Linseed oil, epoxidized

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Studies of genetic toxicity in vitro are available, and report universally negative results.

Link to relevant study records

Reference

Reference 1

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: gene mutation

Type of information:

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

Adequacy of study:

supporting study

Study period:

completed 20 July 1981

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

There is a deviation in this study as current guidelelines recommend E. coli WP2 uvrA, E. coli WP2 uvrA (pKM101) or S. typhimurium TA102 tester strains are included but at time of study conduct this was not the case and so none of the aforementioned strains were used in this study. Read across to a study result from an investigation using a similar material is justified for members of the Epoxidised Oils and Derivatives group. Four epoxidised oils (linseed, soybean, 2-ethylhexyl tallate and fatty acids, C14-C22, 2-ethylhexylesters) have been identified as sharing common structural and functional similarities, recognised in an OECD SIDS review as a single category, and therefore justifying read-across between data for different members of the group. Consequently data sharing between ESBO epoxidised soybean oil and epoxidised linseed oil is commonly utilised in the preparation of this dossier and other read-across bridges are used for other members of the EOD group where appropriate.

Justification for type of information:

Read across to a study result from an investigation using a similar material is justified for members of the Epoxidised Oils and Derivatives group. Four epoxidised oils (linseed, soybean, 2-ethylhexyl tallate and fatty acids, C14-C22, 2-ethylhexylesters) have been identified as sharing common structural and functional similarities, recognised in an OECD SIDS review as a single category, and therefore justifying read-across between data for different members of the group. Consequently data sharing between ESBO epoxidised soybean oil and epoxidised linseed oil is commonly utilised in the preparation of this dossier and other read-across bridges are used for other members of the EOD group where appropriate.

Qualifier:

according to guideline

Guideline:

other: Method described by AMES et al.

Principles of method if other than guideline:

The study design followed that of the Ames test as described in:
AMES, B.N., F.D. LEE, and W.E. DURSTON (1973), An Improved Bacterial Test System for the Detection and Classification of Mutagens and Carcinogens.
Proc, Natl. Acad. Sei. USA 70, 782-786.
AMES, B.N., W.E. DURSTON, E. YAMASAKI, and F.D. LEE (1973), Carcinogens are Mutagens: A Simple Test System Combining Liver Homogenates for Activation and Bacteria for Detection.
Proc. Natl. Acad. Sei. USA 70, 2281-2285.
AMES, B.N., J. McCANN, and E. YAMASAKI (1975), Methods for Detecting Carcinogens and Mutagens with the Salmonella/Mammalian- Microsome Mutagenicity Test.
Mutation Res. 31, 347-364.

GLP compliance:

no

Type of assay:

bacterial reverse mutation assay

Target gene:

histidine
4 histidine auxotrophic tester strains were used consistent with the study designs extant in the early 1980's.

Species / strain / cell type:

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

Additional strain / cell type characteristics:

other: histidine-auxotrophic

Metabolic activation:

with and without

Metabolic activation system:

rat liver microsomes and co-factors

Test concentrations with justification for top dose:

The tests were performed with the following concentrations of the trial substance without and with microsomal activation: 25, 75, 225, 675 and 2025 µg/0.1 mL.

Vehicle / solvent:

The substance was dissolved in acetone.

Untreated negative controls:

yes

Remarks:

Solvent acetone

Positive controls:

yes

Positive control substance:

other: TA98: Daunorubicin-HCl, 5 and 10 µg/0.1 mL phosphate buffer; TA100: 4-nitroquinoline-N-oxide, 0.125 and 0.25 µg/0.1 mL phosphate buffer; TA1535: N-methyl-N'-nitro-N-nitrosguanidine, 3 and 5 µg/0.1 mL phosphate buffer; TA1537: 9(5)aminoacridine hydrochlori

Details on test system and experimental conditions:

The substance was dissolved in acetone. Each Petri dish contained approx. 20 mL of minimum agar; 0.1 mL of the solution of the test substance or the vehicle and 0.1 mL of a bacterial culture in 2.0 mL of soft agar. The soft agar was composed of: 100 mL of 0.6 % agar solution with 0.6 % NaCl and 10 mL of a solution of 0.5 mM 1-histidine and 0.5 mM +biotin. In the experiments in which the substance was metabolically activated, 0.5 mL of an activation mixture was added. 1 mL activation mixture contained: 0.3 mL S9 fraction of liver from rats induced with Aroclor 1254 and 0.7 mL of a solution of co-factors.

Positive control experiments were carried out simultaneously with the following substances:
1) for Strain TA 98: daunorubicin-HCl (DAUNOBLASTIN , Farmitalia, Montedison Farmaceutica GmbH, Freiburg i. Br. , Germany),
5 and 10 \ig/0.1 ml phosphate buffer;
2) for Strain TA 100: 4-nitroquinoline-N-oxide (Fluka, Buchs, Switzerland) , 0.125 and 0.25 jig/0.1 ml phosphate buffer;
3) for Strain TA 1535: N-methyl-N'-nitro-N-nitrosoguanidine (Serva, Heidelberg, Germany), 3 and 5 ug/0.1 ml phosphate buffer;
4) for Strain TA 1537: 9(5)aminoacridine hydrochloride monohydrate (Fluka, Buchs, Switzerland), 50 and 100 \iq/0.l ml DMSO.
The activation mixture was tested with Strain TA 1535 and cyclo- ® phosphamide (ENDOXAN-ASTA , Asta-Werke, Bielefeld, Germany), 250 pg/O.l ml phosphate buffer.

In experiments without and with the addition of microsomal activation mixture three Petri dishes were prepared per strain and per group (i.e. per concentration or per control group).

The plates were incubated for about 48 hours at 37 °C in darkness.

Evaluation criteria:

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

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, but tested up to precipitating concentrations

Additional information on results:

In the experiments performed without and with microsomal activation, comparison of the number of histidine-prototrophic mutants in the controls and after treatment with TK 11 278 revealed no marked differences.

At the concentrations of 675 and 2025 µg/0.1 mL the substance precipitated in soft agar.

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

No further information

Conclusions:

Interpretation of results (migrated information):
negative

In the experiments performed without and with microsomal activation, comparison of the number of histidine-prototrophic mutants in the controls and after treatment with TK 11 278 revealed no marked differences.
According to Directive 67/548/EEC, no classification is warranted.
According to Regulation (EC) No. 1272/2008, no classification is warranted.

Executive summary:

TK 11 278 was tested for mutagenic effects on histidine-auxotrophic mutants of Salmonella typhimurium. The investigations were performed with the following concentrations of the trial substance without and with microsomal activation: 25, 75, 225, 675, and 2025 µg/0.1 mL.

