronounced.

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

NUMBER OF BACK-MUTANT COLONIES PER PLATE (ARITHMETIC MEAN)

Experiment 1:

	TA98		TA100		TA1535		TA1537
	+ S9	-S9	+ S9	-S9	+ S9	-S9	+ S9	-S9
vehicle control	32	28	144	137	13	12	16	11
20 µg/0.1ml	36	20	134	122	10	14	10	11
80 µg/0.1ml	43	27	143	148	16	13	9	8
320 µg/0.1ml	42	19	123	111	9	10	9	7
1280 µg/0.1ml	27	19	102	86	6	8	4	2
5120 µg/0.1ml	15	7	36	27	1	1	2	7
Positive controls*
vehicle control		25	120	125	12	13		11
concentration 1		318	1798	843	283	-		47
concentration 2		537		1308		2372		965

Experiment II:

	TA98		TA100		TA1535		TA1537
	+ S9	-S9	+ S9	-S9	+ S9	-S9	+ S9	-S9
vehicle control	39	30	148	140	16	21	11	5
20 µg/0.1ml	38	19	133	156	19	16	10	5
80 µg/0.1ml	49	22	151	120	16	16	12	6
320 µg/0.1ml	49	21	145	104	15	11	8	7
1280 µg/0.1ml	35	25	111	8	12	4	4	0
5120 µg/0.1ml	13	4	50	2	4	3	0	0
Positive controls*
vehicle control		28		167	18	13		8
concentration 1		438		1030	561	737		42
concentration 2		816		1809		2403		549

* for details on positive controls, see "details on test system and conditions"

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative

No evidence of the induction of point mutations by the test article or by the metabolites of the substance formed as a result of microsomal
activation was detectable in the strains of S. typhimurium used in these experiments.

Executive summary:

The test article was tested for mutagenic effects on histidine-auxotrophic mutants of Salmonella typhimurium strains TA 98, TA 100, TA 1535 and TA 1537 with the following concentrations of the trial substance: 20, 80, 320, 1280 and 5120 µg/0.1 ml. In order to confirm the results the experiments were repeated. To ensure that mutagenic effects of metabolites of the test substances formed in mammals would also be detected, experiments were performed in which the cultures were additionally treated with an activation mixture (rat liver microsomes and co-factors). In the experiments performed without and with microsomal activation, comparison of the number of back-mutant colonies in the controls and the cultures treated with the various concentrations of the test substance revealed a reduction in the colony count due to a growth-inhibiting effect of the compound at the upper concentrations. No evidence of the induction of point mutations by the test article or by the metabolites of the substance formed as a result of microsomal activation was detectable in the strains of S. typhimurium used in these experiments. Therefore, the test article is considered to be not mutagenic under the presented experimental conditions.