1,1-dimethoxyethane

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to fish

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model, but not (completely) falling into its applicability domain, with adequate and reliable documentation / justification

Justification for type of information:

1 Substance
1.1 CAS number 534-15-6
1.2 EC number 208-589-8
1.3 Chemical name
IUPAC 1,1-dimethoxyethane
Other (ISO) dimethyl acetal
Other
1.4 Structural formula
1.5 Structure codes
SMILES COC(C)OC
InChI 1S/C4H10O2/c1-4(5-2)6-3/h4H,1-3H3
Other
Stereochemical features Not applicable

2 General Information
2.1 Date of QPRF 29 May 2018
2.2 Author and contact details Dr. Stefan Pudenz, Envigo CRS Switzerland Ltd.,
Rheinstrasse 74, 4414 Füllinsdorf, Switzerland,
Email: [e-mail]

3 Prediction
3.1 Endpoint (OECD Principle 1)
Endpoint Fish acute toxicity (96 hour LC50)
Dependent variable Log 96-h LC50 (mmol/L)
3.2 Algorithm (OECD Principle 2)
Model or submodel name FISH 96-h LC50 (Mortality). Due to structural classification of the query structure, submodels are:
SAR Neutral Organics
Model version SAR Neutral Organics 5/2012
Reference to QMRF There is no QMRF available. Information to ECOSAR models can be found at https://www.epa.gov/chemicalresearch/toxicity-estimation-software-tool-test. For information similar to those provided in the QMRF it is also referred to section Interpreting ECOSAR QSAR.
Predicted values (model result) Class Neutral organics: 2921.661 mg/L
Predicted values (comments) -
Input for prediction Smiles
Calculated descriptor values Predicted log Kow: 0.223 and exp. water solubility of 1.0E+06
mg/L.
3.3 Applicability domain (OECD Principle 3)
Domains
i. The predicted compound is in the Applicability Domain of the model: log Kow < 5 and MW < 1000 g/mol.
ii. Structure belongs to class neutral organics.
iii. SAR based on structural classes
Structural analogues ECOSAR does not provide information on structural analogues due to the nature of the regression algorithm.
Neutral organics: Model equation based on 296 structures.
Consideration on structural analogues
Not applicable, see above.
3.4 The uncertainty of the prediction (OECD principle 4)
An r2 of 0.878 with n =296 + 55 may suggest high predictive
accuracy of the model.
3.5 The chemical and biological mechanisms according to the model underpinning the predicted
result (OECD principle 5)
SAR based on structural classes. Toxicity to organisms via
narcosis.

4 Adequacy (Optional)
4.1 Regulatory purpose Acute toxicity to fish endpoint for providing information on aquatic pelagic toxicity.
4.2 Approach for regulatory interpretation of the model result
Unit conversion provided by the software.
4.3 Outcome The structure belongs to the SAR class of neutral organics. Neutral organic chemicals are non-ionisable and nonreactive and act via simple nonpolar narcosis generally thought of as a reversible, drug-induced loss of conscience (general anesthesia). The predicted value of 2921.661 mg/L suggest low acute toxicity to fish.
4.4 Conclusion The prediction is considered reliable and will be used together with other predictions in a weight of evidence.

Qualifier:

no guideline followed

Principles of method if other than guideline:

- Principle of test: QSAR prediciton of Acute toxicity to fish
- Short description of test conditions: n/a
- Parameters analysed / observed: LC50

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

2 921.661 mg/L

Sublethal observations / clinical signs:

ECOSAR

1 Substance

1.1 CAS number 534-15-6

1.2 EC number 208-589-8

1.3 Chemical name

IUPAC 1,1-dimethoxyethane

Other (ISO) dimethyl acetal

Other

1.4 Structural formula

1.5 Structure codes

SMILES COC(C)OC

InChI 1S/C4H10O2/c1-4(5-2)6-3/h4H,1-3H3

Other

Stereochemical features Not applicable

2 General Information

2.1 Date of QPRF 29 May 2018

2.2 Author and contact details Dr. Stefan Pudenz, Envigo CRS Switzerland Ltd.,

Rheinstrasse 74, 4414 Füllinsdorf, Switzerland,

Email: [e-mail]

3 Prediction

3.1 Endpoint (OECD Principle 1)

Endpoint Fish acute toxicity (96 hour LC50)

Dependent variable Log 96-h LC50 (mmol/L)

3.2 Algorithm (OECD Principle 2)

Model or submodel name FISH 96-h LC50 (Mortality). Due to structural classification of the query structure, submodels are:

SAR Neutral Organics

Model version SAR Neutral Organics 5/2012

Reference to QMRF There is no QMRF available. Information to ECOSAR models can be found at https://www.epa.gov/chemicalresearch/toxicity-estimation-software-tool-test. For information similar to those provided in the QMRF it is also referred to section Interpreting ECOSAR QSAR.

Predicted values (model result) Class Neutral organics: 2921.661 mg/L

Predicted values (comments) -

Input for prediction Smiles

Calculated descriptor values Predicted log Kow: 0.223 and exp. water solubility of 1.0E+06

mg/L.

3.3 Applicability domain (OECD Principle 3)

Domains  

i. The predicted compound is in the Applicability Domain of the model: log Kow < 5 and MW < 1000 g/mol.

ii. Structure belongs to class neutral organics.

iii. SAR based on structural classes

Structural analogues ECOSAR does not provide information on structural analogues due to the nature of the regression algorithm.

Neutral organics: Model equation based on 296 structures.

Consideration on structural analogues

Not applicable, see above.

3.4 The uncertainty of the prediction (OECD principle 4)

An r2 of 0.878 with n =296 + 55 may suggest high predictive

accuracy of the model.

3.5 The chemical and biological mechanisms according to the model underpinning the predicted

result (OECD principle 5)

SAR based on structural classes. Toxicity to organisms via

narcosis.

4 Adequacy (Optional)

4.1 Regulatory purpose Acute toxicity to fish endpoint for providing information on aquatic pelagic toxicity.

4.2 Approach for regulatory interpretation of the model result

Unit conversion provided by the software.

