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Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Some information in this page has been claimed confidential.

Administrative data

Endpoint:
toxicity to aquatic algae and cyanobacteria
Type of information:
(Q)SAR
Adequacy of study:
key study
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

Data source

Referenceopen allclose all

Reference Type:
other: QSAR calculation report
Title:
Unnamed
Year:
2018
Reference Type:
other: Estimation software
Title:
Unnamed
Year:
2012

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
ECOSAR v1.11: Estimation of acute and chronic toxicity to green algae for chemical class "Neutral Organic SAR (Baseline Toxicity)"
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder

Test organisms

Test organisms (species):
other: green algae

Study design

Test type:
not specified
Water media type:
freshwater
Total exposure duration:
96 h

Results and discussion

Effect concentrations
Duration:
96 h
Dose descriptor:
EC50
Effect conc.:
2.743 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
not specified
Remarks on result:
other:
Remarks:
The substance is within the applicability domain of the model.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Executive summary:

QPRF: ECOSAR v1.11

1.

Substance

See “Test material identity”

2.

General information

 

2.1

Date of QPRF

See “Data Source (Reference)”

2.2

QPRF author and contact details

See “Data Source (Reference)”

3.

Prediction

3.1

Endpoint
(OECD Principle 1)

Endpoint

Toxicity to aquatic organisms:

-       Green algae: 96-h EC50

-       Green algae: chronic value

Dependent variable

-       Green algae: 96-h EC50

-       Green algae: chronic value

3.2

 

Model or submodel name

ECOSAR – Chemical Class: Neutral Organics:

-       Green algae: 96-h EC50

-       Green algae: chronic value

Model version

1.11

Reference to QMRF

QMRF: Estimation of Toxicity to Aquatic Organisms Using ECOSAR v1.11 (EPI Suite v4.11): Chemical Class: Neutral Organics: Green Algae 96-h EC50 and Chronic Value

Predicted value (model result)

See “Results and discussion”

Input for prediction

- For chemical identity: CAS number or SMILES

- Log Kow (optionally entered by user, or estimated by KOWWIN v1.68)

Descriptor values

See “Any other information on materials and methods incl. tables”

3.3

Algorithm
(OECD Principle 2)

Domain: The complete training sets for ECOSAR’s estimation methodology are not available since some of the information is confidential; therefore, the description of a precise estimation domain for this methodology is not possible.

The substance is an organic chemical with a molecular weight ≤ 1000 g/mol.

Fulfilled

The substance is a member of the chemical class “Neutral Organics”.

Fulfilled

In case the log Kow is estimated via KOWWIN v1.68: The substance is within the estimation domain of KOWWIN v1.68.

Fulfilled

3.4

The uncertainty of the prediction
(OECD principle 4)

Neutral Organics:

Effect level

n

r2

Green algae

96-h EC50

41 + 9

0.6782

chronic value

34 + 5

0.6971

3.5

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

The octanol/water partition coefficient (Kow) is the major physical-chemical attribute correlating a chemical structure to toxic effect for nonreactive neutral organic chemicals. The most frequently used relationship is the logarithm of the Kow value versus the median toxicity (LC50 and EC50) value.

If the log Kow value exceeds a model specific value (acute: 6.4; chronic: 8.0), or if the compound is solid and the LC50 exceeds the water solubility by 10X, no effects at saturation are predicted.

Members of the chemical class “Neutral Organics” act via simple nonpolar narcosis generally thought of as a reversible, drug-induced loss of conscience (general anesthesia) which is also referred to as baseline toxicity.

 

References

- US EPA (2012). On-Line ECOSAR User’s Guide.