These tests permit the detection of point mutations in bacteria induced by chemical substances. Any mutagenic effects of the substances are demonstratable on comparison of the numbers of bacteria in the treated and control cultures that have undergone back-mutation to histidine-prototrophism. To ensure that mutagenic effects of metabolites of the test substane 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 TK 11 278 revealed no marked deviations.

No evidence of the induction of point mutations by TK 11 278 or by the metabolites of the substance formed as a result of microsomal activation ws detectable in the strains of S. typhimurium used in these experiments.

According to Directive 67/548/EEC, no classification is warranted.

According to Regulation (EC) No. 1272/2008, no classification is warranted.

Reference 2

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: gene mutation

Type of information:

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

Adequacy of study:

key study

Study period:

8 May 1992 to 1 June 1992

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

There is no indication of the duration of the incubation period in Experiment 2. This is not expected to effect the validity of the results. Read across to a study result from an investigation using a similar material is justified for members of the Epoxidised Oils and Derivatives group. Four epoxidised oils (linseed, soybean, 2-ethylhexyl tallate and fatty acids, C14-C22, 2-ethylhexylesters) have been identified as sharing common structural and functional similarities, recognised in an OECD SIDS review as a single category, and therefore justifying read-across between data for different members of the group. Consequently data sharing between ESBO epoxidised soybean oil and epoxidised linseed oil is commonly utilised in the preparation of this dossier and other read-across bridges are used for other members of the EOD group where appropriate.

Justification for type of information:

Read across to a study result from an investigation using a similar material is justified for members of the Epoxidised Oils and Derivatives group. Four epoxidised oils (linseed, soybean, 2-ethylhexyl tallate and fatty acids, C14-C22, 2-ethylhexylesters) have been identified as sharing common structural and functional similarities, recognised in an OECD SIDS review as a single category, and therefore justifying read-across between data for different members of the group. Consequently data sharing between ESBO epoxidised soybean oil and epoxidised linseed oil is commonly utilised in the preparation of this dossier and other read-across bridges are used for other members of the EOD group where appropriate.

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Qualifier:

according to guideline

Guideline:

other: EEC Annex V Test B14

Qualifier:

according to guideline

Guideline:

other: UKEMS Guidelines

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Target gene:

histidine gene

Species / strain / cell type:

S. typhimurium, other: TA98; TA100; TA 1535; TA1537 and TA102

Additional strain / cell type characteristics:

other: biotin and histidine required for growth

Metabolic activation:

with and without

Metabolic activation system:

mammalian liver post-mitochondrial fraction (S9)

Test concentrations with justification for top dose:

Please see Table 1 and 2 below.
An initial toxicity range-finder was carried out in TA100 strain only, using final concentrations of Epoxidised Soybean Oil at 8, 40, 200, 1000 and 5000 µg/plate plus a solvent and a positive control. These treatments were non-toxic and the same dose range was used for experiment 1. For experiment 2 treatments, the dose range was narrowed to 312.5 - 5000 µg/plate in order to investigate those concentrations most likely to exhibit a mutagenic response.

Vehicle / solvent:

Test chemical solutions were prepared by dissolving Epoxidised Soybean Oil in analytical grade acetone, immediately prior to assay to give the required maximum concentration treatment solution. Further dilutions were then made using acetone. The test chemical solutions were protected from light and used within approximately 4 hours of the initial formulation of the test agent.

Untreated negative controls:

yes

Remarks:

solvent acetone

Positive controls:

yes

Remarks:

Please Table 2 below

Details on test system and experimental conditions:

An initial toxicity range-finder was carried out in TA100 strain only, using final concentrations of Epoxidised Soybean Oil at 8, 40, 200, 1000 and 5000 µg/plate plus a solvent and a positive control. These treatments were non-toxic and the same dose range was used for experiment 1.

Five strains of bacteria were used in this study. For all assays, bacteria were cultured for about 10 hours at 37 °C in nutrient broth (containing ampicillin for strains TA98 and TA100 and ampicillin and tetracycline for strain TA102). Bacteria were taken from vials of frozen cultures, which had been checked for strain characteristics (histidine dependence, rfa character and resistance to ampicillan (TA98 and TA100) or ampicillin plus tetracycline (TA102). Checks were carried out according to Maron and Ames and De Serres and Shelby. For all treatments, cultures were used within 2 hours of the end of the incubation period.

Epoxidised Soybean Oil was tested for mutation in 5 strains of Salmonella typhurium at the concentrations detailed in Table 1. Triplicate plates with and without S-9 mix were used. Negative (solvent) and positive controls were included in both assays, in quintuplicate without and with S-9 mix. In each experiment, bacterial strains were treated with diagnostic mutagens in triplicate in the absence of S-9. The activity of the S-9 mix used in each experiment was confirmed by AAN treatments (again in triplicate) of at least one strain in the presence of S-9.

Because the results of the first experiment were negative, treatments in the presence of S-9 in Experiment 2 included a pre-incubation step, where the quantities of test chemical or control solution, bacteria and S-9 mix detailed, were mixed together and incubated for 1 hour at 37 °C, before the addition of 2.5 mL molten agar at 46 °C. Plating of these treatments then proceeded as for the normal plate-incorporation procedure. In this way, it was hoped to increase the range of mutagenic chemicals that could be detected in the assay.

Colony Counting:
Colonies were counted electronically using a Seescan Colony Counter or manually where minor agar damage might have interfered with automatic counting, and the background lawn inspected for signs of toxicity.

Evaluation criteria:

Acceptance Criteria:
The assay was considered valid if the following criteria were met:
i) the mean negative control counts fell within the normal range as defined in Appendix 4
ii) the positive control chemicals induced clear increases in revertant numbers confirming discrimination between different strains, and an active S-9.
iii) no more than 5 % of the plates were lost through contamination or some other unforeseen event

Evaluation criteria:
A test compound was considered to be mutagenic if
i) the assay was valid
ii) Dunnett's test gave a significant response (p <= 0.01), and the data set showed a significant dose-correlation
iii) the positive responses described in (ii) were reproducible

Statistics:

The m-statistic was first calculated to check that the data were Poisson-distributed and then Dunnett's test was used to compare the counts of each dose with the control. The presence or otherwise of a dose response was then checked by linear regression analysis.

Species / strain:

S. typhimurium TA 102

Metabolic activation:

with

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Untreated negative controls validity:

valid

Positive controls validity:

valid

Species / strain:

S. typhimurium TA 102

Metabolic activation:

without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Untreated negative controls validity:

valid

Positive controls validity:

valid

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

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

Toxicity:
Only treatments of strain TA102 in Experiment 2 (+ S-9 only) showed signs of toxicity (as indicated by thinning of the background bacterial lawn) in this study. In this case, toxic effects were seen mostly at the 3 highest doses. It would appear that the use of a pre-incubation step particularly enhanced the toxicity of the test agent to this test strain.