4.3 Outcome The structure belongs to the SAR class of neutral organics. Neutral organic chemicals are non-ionisable and nonreactive and act via simple nonpolar narcosis generally thought of as a reversible, drug-induced loss of conscience (general anesthesia). The predicted value of 2921.661 mg/L suggest low acute toxicity to fish.

4.4 Conclusion The prediction is considered reliable and will be used together with other predictions in a weight of evidence.

Conclusions:

The structure belongs to the SAR class of neutral organics. Neutral organic chemicals are non-ionisable and nonreactive and act via simple nonpolar narcosis generally thought of as a reversible, drug-induced loss of conscience (general anesthesia). The predicted value of 2921.661 mg/L suggest low acute toxicity to fish.
The prediction is considered reliable and will be used together with other predictions in a weight of evidence.

Reference 2

Endpoint:

short-term toxicity to fish

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

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 limited documentation / justification

Justification for type of information:

1 Substance
1.1 CAS number 534-15-6
1.2 EC number 208-589-8
1.3 Chemical name
IUPAC 1,1-dimethoxyethane
Other (ISO) dimethyl acetal
Other
1.4 Structural formula
1.5 Structure codes
SMILES COC(C)OC
InChI 1S/C4H10O2/c1-4(5-2)6-3/h4H,1-3H3
Other
Stereochemical features Not applicable

2 General Information
2.1 Date of QPRF 29 May 2018
2.2 Author and contact details Dr. Stefan Pudenz, Envigo CRS Switzerland Ltd.,
Rheinstrasse 74, 4414 Füllinsdorf, Switzerland,
Email: [e-mail]

3 Prediction
3.1 Endpoint (OECD Principle 1)
Endpoint Fish acute toxicity
Dependent variable The model performs a read-across and provides a quantitative prediction of acute toxicity in fish, given in -log(mg/L)
3.2 Algorithm (OECD Principle 2)
Model or submodel name Fish Acute Toxicity Read-Across (KNN/Read-across) within VEGA 1.1.4
Model version 1.0.0
Reference to QMRF There is no QMRF available. Information to the VEGA models can be found at vega-qsar.eu
Predicted values (model result) 15451.03 mg/L
Predicted values (comments) -
Input for prediction Smiles
Calculated descriptor values Not provided by the software
3.3 Applicability domain (OECD Principle 3)
Domains
i. According to VEGA’s evaluation scheme the predicted compound is within the Applicability Domain of the model
ii. All fragments of the query compound have been found in the structures of the training set.
iii. Not applicable. Structural analogues (for details, it is referred to the software printout)
i. CAS: 123-91-1, 1,4-dioxane
ii. CAS: 109-86-4, 2-methoxyethanol
iii. CAS: 110-80-5, ethylene glycol monoethyl ether
iv. CAS: 107-98-2, 1-methoxy-2-hydroxypropane
Consideration on structural analogues
With 84.7%, the average similarity of the four most similar analogues to the query structure is considered high. Predicted and experimental values of the four most similar structures vary by a factor of up to 2.7, which is well below a default factor of 10 often used in traditional risk assessment of environmental chemicals to compensate for uncertainties*. Hence accuracy between predicted and actual value for the
most similar structures is considered high. Concordance is also high since the experimental results of the most similar structures are in the same range as the predicted result of the query structure.
3.4 The uncertainty of the prediction (OECD principle 4)
High similarity, concordance and accuracy suggest high confidence in the prediction.
3.5 The chemical and biological mechanisms according to the model underpinning the predicted result (OECD principle 5)
No structural alerts triggered.
4 Adequacy (Optional)
4.1 Regulatory purpose Acute toxicity to fish endpoint for providing information on aquatic pelagic toxicity
4.2 Approach for regulatory interpretation of the model result
Unit conversion provided by the software.
4.3 Outcome There is confidence in the prediction and therefore no evidence that 1,1-dimethoxyethane is acute toxic to fish.
4.4 Conclusion The prediction is considered reliable and will be used together with other predictions in a weight of evidence.

*Stedeford, T.; Zhao, Q.J.; Dourson, M.L.; Banasik, M.; Hsu, C.H. The application of non-default uncertainty factors in the
US EPA’s Integrated Risk Information System (IRIS). Part I: UFL, UFS, and “Other uncertainty factors”. J. Environ. Sci.
Heal. C 2007, 25, 245–279.

Qualifier:

no guideline followed

Principles of method if other than guideline:

- Principle of test: QSAR prediciton of Acute toxicity to fish
- Short description of test conditions: n/a
- Parameters analysed / observed: LC50

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

15 451.03 mg/L

Sublethal observations / clinical signs:

KNN/Read-Across

1 Substance

1.1 CAS number 534-15-6

1.2 EC number 208-589-8

1.3 Chemical name

IUPAC 1,1-dimethoxyethane

Other (ISO) dimethyl acetal

Other

1.4 Structural formula

1.5 Structure codes

SMILES COC(C)OC

InChI 1S/C4H10O2/c1-4(5-2)6-3/h4H,1-3H3

Other

Stereochemical features Not applicable

2 General Information

2.1 Date of QPRF 29 May 2018

2.2 Author and contact details Dr. Stefan Pudenz, Envigo CRS Switzerland Ltd.,

Rheinstrasse 74, 4414 Füllinsdorf, Switzerland,

Email: [e-mail]

3 Prediction

3.1 Endpoint (OECD Principle 1)

Endpoint Fish acute toxicity

Dependent variable The model performs a read-across and provides a quantitative prediction of acute toxicity in fish, given in -log(mg/L)

3.2 Algorithm (OECD Principle 2)

Model or submodel name Fish Acute Toxicity Read-Across (KNN/Read-across) within VEGA 1.1.4

Model version 1.0.0

Reference to QMRF There is no QMRF available. Information to the VEGA models can be found at vega-qsar.eu

Predicted values (model result) 15451.03 mg/L

Predicted values (comments) -

Input for prediction Smiles

Calculated descriptor values Not provided by the software

3.3 Applicability domain (OECD Principle 3)

Domains

i. According to VEGA’s evaluation scheme the predicted compound is within the Applicability Domain of the model

ii. All fragments of the query compound have been found in the structures of the training set.

iii. Not applicable. Structural analogues (for details, it is referred to the software printout)

i. CAS: 123-91-1, 1,4-dioxane

ii. CAS: 109-86-4, 2-methoxyethanol

iii. CAS: 110-80-5, ethylene glycol monoethyl ether

iv. CAS: 107-98-2, 1-methoxy-2-hydroxypropane

Consideration on structural analogues

With 84.7%, the average similarity of the four most similar analogues to the query structure is considered high. Predicted and experimental values of the four most similar structures vary by a factor of up to 2.7, which is well below a default factor of 10 often used in traditional risk assessment of environmental chemicals to compensate for uncertainties*. Hence accuracy between predicted and actual value for the

most similar structures is considered high. Concordance is also high since the experimental results of the most similar structures are in the same range as the predicted result of the query structure.

