Reaction mass of 1-phenylethanone and 2-phenylpropanal and 1,4-diphenylbut-2-ene-1,4-dione

Endpoint summary

Additional information

Reaction mass of acetophenone and hydratropaldehyde and (E)-1,4-diphenyl-2-butene-1,4-dione:

Mutagenicity in vitro gene mutation in bacteria and classification with regard to germ cell mutagenicity

 

No tests are available with the registered substance. The procedure laid down in the CLP regulation (1272/2008/EG) to base the classification and labelling on the available data and classification of the known main and relevant constituents was used.

Table Main constituents of the registered substance and other relevant substances that were analytically determined and respective data on Mutagenicity in vitro gene mutation in bacteria and classification with regard to germ cell mutagenicity according to CLP regulation (1272/2008/EG)

Substance (other names), main constituents marked in bold letters	CAS	LL (%)	UL (%)	typical concentration (%)	Mutagenicity in vitro gene mutation in bacteria	Classification with regard to germ cell mutagenicity
(E)-1,4-diphenyl-2-butene-1,4-dione (trans-1,2-Dibenzoylethylene)	959-28-4	3	10	5.5	no data	not classified
1,1'-(1,1-dimethyl-3-methylene-1,3-propanediyl)bisbenzene (dim. A-MS)	6362-80-7	1	2.2	1.9	negative. (Ames)(OECD 471) acc. to SDS (Sigma Aldrich) and ECHA-Information on registered substance)	not classified
2-phenylpropan-2-ol (DMPC)	617-94-7	0.5	5	1.6	no data	not classified
acetophenone (Acvph)	98-86-2	40	80	69	negative	not classified (Legal classification, and self classification of registrants)
cresol	1319-77-3	0.2	4	0.71	Negative (based on negative results foro-, m-, p-cresol(based onECHA-Information on registered substance)	not classified
hydratropaldehyde (Phenylpropionaldehyd-2)	93-53-8	5	20	8.5	no data	not classified
phenol	108-95-2	0.1	0.5	0.11	Negative	Muta 2 (Legal classification according to Tab 3.1 of CLP Regulation (1272/2008/EG)
β,β-dimethylstyrene	768-49-0	0.2	5	1.2	no data	not classified
unknown constituents		1	15	11.5	no data	not classified

 

Data on Mutagenicity in vitro gene mutation in bacteria with negative results (Ames-tests) is available for the main constituent Acetophenone (with up to 80% concentration) and the impurities 1,1'-(1,1-dimethyl-3-methylene-1,3-propanediyl)bisbenzene and Phenol. For the impurity isomeric mixture cresol (CAS 1319-77-3) the negative results for the isomers o-, m-, p-cresol were extrapolated to cresol by the REACH registrants (based on available disseminated information by ECHA). No data on Mutagenicity in vitro gene mutation in bacteria is available for the other constituents and impurities. Based on the available information only the impurity Phenol is classified as germ cell mutagen (Muta 2). None of the other identified impurities and main constituents are classified as germ cell mutagen.

  

According to the available information phenol is currently classified as Muta 2 (Legal classification according to Tab 3.1 of CLP Regulation (1272/2008/EG), which is also supported by the REACH registrants:

”… but the results from in vivo test systems suggested a possible threshold mechanism above 100 mg/kg bw/d for the induction of micronuclei via prolonged hypothermia. …”

However, because the substance constitutes up to 0.5 % phenol only, this value is below the generic concentration limit of 1% for classification according to the Table 3.5.2 of the CLP- Regulation (1272/2008/EC) (Generic concentration limits of ingredients of a mixture classified as germ cell mutagens that trigger classification of the mixture.). Therefore, the registered substance does not need to be classified as germ cell mutagen based on the constituent Phenol.

Based on the fact that the other known constituents and impurities are not classified according to the criteria of the CLP regulation the registered substance is not classified according to the criteria of the CLP regulation for mixtures.

However it needs to be pointed out that there is no data available with regard to Mutagenicity in vitro gene mutation in bacteria for a minor part of the substance composition.

With regard to Acetophenone (main constituent):

In vitro, acetophenone was found not to induce gene mutations in a Salmonella typhimurium reverse mutation assay (Key study/guideline study: Sokolowski, 2006) and in a mouse lymphoma cell mutagenicity assay at the thymidine kinase locus (Key study/guideline study: Wollny et al., 2007) when tested up to cytotoxic concentrations. The absence of a mutagenic activity in bacteria is supported by further data from Salmonella typhimurium reverse mutation studies (Commoner, 1976; Elliger et al., 1984; Florin et al., 1980), from a mutagenicity assay with Escherichia coli strains being deficient and proficient in DNA repair (DNA polymerase activity) (Fluck et al., 1976), and from a DNA repair assay in Salmonella typhimurium TA 1535/pSK1002 (umu test) (Ono et al., 1991).

A clastogenic potential was indicated in an in vitro chromosome aberration test in V79 cells, only in the presence of metabolic activation and at test concentrations of at least 900 µg/mL (Key study/guideline study: Höpker, 2007). In contrast, there was no indication of a clastogenic activity in an in vivo micronucleus assay in peripheral blood erythrocytes after application up to the MTD (515 mg/kg bw by intraperitoneal injection) (Key study/guideline study: Hofman-Hüther, 2008).

There exists some weight of evidence from in vitro studies with artificial test conditions that acetophenone principally has the capacity to be activated in the presence of UV radiation (photosensitising effect) or oxidative agents to induce modifications in DNA or nucleotides or in repair deficient strains of E. coli (Demidov et al., 1991; Epe et al., 1993; Adam et al., 2001, 2002; Mennigmann, 1972.; Fix and Bockrath, 1983; Midorikawa et al., 2004). All data come from test systems that are not validated for assessment of a mutagenic potential under biologically relevant conditions. Up to now, there are no data to assess if mechanisms of photosensitization and photooxidation play any role in mammalian cells in vitro or in vivo.

Short description of key information:
With Regard to the main constituent Acetophenone:
In vitro assays:
Absence of gene mutation without and with metabolic activation: S. typhimurium reverse mutation assay (Key study: Sokolowski, 2006), mouse lymphoma mutagenicity assay (Key study: Wollny, 2007)
Clastogenic effect in the presence of metabolic activation: Chromosomal aberration test in V79 cells (Key study: Höpker, 2007)
In vivo assays:
Absence of clastogenic effect in micronucleus test in mouse peripheral blood erythrocytes (Key study: Hofman-Hüther, 2008)

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

For the main constituent Acetophenon can be concluded:

According to CLP and EC regulation 1272/2008 no classification of acetophenone for germ cell mutagenicity results. Based on the available key studies, there is no mutagenic potential in vitro. There is no evidence of a clastogenic effect in somatic cells in vivo in a guideline study, so that the indication of a possible clastogenic effect from an vitro study in the presence of metabolic activation is not supported in the in vivo condition.