Range-finder and Experiment 1 treatments were carried out using final concentrations of Epoxidised SOybean Oil at 8, 40, 200, 1000 and 5000 µg/plate, Precipitation, in the form of oil droplets, was observed at concentrations of 1000 and 5000 µg/plate. For experiment 2, testing was again carried out up to maximum concentration of 5000 µg/plate (despite the observation of precipitation), as it was possible that the compund formed an emulsion within the test system and it was felt important to maximise the exposure of the cells to this. A narrowed dose range was also used in this experiment (312.5 - 5000 µg/plate) in order to examine those doses most likely to exhibit a mutagenic response. Oil droplets were observed on test plates in this experiment, following treatments of 1250 µg/plate and above.

Mutation:
The individual plate counts were averaged to give mean values. From the data it can be seen that mean solvent control counts fell within the normal historical range, that the positive control chemicals all induced large increases in revertant numbers in the appropriate strains, and that < 5 % of plates were lost, leaving adequate numbers of plates at all treatments. The study was accepted as valid.

The mutation data were evaluated as follows:
No treatment with Epoxidised Soybean Oil of any of the tester strains, earlier in the absence or presence of S-9, resulted in a significant increase in revertant numbers. The data obtained therefore gave no indication of an ability of the test agent to induce mutation.

Remarks on result:

other: strain/cell type: S. typhimurium TA 102

Remarks:

Migrated from field 'Test system'.

No further information

Conclusions:

Interpretation of results (migrated information):
negative

It is concluded that Epoxidised Soybean Oil failed to induce mutation in 5 strains of Salmonella typhimurium, when treated up to a maximum concentration of 5000 µg/plate, in the absence and presence of a rat liver metabolic activation system.
According to Directive 67/548/EEC, no classification is warranted.
According to Regulation (EC) No. 1272/2008, no classification is warranted.

Executive summary:

Epoxidised Soyban Oil was assayed for mutation in 5 -histidine-requiring strains (TA98, TA100, TA1535, TA1537 and TA102) of Salmonella typhimurium, both in the absence and presence of metabolic activation by an Aroclor 1254 induced rat liver post-mitochondrial fraction (S-9), in two separate experiments.

It was concluded that Epoxidised Soybean Oil failed to induce mutation in 5 strains of Salmonella typhimurium, when treated up to a maximum concentration of 5000 µg/plate, in the absence and presence of a rat liver metabolic activation system. According to Directive 67/548/EEC, no classification is warranted. According to Regulation (EC) No. 1272/2008, no classification is warranted.

Reference 3

Endpoint:

in vitro cytogenicity / chromosome aberration study in mammalian cells

Remarks:

Type of genotoxicity: chromosome aberration

Type of information:

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

Adequacy of study:

key study

Study period:

August 3, 1992 - October 16, 1992

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

GLP compliant, according to guidelines Read across to a study result from an investigation using a similar material is justified for members of the Epoxidised Oils and Derivatives group. Four epoxidised oils (linseed, soybean, 2-ethylhexyl tallate and fatty acids, C14-C22, 2-ethylhexylesters) have been identified as sharing common structural and functional similarities, recognised in an OECD SIDS review as a single category, and therefore justifying read-across between data for different members of the group. Consequently data sharing between ESBO epoxidised soybean oil and epoxidised linseed oil is commonly utilised in the preparation of this dossier and other read-across bridges are used for other members of the EOD group where appropriate.

Justification for type of information:

Read across to a study result from an investigation using a similar material is justified for members of the Epoxidised Oils and Derivatives group. Four epoxidised oils (linseed, soybean, 2-ethylhexyl tallate and fatty acids, C14-C22, 2-ethylhexylesters) have been identified as sharing common structural and functional similarities, recognised in an OECD SIDS review as a single category, and therefore justifying read-across between data for different members of the group. Consequently data sharing between ESBO epoxidised soybean oil and epoxidised linseed oil is commonly utilised in the preparation of this dossier and other read-across bridges are used for other members of the EOD group where appropriate.

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to other study

Qualifier:

according to guideline

Guideline:

OECD Guideline 473 (In Vitro Mammalian Chromosome Aberration Test)

Qualifier:

according to guideline

Guideline:

EU Method B.10 (Mutagenicity - In Vitro Mammalian Chromosome Aberration Test)

Principles of method if other than guideline:

Not relevant

GLP compliance:

yes

Type of assay:

in vitro mammalian chromosome aberration test

Target gene:

This test evaluated the effect of Epoxidised Soybean Oil on mitotic index/chromosomal aberrations.

Species / strain / cell type:

lymphocytes: Human Peripheral Blood Lymphocytes

Details on mammalian cell type (if applicable):

Two healthy, non-smoking volunteers (male in Experiment 1 and female in Experiment 2) were used in this study. Neither donor was suspected of any virus infection nor had been exposed to high levels of radiation or hazardous chemicals. For each experiment an appropriate volume of whole blood was drawn from the peripheral circulation on the day of culture. Whole blood cultures were established in sterile disposable centrifuge tubes by placing 0.4 mL heparinised blood into 9.0 mL Hepes-buffered RPMI medium containing 20 % (v/v) foetal calf serum and 50 ug/mL gentamycin. Photohaemagglutinin (PHA, reagent grade) was included at a concentration of 37.5 uL per ml of culture to stimulate the lymphocytes to divide. Cultures were rocked continuously during incubation. The blood cultures were incubated at 37 C for approx. 48 hours.

Additional strain / cell type characteristics:

not specified

Metabolic activation:

with and without

Metabolic activation system:

S-9 mammalian liver post-mitochondrial fraction

Test concentrations with justification for top dose:

Preliminary solubility data indicated that limited precipitation occurred when an acetone solution at 6 mg/mL was diluted 100-fold into culture medium. No precipitation was observed when a 5.3 mg/ml acetone solution was diluted similarly to give 53 ug/ml. A concentration of 55 ug/ml was therefore considered close to the solubility limit and an appropriate maximum concentration for the main study. Test chemical stock solutions were prepared by dissolving Epoxidised soybean oil in analytical grade acetone to give 5.5 mg/ml. Stock solutions were not membrane filter-sterilised (because of the nature of the solvent ) and further dilutions made in acetone. Solutions were then used within 2 hours of initial dissolution as seen in Table 1 and 2.