3.4 The uncertainty of the prediction (OECD principle 4)

High similarity, concordance and accuracy suggest high confidence in the prediction.

3.5 The chemical and biological mechanisms according to the model underpinning the predicted result (OECD principle 5)

No structural alerts triggered.

4 Adequacy (Optional)

4.1 Regulatory purpose Acute toxicity to fish endpoint for providing information on aquatic pelagic toxicity

4.2 Approach for regulatory interpretation of the model result

Unit conversion provided by the software.

4.3 Outcome There is confidence in the prediction and therefore no evidence that 1,1-dimethoxyethane is acute toxic to fish.

4.4 Conclusion The prediction is considered reliable and will be used together with other predictions in a weight of evidence.

*Stedeford, T.; Zhao, Q.J.; Dourson, M.L.; Banasik, M.; Hsu, C.H. The application of non-default uncertainty factors in the

US EPA’s Integrated Risk Information System (IRIS). Part I: UFL, UFS, and “Other uncertainty factors”. J. Environ. Sci.

Heal. C 2007, 25, 245–279.

Conclusions:

There is confidence in the prediction and therefore no evidence that 1,1-dimethoxyethane is acute toxic to fish.
The prediction is considered reliable and will be used together with other predictions in a weight of evidence.

Reference 3

Endpoint:

short-term toxicity to fish

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

results derived from a (Q)SAR model, with limited documentation / justification, but validity of model and reliability of prediction considered adequate based on a generally acknowledged source

Justification for type of information:

1 Substance
1.1 CAS number 534-15-6
1.2 EC number 208-589-8
1.3 Chemical name
IUPAC 1,1-dimethoxyethane
Other dimethyl acetal
Other
1.4 Structural formula
1.5 Structure codes
SMILES COC(C)OC
InChI 1S/C4H10O2/c1-4(5-2)6-3/h4H,1-3H3
Other
Stereochemical features Not applicable

2 General Information
2.1 Date of QPRF 29 May 2018
2.2 Author and contact details Dr. Stefan Pudenz. Envigo CRS Switzerland Ltd.,
Rheinstrasse 74, 4414 Füllinsdorf, Switzerland,
Email: [e-mail]

3 Prediction
3.1 Endpoint (OECD Principle 1)
Endpoint Fish acute toxicity
Dependent variable Acute toxicity in fish (LC50), log(1/(mmol/L)).
3.2 Algorithm (OECD Principle 2)
Model or submodel name Fish Acute (LC50) Toxicity model (NIC) within VEGA 1.1.4
Model version 1.0.0
Reference to QMRF There is no QMRF available. Information to the VEGA models can be found at vega-qsar.eu
Predicted values (model result) 1485.42 mg/L
Predicted values (comments) log(1/(mmol/L)): -1.22
Input for prediction Smiles
Descriptor values Not provided by the software
3.3 Applicability domain (OECD Principle 3)
Domains i. According to VEGA’s evaluation scheme the predicted
compound is outside the Applicability Domain of the
model
ii. One fragment of the query compound was infrequently
found in the structures of the training set.
iii. No structural alerts triggered.
Structural analogues
(for details, it is referred to the
software printout)
i. CAS: 123-91-1, 1,4-dioxane
ii. CAS: 109-86-4, 2-methoxyethanol
iii. CAS: 110-80-5, ethylene glycol monoethyl ether
iv. CAS: 107-98-2, 1-methoxy-2-hydroxypropane
Consideration on structural analogues
With 87 %, the average similarity of the four most similar analogues to the query structure is considered high. Predicted and experimental values of the four most similar structures vary by a factor of up to 30.3 which is far above a default factor of 10 often used in traditional risk assessment of environmental chemicals to compensate for uncertainties*. Hence accuracy between predicted and actual value for the
most similar structures is considered poor. Concordance is also low since the experimental results of the most similar structures are notably different to predicted result of the query structure.
3.4 The uncertainty of the prediction (OECD principle 4)
Low accuracy and concordance suggest uncertainty. The query structure is considered out the applicability domain of the model.
3.5 The chemical and biological mechanisms according to the model underpinning the predicted result (OECD principle 5)
Not applicable since statistical model

4 Adequacy (Optional)
4.1 Regulatory purpose Acute toxicity to fish endpoint for providing information on aquatic pelagic toxicity
4.2 Approach for regulatory interpretation of the model result Unit conversion provided by the software.
4.3 Outcome Uncertainty due to low concordance and accuracy suggest low confidence in the prediction.
4.4 Conclusion The prediction is not considered reliable.

*Stedeford, T.; Zhao, Q.J.; Dourson, M.L.; Banasik, M.; Hsu, C.H. The application of non-default uncertainty factors in the
US EPA’s Integrated Risk Information System (IRIS). Part I: UFL, UFS, and “Other uncertainty factors”. J. Environ. Sci.
Heal. C 2007, 25, 245–279.

Qualifier:

no guideline followed

Principles of method if other than guideline:

- Principle of test: QSAR prediciton of Acute toxicity to fish
- Short description of test conditions: n/a
- Parameters analysed / observed: LC50

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

1 485.42 mg/L

Sublethal observations / clinical signs:

NIC

1 Substance

1.1 CAS number 534-15-6

1.2 EC number 208-589-8

1.3 Chemical name

IUPAC 1,1-dimethoxyethane

Other dimethyl acetal

Other

1.4 Structural formula

1.5 Structure codes

SMILES COC(C)OC

InChI 1S/C4H10O2/c1-4(5-2)6-3/h4H,1-3H3

Other

Stereochemical features Not applicable

2 General Information

2.1 Date of QPRF 29 May 2018

2.2 Author and contact details Dr. Stefan Pudenz. Envigo CRS Switzerland Ltd.,

Rheinstrasse 74, 4414 Füllinsdorf, Switzerland,

Email: [e-mail]

3 Prediction

3.1 Endpoint (OECD Principle 1)

Endpoint Fish acute toxicity

Dependent variable Acute toxicity in fish (LC50), log(1/(mmol/L)).

