Glycerol trioctanoate

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Ames test (similar to OECD 471, only 4 strains tested): negative with and without metabolic activation in S. typhimurium TA 97, TA 98, TA 100, negative without metabolic activation in TA1535, positive with metabolic activation in TA1535 only at concentrations above the recommended maximum test concentration for soluble non-cytotoxic substances

Ames test (OECD 471, read across): negative with and without metabolic activation in S. typhimurium TA 1535, TA 1537, TA 98 and TA 100 and in E. coli WP2 uvrA.

Chromosome aberration (OECD 473, read across): negative in Chinese hamster lung cells (CHL/IU) with and without metabolic activation.

Gene mutation in mammalian cells (OECD 476, read across): negative in mouse lymphoma L5178Y cells with and without metabolic activation.

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:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Remarks:

Acceptable, well documented study report which meets basic scientific principles.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Version / remarks:

adopted in 1981

Deviations:

yes

Remarks:

S9 mix from hamster used

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Version / remarks:

adopted in 1997

Deviations:

yes

Remarks:

2-Aminoanthracene was used as the sole indicator of the efficacy of the S9-mix; only four strains were tested and no strain was included to cross-linking mutagens (e.g. TA102 or E.coli); lack of cytotoxicity data.

GLP compliance:

not specified

Type of assay:

bacterial reverse mutation assay

Target gene:

his operon

Species / strain / cell type:

S. typhimurium, other: TA 1535, TA 97, TA 98 and TA 100

Metabolic activation:

with and without

Metabolic activation system:

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

Test concentrations with justification for top dose:

TA100 / TA97/ TA 98: 100, 333, 1000, 3333, 10000 µg/plate with and without S9 mix
TA 1535: 100, 333, 1000, 3333, 6666, 10000, 16666 µg/plate with and without S9 mix

Vehicle / solvent:

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

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: -S9: 2-nitrofluorene (TA98), sodium azide (TA100 and TA1535), 9-aminoacridine (TA97); +S9: 2-aminoanthracene or occasionally sterigmatocystin (all strains)

Details on test system and experimental conditions:

METHOD OF APPLICATION: preincubation, agar plates

DURATION
- Preincubation period: 20 min. at 37°C
- Exposure duration: 48 hours

NUMBER OF REPLICATIONS: triplicates

DETERMINATION OF CYTOTOXICITY
- Method: cloning efficiency

Evaluation criteria:

If the test chemical was mutagenic to any particular strain of bacterium, the number of histidine-independent colonies arising on those plates must be significantly greater than the corresponding control plates for that strain of bacteria. The positive control plates were also counted, and the number of mutant colonies appearing on them must be significantly increased over the spontaneous control number for the test to be considered valid. Failure of the positive control chemical to induce mutation is reason to discard the experiment.
In analyzing the data, the pattern and the strength of the mutant response are taken into account in determining the mutagenicity of a chemical. If no increase in mutant colonies is seen after testing several strains under several different culture conditions, the test chemical is considered to be nonmutagenic in the Ames test.

Key result

Species / strain:

S. typhimurium, other: TA 97, TA 98 and TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Remarks:

but tested up to limit concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Key result

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with

Genotoxicity:

positive

Remarks:

at concentrations >= 6666 µg/plate

Cytotoxicity / choice of top concentrations:

not specified

Remarks:

but tested up to limit concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Key result

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Remarks:

but tested up to limit concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Remarks on result:

other:

Remarks:

in the presence of hamster or rat S9 mix

Table 1: Mutant frequency (revertants per plate ± standard error from 3 plates) in TA1535, TA97, TA98, TA100 after treatment with the test substance.