Vehicle / solvent:

Acetone

Negative solvent / vehicle controls:

yes

Remarks:

Acetone was added to cultures designated as negative controls

Positive controls:

yes

Remarks:

Positive control chemicals were dissolved in sterile anhydrous analytical grade dimethyl sulphoxide immediately prior to use

Positive control substance:

4-nitroquinoline-N-oxide

Remarks:

Please see table 3 for concentration levels

Positive controls:

yes

Remarks:

Positive control chemicals were dissolved in sterile anhydrous analytical grade dimethyl sulphoxide immediately prior to use

Positive control substance:

cyclophosphamide

Remarks:

Please see table 3 for concentration levels

Details on test system and experimental conditions:

METHOD OF APPLICATION:
Test chemical stock solutions were prepared by dissolving epoxidised soybean oil in analytical grade acetone to give 5.5 mg/ml. Solutions were made according to Tables 1 and 2.

Glucose-6-phosphate (180 mg/ml), NADP (25 mg/ml), 150 mM KCl and rat liver S-9 were mixed in the ratio 1:1:1:2. A 0.5 ml aliquot of the resulting S-9 mix was added to each cell culture 99.5 mL) containing the test chemical to achieve the required final concentration in a total of 10 mL. Cultures treated in the absence of S-9 received 0.5 ml 150 mM KCl.

DURATION
- Preincubation period: approx 48 hours
- Exposure duration: 3 hours
- Expression time (cells in growth medium): 20 or 44 hours. Please see Table 5.

SPINDLE INHIBITOR (cytogenetic assays): Colchicine
STAIN (for cytogenetic assays): the cells were stained for 5 minutes in 4 % (v/v) filtered Giemsa stain in pH 6.8 buffer.

NUMBER OF REPLICATIONS: Please see Table 4

DETERMINATION OF CYTOTOXICITY
Slides were examined, uncoded, for mitotic index or percentages of cells in mitosis

Evaluation criteria:

Slides were examined, uncoded, for mitotic index or percentages of cells in mitosis.
Scoring of aberrations - where possible 25 cells from each of the selected NQO and CPA positive control treatments were analysed to ensure that the system was operating satisfactorily. One hundred metaphases from each culture were analysed for chromosome aberrations. Only cells with 44-46 chromosomes were considered accepatble for analysis of structural aberrations. Any cell with more than 46 chromosomes, that is polyploid, endoreplicated and hyperdiploid cells, observed during this search was noted and recorded seperately.

Statistics:

None reported

Species / strain:

lymphocytes: Human Peripheral Blood Lymphocytes

Metabolic activation:

with and without

Genotoxicity:

other: not required

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Additional information on results:

The results of mitotic index determinations for the treatments in Experiment 1, without and with S-9 sampled at 20 hours are shown in Table 6. No mitotic inhibition was observed in the absence of S-9 and little (approx. 14 %) in its presence, although this was not clearly dose-related. The following doses were then chosen:

Mitotic Inhibition *
20 hours, -S-9: 26.95, 38.5, 55 ug/mL 0 %
20 hours, +S-9: 26.95, 38.5, 55 ug/mL 14 %

* = at highest analysed dose

The results of mitotic index determinations for the treatments in Experiment 2, without and with S-9 sampled at 20 and 44 hours are seen in Table 7.


In contrast to Experiment 1, mitotic inhibition was observed in the absence of S-9 at the 20 hour sampling in Experiment 2. Approximately 47 % mitotic inhibition was seen at the highest level in the absence of S-9 and 25 % in its presence. No mitotic inhibition was seen at the 44 hour sampling time. The following doses were selcted for analysis:

Mitotic Inhibition *
20 hours, -S-9: 30.94, 41.25, 55 ug/mL 47 %
20 hours, +S-9: 30.94, 41.25 55 ug/mL 25 %
44 hours, - and + S-9; 55 ug/mL 0%

* = at highest analysed dose

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Table 6: Mitotic Index Determinations for Experiment 1

Treatment (ug/ml)	Mitotic index (%)
	-S-9		+S-9
	A	B	A	B
Untreated	NS	NS	NS	NS
Solvent	3.2	2.3	4.3	3.5
1.554	NM	NM	NM	NM
2.219	NM	NM	NM	NM
3.171	NM	NM	NM	NM
4.530	NM	NM	NM	NM
6.471	NM	NM	NM	NM
9.244	NM	NM	NM	NM
13.21	NM	NM	NS	NS
18.87	NS	NS	NS	NS
26.95	3.1	2.2	3.6	2.7
38.5	2.1	2.3	2.9	4.0
55	2.8	2.5	3.0	3.7

NS = not scored

NM = slides not made

(Slides from solvent control cultures C and D not made)

Table 7: Mitotic index determinations for Experiment 2.

Treatment (ug/mL)	Mitotic index (%)
	20 hours				44 hours
	A	B	A	B	A	B	A	B
Untreated	NS	NS	NS	NS	NS	NS	NS	NS
Solvent	4.7	3.8	5.0	6.9	3.8	3.5	5.9	6.7
5.506	NT	NT	NT	NT	NM	NM	NT	NT
7.342	NT	NT	NT	NT	NM	NM	NT	NT
9.789	NT	NT	NT	NT	NM	NM	NT	NT
13.05	NT	NT	NT	NT	NM	NM	NM	NM
17.4	NT	NT	NT	NT	NM	NM	NM	NM
23.2	NS	NS	NS	NS	NS	NS	NM	NM
30.94	3.2	3.7	5.5	6.8	NS	NS	NS	NS
41.25	4.2	3.8	5.4	6.0	NS	NS	NS	NS
55	1.5	3.0	3.6	5.3	3.8	4.1	6.0	6.7

NS = not scored

NM = slides not made

NT = not tested

Conclusions:

Interpretation of results (migrated information):
ambiguous Some differences in response between experiment 1 and 2 but no consistent indication of an effect on structure or frequency of chromosomal aberrations, with or without metabolic activation

It is concluded that Epoxidised soybean oil was unable to induce chromosome aberrations in cultured human peripheral blood lymphocytes when tested to its limit of solubility in both the absence and presence of S-9.

Executive summary:

Epoxidised soybean oil was tested in an in vitro cytogenetics assay using duplicate human lymphocyte cultures from a male and female donor in 2 independent experiments. The highest dose level used, 55 ug/ml, was close to the solubility limit of Epoxidised soybean oil in culture medium. Treatments covering a broad range of doses, separated by narrow intervals, were performed both in the absence and presence of metabolic activation by a rat liver post-mitochondrial fraction (S-9) from Aroclor 1254 induced animals. In Experiment 1, treatment in the absence of S-9 was continuous for 20 hours. Treatment in the presence of S-9 was for 3 hours only followed by a 17 hour recovery period prior to harvest. The test compound dose levels for chromosome analysis were selected by evaluating the effect of Epoxidised soybean oil on mitotic index. Chromosome aberrations were analysed at 3 consecutive dose levels. The highest concentration chosen for analysis at this time, 55 ug/ml, induced no mitotic inhibition in the absence of S-9 and approximately 14 % in its presence, although this was not clearly dose-related. Experiment 2 included a delayed sampling time. Treatment in the absence of S-9 was continuous for 20 or 44 hours. Treatment in the presence of S-9 was for 3 hours followed by 17 or 41 hour recovery period. The highest concentration chosen for analysis at 20 hours, was again 55 ug/ml which on this occasion induced approximately 47 % and 25 % mitotic inhibition in the absence and presence of S-9 respectively. The effect of this single concentration only was investigated at the delayed harvest at which time no mitotic inhibition was induced.

Appropriate negative (solvent and untreated) control cultures were included in the test system in both experiments at both sampling times. Acceptable numbers of cells with structural aberrations were observed in solvent control cultures, slides from untreated cultures were not analysed. 4-Nitroquinoline 1-oxide (NQO) and cyclophosphamide (CPA) were employed as positive control chemicals in the absence and presence of liver S-9 respectively. Cells receiving these sampled in each experiment 20 hours after the start of treatment; both compounds induced statistically significant increases in the proportion of cells with structural aberrations.

In most cases, treatment of cultures with Epoxidised soybean oil in either the absence or presence of S-9 resulted in frequencies of cells with aberrations which were similar to and not significantly different from those seen in concurrent negative controls. Small increases in cells with aberrations were seen at the 20 hour sampling time following treatment with 26.95 ug Epoxidised soybean oil/ml in the presence of S-9 in Experiment 1 and 41.25 ug Epoxidised soybean oil/ml in the absence of S-9 in Experiment 2. In neither case, however, was the increase characterised by both statistical significance and frequencies of aberrant cells outside negative historical control ranges and could not therefore be considered biologically important.

It is concluded that Epoxidised soybean oil was unable to induce chromosome aberrations in cultured human peripheral blood lymphocytes when tested to its limit of solubility in both the absence and presence of S-9.

Reference 4

Endpoint:

in vitro gene mutation study in mammalian cells

Remarks:

Type of genotoxicity: gene mutation

Type of information:

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

Adequacy of study:

supporting study

Study period:

28 May 1986 to 26 June 1986

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Test and control substance concentrations in carner were not determined by analytical method. The stability of test substances in carrier were not determined. Solutions of test substance were prepared on each day of use Read across to a study result from an investigation using a similar material is justified for members of the Epoxidised Oils and Derivatives group. Four epoxidised oils (linseed, soybean, 2-ethylhexyl tallate and fatty acids, C14-C22, 2-ethylhexylesters) have been identified as sharing common structural and functional similarities, recognised in an OECD SIDS review as a single category, and therefore justifying read-across between data for different members of the group. Consequently data sharing between ESBO epoxidised soybean oil and epoxidised linseed oil is commonly utilised in the preparation of this dossier and other read-across bridges are used for other members of the EOD group where appropriate.

Justification for type of information:

Read across to a study result from an investigation using a similar material is justified for members of the Epoxidised Oils and Derivatives group. Four epoxidised oils (linseed, soybean, 2-ethylhexyl tallate and fatty acids, C14-C22, 2-ethylhexylesters) have been identified as sharing common structural and functional similarities, recognised in an OECD SIDS review as a single category, and therefore justifying read-across between data for different members of the group. Consequently data sharing between ESBO epoxidised soybean oil and epoxidised linseed oil is commonly utilised in the preparation of this dossier and other read-across bridges are used for other members of the EOD group where appropriate.

Qualifier:

no guideline followed

Principles of method if other than guideline:

The study design followed the principles of the widely accepted mammalian mutation assay CHO/HGPRT, although the guideline had not been formally adopted at the time of study conduct. The assay had been reviewed by the EPA Gene-Tox program (Hsie et al, 1981) and the method was subsequently adopted by the OECD as Test Method 476.

GLP compliance:

yes

Type of assay:

mammalian cell gene mutation assay

Target gene:

hypoxanthine guanine phosphoribosyl transferase (HGPRT) in Chinese hamster ovary (CHO) cells

Species / strain / cell type:

Chinese hamster Ovary (CHO)

Details on mammalian cell type (if applicable):

The subclone K1BH$ of CHO cells, originally obtained from Dr. A.W. Hale of Oak Ridge National Laboratory was used. The cells were routinely maintained in the laboratory as exponentially growing cultures in Ham's F12 medium (K. C. Biological) supplemented with heat-inactivated 10 % newborn calf serum (K.C. Biological) in an incubator-controlled environment of a 95 % humidified atmosphere of 5 % ± 1 % CO2 and 95 % air at 37.5 °C.

Metabolic activation:

with and without

Metabolic activation system:

Aroclor 1254- induced rat liver homogenate (S9)

Test concentrations with justification for top dose:

200, 500, 1000 and 2000 µg/mL of both ESO and Cl-ESO.

Vehicle / solvent:

Cytoxicity Determination: Ham's F12 medium without serum (5 mL) with or without activation.
Mutagenesis: Subculture medium (hypoxanthine-free Ham's F12 medium (K.C. Biological) supplemented with 5 % dialysed foetal calf serum).

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Remarks:

ethylmethane sulfonate and benzo(a)pyrene

Details on test system and experimental conditions:

CYTOXICITY DETERMINATION
CHO cells were seeded in 25 cm2 plastic culture flasks at 0.5 x 10 ^6 cells per flask in growth medium 18-24 hours before treatment. On the day of treatment, the medium was changed to Ham's F12 medium without serum (5 mL) with or without S-9 activation. Volumes of 25 µL of different concentrations of the test chemical were added. After an incubation of 3 hours at 37.5 °C ± 2 °C, the treatment medium was discarded. The cells were washed with 5 mL Hank's balanced salt solution and the cells were removed from the flasks by trypsinization and counted. Three aliquots of approximately 200 cells were plated per sample for determination of cloning efficiency. The plates were returned to incubation for 7 - 9 days. The colonies developed were fixed with 70 % methanol, stained with 10 % Giemsa and counted by hand. Cytoxicity was expressed as relative survival.

MUTAGENESIS
CHO cells were plated on the day before treatment. The next day, they were treated with test chemicals, positive controls and negative solvent control as described for cytotoxicity above. The cells were then processed, as described above for the cytoxicity determination, except that in addition to plating 200 cells for cloning efficiency, 10 ^6 cells per sample were plated in 10 mL of subculture medium (hypoxanthine-free Ham's F12 medium (K.C. Biological) supplemented with 5 % dialysed foetal calf serum). The cells were subcultured every 2 - 3 days for 7 -9 days for the expression of the mutant phenotype. Mutant selection was performed as previously described (Li, 1982) using selective medium consisting of hypoxanthine-free Ham's F12 medium supplemented with 10 µM 6 TG and 5 % dialysed fetal calf serum. Approximately 10 ^6 cells per sample were plated in 100 mm plates (5 plates, 2 x 10 ^5 cells per plate) in 8 mL of selective medium per plate for mutant selection. Three aliquots of approximately 200 cells per sample were plated in 3 mL of selective medium without 6TG for the determination of cloning efficiency (C.E.). The plates were returned to the incubator for 7-9 days. The colonies that developed were fixed, stained and counted. Results were expressed as mutant frequency.