3.2 Algorithm (OECD Principle 2)

Model or submodel name Fish Acute (LC50) Toxicity model (NIC) within VEGA 1.1.4

Model version 1.0.0

Reference to QMRF There is no QMRF available. Information to the VEGA models can be found at vega-qsar.eu

Predicted values (model result) 1485.42 mg/L

Predicted values (comments) log(1/(mmol/L)): -1.22

Input for prediction Smiles

Descriptor values Not provided by the software

3.3 Applicability domain (OECD Principle 3)

Domains

i. According to VEGA’s evaluation scheme the predicted compound is outside the Applicability Domain of the model

ii. One fragment of the query compound was infrequently found in the structures of the training set.

iii. No structural alerts triggered.

Structural analogues (for details, it is referred to the software printout)

i. CAS: 123-91-1, 1,4-dioxane

ii. CAS: 109-86-4, 2-methoxyethanol

iii. CAS: 110-80-5, ethylene glycol monoethyl ether

iv. CAS: 107-98-2, 1-methoxy-2-hydroxypropane

Consideration on structural analogues

With 87 %, the average similarity of the four most similar analogues to the query structure is considered high. Predicted and experimental values of the four most similar structures vary by a factor of up to 30.3 which is far above a default factor of 10 often used in traditional risk assessment of environmental chemicals to compensate for uncertainties*. Hence accuracy between predicted and actual value for the

most similar structures is considered poor. Concordance is also low since the experimental results of the most similar structures are notably different to predicted result of the query structure.

3.4 The uncertainty of the prediction (OECD principle 4)

Low accuracy and concordance suggest uncertainty. The query structure is considered out the applicability domain of the model.

3.5 The chemical and biological mechanisms according to the model underpinning the predicted result (OECD principle 5)

Not applicable since statistical model

4 Adequacy (Optional)

4.1 Regulatory purpose Acute toxicity to fish endpoint for providing information on aquatic pelagic toxicity

4.2 Approach for regulatory interpretation of the model result Unit conversion provided by the software.

4.3 Outcome Uncertainty due to low concordance and accuracy suggest low confidence in the prediction.

4.4 Conclusion The prediction is not considered reliable.

*Stedeford, T.; Zhao, Q.J.; Dourson, M.L.; Banasik, M.; Hsu, C.H. The application of non-default uncertainty factors in the

US EPA’s Integrated Risk Information System (IRIS). Part I: UFL, UFS, and “Other uncertainty factors”. J. Environ. Sci.

Heal. C 2007, 25, 245–279.

Conclusions:

Uncertainty due to low concordance and accuracy suggest low confidence in the prediction.
The prediction is not considered reliable.

Reference 4

Endpoint:

short-term toxicity to fish

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

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 limited documentation / justification

Justification for type of information:

1 Substance
1.1 CAS number 534-15-6
1.2 EC number 208-589-8
1.3 Chemical name
IUPAC 1,1-dimethoxyethane
Other (ISO) dimethyl acetal
Other
1.4 Structural formula
1.5 Structure codes
SMILES COC(C)OC
InChI 1S/C4H10O2/c1-4(5-2)6-3/h4H,1-3H3
Other
Stereochemical features Not applicable

2 General Information
2.1 Date of QPRF 29 May 2018
2.2 Author and contact details Dr. Stefan Pudenz, Envigo CRS Switzerland Ltd.,
Rheinstrasse 74, 4414 Füllinsdorf, Switzerland,
Email: [e-mail]

3 Prediction
3.1 Endpoint (OECD Principle 1)
Endpoint Fish acute toxicity
Dependent variable Classification for toxicity to fish provided by Directive 92/32/EEC of the EU for dangerous substance. Four toxicity classes.
3.2 Algorithm (OECD Principle 2)
Model or submodel name Fish acute (LC50) toxicity classification (SarPy/IRFMN) within VEGA 1.1.4
Model version 1.0.2
Reference to QMRF There is no QMRF available. Information to the VEGA models can be found at vega-qsar.eu
Predicted values (model result) Predicted toxicity class: Non-Toxic-3 (more than 100 mg/l)
Predicted values (comments) -
Input for prediction Smiles
Calculated descriptor values Not provided by the software
3.3 Applicability domain (OECD Principle 3)Domains i. According to VEGA’s evaluation scheme the predicted
compound could be outside the Applicability Domain of
the model
ii. One fragment of the query compound was infrequently
found in the structures of the training set.
iii. No structural alerts triggered.
Structural analogues
(for details, it is referred to the
software printout)
i. CAS: 123-91-1, 1,4-dioxane
ii. CAS: 60-29-7, diethyl ether
iii. CAS: 79-20-9, methyl acetate
iv. CAS: 141-78-6, ethyl acetate
Consideration on structural analogues
With 84.7%, the average similarity of the four most similar analogues to the query structure is considered high. All structures are non-toxic, thus indicating high concordance with the predicted result for the query structure. There is also high accuracy since all structures have been predicted correctly.
3.4 The uncertainty of the prediction (OECD principle 4)
High similarity, concordance and accuracy suggest high confidence in the prediction. The infrequently found fragment OC(O)C (< 3 occurrences) and the missing hydroxyl groups respectively, are considered not relevant for aquatic toxicity.In conclusion, the query compound is within the applicability domain of the model.
3.5 The chemical and biological mechanisms according to the model underpinning the predicted result (OECD principle 5)
No structural alerts triggered.

4 Adequacy (Optional)
4.1 Regulatory purpose Acute toxicity to fish endpoint for providing information on aquatic pelagic toxicity
4.2 Approach for regulatory interpretation of the model result Toxicity classes, defined on the basis of the classification for toxicity to fish provided by Directive 92/32/EEC of the EU for dangerous substances.
4.3 Outcome There is confidence in the prediction and therefore no evidence that 1,1-dimethoxyethane is acute toxic to fish.
4.4 Conclusion The prediction is considered reliable and will be used together with other predictions in a weight of evidence.