Strain	Dose (µg/plate)	-S9		+30% Hamster S9						+30% rat S9
				Trial 1		Trial 2		Trial 3		Trial 1		Trial 2		Trial 3
		Mean	± SEM	Mean	± SEM	-	-	-	-	Mean	± SEM	-	-	-	-
TA100	0	144	17.7	137	7	-	-	-	-	193	8.5	-	-	-	-
	100	169	5.2	135	4.9	-	-	-	-	197	4.8	-	-	-	-
	333	134	17	142	6.2	-	-	-	-	189	6.5	-	-	-	-
	1000	108	1.9	147	5.7	-	-	-	-	190	3.8	-	-	-	-
	3333	112	1	137	5	-	-	-	-	176	4.5	-	-	-	-
	10000	131	5.2	176	2.2	-	-	-	-	188	9.5	-	-	-	-
	Positive Control*	955	37.8	837	39.5	-	-	-	-	440	26.1	-	-	-	-
Strain	Dose (µg/plate)	-S9		+30% Hamster S9						+30% rat S9
				Trial 1		Trial 2		Trial 3		Trial 1		Trial 2		Trial 3
		Mean	± SEM	Mean	± SEM	Mean	± SEM	Mean	± SEM	Mean	± SEM	Mean	± SEM	Mean	± SEM
TA1535	0	12	0.9	15	0.9	11	0	13	2.6	18	3.8	15	1.2	20	3.8
	100	14	0.9	11	2.3	-	-	-	-	16	3.8	-	-	-	-
	333	13	3.4	14	2	-	-	-	-	17	1.2	-	-	-	-
	1000	15	2.6	12	0.9	12	2.9	24	1.2	17	2.3	15	1.5	28	5.1
	3333	14	1.3	15	0.3	18	1.5	45	4.5	20	2.6	19	1.7	37	1.5
	6666	-	-	-	-	50	6	42	1.9	-	-	37	2.2	39	3.4
	10000	17	1.8	44	9.1	52	2.8	55	1.9	42	1.5	49	5.5	54	3.8
	16666	-	-	-	-	85	2.8	107	10.7	-	-	76	2.4	95	3.2
	Positive Control	958	34.3	607	16.8	408	39.8	351	8.9	105	3.6	91	9.1	90	10.5
Strain	Dose (µg/plate)	-S9		+30% Hamster S9						+30% rat S9
				Trial 1		Trial 2		Trial 3		Trial 1		Trial 2		Trial 3
		Mean	± SEM	Mean	± SEM	-	-	-	-	Mean	± SEM	-	-	-	-
TA97	0	222	6.9	185	6.9	-	-	-	-	216	5.3	-	-	-	-
	100	228	3.8	198	7.3	-	-	-	-	205	20.4	-	-	-	-
	333	223	6.3	210	7.6	-	-	-	-	224	11.9	-	-	-	-
	1000	210	2.6	216	1.8	-	-	-	-	184	6.5	-	-	-	-
	3333	212	7.6	203	21.5	-	-	-	-	168	3.7	-	-	-	-
	10000	225	4	197	19.4	-	-	-	-	152	10.4	-	-	-	-
	Positive Control	742	42.2	436	2.2	-	-	-	-	442	3.5	-	-	-	-
Strain	Dose (µg/plate)	-S9		+30% Hamster S9						+30% rat S9
				Trial 1		Trial 2		Trial 3		Trial 1		Trial 2		Trial 3
		Mean	± SEM	Mean	± SEM	-	-	-	-	Mean	± SEM	-	-	-	-
TA98	0	30	4.7	35	4	-	-	-	-	38	1.9	-	-	-	-
	100	27	1.5	34	2.4	-	-	-	-	41	0.6	-	-	-	-
	333	27	0.9	33	6.7	-	-	-	-	36	3.8	-	-	-	-
	1000	28	4.6	29	1.7	-	-	-	-	31	3.7	-	-	-	-
	3333	28	1.5	28	3.4	-	-	-	-	34	1.7	-	-	-	-
	10000	28	2	31	4.3	-	-	-	-	28	1.5	-	-	-	-
	Positive Control	677	20.6	770	11.3	-	-	-	-	168	3.5	-	-	-	-

* The positive controls in the absence of metabolic activation were sodium azide (TA100 and TA1535), 9-aminoacridine (TA97), and 4-nitro-o-phenylenediamine (TA98). The positive control for metabolic activation with all strains was 2-aminoanthracene.

Conclusions:

Negative in TA 97, TA98 and TA 100 with and without metabolic activation (hamster S9 mix or rat S9 mix).
Positive with metabolic activation in TA1535, but only at very high concentrations of 6666 to 16666 µg/plate, which is above the required limit concentration of 5000 µg/plate.

Reference 2

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

refer to analogue justification provided in IUCLID section 13

Reason / purpose for cross-reference:

read-across source

Key result

Species / strain:

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

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

Growth inhibition of the tested bacterium was observed at concentrations of 10 μg/plate and above in the absence of metabolic activation as well as at concentrations of 156 μg/plate and above in the presence of metabolic activation.

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Key result

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity, but tested up to precipitating concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Remarks on result:

other:

Remarks:

Source: CAS 91052-13-0

Conclusions:

The read across approach is justified in the analogue justification. The target and source substances are considered unlikely to differ in their bacterial mutagenicity potential. The available data from the source substance glycerides, C8-18 and C18-unsatd. mono- and di-,acetates (CAS 91052-13-0) showed no mutagenic potential in bacteria. Therefore, the target substance glycerol trioctanoate (CAS 538-23-8) is not expected to be mutagenic in bacteria.

Reference 3

Endpoint:

in vitro cytogenicity / chromosome aberration study in mammalian cells

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

refer to analogue justification provided in IUCLID section 13

Reason / purpose for cross-reference:

read-across source

Key result

Species / strain:

other: CHL/IU

Remarks:

Chinese hamster lung cell line

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity, but tested up to precipitating concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Remarks on result:

other:

Remarks:

Source: CAS 91052-13-0

Conclusions:

The read across approach is justified in the analogue justification. The target and source substance are considered unlikely to differ in their genotoxic potential. The available in vitro data from the source substance glycerides, C8-18 and C18-unsatd. mono- and di-,acetates (CAS 91052-13-0) showed no clastogenic potential in mammalian cells. Therefore, the target substance glycerol trioctanoate (CAS 538-23-8) is not expected to be clastogenic in mammalian cells.

Reference 4

Endpoint:

in vitro gene mutation study in mammalian cells

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

refer to analogue justification provided in IUCLID section 13

Reason / purpose for cross-reference:

read-across source

Key result

Species / strain:

mouse lymphoma L5178Y cells

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

without S9: starting from 3600 μg/mL (first test (4 h exposure)) and 160 μg/mL (second test (24 h exposure)), with S9: starting from 2500 μg/mL

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Remarks on result:

other:

Remarks:

Source: CAS 736150-63-3

Conclusions:

The read across approach is justified in the analogue justification. The target and source substance are considered unlikely to differ in their genotoxic potential. The available in vitro data from the source substance glycerides, castor-oil.mono, hydrogenated, acetates (CAS 736150-63-3) showed no mutagenic potential in mammalian cells. Therefore, the target substance glycerol trioctanoate (CAS 538-23-8) is not expected to be mutagenic in mammalian cells.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Genetic toxicity in vivo

Description of key information

Micronucleus test, dominant lethal study, chromosome aberration assay, sister chromatid exchange assay: negative; target substance used as solvent control at low doses

Link to relevant study records

Reference

Endpoint:

in vivo mammalian germ cell study: cytogenicity / chromosome aberration

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Remarks:

Acceptable, well documented publication which meets basic scientific principles.

Principles of method if other than guideline:

Tricaprylin was used as solvent control in a female dominant-lethal study with 1,2-dibromo-3-chloropropane (DBCP).

GLP compliance:

not specified

Type of assay:

rodent dominant lethal assay

Species:

mouse

Strain:

other: T-stock and (C3HxC57BL)F1

Sex:

female

Route of administration:

intraperitoneal

Vehicle:

- Vehicle(s)/solvent(s) used: None
- Justification for choice of solvent/vehicle: Tricaprylin served as solvent control in the study.

Details on exposure:

One experiment in T-stock females and a second experiment in T-stock and (C3HxC57BL) F1 females were conducted. Over a period of six days post dosing, the females were mated with (C3HxC57BL) F1 males.

Frequency of treatment:

single injection

Dose / conc.:

7.6 mg/kg bw (total dose)

Remarks:

0.2 mL/animal; mean dose value as calculated from a body weight of 25 g and density of 0.954 g/L

No. of animals per sex per dose:

First experiment
T-stock: 44 females

Second experiment
T-stock: 47 females
(C3HxC57BL)F1: 37 females

Control animals:

no

Positive control(s):

none

Key result

Sex:

female

Genotoxicity:

negative

Toxicity:

not specified

Vehicle controls validity:

other: Tricaprylin served as solvent control in the study.

Negative controls validity:

not examined

Positive controls validity:

not examined

Table 1: Dominant-lethal studies in female mice

Experiment	Stock of females	Number of mated females	Number of pregnant females	Number of implantations per pregnant females	Number of living embryos per pregnant females	Dead implants (%)
I	T-stock	44	41	8.4	7.3	13.4
II	(C3HxC57BL)F1	37	29	9.4	8.9	5.5
	T-stock	47	42	8.2	6.9	15.9

For both, tricaprylin and DBCP, dominant-lethal parameters were in the same range, revealing no induction of dominant lethal mutations in female germ cells.

Conclusions:

No adverse effects on number of pregnant females, number of implantations/females, number of living embryos/pregnant female, dead implants (%) were found after single intraperitoneal injection of Glycerol trioctanoate (CAS 538-23-8) at a dose of 7.6 mg/kg bw to female mice in a dominant lethal study. The administered dose is not sufficient for assessment.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Mode of Action Analysis / Human Relevance Framework

Not applicable

Additional information

Justification for read-across

The in vitro data on genetic toxicity in bacteria for glycerol trioctanoate (CAS 538-23-8) are insufficient to meet data requirements. The assessment was therefore based on studies conducted with analogue substances as part of a read-across approach, which is in accordance with Regulation (EC) No. 1907/2006, Annex XI, 1.5. For each specific endpoint the source substance(s) structurally closest to the target substance is/are chosen for read-across, with due regard to the requirements of adequacy and reliability of the available data. Structural similarities and similarities in properties and/or activities of the source and target substance are the basis of read-across. A detailed justification for the analogue read-across approach is provided in the technical dossier (see IUCLID Section 13).

Genetic toxicity (mutagenicity) in bacteria in vitro

CAS 538-23-8

A bacterial reverse mutation assay with glycerol trioctanoate (CAS 538-23-8) was performed similar to OECD guideline 471 (WoE, 1989). Salmonella typhimurium strains TA 1535, TA 97, TA 98 and TA 100 were tested in triplicates in the presence or absence of metabolic activation on agar plates using a pre-incubation method. Glycerol trioctanoate (CAS 538-23-8) was tested at concentrations up to 10000 µg/plate in strains TA 97, TA 98, and TA 100 and up to 16666 µg/plate in strain TA 1535 for an exposure duration of 48 hours, following a preincubation period of 20 minutes at 37°C. The positive and negative (vehicle) controls revealed the expected results. In the presence of metabolic activation (30% S9 mix) Glycerol trioctanoate (CAS 538-23-8) was mutagenic in the Salmonella typhimurium strain TA 1535, but only at very high concentrations (6666 and 16666 µg/plate). The result was negative up to and including the 3rd highest dose level of 3333 µg/plate. No mutagenic activity was detected in the other tested strains.

CAS 91052-13-0

A bacterial gene mutation assay with glycerides, C8-18 and C18-unsatd. mono- and di-, acetates was performed according to OECD guideline 471 under GLP conditions (WoE, 2010). Two independent experiments were performed both in the presence or absence of metabolic activation in S. typhimurium TA 1535, TA 1537, TA 98 and TA 100 and in E. coli WP2 uvrA. In the preliminary toxicity screening, growth inhibitory effects were observed at ≥ 20 µg/plate in S. typhimurium TA 98 and TA 1537 (without metabolic activation), at ≥ 78 µg/plate in S. typhimurium TA 100 and TA 1535 (without metabolic activation), and at ≥ 313 µg/plate in all S. typhimurium strains with metabolic activation. Based on these results, concentrations ranging from 0.61 to 78 µg/plate were used for the tester strains TA 100, TA 1535, TA98 and TA 1537 in the absence of metabolic activation, whereas concentrations ranging from 10 to 313 µg/plate were applied for treatment of the tester strains TA 100, TA 1535, TA 98 and TA 1537 in the presence of metabolic activation. Since no cytotoxicity was seen in E. coli WP2 uvrA, the maximum test concentration of 5000 µg/plate and concentrations of 2500, 1250, 625 and 313 µg/plate were selected for treatment in the main assay. Precipitation of the test substance was observed on the plates with E. coli WP2 uvrA at test concentrations ≥ 1250 µg/plate without metabolic activation and at ≥ 2500 µg/plate with metabolic activation in both experiments. No increase in mean revertant number was observed in any bacterial strain after exposure to the test substance in the presence or absence of metabolic activation. The positive and negative controls revealed the expected results. Under the conditions of this assay, the test substance did not induce gene mutations in the selected strains of S. typhimurium and in E. coli WP2 uvrA in the absence and presence of metabolic activation, respectively.

Genetic toxicity in mammalian cells in vitro

CAS 91052-13-0

The clastogenic potential of glycerides, C8-18 and C18-unsatd. mono- and di-, acetates was assessed in a study performed according to OECD guideline 473 under GLP conditions using Chinese hamster lung cells (CHL/IU) (WoE, 2010). In a preliminary cell growth inhibition test with concentrations ranging from 9.8 to 5000 µg/plate, no significant inhibition of cell growth was observed after 4 h exposure in the presence and absence of metabolic activation (S9 mix). However, a moderate reduction of cell growth of ca. 30-40% compared with the solvent control was observed at concentrations in the range 156-1250 µg/mL after 24 and 48 h continuous exposure. Based on the results of this study, concentrations of 20, 39, 78 and 156 µg/mL (± S9 mix) were used for the analysis of chromosomal aberrations after short-term exposure (6 h), while concentrations of 78, 156, 313, 625, 1250, 2500 and 5000 µg/mL (± S9 mix) were chosen for analysis chromosomal aberrations after continuous exposure (24 and 48 h). No increase in the number of cells with chromosomal aberrations was observed compared to controls in any of the experiments performed. No cytotoxic effects were observed in any of the experiments performed. An oily precipitation of the test substance was observed at concentrations ≥ 78 µg/mL, but did not interfere with chromosomal analysis of the cells. The positive controls included during short-term and continuous exposure showed the expected results. Under the conditions of this experiment, the test substance was considered to be not clastogenic in Chinese hamster lung cells (CHL/IU) in the presence and absence of metabolic activation.

CAS 736150-63-3

An in vitro mammalian cell gene mutation assay was performed with glycerides, castor-oil mono, hydrogenated, acetates (CAS 736150-63-3) according to OECD guideline 476 under GLP conditions (WoE, 2002). In the first experiment, mutations at the TK locus of mouse-lymphoma L5178Y cells were investigated at concentrations of 625, 1250, 2500, 3600 and 5000 µg/mL. In this experiment, cells were exposed to the test material for a period of 3 h in the presence and for 4 h in the absence of metabolic activation (S9-mix). At 3600 µg/mL, the relative total growth was 10-20% compared to the negative controls, thus providing an appropriate maximum concentration for treatment in the second experiment. In this experiment, cells were exposed without S9-mix to concentrations ranging from 313 to 3600 µg/ for a period of 24 h, whereas in the presence of S9-mix, cells were treated with concentrations of 156-3600 µg/mL for a period of 4 h. Since the relative growth with S9-mix was very low (0-2%) at all test concentrations, the 24-h treatment of cells in the absence of S9-mix was repeated with concentrations ranging from 2.5-320 µg/mL, which resulted in appropriate levels of cytotoxicity (10-20% relative growth) at 160 µg/mL. In the presence of metabolic activation, the relative total growth was 9% at 2500 µg/mL in the first experiment and 37 and 0% at 2500 and 3600 µg/mL in the second experiment, respectively. After a 3-day expression period of the cultures, the resistance to 5-trifluorothymidine (TFT) was determined in all experiments. The test substance did not induce a significant increase in the mutant frequency at any preparation time and dose concentration. The positive controls significantly increased mutant frequency. In conclusion, the test substance did not induce mutations in mouse-lymphoma L5178Y cells, neither in the presence nor in the absence of a metabolic activation system, under these experimental conditions.

Genetic toxicity in vivo

CAS 538-23-8

An in vivo mammalian somatic cell study was performed with glycerol trioctanoate (CAS 538-23-8) which was used as the solvent control in a micronucleus test (WoE, 1978, MNT). After a single intraperitoneal injection of glycerol trioctanoate at 38 mg/kg bw (equivalent to 1 mL per animal) to each of 7 male Chinese hamsters, bone marrow smears were prepared after an exposure duration of 30 hours. At least 2000 micro-nucleated polychromatic erythrocytes were investigated per animal. No increase in the incidence of micro-nucleated polychromatic erythrocytes was found. The administered dose was very low considering that according to OECD guideline 474 (in vivo mammalian micronucleus test) dosing 2000 mg/kg is recommended as limit dose. The results of the study cannot be used for classification and labelling purposes.

