Methyl o-toluate

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to aquatic algae and cyanobacteria

Remarks:

EC10/NOEC

Type of information:

(Q)SAR

Adequacy of study:

key study

Study period:

2016

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Justification for type of information:

Executive summary:
The chronic algae (EC10) for the ester Ylanganate is predicted to be 2.8 mg/l based on the ECOSAR SAR for esters using an calculated log Kow of 2.375, molecular weight of 150 and the equation: Log 96h ChV (mmol/L) = -0.5583 (log Kow) - 0.4017, ChV being equivalent to EC10.
Ylanganate is in the applicability domain of the ECOSAR prediction because: a) Ylanganate is an ester presenting the toxicity solely by its bioavailability (i.e. without fragments that activate this chemical class); b) its log Kow is 2.375 (≤ 5); c) its MW is 150 (≤1000); and; d) the toxicity predicted is below its water solubility of 572.9 mg/l.
The fit in the applicability domain results in limited uncertainty of the Ylanganate prediction. The calculated log Kow is used instead of the measured one to remain within the domain of the model descriptor domain. The fit in the domain shows that the prediction is reliable and a Klimisch 2 can be assigned. In accordance with REACH Annex XI, the validity of the (Q)SAR is documented in a QMR for chronic algae toxicity on esters (see attached report). The adequate and reliable documentation, presented below, further supports this prediction.

Qualifier:

according to guideline

Guideline:

other: REACH guidance R.6

Key result

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

2.8 mg/L

Nominal / measured:

not specified

Conc. based on:

test mat.

Basis for effect:

growth rate

Validity criteria fulfilled:

yes

Remarks:

The substance is in the applicability domain of the scientific valid model. In addition, N=41 and R2=0.68

Conclusions:

The acute algae toxicity results in 9.7 mg/l

Executive summary:

The acute algae ErC50 for the ester Ylanganate is predicted to be 9.7 mg/l based on the ECOSAR SAR for esters using an estimated log Kow of 2.375,molecular weight of 150 and the equation: Log 96-h EC50 (mmol/L) = -0.6993 (log Kow) + 0.4715

Ylanganate is in the applicability domain of the ECOSAR prediction because: a) Ylanganate is an ester presenting the toxicity solely by its bioavailability (i.e. without fragments that activate this chemical class); b) its log Kow is 2.375 (≤ 6.4); c) its MW is 150 (≤1000); and; d) the toxicity predicted is below its water solubility of 572.9 mg/l.

The fit in the applicability domain results in limited uncertainty of the Ylanganate prediction. This shows that the prediction is reliable and a Klimisch 2 can be assigned. In accordance with REACH Annex XI, the validity of the (Q)SAR is documented in a QMR for acute algae toxicity on esters (see attached report

Reference 2

Endpoint:

toxicity to aquatic algae and cyanobacteria

Remarks:

ErC50 at 72h

Type of information:

(Q)SAR

Adequacy of study:

key study

Study period:

2016

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Remarks:

QSAR

Justification for type of information:

Executive summary:
The acute algae ErC50 for the ester Ylanganate is predicted to be 9.7 mg/l based on the ECOSAR SAR for esters using an estimated log Kow of 2.375, molecular weight of 150 and the equation: Log 96-h EC50 (mmol/L) = -0.6993 (log Kow) + 0.4715
Ylanganate is in the applicability domain of the ECOSAR prediction because: a) Ylanganate is an ester presenting the toxicity solely by its bioavailability (i.e. without fragments that activate this chemical class); b) its calculated log Kow is 2.375 (≤ 6.4); c) its MW is 150 (≤1000); and; d) the toxicity predicted is below its water solubility of 572.9 mg/l.
The fit in the applicability domain results in limited uncertainty of the Ylanganate prediction. The use of the calculated log Kow instead of the measured log Kow is justified because this limits the uncertainty of the log Kow descriptor. The prediction is reliable and a Klimisch 2 can be assigned. In accordance with REACH Annex XI, the validity of the (Q)SAR is documented in a QMR for acute algae toxicity on esters (see attached report). The adequate and reliable documentation, presented below, further supports this prediction.

Reason / purpose for cross-reference:

read-across source

Guideline:

other: REACH Guidance R.6: QSARs and grouping of chemicals. Version May 2008.

GLP compliance:

no

Test organisms (species):

other: green algae

Water media type:

freshwater

Total exposure duration:

96 h

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

9.7 mg/L

Nominal / measured:

estimated

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: ECOSAR class: Esters

Key result

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

2.8 mg/L

Nominal / measured:

estimated

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: ECOSAR class: Esters

Details on results:

The EC10 is considered to be similar to the predicted chronic value (ChV) as presented in ECOSAR

Validity criteria fulfilled:

yes

Conclusions:

The 96-h ErC50 and 96-h ChV values are 9.7 mg/L and 2.8 mg/L, respectively in freshwater (green) algae.

Executive summary:

The acute algae ErC50 for the ester Ylanganate is predicted to be 9.7 mg/l based on the ECOSAR SAR for esters using an estimated log Kow of 2.375,molecular weight of 150 and the equation: Log 96-h EC50 (mmol/L) = -0.6993 (log Kow) + 0.4715

Ylanganate is in the applicability domain of the ECOSAR prediction because: a) Ylanganate is an ester presenting the toxicity solely by its bioavailability (i.e. without fragments that activate this chemical class); b) its log Kow is 2.375 (≤ 6.4); c) its MW is 150 (≤1000); and; d) the toxicity predicted is below its water solubility of 572.9 mg/l.

The fit in the applicability domain results in limited uncertainty of the Ylanganate prediction. This shows that the prediction is reliable and a Klimisch 2 can be assigned. In accordance with REACH Annex XI, the validity of the (Q)SAR is documented in a QMR for acute algae toxicity on esters (see attached report). The adequate and reliable documentation, presented below, further supports this prediction.

Description of key information

Algae ErC50 (ECOSAR-ester): 9.7 mg/l

Algae EC10/NOEC (ECOSAR-ester): 2.8 mg/l

Key value for chemical safety assessment

EC50 for freshwater algae:

9.7 mg/L

EC10 or NOEC for freshwater algae:

2.8 mg/L