Qualifier:

no guideline followed

Principles of method if other than guideline:

- Principle of test: QSAR prediciton of Acute toxicity to fish
- Short description of test conditions: n/a
- Parameters analysed / observed: LC50

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 100 mg/L

Sublethal observations / clinical signs:

SarPy/IRFMN

1 Substance

1.1 CAS number 534-15-6

1.2 EC number 208-589-8

1.3 Chemical name

IUPAC 1,1-dimethoxyethane

Other (ISO) dimethyl acetal

Other

1.4 Structural formula

1.5 Structure codes

SMILES COC(C)OC

InChI 1S/C4H10O2/c1-4(5-2)6-3/h4H,1-3H3

Other

Stereochemical features Not applicable

2 General Information

2.1 Date of QPRF 29 May 2018

2.2 Author and contact details Dr. Stefan Pudenz, Envigo CRS Switzerland Ltd.,

Rheinstrasse 74, 4414 Füllinsdorf, Switzerland,

Email: [e-mail]

3 Prediction

3.1 Endpoint (OECD Principle 1)

Endpoint Fish acute toxicity

Dependent variable Classification for toxicity to fish provided by Directive 92/32/EEC of the EU for dangerous substance. Four toxicity classes.

3.2 Algorithm (OECD Principle 2)

Model or submodel name Fish acute (LC50) toxicity classification (SarPy/IRFMN) within VEGA 1.1.4

Model version 1.0.2

Reference to QMRF There is no QMRF available. Information to the VEGA models can be found at vega-qsar.eu

Predicted values (model result) Predicted toxicity class: Non-Toxic-3 (more than 100 mg/l)

Predicted values (comments) -

Input for prediction Smiles

Calculated descriptor values Not provided by the software

3.3 Applicability domain (OECD Principle 3)Domains i. According to VEGA’s evaluation scheme the predicted

compound could be outside the Applicability Domain of

the model

ii. One fragment of the query compound was infrequently

found in the structures of the training set.

iii. No structural alerts triggered.

Structural analogues

(for details, it is referred to the

software printout)

i. CAS: 123-91-1, 1,4-dioxane

ii. CAS: 60-29-7, diethyl ether

iii. CAS: 79-20-9, methyl acetate

iv. CAS: 141-78-6, ethyl acetate

Consideration on structural analogues

With 84.7%, the average similarity of the four most similar analogues to the query structure is considered high. All structures are non-toxic, thus indicating high concordance with the predicted result for the query structure. There is also high accuracy since all structures have been predicted correctly.

3.4 The uncertainty of the prediction (OECD principle 4)

High similarity, concordance and accuracy suggest high confidence in the prediction. The infrequently found fragment OC(O)C (< 3 occurrences) and the missing hydroxyl groups respectively, are considered not relevant for aquatic toxicity.In conclusion, the query compound is within the applicability domain of the model.

3.5 The chemical and biological mechanisms according to the model underpinning the predicted result (OECD principle 5)

No structural alerts triggered.

4 Adequacy (Optional)

4.1 Regulatory purpose Acute toxicity to fish endpoint for providing information on aquatic pelagic toxicity

4.2 Approach for regulatory interpretation of the model result Toxicity classes, defined on the basis of the classification for toxicity to fish provided by Directive 92/32/EEC of the EU for dangerous substances.

4.3 Outcome There is confidence in the prediction and therefore no evidence that 1,1-dimethoxyethane is acute toxic to fish.

4.4 Conclusion The prediction is considered reliable and will be used together with other predictions in a weight of evidence.

Conclusions:

There is confidence in the prediction and therefore no evidence that 1,1-dimethoxyethane is acute toxic to fish.
The prediction is considered reliable and will be used together with other predictions in a weight of evidence.

Reference 5

Endpoint:

short-term toxicity to fish

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model, but not (completely) falling into its applicability domain, with adequate and reliable documentation / justification

Justification for type of information:

1 Substance
1.1 CAS number 534-15-6
1.2 EC number 208-589-8
1.3 Chemical name
IUPAC 1,1-dimethoxyethane
Other dimethyl acetal
Other
1.4 Structural formula
1.5 Structure codes
SMILES COC(C)OC
InChI 1S/C4H10O2/c1-4(5-2)6-3/h4H,1-3H3
Other
Stereochemical features Not applicable

2 General Information
2.1 Date of QPRF 29 May 2018
2.2 Author and contact details Dr. Stefan Pudenz. Envigo CRS Switzerland Ltd.,
Rheinstrasse 74, 4414 Füllinsdorf, Switzerland,
Email: [e-mail]

3 Prediction
3.1 Endpoint (OECD Principle 1)
Endpoint Fathead minnow LC50 (96 hr) -Log10(mol/L)
Dependent variable Fathead minnow LC50 (96 hr) -Log10(mol/L)
3.2 Algorithm (OECD Principle 2)
Model or submodel name US EPA T.E.S.T Fathead minnow LC50 (96 hr); Consensus method
Model version 4.2
Reference to QMRF There is no QMRF available and provided by US EPA, respectively.
Predicted values (model result) LC50 = 2419.59 mg/L
Predicted values (comments) Unit conversion provided by the software
Input for prediction Smiles
Descriptor values Due to the large number of descriptors used all information are attached in the software printout section.
3.3 Applicability domain (OECD Principle 3)
Domains i. Query structure is within the domain of the model
ii. All descriptors of the query structure are within ranges
iii. Considerations on the mechanism domain are not applicable since statistical model
Structural analogues (training set)
i. CAS 109-87-5: dimethoxymethane
ii. CAS 160-29-7: diethyl ether
iii. CAS 79-20-9: methyl acetate
iv. CAS 110-88-3: 1,3,5-Trioxane
Consideration on structural analogues
With 85% the average similarity of the four most similar structures in the training set to the query structure is considered high. Predicted and experimental values of the four most similar structures vary by a factor of up to 2.9 which is well within a default factor of 10 often used in traditional risk assessment of environmental chemicals to compensate for uncertainties*. Hence accuracy between predicted and actual values is considered high. The predicted value for 1,1-dimethoxyethane agrees with the experimental values of the four most similar structures, hence concordance is considered high.
3.4 The uncertainty of the prediction (OECD principle 4)
High similarity, accuracy and concordance suggest confidence in the prediction which is supported by an MAE of the prediction with the training/external set which is lower than the MAE of the respective entire set.
3.5 The chemical and biological mechanisms according to the model underpinning the predicted result (OECD principle 5)
Not applicable since statistical model
4 Adequacy (Optional)
4.1 Regulatory purpose Acute toxicity to fish endpoint for providing information on aquatic pelagic toxicity.
4.2 Approach for regulatory interpretation of the model result
Unit conversion provided by the software.
4.3 Outcome The prediction suggests an LC50 of 2419.59 mg/L and there is confidence in the prediction.
4.4 Conclusion The prediction is considered reliable and will be used together with other QSARs in a weight of evidence conclusion.