ACTIVATION SYSTEM
Aroclor 1254-induced rat liver homogenate (S9), lot No. 03830, commercially purchased from Microbiological Associates, was used as an exogenous activation system. The S9/cofactor mixture consisted of 50 mM sodium phosphate (pH 7.5), 4 mM NADP, 5 mM glucose-6-phosphate, 30 mM KCl, 10 mM MgCl2, 10 mM CaCl2 and different amounts of liver S9. The 5 % S9 in this report represents the percent of S9 (v/v) in the S9/cofactor mixtures. One mL of the S9/cofactor mixture was added to 4 mL of medium for cytoxicity and mutagenicity testing.

Evaluation criteria:

The general experimental design used to determine the mutagenicity of the test chemical in the CHO-HPGRT assay is described below:
1 - Mutagenicity Determination in the Absence of Aroclor 1254-Induced Rat Liver Homogenate (S9):
This experiment was designed to test for mutagenicity of ESO and Cl-ESO in the absence of an exogenous activating system. Duplicate treatment s amples of solvent control, 4 doses (0.2, 0.5, 1 and 2 mg/mL) of the test chemicals, and positive control were used with a treatment time of 3 hours.
2 - Mutagenicity Determination in the presence of S9:
This experiment, using information obtained from experiments discussed previously, served to determine if the mutagenicity of the test chemical can be modified by exogenous activation. A concentration of 5 % S9 was used for this experiment. This level of S9 has been shown to provide signi ficant mutagenic responses when tested with a variety of promutagens used in this assay (A.P. Li, 1984). As in the first experiment, testing was per formed using duplicate samples with a treatment time of 3 hours.

Statistics:

Mutagenicity data were analysed according to the statistical method of Snee and Irr (1981) designed specifically for the CHO/HGPRT mutation assay. Mutant frequency values were transformed according to the equation Y=(X-1)^0.15, where Y=transformed mutant frequency and X= observed mutant frequency. Student's t-test was then used to compare treatment data to solvent control data. The Snee and Irr analysis also allowed the determination of dose-response relationship as linear, quadratic or higher-order.

Species / strain:

Chinese hamster Ovary (CHO)

Metabolic activation:

without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Positive controls validity:

valid

Species / strain:

Chinese hamster Ovary (CHO)

Metabolic activation:

with

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Positive controls validity:

valid

Additional information on results:

ESO and Cl-ESO were tested for mutagenicity in the absence and presence of exogenous activation in two separate experiments.

In the first experiment, no exogenous activating system was used. Four concentrations of each test chemical were tested, with 2000 µg/mL as the highest concentration. Dose-related cytoxicity was observed for both ESO and Cl-ESO. The lowest relative survival values (highest cell killing) observed for the two test chemicals were 0.32 (at 2000 µg/mL ESO) and 0.17 (at 1000 µg/mL Cl-ESO). No statistically significant mutagenicity was observed for either chemical at any of the doses tested.

In the second experiment, the chemicals were tested for mutagenicity in the presence of activation, using Aroclor 1254-induced rat liver homogenate (S9) as the exogenous activating system. As in the first experiment, four doses of ESO and Cl-ESO were tested up to the highest concentration of 2000 µg/mL. No significant cytoxicity (> 50 % cell killing) or statistically significant mutagenicity was observed for the test chemicals.

The positive controls, ethylmethane sulfonate and benzo(a)pyrene, for testing in the absence and presence of S9, respectively, yielded the expected strong positive responses indicating that the experimental conditions were adequate for the detections of mutagens.

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Table 1        Colony Counts for the Mutagenicity Determination of ESO and Cl-ESO in the Absence of S9

Treatment (a)(µg/mL)		Cytoxicity (b)			Mutagenicity
					Survival (c)			Selection (d)
DMSO Control		112	125	103	119	103	123	1	1	2	1	1
DMSO Control		142	154	160	107	105	117	0	0	0	0	1
ESO	200	105	111	127	110	118	137	4	1	0	0	0
	200	80	83	98	132	131	150	2	0	0	0	0
	500	56	59	70	134	126	105	0	0	0	0	0
	500	60	73	57	146	135	129	0	0	1	0	0
	1000	73	57	70	124	146	120	4	3	3	2	3
	1000	52	66	55	115	120	115	2	0	0	0	1
	2000	40	52	54	102	119	101	0	1	0	0	0
	2000	28	45	36	153	146	160	0	0	0	0	0
Cl-ESO	200	61	62	59	-	-	-	2	0	3	0	0
	200	58	76	52	127	111	118	1	0	0	1	0
	500	73	78	79	100	97	100	2	3	0	1	2
	500	51	56	56	119	122	116	1	0	0	0	0
	1000	23	23	19	134	113	131	0	0	0	0	1
	1000	13	26	30	141	124	139	0	0	0	0	0
	2000	89	98	82	143	147	120	0	1	1	2	0
	2000	69	76	78	109	139	128	1	0	0	0	0
	2	105	99	100	65	83	77	9	13	18	20	12
	2	87	117	97	91	107	88	8	14	15	13	19

(a) Duplicate samples per treatment. Each line represents results from each sample/

(b) Colonies developed after plating of 200 cells per plate, 3 plates/sample, immediately after treatment

(c) Colonies developed in medium without selectie agent after plating of 200 cells per plate, 3 plates/sample, after the expression period at the time of mutant selection

(d) Colonies developed in selective medium after plating of 2 x 10 ^5 cells per plate, 5 plates/sample, after the expression period

- no data due to contamination or drying of plates

Conclusions:

ESO and Cl-ESO were tested in CHO cells in the absence and presence of S9. Significant cytoxicity (> 50 % cell death) was observed in the absence of S9. No statistically significant mutagenicity was observed. The test chemicals are, therefore, concluded to be non-mutagenic in CHO cells under the experimental conditions.

