Fatty acids, C8-10, 2-ethylhexyl esters

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: gene mutation

Type of information:

migrated information: read-across based on grouping of substances (category approach)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study with acceptable restrictions (incomplete strain selection; E. coli is missing).

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1996

Report date:

1996

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

yes

Remarks:

incomplete strain selection; E. coli is missing

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Hexyl laurate

EC Number:

251-932-1

EC Name:

Hexyl laurate

Cas Number:

34316-64-8

IUPAC Name:

hexyl laurate

Details on test material:

- Name of test material (as cited in study report): only trade name given
- Chemical denomination: Hexyl laurate
- Physical state: colourless liquid
- Analytical purity: 100% active substance
- Lot/batch No.: 3805227
- Expiration date of the lot/batch: August, 1997
- Storage condition of test material: at room temperature

Method

Target gene:

his operon

Species / strain

Species / strain 1

Species / strain / cell type:

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

Species / strain 2

Species / strain / cell type:

S. typhimurium TA 1538

Metabolic activation:

with and without

Metabolic activation system:

cofactor supplemented post-mitochondrial fraction (S9 mix), prepared from the livers of rats treated with Aroclor 1254.

Test concentrations with justification for top dose:

1st and 2nd experiment: 8, 40, 200, 1000 and 5000 µg/plate

Vehicle / solvent:

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

Controls

Controls 1

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

sodium azide

Remarks:

Migrated to IUCLID6: 2 µg/plate for TA 1535 and TA 100 without S9

Controls 2

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

9-aminoacridine

Remarks:

Migrated to IUCLID6: 80 µg/plate for TA 1537 without S9

Controls 3

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 4-nitro-o-phenylene; 40 µg/plate for TA 1538 and TA 98 without S9

Controls 4

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 2-aminoanthracene; 2.5 µg/plate for TA 1535 and TA 1537 with S9 and 5.0 µg/plate for TA 100, TA 1538 and TA 98 with S9

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation)

DURATION
- Exposure duration: 48 hours

NUMBER OF REPLICATIONS: Two independent experiments were performed in triplicates each.

DETERMINATION OF CYTOTOXICITY
- Method: Reduction in the number of revertant colonies, background lawn

Evaluation criteria:

A combination of the following criteria was considered as a positive result:
1) The plate background of non-reverted bacteria did not show any growth reduction versus the respective negative controls.
2) The spontaneous mutation rates of each tester strain per plate were within the characteristic spontaneous mutation range.
3) As a rule, the positive controls showed mutation rates exceeding the control values of TA 100 at least by the factor 2.0 and those of the other tester strains at least by the factor 3.0.
4) At more than one dose tested, the test substance caused at least a 2.0-fold increase in comparison with the negative controls in the tester strain TA 100. For the other tester strains, an increase in the mutation rate of more than 3.0 above the corresponding negative controls was considered positive.

Reproducibility:
If the test substance induces reverse mutations in only one test, and if this effect cannot be reproduced in one or several repeated tests, the initially positive test data will lose their significance.

Statistics:

No data

Results and discussion

Test results

Test results 1

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:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 2

Species / strain:

S. typhimurium TA 1538

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation was not observed

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

Table 1: Test Results of Experiment 1 (plate incorporation)

With or without S9-Mix	Test substance concentration (μg/plate)	Mean number of revertant colonies per plate (average of 3 plates)
		Base-pair substitution type				Frameshift type
		TA 100		TA1535		TA1538		TA98		TA1537
–	Medium control	107		11		14		19		13
–	Solvent control	105		6		10		16		13
–	8	101		7		7		14		10
–	40	103		9		8		19		7
–	200	110		6		7		14		10
–	1000	109		7		11		17		10
–	5000	115		11		11		22		10
Positive controls, –S9	Name	SA	2-AA	SA	2-AA	4-NoP	2-AA	4-NoP	2-AA	9-AA	2-AA
	Concentrations (μg/plate)	2	5	2	2.5	40	5	40	5	80	2.5
	Mean No. of colonies/plate (average of 3)	628	116	581	11	1942	22	1378	27	852	13
+	Medium control	135		11		13		25		13
+	Solvent control	122		13		16		27		14
+	8	124		12		22		20		12
+	40	132		10		16		24		13
+	200	122		9		21		26		7
+	1000	109		9		17		24		16
+	5000	113		12		14		28		18
Positive controls, +S9	Name	SA	2-AA	SA	2-AA	4-NoP	2-AA	4-NoP	2-AA	9-AA	2-AA
	Concentrations (μg/plate)	2	5	2	2.5	40	5	40	5	80	2.5
	Mean No. of colonies/plate (average of 3)	258	1464	162	148	870	875	614	648	866	101

Table 2: Test Results of Experiment 2 (plate incorporation)

With or without S9-Mix	Test substance concentration (μg/plate)	Mean number of revertant colonies per plate (average of 3 plates)
		Base-pair substitution type				Frameshift type
		TA 100		TA1535		TA1538		TA98		TA1537
–	Medium control	112		11		14		19		13
–	Solvent control	103		6		10		16		13
–	8	111		7		7		14		10
–	40	135		9		8		19		7
–	200	123		6		7		14		10
–	1000	113		7		11		17		10
–	5000	141		11		11		22		10
Positive controls, –S9	Name	SA	2-AA	SA	2-AA	4-NoP	2-AA	4-NoP	2-AA	9-AA	2-AA
	Concentrations (μg/plate)	2	5	2	2.5	40	5	40	5	80	2.5
	Mean No. of colonies/plate (average of 3)	476	136	581	11	1942	22	1378	27	852	13
+	Medium control	130		11		13		25		13
+	Solvent control	139		13		16		27		14
+	8	136		12		22		20		12
+	40	119		10		16		24		13
+	200	132		9		21		26		7
+	1000	120		9		17		24		16
+	5000	129		12		14		28		18
Positive controls, +S9	Name	SA	2-AA	SA	2-AA	4-NoP	2-AA	4-NoP	2-AA	9-AA	2-AA
	Concentrations (μg/plate)	2	5	2	2.5	40	5	40	5	80	2.5
	Mean No. of colonies/plate (average of 3)	235	1874	162	148	870	875	614	648	866	101

SA = sodium azide

2-AA =2 -aminoanthracene

4 -NoP = 4 -nitro-o-phenylenediamine

9 -AA =9-aminoacridine

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative