Docosyl docosanoate

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

In vitro gene mutation in bacteria (OECD 471): negative with and without metabolic activation

Study performed with the analogue source substance fatty acids C20-22 (even numbered), C18-22 (even numbered) alkyl esters (EC 701-233-7)

In vitro chromosome aberration in mammalian cells (OECD 473): negative with and without metabolic activation

Study performed with the analogue source substance (Z)-octadec-9-enyl oleate (CAS 3687-45-4)

In vitro gene mutation in mammalian cells (OECD 473): negative with and without metabolic activation

Study performed with the analogue source substance (Z)-octadec-9-enyl oleate (CAS 3687-45-4)

Link to relevant study records

Reference

Reference 1

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

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

Adequacy of study:

key study

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 TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity, but tested up to precipitating concentrations

Remarks:

Precipitation at and above 333 µg/plate in experiment I and at and above 33 µg/plate in experiment II, each +/- S9.

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

True negative controls validity:

not examined

Positive controls validity:

valid

Remarks:

Source: EC 701-233-7, NOF, 2008, Ames

Key result

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

In experiment II at and above 1000 µg/plate, with and without S9 mix; precipitation at and above 333 µg/plate in experiment I and at and above 33 µg/plate in experiment II, each +/- S9.

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

True negative controls validity:

not examined

Positive controls validity:

valid

Remarks:

Source: EC 701-233-7, NOF, 2008, Ames

Key result

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

In experiment II at and above 2500 µg/plate, without S9 mix; precipitation at and above 333 µg/plate in experiment I and at and above 33 µg/plate in experiment II, each +/- S9.

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

True negative controls validity:

not examined

Positive controls validity:

valid

Remarks:

Source: EC 701-233-7, NOF, 2008, Ames

Key result

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity, but tested up to precipitating concentrations

Remarks:

Precipitation at and above 333 µg/plate in experiment I and at and above 33 µg/plate in experiment II, each +/- S9.

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

True negative controls validity:

not examined

Positive controls validity:

valid

Remarks:

Source: EC 701-233-7, NOF, 2008, Ames

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

Remarks:

Precipitation at and above 333 µg/plate in experiment I and at and above 33 µg/plate in experiment II, each +/- S9.

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

True negative controls validity:

not examined

Positive controls validity:

valid

Remarks:

Source: EC 701-233-7, NOF, 2008, Ames

Conclusions:

Interpretation of results: negative

A reliable study conducted in accordance with OECD guideline 471 and GLP found the test material to induce no gene mutation in bacteria. No base substitution or frame shift mutations were detected in S. typhimurium and E. coli strains.

Executive summary:

The potential of the target substance docosyl docosanoate (CAS 17671-27-1) to induce gene mutation in bacteria is estimated based on an adequate and reliable in vitro study with an analogue source substance. In this study the test substance did not induce base substitution or frame shift mutations in S. typhimurium and E. coli tester strains. Therefore, the lack of a gene mutation potential in bacteria is taken forward to the hazard assessment and the determination of the classification of the target substance. As explained in the Analogue Justification, the differences in molecular structure between the target and the source substances are unlikely to lead to differences in the genetic toxicity potential.

Reference 2

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:

key study

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:

Chinese hamster lung fibroblasts (V79)

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:

Source: CAS 3687-45-4, Emery, 1994, CA

Conclusions:

Interpretation of results: negative

A reliable study conducted in accordance with OECD guideline 473 and GLP found the test material did not induce chromosome aberrations in Chinese hamster lung fibroblasts (V79).

Executive summary:

The potential of the target substance docosyl docosanoate (CAS 17671-27-1) to induce chromosome aberrations in mammalian cells is estimated based on an adequate and reliable in vitro study with an analogue source substance. In this study the test substance did not induce chromosome aberrations in Chinese hamster lung fibroblasts (V79). Therefore, the lack of the potential to induce chromosome aberrations is taken forward to the hazard assessment and the determination of the classification of the target substance. As explained in the Analogue Justification, the differences in molecular structure between the target and the source substances are unlikely to lead to differences in the genetic toxicity potential.

Reference 3

Endpoint:

in vitro gene mutation study in mammalian cells

Type of information:

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

Adequacy of study:

key study

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:

Chinese hamster lung fibroblasts (V79)

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity, but tested up to precipitating concentrations

Remarks:

precipitation at limit of water solubility at 100 µg/mL observed.

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Remarks:

Source: CAS 3687-45-4, Emery, 1994, HPRT

Conclusions:

Interpretation of results: negative

A reliable study conducted in accordance with OECD guideline 476 and GLP found the test material did not induce gene mutation in Chinese hamster lung fibroblasts (V79).

