Reaction mass of 1-phenyloctadecane-1,3-dione and phenylicosane-1,3-dione

Endpoint summary

Additional information

Bacterial reverse mutation:

Two studies are available for the evaluation of the mutagenic potential in bacteria. One study (Sarlang, 2011) was of reliability 1 according to Klimisch cotation criteria and was therefore selected as the key study. The other study (Benazet, 1978) was of reliability 3 according to Klimisch cotation criteria and was used as part of a weight of evidence approach.

The key study was conducted according to OECD TG 471 and GLP. Five strains of bacteria Salmonella typhimurium: TA 1535, TA 1537, TA 98, TA 100 and TA 102 were used. The test item was tested in three independent experiments, with or without a metabolic activation system. Since the test item was found poorly soluble in the preliminary test (solvent = Tetrahydrofuran), the choice of the highest dose-level was based on the level of precipitate, according to the criteria specified in the international guidelines. The selected treatment-levels were 12.3, 37, 111.1, 333.3 and 1000 µg/plate for the first and second experiments with and without S9 mix. Due to a severe toxicity observed with S9 mix using the preincubation method, a third experiment was undertaken using a lower range of dose-levels. The selected dose-levels for this third experiment were:   0.137, 0.412,1.23,3.7, 11.1 and 33.3 µg/plate for the TA 102 strain ; 0.412,1.23,3.7, 11.1, 33.3 and 100 µg/plate for the TA 1537 strain ;  0.8, 2.5, 7.4, 22.2, 66.7 and 200 µg/plate for the TA 98 strain and 1.23,3.7, 11.1, 33.3, 100 and 300 µg/plate for the TA 100 strain.

The test item did not induce any noteworthy increase in the number of revertants, in any of the five strains and in either experiment.

The second study was similar to an OECD 471 but using 4 bacterial strains (TA 1535, TA 1537, TA 98, TA 100) instead of 5 and was therefore used as part of a weight of evidenceapproach. No cytotoxicity or significant increase in the number of revertants were observed with or without a metabolic activation system. Therefore the results of this study are consistent with those of the key study and support the absence of classification for mutagenicity in the Salmonella typhimurium reverse mutation assay.

 

 In vitro mammalian cell gene mutation:

One study of reliability 1 according to Klimisch cotation criteria and conducted according to OECD TG 476 and GLP is available (Rokh, 2011). This study was performed to investigate the potential of the test item to induce mutations at the TK (Thymidine Kinase) locus in L5178Y TK^+/-mouse lymphoma cells in the presence or absence of a rat metabolising system (S9 mix).

Since the test item was non-toxic in the preliminary test but was found poorly soluble, in the final treatment medium, the choice of the highest dose-level to be used in the main test was based on the level of precipitate, according to the criteria specified in the international guidelines. The selected dose-levels were1.25,2.5, 5, 10, 20 and 40 µg/mL for both experiments, with and without S9 mix.

At the end of the treatment periods (3- or 24- hour treatments), a slight to moderate precipitate was noted in the culture medium, at dose-levels ≥ 20 µg/mL.

Following the 3-hour treatment either with or without S9 mix as well as the 24-hour treatment without S9 mix, no noteworthy increase in the mutation frequency was noted in comparison to the vehicle control. The test item is therefore considered not to be mutagenic in the mouse lymphoma assay, in the absence or in the presence S9 mix.

 

In vitro mammalian chromosome aberration:

One study of reliability 1 according to Klimisch cotation criteria and conducted according to OECD TG 473 and GLP is available (Rokh, 2011). This study was performed to investigate the potential of the test item to induce structural chromosome aberrations in human lymphocytes in vitro both with and without a liver metabolizing system (S9 mix).

Since the test item was found poorly soluble in the final treatment medium, the choice of the highest dose-level to be used in the main test (68.18 µg/mL) was based on the level of precipitate, according to the criteria specified in the international guidelines. Exposure period were 3, 20 and 44 hours in the absence of S9 mix and 3 hours in the presence of S9 mix.

No noteworthy toxicity was noted at any of the tested dose-levels in either experiment and at either harvest time in the absence as well as in the presence of S9 mix.

In the absence of S9 mix, following the 3-hour treatment in the first experiment, a statistically significant increase (p < 0.05) in the frequency of cells with structural chromosomal aberrations was noted. This increase was not dose-related and the frequency of aberrant cells obtained remained within the historical data range for the vehicle control. Moreover, in a second independent experiment, no statistically significant increase in the frequency of cells with structural or numerical chromosomal aberrations was noted after either the 20 or the 44-hour treatments. Therefore, the increase in the frequency of aberrant cells noted in the first experiment was considered to be non‑biologically significant.

In the presence of S9 mix, no significant increase in the frequency of cells with structural chromosomal aberrations was noted in either experiment and at either harvest time. The test item is therefore considered not to be clastogenic in this in vitro mammalian chromosome aberration assay in the absence or in the presence S9 mix.

 

In vivo mammalian erythrocyte micronucleus test:

One study of reliability 2 according to Klimisch cotation criteria is available and was selected as a key study (Siou, 1978). In this study, bone marrow micronucleus assay was conducted in Swiss mouse according to the micronucleus test. The study was conducted before mutagenic test guidelines and good laboratory practices. Animals (10 males/test substance dose, 10 males for the negative control) were treated by gavage with the test substance at 1000 and 2500 mg/kg bw (the highest obtainable suspension in Arachis oil) as two doses administered with an interval of 24 hours. Bone marrow cells were harvestedat 6hours post-treatment for all dose groups. Ten males were treated by gavage with arachis oil as concurrent vehicle negative control group. Bone marrow cells were harvested at 6-hour post-treatment and 2000 cells per dose group were examined.
There were no signs of toxicity during the study, at doses up to and above the 2000 mg/kg limit dose specified in OECD 474. There was no increase in the frequency of micronucleated polychromatic erythrocytes in bone marrow by comparison with results from negative control animals. Under the conditions of the in vivo test, the registered substance showed no evidence of causing chromosome damage or bone marrow cell toxicity.

Justification for selection of genetic toxicity endpoint
No specific study was selected since all available in vitro and in vivo studies were negative.

Short description of key information:
- genetic toxicity in vitro: negative (bacterial reverse mutation test, mammalian cell gene mutation test and mammalian chromosome abberation test)
- genetic toxicity in vivo: negative (mammalian erythrocyte micronucleus test)

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

Four in vitro and one in vivo genotoxicity tests are available. None of the tests showed evidence of genotoxicity. The reaction mass of Stearoylbenzoylmethane and Palmitoylbenzoylmethane is therefore considered to be non-genotoxic and does not require classification for genetic toxicity according to the classification criteria of Annexe VI Directive 67/548/EEC or EU Regulation 1272/2008 (CLP).