Reaction mass of 3,7-dimethyl-1-octyl acetate and citronellyl acetate

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Gene mutation in bacteria (Ames test): negative, based on read-across from Citronellyl Acetate mono tested in an OECD TG 471

Gene mutation in mammalian cells (CHO): negative, based on read-across from Geraniol 60 tested in an OECD TG 476

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Genetic toxicity in vivo

Description of key information

In vivo micronucleus test information: negative, based on read-across from Geraniol EXTRA tested in an OECD TG 474

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Additional information

Genetic toxicity is assessed based on read-across from Citronellyl Acetate mono and Geraniol (Geraniol 60/Nerol 40%; and Geraionol EXTRA (pure trans) to Citronellyl Acetate Multi. The executive summary of the source information is presented below followed by the read-across rationale.

Ames test information of Citronellyl Acetate mono

For Citronellyl Acetate mono, an Ames test was performed according to OECD TG 471 and in compliance with GLP criteria. The substance did not induce a significant increase in the mutation frequency of the mutant strains of Salmonella typhimurium (TA1535, TA1537, TA98, TA100 and TA102) in the presence and absence of a metabolic activation system.

Effect on in vitro gene mutations in mammalian cells for Geraniol 60 (Geraniol 60/Nerol 40)

Geraniol 60 was assessed for its potential to induce gene mutations at the hypoxanthine-guanine phosphoribosyl transferase (HPRT) locus in Chinese hamster ovary (CHO) cells in vitro. Two independent experiments were carried out, both with and without the addition of liver S9 mix from induced rats (exogenous metabolic activation), up to 200 μg/mL (up to and including cytotoxic concentrations). Based on the results, it was concluded that the test substance did not cause any relevant increase in the mutant frequencies both without S9 mix and after adding a metabolic system in two experiments performed independently of each other. Thus, under the experimental conditions of this study, Geraniol 60 is not mutagenic in the HPRT locus assay under in vitro conditions in CHO cells in the absence and the presence of metabolic activation.

In vivo Micronucleus test effects in Geraniol EXTRA (only trans-Geraniol and no Nerol)

For Geraniol EXTRA, an in vivo Micronucleus study is available, performed according to OECD TG 474 and in compliance with GLP. In this study, mice were exposed to a single dose of 375, 750 or 1500 mg/kg bw. Clinical signs (piloerection and hunched posture) were seen in the groups exposed to the highest dose. Mice (5/group) were sacrificed at 24 and 48 hours after exposure. As no statistical significances or biologically relevant differences in the frequency of erythrocytes containing micronuclei either between the vehicle control groups and the three dose groups or between the two sacrifice intervals (24 and 48 hours) were seen, it was concluded that the test item has no chromosome-damaging (clastogenic) effect nor does it lead to any impairment of chromosome distribution in the course of mitosis (aneugenic activity) in bone marrow cells of NMRI mice in vivo.

Genotoxic properties of Citronellyl Acetate Multi using read across from Citronellyl Acetate mono (CAS# 150-84-5) and Geraniol (CAS# 106-24-1)

Introduction and hypothesis for the analogue approach

Citronellyl Acetate Multi is a multi-constituent. The main constituent of Citronellyl Acetate Multi is Citronellyl Acetate mono. It has an unsaturated hydrocarbon backbone to which an acetic ester is attached. The minor constituent is Dihydro-Citronellyl Acetate, which has the same structure except that it has a saturated hydrocarbon backbone. For Citronellyl Acetate Multi no genetic toxicity data are available. In accordance with Article 13 of REACH, lacking information can be generated by other means, i.e. applying alternative methods such as in vitro tests, QSARs, grouping and read-across. For assessing the genetic toxicity of Citronellyl Acetate Multi the analogue approach is selected because for the main constituent, Citronellyl Acetate mono, and for a close structural analogue, Geraniol, information is available which can be used for read-across.

Hypothesis: Citronellyl Acetate Multi has the same results in genemutations in bacterial cells as Dihydro-Citronellyl Acetate, the same genemutations in mammalian cells as Geraniol 60 (Geraniol 60/Nerol 40) and the same effects in the in vivo micronucleus test as Geraniol EXTRA (pure trans).

Available information,Ames: For Citronellyl Acetate Multi’s key constituent, Citronellyl Acetate mono, a negative Ames test is available (OECD TG 471, Klimisch 1).

Available information on in vitro gene mutation mammalian cells: For Geraniol 60 (Geraniol 60/Nerol 40) a negative gene mutation test in Chinese hamster ovary cells is available (OECD TG 476, Rel. 1 carried out with sufficiently high cytotoxic concentrations.

Available information on in vivo Micronucleus test: For Geraniol EXTRA (trans-geraniol mono-constituent) a negative in vivo Micronucleus study is available (OECD TG 474, GLP and Klimisch 1) in which mice were exposed to a single dose of 375, 750 or 1500 mg/kg bw at which clinical signs (piloerection and hunched posture) were seen in the groups exposed to the highest dose. No differences in the frequency of erythrocytes containing micronuclei either between the vehicle control groups and the three dose groups or between the two sacrifice intervals (24 and 48 hours) were seen.

Target chemical and source chemical(s)

Chemical structures of the target chemical and the source chemicals are shown in the data matrix, including physico-chemical properties and toxicological information, thought relevant for acute dermal toxicity, of all substances.

Purity / Impurities

The purity and impurities of the target chemical do not indicate genotoxicity potential other than indicated by the parent substance. The impurities are all below < 10%.