Qualifier:

no guideline followed

Principles of method if other than guideline:

- Principle of test: QSAR prediciton of Acute toxicity to fish
- Short description of test conditions: n/a
- Parameters analysed / observed: LC50

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

2 419.59 mg/L

Sublethal observations / clinical signs:

T.E.S.T.

1 Substance

1.1 CAS number 534-15-6

1.2 EC number 208-589-8

1.3 Chemical name

IUPAC 1,1-dimethoxyethane

Other dimethyl acetal

Other

1.4 Structural formula

1.5 Structure codes

SMILES COC(C)OC

InChI 1S/C4H10O2/c1-4(5-2)6-3/h4H,1-3H3

Other

Stereochemical features Not applicable

2 General Information

2.1 Date of QPRF 29 May 2018

2.2 Author and contact details Dr. Stefan Pudenz. Envigo CRS Switzerland Ltd.,

Rheinstrasse 74, 4414 Füllinsdorf, Switzerland,

Email: [e-mail]

3 Prediction

3.1 Endpoint (OECD Principle 1)

Endpoint Fathead minnow LC50 (96 hr) -Log10(mol/L)

Dependent variable Fathead minnow LC50 (96 hr) -Log10(mol/L)

3.2 Algorithm (OECD Principle 2)

Model or submodel name US EPA T.E.S.T Fathead minnow LC50 (96 hr); Consensus method

Model version 4.2

Reference to QMRF There is no QMRF available and provided by US EPA, respectively.

Predicted values (model result) LC50 = 2419.59 mg/L

Predicted values (comments) Unit conversion provided by the software

Input for prediction Smiles

Descriptor values Due to the large number of descriptors used all information are attached in the software printout section.

3.3 Applicability domain (OECD Principle 3)

Domains i. Query structure is within the domain of the model

ii. All descriptors of the query structure are within ranges

iii. Considerations on the mechanism domain are not applicable since statistical model

Structural analogues (training set)

i. CAS 109-87-5: dimethoxymethane

ii. CAS 160-29-7: diethyl ether

iii. CAS 79-20-9: methyl acetate

iv. CAS 110-88-3: 1,3,5-Trioxane

Consideration on structural analogues

With 85% the average similarity of the four most similar structures in the training set to the query structure is considered high. Predicted and experimental values of the four most similar structures vary by a factor of up to 2.9 which is well within a default factor of 10 often used in traditional risk assessment of environmental chemicals to compensate for uncertainties. Hence accuracy between predicted and actual values is considered high. The predicted value for 1,1-dimethoxyethane agrees with the experimental values of the four most similar structures, hence concordance is considered high.

3.4 The uncertainty of the prediction (OECD principle 4)

High similarity, accuracy and concordance suggest confidence in the prediction which is supported by an MAE of the prediction with the training/external set which is lower than the MAE of the respective entire set.

3.5 The chemical and biological mechanisms according to the model underpinning the predicted result (OECD principle 5)

Not applicable since statistical model

4 Adequacy (Optional)

4.1 Regulatory purpose Acute toxicity to fish endpoint for providing information on aquatic pelagic toxicity.

4.2 Approach for regulatory interpretation of the model result

Unit conversion provided by the software.

4.3 Outcome The prediction suggests an LC50 of 2419.59 mg/L and there is confidence in the prediction.

4.4 Conclusion The prediction is considered reliable and will be used together with other QSARs in a weight of evidence conclusion.

Conclusions:

The prediction suggests an LC50 of 2419.59 mg/L and there is confidence in the prediction.
The prediction is considered reliable and will be used together with other QSARs in a weight of evidence conclusion.

Reference 6

Endpoint:

short-term toxicity to fish

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a (Q)SAR model, with limited documentation / justification, but validity of model and reliability of prediction considered adequate based on a generally acknowledged source

Justification for type of information:

1.SOFTWARE
QSAR Toolbox 4.2

2. MODEL (incl. version number)
QSAR Toolbox 4.2
Database version: 4.2
TPRF v4.2

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
COC(C)OC

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
see attached justificaiton

5. APPLICABILITY DOMAIN
see attached justification

6. ADEQUACY OF THE RESULT
Acute toxicity to fish (LC50; EC50: fathead minnow) of 1,1-dimethoxyethane was predicted to be 4390 mg/L. The prediction is based on trend analysis with 74 data points and the statistics suggests confidence in the prediction.

Qualifier:

no guideline followed

Principles of method if other than guideline:

- Principle of test: QSAR prediciton of Acute toxicity to fish
- Short description of test conditions: n/a
- Parameters analysed / observed: LC50

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

4 390 mg/L

Conclusions:

Acute toxicity to fish (LC50; EC50: fathead minnow) of 1,1-dimethoxyethane was predicted to be 4390 mg/L. The prediction is based on trend analysis with 74 data points and the statistics suggests confidence in the prediction.