Executive summary:

The potential of the target substance docosyl docosanoate (CAS 17671-27-1) to induce gene mutation in mammalian cells is estimated based on an adequate and reliable in vitro study with an analogue source substance. In this study the test substance did not induce gene mutation in Chinese hamster lung fibroblasts (V79). Therefore, the lack of the potential to induce gene mutation in mammalian cells is taken forward to the hazard assessment and the determination of the classification of the target substance. As explained in the Analogue Justification, the differences in molecular structure between the target and the source substances are unlikely to lead to differences in the genetic toxicity potential.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Genetic toxicity in vivo

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

No data on genetic toxicity are available for docosyl docosanoate (CAS 17671-27-1). Adequate and reliable studies performed with analogue source substances are, therefore, used to assess the endpoints gene mutation in bacteria, chromosome aberration in mammalian cells in vitro and gene mutation in mammalian cells in vitro.

Gene mutation in bacteria

A study according to OECD guideline 471 under GLP conditions was performed to investigate the potential of fatty acids C20-22 (even numbered), C18-22 (even numbered) alkyl esters (EC 701-233-7) to induce gene mutations in bacteria (Ames test; NOF, 2008, Ames). In the plate incorporation test and the pre-incubation test the S. typhimurium strains TA1535, TA1537, TA98, and TA100, and the E. coli strain WP2 uvrA, were exposed to the test substance with and without liver microsomal activation. The test item was tested at the following concentrations: 3, 10, 33, 100, 333, 1000, 2500 and 5000 µg/plate (plate incorporation) and 33, 100, 333, 1000, 2500 and 5000 µg/plate (pre-incubation). While cytotoxicity was observed only in strains TA1537 at and above 1000 µg/plate (± S9) and TA98 at and above 2500 µg/plate (- S9), precipitation occurred in all strains in experiment I at and above 333 µg/plate (± S9) and in experiment II at and above 33 µg/plate (± S9). No substantial increase in revertant colony numbers of any of the tester strains was observed following treatment with the test substance at any dose level, neither in the presence nor in the absence of metabolic activation. Appropriate reference mutagens were used as positive controls and showed a distinct increase of induced revertant colonies. In conclusion, the test substance fatty acids C20-22 (even numbered), C18-22 (even numbered) alkyl esters was considered to be non-mutagenic in this S. typhimurium and E. coli reverse mutation assay.

Chromosome aberration in mammalian cells in vitro

The potential of oleyl oleate (CAS 3687-45-4) to induce chromosomal aberrations was assessed using Chinese hamster V79 cells, in a study performed according to OECD guideline 473 (Emery, 1994, CA). The V79-cells were exposed to the test substance at concentrations up to 100 µg/mL, with and without metabolic activation (S9-mix). One experiment with duplicate replications was performed with short-term treatment (4 h) and fixation time 18 and 28 h, without metabolic activation; and with metabolic activation using 18 h treatment time and 18 h fixation time and 28 h treatment time and 28 h fixation time, respectively. The test material did not induce a statistically significant increase in the frequency of cells with chromosome aberrations, with or without metabolic activation. The mitotic indices of the treated cultures without metabolic activation were 83.4 - 119% and with metabolic activation 91 - 127.1%, compared with the vehicle control. Precipitation was observed at concentrations from 100 µg/mL, while no cytotoxicity was noted at any concentration. The vehicle and positive controls were valid. It was concluded that the test substance oleyl oleate did not induce chromosomal aberrations in Chinese hamster V79 cells under the conditions of the test.

Gene mutation in mammalian cells in vitro

An in vitro mammalian cell gene mutation assay was performed using oleyl oleate (CAS 3687-45-4), according to OECD guideline 476 (Emery, 1994, HPRT). Chinese hamster lung fibroblasts (V79) were treated with the test substance at concentrations of up to 100 µg/mL for 4 h both with and without metabolic activation (S9-mix). After an expression time of 7 days in growth medium, cells were incubated for 9 or 12 days with 6 -thioguanine as selection agent for forward mutation at the HPRT locus. Both with and without metabolic activation, no increases in mutant frequency were observed in the initial and in the confirmatory gene mutation assay. There was no evidence of excessive cytotoxicity (i.e., < 10% relative cloning efficiency) at any of the tested concentrations either in the presence or absence of metabolic activation in any of the experiments performed. The test substance oleyl oleate did not induce gene mutation at the HPRT locus in Chinese hamster V79 cells under the conditions of this experiment.

Justification for classification or non-classification

The available data on genetic toxicity for adequate analogue source substances do not meet the criteria for classification according to Regulation (EC) No. 1272/2008 (CLP). Data are conclusive but not sufficient for classification. Based on an analogue read-across approach, the target substance docosyl docosanoate (CAS 17671-27-1) is, therefore, also not classified for genetic toxicity.