Executive summary:

The mutagenic potential of epoxidised soybean oil (ESO) and chlorinated ESO (Cl-ESO) were tested in cultured Chinese hamster ovary (CHO) cells. Mutation at the hypoxanthine guanine phosphoribosyl transferase (HGPRT) gene locus was measured. Mutagenicity testing was performed in the presence or absence of Aroclor 1254 -induced rat liver homogenate (S9). Both test chemicals were tested up to a maximum of 2 mg/mL. In the absence of S9, significant cytotoxicity (> 50 % cell killing) was observed at 0.5, 1.0 and 2.0 mg/mL of ESO and 0.2, 0.5 and 1.0 mg/mL of Cl-ESO. No significant cytotoxicity was observed in the presence of S9. No test chemical related mutagenicity was observed in the two experiments conducted in the absence or in the presence of S9. ESO and Cl-ESO are therefore concluded not to be a mutagen in CHO cells under the experimental conditions.

Reference 5

Endpoint:

in vitro gene mutation study in mammalian cells

Remarks:

Type of genotoxicity: gene mutation

Type of information:

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

Adequacy of study:

key study

Study period:

April 15, 1992 - June 25, 1992

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

GLP compliant. According to guidelines. Read across to a study result from an investigation using a similar material is justified for members of the Epoxidised Oils and Derivatives group. Four epoxidised oils (linseed, soybean, 2-ethylhexyl tallate and fatty acids, C14-C22, 2-ethylhexylesters) have been identified as sharing common structural and functional similarities, recognised in an OECD SIDS review as a single category, and therefore justifying read-across between data for different members of the group. Consequently data sharing between ESBO epoxidised soybean oil and epoxidised linseed oil is commonly utilised in the preparation of this dossier and other read-across bridges are used for other members of the EOD group where appropriate.

Justification for type of information:

Read across to a study result from an investigation using a similar material is justified for members of the Epoxidised Oils and Derivatives group. Four epoxidised oils (linseed, soybean, 2-ethylhexyl tallate and fatty acids, C14-C22, 2-ethylhexylesters) have been identified as sharing common structural and functional similarities, recognised in an OECD SIDS review as a single category, and therefore justifying read-across between data for different members of the group. Consequently data sharing between ESBO epoxidised soybean oil and epoxidised linseed oil is commonly utilised in the preparation of this dossier and other read-across bridges are used for other members of the EOD group where appropriate.

Qualifier:

according to guideline

Guideline:

OECD Guideline 476 (In Vitro Mammalian Cell Gene Mutation Test)

Principles of method if other than guideline:

Not relevant

GLP compliance:

yes

Type of assay:

mammalian cell gene mutation assay

Target gene:

tk gene locus

Species / strain / cell type:

mouse lymphoma L5178Y cells

Details on mammalian cell type (if applicable):

L5178Y TK +/- mouse lymphoma cells were obtained from the American Type Culture Collection. They were stored as frozen stocks in liquid nitrogen. Each batch of cells was purged of TK mutants, checked for spontaneous mutant frequency and that they were mycoplasma free. For each experiment the vials were thawed rapidly, the cells were diluted in RPMI 10 and incubated in a humidified atmosphere of 5 % v/v CO2 in air. When the cells were growing well, subcultures were established in an appropriate number of flasks.

Additional strain / cell type characteristics:

not specified

Metabolic activation:

with and without

Metabolic activation system:

S-9 mammalian liver post-mitochondrial fraction

Test concentrations with justification for top dose:

The concentrations were selected using a cytotoxicity range-finder. See Table 1 below.

Vehicle / solvent:

Acetone was used as a solvent. The test item was added and the culture was then vortexed for approx. 10 seconds to obtain a good emulsion. A top dose of 5000 ug/ml was achievable using an emulsion.

Negative solvent / vehicle controls:

yes

Remarks:

Comprised of solvent, acetone, diluted 100-fold in the treatment medium.

Positive controls:

yes

Remarks:

Please see Below

Positive control substance:

benzo(a)pyrene

Remarks:

The positive controls were also made to certain concentrations please see table 2 below Migrated to IUCLID6: Please see Below

Positive controls:

yes

Remarks:

Please see Below

Positive control substance:

4-nitroquinoline-N-oxide

Remarks:

The positive controls were also made to certain concentrations please see table 2 below Migrated to IUCLID6: Please see Below

Details on test system and experimental conditions:

METHOD OF APPLICATION:

Preparations of cofactor solutions with and without S-9

Quantity (ml)
With S-9 Without S-9
Glucose-6-phosphate (180 mg/ml) 1.0 -
NADP (25 mg/ml) 1.0 -
150 mM KCL 1.0 5.0
Rat Liver S-9 2.0 -

The above were used at the rate of 1.0 ml per 19 ml of cell culture containing the test chemical (to achieve the required final concentration in a total of 20 ml).


Three types of RPMI 1640 medium were prepared as follows:
Final Concentration in:
RPMI A RPMI 10 RPMI 20
Horse Serum (heat inactivated) 0 % v/v 10 % v/v 20 % v/v
Gentamycin 100 ug/ml 100 ug/ml 100 ug/ml
Fungizone 2.5 ug/ml 2.5 ug/ml 2.5 ug/ml
Pluronic 0.5 ug/ml 0.5 ug/ml -


DURATION
- Exposure duration: 9- 15 days
- Expression time (cells in growth medium): 2 days

NUMBER OF CELLS EVALUATED: 1 x E7 cells per flask

DETERMINATION OF CYTOTOXICITY
Following adjustment of the cultures to 2 x E5 cells/ml after treatment, samples from these were diluted to 8 cells/ml as seen in table 3. using a 8-channel pipette, 0.2 ml of concentration C of each culture was placed into each well of two 96-well microtitre plates (192 wells, at an average of 1.6 cells per wall). The plates were incubated at 37 C in a humidified incubator gassed with 5 % v/v CO2 in air until scorable (9-15 days). Wells containing viable clones were identified by eye using background illumination and counted.

Evaluation criteria:

At the end of the expression period the cell densities in the selected cultures were adjusted to 1 x E4/ml. TFT (300 ug/ml) was diluted 100-fold into these suspensions to give a final concentration of 3 ug/ml. Using a 8-channel pipette, 0.2 ml of each suspension was placed into each well of four 96-well microtitre plates (384 wells at 2 x E3 cells per well). Plates were incubated until scorable (13 days) and wells containing clones were identified as above and counted. In addition, the number of wells containing large colonies and the number containing small colonies were scored for the negative and positive controls and for doses of test chemical showing a significant increase in mutant frequency over the negative control.

Statistics:

All calculations were performed on a microcomputer.

Determination of survival or viability: Poison distribution, plating efficiency, % relative survival
Determination of mutant frequency: Mutant frequency, plating efficiency,
Statistical significance of mutant frequencies.

Species / strain:

mouse lymphoma L5178Y cells

Metabolic activation:

with and without

Genotoxicity:

negative

Remarks:

Please see Tables 5 & 6 below

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Remarks:

No marked toxicity was seen after the application of the highest dose. Please see Table 4

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Additional information on results:

RANGE-FINDING/SCREENING STUDIES: Please see table 4 below

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Table 4: raw plate counts and % relative survival for Epoxidised Soybean Oil in the cytotoxicity range-finder.