Reference 7

Endpoint:

short-term toxicity to fish

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a (Q)SAR model, with limited documentation / justification, but validity of model and reliability of prediction considered adequate based on a generally acknowledged source

Justification for type of information:

1 Substance
1.1 CAS number 534-15-6
1.2 EC number 208-589-8
1.3 Chemical name
IUPAC 1,1-dimethoxyethane
Other (ISO) dimethyl acetal
CAS
1.4 Structural formula
1.5 Structure codes
SMILES COC(C)OC
InChI 1S/C4H10O2/c1-4(5-2)6-3/h4H,1-3H3
Other
Stereochemical features Not applicable

2 General Information
2.1 Date of QPRF 29 May 2018
2.2 Author and contact details Dr. Stefan Pudenz, Envigo CRS Switzerland Ltd.,
Rheinstrasse 74, 4414 Füllinsdorf, Switzerland,
Email: [e-mail]

3 Prediction
3.1 Endpoint (OECD Principle 1)
Endpoint Acute toxicity to fish (lethality)
Dependent variable pLC50 = -log(LC50) [mol/L]
3.2 Algorithm (OECD Principle 2)
Model or submodel name Biovia toxicity prediction model – acute fish toxicity
Model version Biovia Discovery Studio v4.5
Reference to QMRF The corresponding QMRF BIOVIA toxicity prediction model
– acute fish toxicity is available from JRC QSAR Model
Database (https://qsardb.jrc.ec.europa.eu/qmrf; ID: Q17-33-0048)
Predicted values (model result) 0.451 g/L
Predicted values (comments) Unit conversion provided by software
Input for prediction Smiles
Calculated descriptor values Descriptor Value
LogP 0.079
Molecular weight (g/mol) 90.121
Number of hydrogen bond donors 0
Number of hydrogen bond acceptors 2
Number of rotatable bonds in the molecule 2
The polar surface area over the molecule 0.142
The polar solvent accessible surface area 28.7127
Number of aromatic rings 0
ECFP_6: Unitless Extended-connectivity
fingerprint with a maximum bond length of
6
Not
provided
FCFP_6 Unitless Functional class-extended
fingerprint with maximum bond length of 6
Not
provided
MDL Public Keys Unitless Fingerprint
comprised of features defined in the MDL
Public Keys
Not
provided
3.3 Applicability domain (OECD Principle 3)
Domains i. All properties and OPS components are within expected
ranges.
ii. All features of the query compound have been found in the
compounds of the training setiii.
Considerations on the mechanism domain are not
applicable since statistical model.
Structural analogues i. Dimethoxymethane
ii. Methylacetate
iii. Tert-butylmethyl ether
iv. Diethylether
Consideration on structural analogues
The structural distance between 1,1-dimethoxyethane and
dimethoxymethane is considered close (distance = 0.253),
while the other three structures are not acetals with distances
between 0.32 and 0.376. Predicted and actual value of
dimethoxmethane vary by a factor of 19.4 which is well above
a default factor of 10 often used in traditional risk assessment
of environmental chemicals to compensate for uncertainties*.
For the three remaining similar structures predicted and actual
value vary up to a factor of 7.0. The predicted value for 1,1-
dimethoxyethane disagrees with the experimental values of
two out of four structures provided.
3.4 The uncertainty of the prediction (OECD principle 4)
Moderate similarity of three structural analogues and low
accuracy in the prediction of the structurally similar
dimethoxymethane indicate uncertainty. Concordance is also
low, since two similar structures have experimental values that
disagree with the predicted value for 1,1-dimethoxyethane.
3.5 The chemical and biological mechanisms according to the model underpinning the predicted
result (OECD principle 5)
Not applicable since statistical model

4 Adequacy (Optional)
4.1 Regulatory purpose Acute toxicity to fish endpoint for providing information on
aquatic pelagic toxicity
4.2 Approach for regulatory interpretation of the model result
Result is directly applicable since no conversion of the result
is required.
4.3 Outcome The predicted LC50 of 451 mg/L suggest low acute toxicity to
fish but may cause long term adverse effects to aquatic
organisms according to classification for toxicity to fish
provided by Directive 92/32/EEC of the EU for dangerous
substances. Due to the uncertainties described above there is
only low confidence in the prediction.
4.4 Conclusion This prediction is considered to be of low reliability and
further predictions with other QSAR models are
recommended.
*Stedeford, T.; Zhao, Q.J.; Dourson, M.L.; Banasik, M.; Hsu, C.H. The application of non-default uncertainty factors in the
US EPA’s Integrated Risk Information System (IRIS). Part I: UFL, UFS, and “Other uncertainty factors”. J. Environ. Sci.
Heal. C 2007, 25, 245–279.

Qualifier:

no guideline followed

Principles of method if other than guideline:

- Principle of test: QSAR prediciton of Acute toxicity to fish
- Short description of test conditions: n/a
- Parameters analysed / observed: LC50

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

451 mg/L

Sublethal observations / clinical signs:

TOPKAT

1 Substance

1.1 CAS number 534-15-6

1.2 EC number 208-589-8

1.3 Chemical name

IUPAC 1,1-dimethoxyethane

Other (ISO) dimethyl acetal

CAS

1.4 Structural formula

1.5 Structure codes

SMILES COC(C)OC

InChI 1S/C4H10O2/c1-4(5-2)6-3/h4H,1-3H3

Other

Stereochemical features Not applicable

2 General Information

2.1 Date of QPRF 29 May 2018

2.2 Author and contact details Dr. Stefan Pudenz, Envigo CRS Switzerland Ltd.,

Rheinstrasse 74, 4414 Füllinsdorf, Switzerland,

Email: [e-mail]

3 Prediction

3.1 Endpoint (OECD Principle 1)

Endpoint Acute toxicity to fish (lethality)

Dependent variable pLC50 = -log(LC50) [mol/L]

3.2 Algorithm (OECD Principle 2)

Model or submodel name Biovia toxicity prediction model – acute fish toxicity

Model version Biovia Discovery Studio v4.5

Reference to QMRF The corresponding QMRF BIOVIA toxicity prediction model

– acute fish toxicity is available from JRC QSAR Model

Database (https://qsardb.jrc.ec.europa.eu/qmrf; ID: Q17-33 -0048)

Predicted values (model result) 0.451 g/L

Predicted values (comments) Unit conversion provided by software

Input for prediction Smiles

Calculated descriptor values Descriptor Value

LogP 0.079

Molecular weight (g/mol) 90.121

Number of hydrogen bond donors 0

Number of hydrogen bond acceptors 2

Number of rotatable bonds in the molecule 2

The polar surface area over the molecule 0.142

The polar solvent accessible surface area 28.7127

Number of aromatic rings 0

ECFP_6: Unitless Extended-connectivity fingerprint with a maximum bond length of 6 Not provided

FCFP_6 Unitless Functional class-extended fingerprint with maximum bond length of 6 Not provided

MDL Public Keys Unitless Fingerprint comprised of features defined in the MDL Public Keys Not provided

3.3 Applicability domain (OECD Principle 3)

Domains i. All properties and OPS components are within expected

ranges.

ii. All features of the query compound have been found in the

compounds of the training setiii.

