Ethyl 3-phenyloxirane-2-carboxylate

Endpoint summary

Additional information

In the table below the acute aquatic toxicity of Ethylphenylglycidate are summarised, which are derived from read across using Ethyl 3 -methylphenylglycidate.

Species	Method	Result in mg/l	Remarks
Pseudokirchneriella subcapitata	Read across from Ethyl 3 -methylphenylglycidate	ErC50 -72h = 36 NOEC-72h = 9.3	This analogue was tested according to OECD TG 201 (Klimisch 1). A conversion is not considered necessary because the value is conservative
Daphnia magna	Read across from Ethyl 3 -methylphenylglycidate	EC50 48h = 52	This analogue was tested according to OECD TG 201). Klimisch 1. A conversion is not considered necessary because the value is conservative.

Ethylphenylglycidate (CAS 121-39-1) and its short term aquatic toxicity for Daphnia and algae and long-term toxicity for algae using read across information from Ethyl 3-methylphenylglycidate (CAS 77-83-8)

Introduction and hypothesis for the analogue approach

The substance is a phenylglycidate to which a carboxylic acid ethyl ester is attached. For this substance 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 substance Ethylphenylglycidate, the analogue approach is selected because for one closely related analogue reliable data are available.

Hypothesis: The aquatic toxicity of Daphnia and algae can be predicted forEthylphenylglycidate using the information ofa close analogueEthyl3-methylphenylglycidate.

Available experimental information: Ethyl 3-methylphenylglycidate has been tested in GLP studies for acute Daphnia (OECD 202), algae (OECD 201) and fish (OECD 203) all receiving Kl. 1.

Target chemical and source chemical(s)

Chemical structures of the target chemical Ethylphenylglycidate and the source chemical Ethyl 3-methylglycidate are shown in Table 1 (data matrix). Also physico-chemical properties thought relevant for aquatic toxicity are listed there.

Purity / Impurities

The constituents and impurities of the target chemical do not indicate other aquatic toxic potential and/or the acute/chronic ratio. 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. The ECHA guidance (2017 is considered for this approach).

Analogue selection:Ethyl 3-phenylglydidate is selected because it is a close analogue for which aquatic toxicity information is available.

Structural similarities and differences:Ethylphenylglycidate (target) and Ethyl 3-methylphenylglycidate (source) have the same backbone and functional group. The latter substance has an additional methyl group at the phenyl site of the structure.

Bioavailability:The bioavailability of Ethylphenylglycidate and Ethyl 3-methylphenylglycidate is very similar due to similar molecular weights, log Kow’s, and water solubilities. The slightly lower log Kow of Ethylphenylglycidate reflects the one carbon less in its chemical structure.

Mode of Action:Ethylphenylglycidate and Ethyl 3-methylphenylglycidatehave the same mode of action based on their conjugated functional groups: mono-epoxides attached to an ethyl- ester. According to ECOSAR the functional groups are a mono-epoxide and an ester.

Uncertainty of the prediction: There are no remaining uncertainties in view of the reasoning above. A conversion is not considered necessary in view of the minimal differences in molecular weight and log Kow. In addition to the algae and Daphnia information, also an LC50 for fish of 4.2 mg/l is available for the source substance. Though this LC50 is the lowest aquatic toxicity value it does not change the conclusion on classification and labelling and therefore is only added here as supporting information.

ECOSAR (Q)SAR predictions using the mon-epoxide functional group are in line with the derived values forEthyl 3-methylphenylglycidate. Though the (Q)SAR does not fulfil all Annex IX criteria this information can still be used for supporting the derived ecotoxicity values (see Data matrix).

Data matrix

The relevant information on physico-chemical properties and ecotoxicological characteristics are presented in the data matrix of Table 1.

Conclusions per endpoint for hazard

When using read across, the derived results should be applicable for C&L and/or risk assessment and be presented with adequate and reliable documentation. The aquatic toxicity information of Ethylphenylglycidate (target) can be derived from Ethyl 3-methylphenylglycidate (source) because of the high similarity in chemical structure: backbone and functional groups and therefore the aquatic toxicity. The EC50 values of Ethyl 3-methylphenylglycidate for Daphnia and algae are: 52 and 36 mg/L, the NOEC of algae is 9.3 mg/L. For the target substance the same values will be used.

Final conclusion on hazard: For Ethylphenylglycidate the EC50 for Daphnia and algae are 52 and 36 mg/L, respectively. Its NOEC for algae is 9.3 mg/L.

Table 1:Data matrix: Information to support the read across of Ethylphenylglycidate fromEthyl 3-methylphenylglycidate

Name of substance	Ethylphenylglycidate	Ethyl 3-methylphenylglycidate
Chemical structure
	Target	Source
Cas no.	121-39-1	77-83-8
REACH	To be registered under Annex VII	Annex VIII registered
EINECS	204-467-3	201-061-8
Empirical	C11H12O3	C12H14O3
Mol weight	192.21	206.24
Phys-Chem
Appearance	Liquid	Liquid
Melting point (oC)	<-20 (IFF, 2015)	<-50 (ECHA disseminated site)
Boiling point (oC)	264.8 (IFF, 2015)	302 (ECHA disseminated site)
Vapour pressure (Pa)	0.12 (IFF, 2015)	0.23 (20°C; ECHA disseminated site)
Water solubility	748.4 (IFF, 2015)	1000 mg/L (ECHA dissemination site)
Log Kow	2.0 and 2.4 (IFF, 2015)	2.4 and 2.8 (ECHA disseminated site)
Aquatic toxicity
72h-ErC50 Algae mg/L ECOSAR for mono-epoxides	Read across 18.7	36 (OECD TG 201) 8.7
48h-EC50 Daphnia magna mg/L ECOSAR for mono-epoxides	Read across 19	52 (OECD TG 202) 10
LC50 Fish mg/L ECOSAR for mono-epoxides	- 9	4.2 (OECD TG 203) 5.9
NOEC Algae mg/L ECOSAR for mono-epoxides	Read across 15	9.3 (OECD TG 201) 8.2