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

Endpoint summary

Description of key information

For Citronellyl Acetate (multi-constituent) the following results were derived:

Species	Method	Result	Remarks
Fish (D. rerio)	Read-across	96-h LC50: 6.1 mg/L	Key study, Rel. 2. Value derived using read-across from Citronellyl Acetate mono (CAS 150 -84 -5; tested in an OECD TG 203 study).
Daphnia magna	Read-across	48-h EC50: 3.48 mg/L	Key study, Rel. 2. Value derived using read-across from Citronellyl Acetate mono (CAS 150 -84 -5; tested in an OECD TG 202 study).
Green algae (D. subspicatus)	Read-across	72-h ErC50: >7.2 mg/L 72-h ErC10: 3.83 mg/L	Key study, Rel. 2. Value derived using read-across from Citronellyl Acetate mono (CAS 150 -84 -5; tested in an OECD TG 201 study).
STP microorganisms	Read-across	28-d NOEC: 10 mg/L	Key study, Rel. 2. Value derived using read-across from Citronellyl Acetate mono (CAS 150 -84 -5; tested in an OECD TG 301D study).

 

Additional information

The aquatic toxicity is assessed based on read-across from Citronellyl Acetate mono to Citronellyl Acetate Multi. The executive summaries of the source information is presented in the respective Endpoint summaries. The read-across rationale is presented below.

Aquatic toxicity of Citronellyl Acetate Multi based on read across from data available for Citronellyl Acetate mono (CAS# 150-84-5).

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 a similar but a saturated backbone and has an acetic ester attached to this.

For Citronellyl Acetate Multi, there are no experimental aquatic toxicity data available. In accordance with Article 13 of REACH, lacking information can be generated by means other than vertebrate animal testing, i.e. applying alternative methods such as in vitro tests, QSARs, grouping and read-across. For assessing the aquatic toxicity of Citronellyl Acetate Multi, the analogue approach is selected because for the main constituent, Citronellyl Acetate mono (CAS# 150-84-5), experimental data is available which can be used for read across.

Hypothesis: Citronellyl Acetate Multi as a whole has the same aquatic toxicity potential as the read-across source chemical Citronellyl Acetate mono based on structural similarity and related physico-chemical parameters and reactivity and conversion is not needed.

Available information: No experimental data is available for Citronellyl Acetate Multi.For the source chemicalCitronellyl Acetate mono,data are available. The LC50 for fish, the EC50 for Daphnia and ErC50 for algae 6.1, 3.48 and > 7.2 mg/l and the EC10 for algae is 3.83 mg/l based on measured concentrations as tested in OECDTG 203, 202 and 201, respectively under GLP (Klimisch 1).

Target chemical and source chemical(s)

Chemical structures of the target chemical and the source chemical are shown in the data matrix, including physico-chemical properties.

Purity / Impurities

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

Analogue approach justification

According to Annex XI section 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 Citronellyl Acetate Multi its key constituentCitronellyl Acetate mono is selected as an analogue for read-across because it covers almost 70% of the aquatic toxicity. The information can be used for read across to Dihydro-Citronellyl Acetate, which is structurally very similar.

Structural similarities and differences: Citronellyl Acetate mono has an unsaturated hydrocarbon backbone (one double bond not conjugated with the ester) compared to the saturated backbone of Dihydro-Citronellyl Acetate. In absence of the conjugation of the double bone with the ester the electrophilicity of the ester bond will be the same.

Bioavailability: Citronellyl Acetate Multi’s key constituent Citronellyl Acetate mono has a slightly lower log Kow compared to Dihydro-Citronellyl Acetate: 4.6 and 5, respectively. In view of the difference being <0.5, this has limited impact on the toxicity.

Reactivity: Citronellyl Acetate Multi’s reactivity is mainly driven by Citronellyl Acetate mono being the key constituent. As presented above at structural similarities the presence of absence of the double bond is not expect to significantly influence the toxicity. Also ECOSAR and other classification systems present both key constituent in the same ester class of reactivity.

Conversion of the effect values to Citronellyl Acetate Multi from the mono: A conversion is not needed because Citronellyl Acetate mono already covers the substance for almost 70% and the toxicity of Dihydro-Citronellyl Acetate is considered the same.

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

Conclusions on aquatic toxicity

For Citronellyl Acetate Multi no aquatic toxicity information is available. Such information is available for its key constituent Citronellyl Acetate mono and this information can be used for read across to Dihydro-Citronellyl Acetate, which is the minor constituent, which is presented with adequate and reliable documentation. ForCitronellyl Acetate mono theLC50 for fish, the EC50 for Daphnia and ErC50 for algae 6.1, 3.48 and > 7.2 mg/l and the EC10 for algae is 3.83 mg/l based on measured concentrations as tested in OECDTG 203, 202 and 201, respectively under GLP (Klimisch 1).

Final conclusion: For Citronellyl Acetate Multi, the 96-h LC50 in fish is 6.1 mg/L, the 48-h EC50 in daphnids is 3.48 mg/L, and the 72-h ErC50 and ErC10 in aquatic algae >7.2 mg/L and 3.83 mg/L, respectively.

Data matrix presenting the information relevant for read across to Citronellyl Acetate Multi from Citronellyl Acetate mono for aquatic toxicity

Substance	Citronellyl Acetate Multi	Citronellyl Acetate mono constituent	Dihydro-Citronellyl Acetate constituent
Read-across	Target	Source	Target
Chemical name	-
Structure	See constituents.
% in product	See constituents	60-75	10-20
CAS	See constituents	150-84-5	20780-49-8
EC no	908-114-0	205-775-0	244-034-6
MW	See constituents	198	200
Phys-chem
MW	See constituents	198	200
Appearance	Liquid	Liquid	Liquid
Log Kow	4.6 (exp.)	4.6 (ECHA site)	4.6 (ECHA site)
Ws (mg/L)	12.1 (exp)	5.7 (ECHA site)	4.7 (ECHA site)
Vp (Pa)	2.6 (exp)	7.0 (ECHA site)	12.9 (ECHA site)
Aquatic toxicity
Algae EC50 and EC10 in mg/l	>7.2 3.83 (RA)	>7.2 3. 83 (OECD 201)	-
Daphnia EC50 in mg/l	3.48 mg/L (RA)	3.48 mg/L (OECD 202)	-
Fish LC50 in mg/l	6.1 mg/L (RA)	6.1 mg/L (OECD 203)	-

RA = read-across.