CAS 538-23-8

An in vivo mammalian germ cell study was performed with glycerol trioctanoate (CAS 538-23-8) which was used as the solvent control in a female dominant-lethal study (WoE, 1985). After a single intraperitoneal injection of 7.6 mg/kg bw to each of 44 female mice, number of pregnant females, number of implantations/females, number of living embryos/pregnant female, and dead implants (%) were investigated. No induction of dominant lethal mutations in female germ cells was found. The administered dose was very low considering that according to OECD guideline 478 (rodent dominant lethal test) dosing of 2000 mg/kg bw is recommended as limit dose. The results of the study cannot be used for classification and labelling purposes.

CAS 538-23-8

An in vivo mammalian germ cell study was performed with glycerol trioctanoate (CAS 538-23-8) which was used as the solvent control in a chromosome aberration assay (WoE, 1978, CA). After a single intraperitoneal injection of 38 mg/kg bw to each of 5 male Chinese hamsters and an exposure duration of 24 hours, bone marrow from both femurs was used for chromosome preparations. The incidence of chromosome aberrations (gaps, breaks) was in the range of known negative controls and therefore not indicative for genotoxicity. The administered dose was very low considering that according to OECD guideline 475 (Mammalian Bone Marrow Chromosomal Aberration Test) dosing of 2000 mg/kg bw is recommended as limit dose. The results of the study cannot be used for classification and labelling purposes.

CAS 538-23-8

An in vivo mammalian DNA damage study was performed with glycerol trioctanoate (CAS 538-23-8) which was used as the solvent control in a sister-chromatid exchange assay (WoE, 1978, SCE). After a single intraperitoneal injection of 38 mg/kg bw to each of 8 male Chinese hamsters, bone marrow from both femurs was used for cell preparations. The rate of sister chromatid exchanges was not different from untreated animals and therefore no indication for DNA damages were found. The administered dose was very low. The results of the study cannot be used for classification and labelling purposes.

Overall conclusion for genetic toxicity

The target substance glycerol trioctanoate (CAS 538-23-8) showed positive result in the presence of metabolic activation in TA1535, one out of 4 Salmonella typhimurium strains tested in an Ames test. However, an increase in mutant frequency was seen only at concentrations ≥ 6666 µg/plate, which is above the recommended maximum test concentration for soluble non-cytotoxic substances according to OECD guideline 471. The available in vivo genotoxicity data on the target substance were not indicative for genotoxicity. However, as glycerol trioctanoate (CAS 538-23-8) had been tested as solvent control group in these in vivo studies, the administered doses were very low.

To meet the requirements for the genetic toxicity endpoint, analogue read-across from two source substances was applied from in vitro gene mutation studies in bacteria, and from studies on in vitro cytogenicity and mutagenicity in mammalian cells. The results of the available studies were consistently negative. Based on the available data on the target and source substances, glycerol trioctanoate (CAS 538-23-8) is not expected to be clastogenic or mutagenic.

Justification for classification or non-classification

According to Article 13 of Regulation (EC) No. 1907/2006 "General Requirements for Generation of Information on Intrinsic Properties of substances", information on intrinsic properties of substances may be generated by means other than tests e.g. from information from structurally related substances (grouping or read-across), provided that conditions set out in Annex XI are met. Annex XI, "General rules for adaptation of this standard testing regime set out in Annexes VII to X” states that “substances whose physicochemical, toxicological and ecotoxicological properties are likely to be similar or follow a regular pattern as a result of structural similarity may be considered as a group, or ‘category’ of substances. This avoids the need to test every substance for every endpoint". Since the analogue concept is applied to glycerol trioctanoate (CAS 538-23-8), data will be generated from data for reference source substance(s) to avoid unnecessary animal testing. Additionally, once the analogue read-across concept is applied, substances will be classified and labelled on this basis.

Therefore, based on the available data on analogue read-across approach, the results on genetic toxicity for the source substances do not meet the classification criteria according to Regulation (EC) 1272/2008, and are therefore conclusive but not sufficient for classification.