Considerations on the mechanism domain are not

applicable since statistical model.

Structural analogues i. Dimethoxymethane

ii. Methylacetate

iii. Tert-butylmethyl ether

iv. Diethylether

Consideration on structural analogues

The structural distance between 1,1-dimethoxyethane and dimethoxymethane is considered close (distance = 0.253), while the other three structures are not acetals with distances between 0.32 and 0.376. Predicted and actual value of dimethoxmethane vary by a factor of 19.4 which is well above a default factor of 10 often used in traditional risk assessment of environmental chemicals to compensate for uncertainties*. For the three remaining similar structures predicted and actual

value vary up to a factor of 7.0. The predicted value for 1,1 -dimethoxyethane disagrees with the experimental values of two out of four structures provided.

3.4 The uncertainty of the prediction (OECD principle 4)

Moderate similarity of three structural analogues and low accuracy in the prediction of the structurally similar dimethoxymethane indicate uncertainty. Concordance is also low, since two similar structures have experimental values that disagree with the predicted value for 1,1-dimethoxyethane.

3.5 The chemical and biological mechanisms according to the model underpinning the predicted result (OECD principle 5)

Not applicable since statistical model

4 Adequacy (Optional)

4.1 Regulatory purpose Acute toxicity to fish endpoint for providing information on aquatic pelagic toxicity

4.2 Approach for regulatory interpretation of the model result

Result is directly applicable since no conversion of the result is required.

4.3 Outcome

The predicted LC50 of 451 mg/L suggest low acute toxicity to fish but may cause long term adverse effects to aquatic organisms according to classification for toxicity to fish provided by Directive 92/32/EEC of the EU for dangerous substances. Due to the uncertainties described above there is only low confidence in the prediction.

4.4 Conclusion This prediction is considered to be of low reliability and further predictions with other QSAR models are recommended.

*Stedeford, T.; Zhao, Q.J.; Dourson, M.L.; Banasik, M.; Hsu, C.H. The application of non-default uncertainty factors in the

US EPA’s Integrated Risk Information System (IRIS). Part I: UFL, UFS, and “Other uncertainty factors”. J. Environ. Sci.

Heal. C 2007, 25, 245–279

Conclusions:

The predicted LC50 of 451 mg/L suggest low acute toxicity to fish but may cause long term adverse effects to aquatic organisms according to classification for toxicity to fish provided by Directive 92/32/EEC of the EU for dangerous substances. Due to the uncertainties described above there is only low confidence in the prediction.
This prediction is considered to be of low reliability and further predictions with other QSAR models are recommended.

Description of key information

Appraisal of (Q)SAR Modelling

The predictions are detailed in the QSAR Prediction Reporting Formats, including discussions on reliability. For further information on the results it is referred to the software printout section.

Acute Fish Toxicity

Predicted LC50`s for acute fish toxicity of 1,1-dimethoxyethane range between 451 and 15451 mg/L (Table 1). Five predictions are considered reliable, while there is low/no confidence in the prediction from TOPKAT and NIC. In particular, low accuracy in the prediction of structural analogues and low concordance between their experimental results and the predicted result for the query structure indicate uncertainties. Moreover, 1,1-dimethoxyethane is out of the applicability domain of the NIC model. Predictions from TOPKAT and NIC are therefore excluded from the assessment.

The predictions with TEST, Sarpy/IRFMN and KNN/Read-across are all characterised by high accuracy in the prediction of structural analogues, high concordance between their experimental results and the prediction for the query structure, and high similarity between structural analogues and the query structure. In addition, 1,1-dimethoxyethane is within the applicability domain of all models. Hence, the predictions are considered reliable. Prediction with ECOSAR and SAR class neutral organics respectively, is based on regression fit of 296 data points including LC/EC50’s of acetals. A coefficient of determination, r2, of 0.878 suggests high predictive accuracy of the model and the prediction is therefore considered reliable.

Trend analysis with OECD Toolbox was performed using automated workflow “ecotoxicological endpoint” and provided 74 data points from neutral organic compounds with

the same profiling result as 1,1-dimethoxyethane (for details on profiling and categorisation, see QPRF and software printout). The model statistics indicates confidence and the prediction is considered reliable.

Prediction results of acute fish toxicity of 1,1-dimethoxyethane

Model	Fish toxicity EC/LC50[mg/L], 96h	Reliability
TOPKAT	451.00	low
US EPA T.E.S.T:	2419.59	reliable
ECOSAR	2921.66 (96h)	reliable
SarPy/IRFMN^*	Non-toxic (> 100 mg/L)	reliable
KNN/Read-Across^*	15451.03	reliable
NIC^*	1485.42	not reliable
OECD Toolbox	4390.00	reliable

*Within VEGA

Excluding the classification provided by SarPy/&IRFMN and using the geometric mean of the four reliable predictions results in an LC/EC50 of 4679.50 mg/L.

The geometric mean of 4679.50 mg/L falls within the range of LC/EC50 values of structurally similar acetals dimethoxymethane and diethoxymethane and therefore substantiates the predictions (Table 2). Taking additionally into account the small differences in terms of water solubility and log Kow there is an argument for a weight of evidence that 1,1-dimethoxyethane does not qualify for classification.

Structurally similar acetals

	1,1-dimethoxyethane	Diethoxymethane^*	Dimethoxymethane^*
CAS	534-15-6	462-95-3	109-87-5
Water solubility [g/L]	> 250	70	330
Log Kow	0.63	0.79	0.0^a)
Acute fish LC/EC50[mg/L]		764	6940
Acute daphnia EC50		468	>1000 >1200
Acute algae EC50			6000

* Data taken from ECHA CHEM & OECD Toolbox database

a) see, also ChemIDplus (experimental result)

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

4 679.5 mg/L