Bulnesia sarmienti, ext., acetate

Endpoint summary

Description of key information

In the table below the acute aquatic toxicity data are summarised.

Species	Guideline	Result in mg/L	Remarks
Pseudokirchneriella subcapitata	Read Across from Cedryl acetate	EC50 growth rate > 0.31 mg/L EC10 growth rate: not determinable NOEC growth rate: not determinable Based on read across information from Cedryl Acetate (OECD TG 201)	Key study, Rel 2
Daphnia magna	Read Across from Cedryl acetate	EC50 48h = 0.33 mg/L  Based on read across information from Cedryl Acetate (OECD TG 202)	Key study, Rel 2

Additional information

Justification for the read across

Guaiyl Acet-multi (Cas no. 94333-88-7) and its Daphnia and Algae aquatic toxicity using read across information from Cedryl Acetate (Cas no.77-54-3).

 

Introduction and hypothesis for the analogue approach

Guaiyl Acet-multi is a multi-constituent containing two main constituents. The substance has a hydrocarbon backbone to which an ester is attached. This backbone contains two fused rings: a cyclopentane and a cycloheptane ring, with a double bond. The ester is an acetate group attached to the larger ring via an isopropyl group.For Guaiyl Acet no aquatic toxicity data are available. In accordance with Article 13 of REACH,lacking information can be generated by means of applying alternative methods such asin vitrotests, QSARs, grouping and read-across. For assessing the aquatic toxicity of Guaiyl Acet –multi the analogue approach is selected because for one closely related analogue, Cedryl Acetate, reliable Daphnia and algae data are available.

Hypothesis: Guaiyl Acet-multi has similar aquatic toxicity compared to Cedryl Acetate based on similar structure, functional group and similarities in physico-chemical properties.

Available experimental information: For Cedryl Acetate experimental data are available for Daphnia and algae. A Daphnia sp. Acute Immobilisation Test is available, according to OECD TG 202, resulting in an EC50 of 0.33 mg/L. The Algae Growth Inhibition Test, according to OECD TG 201, resulted in an EC50 of > 0.31 mg/L. Both tests receive Klimisch 1.

Target chemical and source chemical(s)

Chemical structures of Guaiyl Acet and Cedryl Acetate are shown in the data matrix. Also physico-chemical properties thought relevant for aquatic toxicity are listed in there.

Purity / Impurities

Guaiyl Acet-multi is a multi-constituent containing two main constituents and some minor constituents (<10%) which all indicate a similar aquatic toxicity potential compared to its main constituent.

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.

Analogue selection:In the RIFM database and using the OECD QSAR toolbox (using the Tanimoto index > 60%) no relevant analogues were identified. From IFF’s portfolioCedryl Acetate is selected. Cedryl Acetate has a similar hydrocarbon backbone and has a similar functional ester group: acetate.

Structural similarities and differences:Guaiyl Acet-multi, Cedryl Acetate and their constituents are highly similar because the key constituentscontain a hydrocarbon backbone and acetate group. The differences in the hydrocarbon backbone are minor. The unsaturated bond in Guaiyl Acet-multi is not present in Cedryl Acetate’s main constituent but is present in a number of its minor constituents. The constituents of both Guaiyl Acet-multi and of Cedryl Acetate though slightly different all have this hydrocarbon backbone with or without the functional acetate group.

Bioavailability:Guaiyl Acet-multi and Cedryl Acetate have similar bioavailability based on the similarity in chemical structure and physico-chemical properties. The molecular weight of both substances is 264.4, they are both liquids and they have similar vapour pressures 0.09 and 0.066, respectively. It can be seen that the water solubility and log Kow of Guaiyl Acet-multi are in the same range as for Cedryl Acetate (water solubility 1-10 mg/L and log Kow of 6.0-6.6).

Mode of Action and the prediction of the aquatic toxicity information:Guaiyl Acet and Cedryl Acetate are expected to present a similar ester mode of action due to their similar backbone and similar functional group, being an ester (acetate). This is supported by the ester classification in ECOSAR.

Uncertainty of the prediction: Based on the information above there are no remaining uncertainties. Both Guaiyl Acet-multi and Cedryl Acetate are expected to have acute toxicity values close to or just below the water solubility and therefore the read across is justified.

Data matrix

The relevant information on physico-chemical properties and toxicological characteristics are presented in the data matrix below.

Conclusions per endpoint for C&L and risk assessment

When using read across the result derived should be applicable for C&L and/or risk assessment and be presented with adequate and reliable documentation. For Cedryl Acetate the Daphnia 48-h EC50 is 0.33 mg/L and for Algae 72-h EC50 is > 0.31 mg/L. An EC10 for Algae could not be determined. In view of the similarity in structure, functional group, physico-chemical properties and similar mode of action these aquatic toxicity data are also used for Guaiyl Acet-multi.

Final conclusion on hazard, C&L and risk assessment:

For Guaiyl Acet the 48-h EC50 forDaphnia is 0.33 mg/L and for 72-h ErC50 for algae is > 0.31 mg/L. These results are applied for C&L and risk assessment.

 

Data matrix of Guaiyl Acet-multi aquatic toxicity using read across from Cedryl Acetate                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       

Common names	Guaiyl Acet-multi	Cedryl Acetate
Chemical structures
Empirical formula	C17H28O2	C17H28O2
Cas no of the generic Cas no of the main isomer	94333-88-7 882881-27-8	77-54-3
EC number	305-067-2	201-036-1
REACH registration	Registered for 2018	Registered for 2018
Molecular weight	264.4	264.4
Physico-chemical data
Physical state	Liquid	Liquid
Melting point °C	< -20	< -20
Boiling point °C	299.2	295.0
Vapour pressure Pa (measured)	0.09	0.066
Water solubility mg/L (measured)	2.51	0.99
Water solubility mg/L (calculated - ECOSAR)	0.1779	0.5502
Log Kow (measured)	6.6	6.0
Log Kow (calculated - ECOSAR)	5.91	5.33
Acute Aquatic toxicity
Daphnia (48h-EC50) mg/L (measured)	Read across from Cedryl Acetate	0.33
Algae (72h-EC50) mg/L (measured)	Read across from Cedryl Acetate	>0.31
Long-term Aquatic toxicity
Algae (72h-EC10) mg/L (measured)	Read across from Cedryl Acetate	Could not be determined.