Analogue approach justification

According to Annex XI 1.5 read across can be used to replace testing when the similarity can be based on a common backbone and a common functional group. When using read across the result derived should be applicable for C&L and/or risk assessment and it should be presented with adequate and reliable documentation, which is presented below.

Analogue selection for Ames: For Citronellyl Acetate Multi the key constituent Citronellyl Acetate mono can be used to read across to Dihydro-Citronellyl Acetate because of the similarity in structure and for this mono Ames test information is available.

Analogue selection for genemutation in mammalian cells: For Citronellyl Acetate Multi the substance Geraniol EXTRA (pure trans) is used because it has the relevant information and a similar backbone as the key constituents of Citronellyl Acetate Multi. After hydrolysation/metabolisation of the acetate it has the same functional group: primary alcohol.

Analogue selection for in vivo effects on micronuclei: For Citronellyl Acetate Multi the substance Geraniol 60 (Geraniol 60/Nerol 40%)was selected as source chemical for read-across as itis has relevant information and a similar backbone compared to Citronellyl Acetate Muti’s key constituents. After hydrolysation/metabolisation of the acetate it has the same functional group: primary alcohol.

Structural similarities and differences: All constituents of Citronellyl Acetate Multi, including Citronellyl Acetate mono, are acetate esters of a 3,7-dimethyloctanol chain only differing in the number and/or position of the unconjugated double bonds in the hydrocarbon chain. Geraniol 60 Geraniol 60/Nerol 40%) share a common hydrocarbon backbone. Citronellyl Acetate Multi’s main and minor constituents have one or no unsaturated bond, while Geraniol (and Nerol) has 2 unconjugated bonds.

Toxico-kinetic: Citronellyl Acetate Multi constituents and their metabolites all show similar high absorption as do the analogues, based on the similarity in backbone and relative low MW. Metabolism: Citronellyl Acetate Multi constituents will all metabolise into primary alcohols of which two are used for read across, Geraniol 60 and Geraniol EXTRA. The acetate hydrolysation/ metabolisation is experimentally shown for Geranyl Acetate (see Toxico-kinetic section). It shows that Geraniol has more metabolites compared to Citronellyl Acetate Multi constituents, which is due to the additional bond in Geraniol which gives more sites for metabolic attack.

Genotoxicity reactivity: Citronellyl Acetate Multi’s key constituents do not present genotoxicity alerts and Geraniol also not in the OECD Toolbox and show a similar profile not only for genotoxicity also for some other endpoints. The acetate alert fired in the Toolbox is related to aromatic acetates not for alkyl acetates. Geraniol may be somewhat more reactive based on the conjugated alcohol and therefore also present some different reactivity for its metabolites e.g. aldehydes versus epoxides, see Annex 1 and 2.

Uncertainty of the prediction: There are no uncertainties than those already addressed above.

Data matrix

The relevant information on physico-chemical properties and toxicological characteristics are presented in the Data Matrix.

Conclusions genetic toxicity for hazard and risk assessment

For Citronellyl Acetate Multi no genotoxicity information is available. For filling the data gaps Citronellyl Acetate mono and Geraniol are used, based on similarities in backbone and functional groups after metabolisation, and is provided with adequate and reliable information. Citronellyl Acetate mono is negative in the Ames test and Geraniol is negative for both other genotoxic endpoints

Final conclusion: Citronellyl Acetate Multi is considered negative in the Ames test, negative for genemutations in mammalian cells and negative for micronuclei in vivo.

Data matrix presenting the information relevant for read-across to Citronellyl Acetate Multi from the main constituent Citronellyl Acetate ‘mono’, and the close structural analogue Geraniol for genotoxicity

Substance	Citronellyl Acetate Multi	Citronellyl Acetate mono constituent	Dihydro-Citronellyl Acetate	Geraniol 60 (Geraniol 60/Nerol 40)	Geraniol EXTRA (pure trans)
Read-across	Target	Source	Target	Source	Source
Structure *	See constituents
% in product	See constituents	60-75	10-20	n.a.	n.a.
CAS#	See constituents	150-84-5	20780-49-8	106-24-1 / 106-25-2	106-24-1
MW	See constituents	198	200	154	154
Phys-chem
Appearance	Liquid	Liquid (ECHA site)	Liquid (ECHA site)	Liquid (ECHA site)	Liquid (ECHA site)
Log Kow	4.6 (exp)	4.6 (ECHA site)	4.6 (ECHA site)	3.5(ECHA site)	3.5(ECHA site)
Ws (mg/L)	12.1 (exp)	5.7 (ECHA site)	4.7 (ECHA site)	>1000(ECHA site)	>1000(ECHA site)
Vp (Pa)	2.6 (exp)	7.0 (ECHA site)	12.9 (ECHA site)	2.12(ECHA site)	2.12(ECHA site)
Human health
Genotoxicity - Ames	Negative (RA)	Negative (OECD TG 471)	--	--	--
Genotoxicity - CHO-HPRT	Negative (RA, Geraniol 60)	--	--	Negative (OECD TG 476)	--
Genotoxicity - MNT	Negative (RA Geraniol EXTRA)	--	--	--	Negative (OECD TG 474)

RA = read-across.

 

Annex 1 OECD Toolbox profiler of genotoxicity of parent compounds

 

OECD Toolbox Metabolite profiling of metabolites

Justification for classification or non-classification

Based on the results presented, the substance does not need to be classified for genetic toxicity according to EU CLP (EC No. 1272/2008, and its amendments).