2-methoxy-4-(methoxymethyl)phenol

Endpoint summary

Description of key information

See additional information below.

Additional information

In the table below the acute aquatic toxicity data are summarised

Species	Guideline	Result in mg/l	Remarks
Pseudokirchneriella subcapitata	Read across from Methyl diantilis which was tested in an OECD TG 201	72h-EC50 growth rate: >100 mg/l NOEC: 46 mg/l The results are based on the nominal concentrations because the test material was stable during the study.	Key study, Rel 2
Daphnia magna	Read across from Methyl diantilis which was tested in an OECD TG 202	48h-EC50: 23 mg/l  The results are based on the nominal concentrations because the test material was stable during the study.	Key study, Rel 2

Vaniwhite and its aquatic toxicity using read across information from Methyl diantilis

Introduction and hypothesis for the analogue approach

The substance is a phenol with two short ether-alkyl chains attached in the ortho and para positions of the phenol ring: one chain has one, and the other has two carbons. For Vaniwhite 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 algae and Daphnia aquatic toxicity of Vaniwhite the analogue approach is selected because for one closely related analogue reliable data are available for both algae and Daphnia. 

Hypothesis: The aquatic toxicity of Vaniwhite is similar to Methyl diantilis based on close similarity of their structures: Methyl diantilis having one more carbon than Vaniwhite.

Available experimental information:The source chemical Methyl diantilis has data on algae and Daphnia. In the study with algae, the 72 h-ErC50 was greater than 100 mg/l and the NOEC for growth rate was 46 mg/l (Givaudan, 2002).In the study with Daphnia, the48 h-EC50 was 23 mg/l(Givaudan, 2002). The tests have been carried out according to OECD guidelines (OECD TG 201 and 202) and GLP and receive Kl. 1.

Target chemical and source chemical(s)

Chemical structures of the target chemical and the source chemical are shown in the data matrix. Also physico-chemical properties thought to be relevant for aquatic toxicity are listed in there.

Purity / Impurities

The purity and impurities of the target chemical do not indicate other aquatic toxic potential. The substance has a purity of > =98% and therefore 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.

ECHA guidance (2017, RAAF) was considered.

Analogue selection:Methyl diantilis was selected because of the close structural similarity and adequate data were available.

Structural similarities and differences:The target and the source chemicals both have a phenol backbone and next to the alcohol group of the phenol, they both have two short chains, with an ether group, attached in the ortho and para positions of the phenol. The difference is that theMethyl diantilishas one more carbon than Vaniwhite at the end of the chain, which is attached at the ortho position. The Tanimoto similarity of the substances is67% (using 60% similarity with atom pairs and atom centered fragments).

Bioavailability:The similarity in bioavailability of both substances for algae and Daphnia can be assessed using the phys-chem properties of the source Methyl diantilis and target Vaniwhite.They are both liquids. The molecular weight of the target substance (Vaniwhite) is168.19, whereas of the source (Methyl diantilis) it is182.22.Methyl diantilis has aslightly higher log Kow because of its one additional methyl group. All the other phys-chem properties are very similar between the two substances indicating similar bioavailability.

Mode of Action and the prediction of the aquatic information:The target and source (Vaniwhite and Methyl diantilis) are expected to have the same phenol type mode of action as presented by ECOSAR.

Conversion using log Kow: A conversion of the aquatic toxicity values is not performed. In view of the slightly higher log Kow of Methyl diantilis but also the slightly higher molecular weight, the aquatic toxicity values are considered conservative (Acute Daphnia result for Vaniwhite after conversion would be: 23 mg/l / 182 MW *1.61/1.12 = 30.3).

Uncertainty of the prediction:There is limited uncertainty based on the reasoning above and in view of the conservative approach taken.

Data matrix

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

Conclusions per endpoint for hazard and C&L

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. Methyl diantilis has acute algae and Daphnia values of > 100 and 23 mg/l, respectively. The NOEC for algae is 46 mg/l. In view of the close similarity between the analogues, the same values for Vaniwhite are derived. A conversion has not been done because the information of Methyl diantilis is considered conservative with a slightly higher log Kow.

Final conclusion on hazard and C&L

For Vaniwhite, for algae the value of72 h-ErC50 and NOEC of > 100 and 46 mg/lis derived, respectively; for Daphnia the value of48 h-EC50 = 23 mg/l is derived. This means that solely based on acute and long-term aquatic toxicity information the substance does not need to be classified. In view of the ready biodegradability, the substance does not need to be classified for the environment. 

 

Data matrix for read across for Vaniwhite (target) and Methyl diantilis (source) for aquatic toxicity                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 

Common names	Target- Vaniwhite	Source- Methyl diantilis
Chemical structures
Cas no of the generic	5533-03-9	5595-79-9
EC number	226-882-9	611-338-8
ECHA registration	Registered in 2018	No data
Physico-chemical data
Molecular weight	168.19	182.22
Physical state	Liquid	Liquid
Melting point °C	65.55 (C) <-20°C(IFF, 2016)	75.61 (C)
Boiling point °C	266.16 (C) 260.0(IFF, 2016)	282.35 (C)
Vapour pressure Pa (measured)	0.25 (C) 0.23(IFF, 2016)	0.0794 (C)
Water solubility mg/l (measured)	6939 (C) 2149.6(IFF, 2016)	2262 (C)
Log Kow (measured)	0.7(IFF, 2016)	No data
Log Kow (calculated - ECOSAR)	1.12 (C)	1.61
Aquatic toxicity
Daphnia mg/l	Read across	48 h-EC50 = 23 mg/l (OECD TG 202)
Algae mg/l	Read across	72 h-ErC50 > 100 mg/l; NOEC = 46 mg/l (OECD TG 201)

C=calculated (EpiSuite)