Treatment ug/mL)	In the absence of S-9		In the presence of S-9
	Survival (1) at Day 0*	% Relative survival	Survival (1) at day 0*	% relative survival
0	18	100.0	23	100.0
78.125	21	129.2	21	84.2
156.25	16	83.8	17	59.7
312.5	18	100.0	19	71.0
625	15	76.5	15	49.9
1250	15	76.5	15	49.9
2500	16	83.8	18	65.2
5000	19	109.0	23	100.0

(1) 1.6 cells/well plated

* 32 wells scored

Table 5: Summary of Results Experiment 1

Treatment (ug/ml)	Absence of S-9		Treatment (ug/mL)	Presence of S-9
	% RS	Mutant Frequency		% RS	Mutant Frequency
0	100.0	312.57	0	100.0	401.83
312.5	95.8	389.82 NS	312.5	97.9	484.86 NS
625	86.6	326.20 NS	625	87.9	563.19 NS
1250	79.9	439.82 NS	1250	86.0	518.57 NS
2500	131.9	520.41 *	2500	152.9	426.40 NS
5000	143.9	467.96 *	5000	178.7	433.74 NS
Linear Trend		**	Linear Trend		NS
NQO			BP
0.05	83.5	1676.58	2	55.2	1794.55
0.1	45.3	2078.73	3	39.4	2122.84

 

Table 6: Summary of Results Experiment 2

Treatment (ug/ml)	Absence of S-9		Treatment (ug/mL)	Presence of S-9
	% RS	Mutant Frequency		% RS	Mutant Frequency
0	100.0	410.98	0	100.0	304.98
312.5	112.9	334.82 NS	312.5	91.7	331.46 NS
625	87.7	466.23 NS	625	82.6	331.03 NS
1250	71.4	404.74 NS	1250	87.7	313.73 NS
2500	84.5	461.15 NS	2500	84.5	283.11 NS
5000 $$	100.7		5000	83.2	311.46 NS
Linear Trend		NS	Linear Trend		NS
NQO			BP
0.05	67.5	1136.27	2	59.5	883.78
0.1	37.7	1143.11	3	32.1	1443.04

 

NS Not significant

$$ Treatment excluded due to excessive heterogeneity

*, **, *** Significant at 5 %, 1% and 0.1 % level respectively

Conclusions:

Interpretation of results (migrated information):
negative ESBO failed to demonstrate an ability to induce mutation at the tk locus of mouse lymphoma L5178Y cells.

It is concluded that, under the conditions employed in this study, ESBO failed to demonstrate the ability to induce mutation at the tk locus of L5178Y mouse lymphoma cells in the absence and presence of S-9. Therefore, ESBO is not considered to be mutagenic.

Executive summary:

Epoxidised Soybean Oil (ESBO) was assayed for its ability to induce mutation at the tk locus (5-trifluorothymidine resistance) in mouse lymphoma cells using a fluctuation protocol. The study consisted of a cytotoxicity range-finder followed by 2 independent experiments, each conducted in the absence and presence of metabolic activation by an Aroclor 1254 induced rat liver post-mitochondrial fraction (S-9).

Following a wide range of treatments in the range-finder experiment, separated by 2-fold intervals and ranging from 78.125 to 5000µg/ml, cells survived all doses of ESBO yielding 109.0 % relative survival in the absence and 100.0 % relative survival in the presence of S-9 at the top dose.

Accordingly, 5 doses were chosen for the first experiment, separated by 2-fold intervals and ranging from 312.5 to 5000µg/ml. All doses were plated for viability and 5-trifluorothymidine resistance 2 days after treatment. The top doses plated yielded 143.9 % and 178.7 % relative survival in the absence and presence of S-9. In the second experiment the same dose range was selected. The top dose plated in this experiment was again 5000µg/ml in the absence and presence of S-9, which yielded 100.7 % and 83.2 % relative survival respectively.

Negative (solvent) and positive control treatments were included in each experiment in the absence and presence of S-9. Mutant frequencies in negative control cultures fell within normal ranges, and statistically significant increases in mutation were induced by the positive control chemicals 4-nitroquinoline 1-oxide (without S-9) and benzo(a)pyrene (with S-9). Therefore the study was accepted as valid.

In the absence of S-9, reproducible statistically significant and dose-related increases in mutant frequency were not observed in the 2 experiments over the dose range 312.5 to 2500µg/ml. At 5000µg/ml, a positive point was obtained in Experiment 1 and due to heterogeneity in the data this dose was excluded from analysis in Experiment 2. However, if each of the replicate cultures at 5000µg/ml in Experiment 2 are considered in turn, neither yields a statistically significant increase in mutant frequency. This, combined with the fact that there were no absolute increases in mutant numbers in Experiment 1 at 5000µg/ml and that carry over of the test compound was a problem at this dose, suggests that the increased mutant frequency seen in experiment 1 was not the result of chemically induced mutation.

In the presence of S-9, no statistically significant increases in mutant frequency were observed at any dose level tested in Experiment 1 or 2.

It is concluded that, under the conditions employed in this study, ESBO failed to demonstrate the ability to induce mutation at the tk locus of L5178Y mouse lymphoma cells in the absence and presence of S-9. Therefore, ESBO is not considered to be mutagenic.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Genetic toxicity in vivo

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Read across to a study result from an investigation using a similar material is justified for members of the Epoxidised Oils and Derivatives group. Four epoxidised oils (linseed, soybean, 2-ethylhexyl tallate and fatty acids, C14-C22, 2-ethylhexylesters) have been identified as sharing common structural and functional similarities, recognised in an OECD SIDS review as a single category, and therefore justifying read-across between data for different members of the group. Consequently data sharing between ESBO epoxidised soybean oil and epoxidised linseed oil is commonly utilised in the preparation of this dossier and other read-across bridges are used for other members of the EOD group where appropriate.

The genotoxic effects of ESBO were investigated in five in-vitro mutagenicity assays. Read across to these resultsfor ELO is justified on similarity of structure and function. Mutagenic effects on histidine-auxotrophic mutants of Salmonella typhimurium were investigated using methods similar to that of OECD test guideline 471. The chromosome damaging potential and effects on cultured human peripheral blood lymphocytes was investigated according to OECD test guideline 473. Mutagenic effects on the thymidine kinase locus in mouse lymphoma cells were investigated according to test guideline 476. The test substance was not found to be genotoxic in any of the tests performed.

Justification for classification or non-classification

Based on the negtaive results in all studies and according to Regulation (EC) No. 1272/2008, no classification for genetic toxicity is warranted.