Registration Dossier

Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:
toxicity to aquatic algae and cyanobacteria
Type of information:
(Q)SAR
Adequacy of study:
key study
Study period:
03Oct2017
Reliability:
1 (reliable without restriction)
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:
The (Q)SARs models used in this assessment have been evaluated by the Joint Research Centre (JRC) and the scientific validity of each software established according to five principles recommended by OECD and ECHA for regulatory purposes (Annex XI of the REACH).
At present, a summary of appropriate information on the (Q)SAR models, based on the topics listed below, is not available in a specific reporting format.
• Endpoint, algorithm
• Domain of applicability
• Measures related to goodness-of-fit
• Robustness
• Predictivity and mechanism

However, the adequacy and reliability of each (Q)SAR prediction was checked for each endpoint following the procedures outlined in REACH Annex XI (1.3) in terms of suitability of the model (reliability, relevance for the purpose), applicability of the model to the substance of interest and adequacy of the predicted endpoint for classification and labelling.

The selected set of software models was used to generate the classification for each endpoint listed in Annex VII of the REACH, and wherever possible, including the (Q)SAR models recommended by ECHA for preparation of the Annex III chemical inventory (ECHA, 2016c,d).

See attached for full QPRF and QMRF.

Data source

Reference
Reference Type:
other company data
Title:
Unnamed
Year:
2017
Report Date:
2017

Materials and methods

Test guideline
Qualifier:
no guideline required
Principles of method if other than guideline:
(Q)SAR analysis - no guideline required
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
other: In SIlico
Details on test material:
In silico test item
Specific details on test material used for the study:
(Q)SAR analysis - no test material details available

Sampling and analysis

Analytical monitoring:
not required
Remarks:
(Q)SAR analysis

Test solutions

Vehicle:
not specified
Remarks:
(Q)SAR analysis
Details on test solutions:
(Q)SAR analysis - not required

Test organisms

Test organisms (species):
other: Green algae - (Q)SAR
Details on test organisms:
Green algae - (Q)SAR

Study design

Test type:
not specified
Water media type:
not specified
Remarks:
(Q)SAR

Test conditions

Details on test conditions:
Not applicable - (Q)SAR
Reference substance (positive control):
not required

Results and discussion

Effect concentrationsopen allclose all
Key result
Duration:
96 h
Dose descriptor:
EC50
Effect conc.:
ca. 21.03 mg/L
Nominal / measured:
not specified
Conc. based on:
not specified
Basis for effect:
not specified
Remarks on result:
other: ECOSAR predicted
Key result
Duration:
96 h
Dose descriptor:
EC50
Effect conc.:
ca. 5.68 mg/L
Nominal / measured:
not specified
Conc. based on:
not specified
Basis for effect:
not specified
Remarks on result:
other: trend-analyses performed for the endpoint “Acute growth for Chlorophyceae” in the OECD Toolbox

Any other information on results incl. tables

Green algae acute toxicity model in ECOSAR predicted that 1,5-dinitronapthalene has an EC50(96h) of 21.03 mg/L. This valid result was considered in the evaluation. Additionally, this substance is not flagged as having water solubility lower than the effect level or a log Kow higher than the maximum for this model. A comparative result of 5.68 mg/L was obtained with good confidence from the trend-analyses performed for the endpoint “Acute growth for Chlorophyceae” in the OECD Toolbox (version 4.1). The primary grouping selected was “Aquatic toxicity classification by ECOSAR” and the subsequent sub-categorisation based on “Chemical elements”, structure similarity” and US-EPA New Chemical Categories”.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Remarks:
Valid (Q)SAR models used, molecule is within the applicability domain.
Conclusions:
Green algae acute toxicity model in ECOSAR predicted that 1,5-dinitronapthalene has an EC50(96h) of 21.03 mg/L. This valid result was considered in the evaluation. Additionally, this substance is not flagged as having water solubility lower than the effect level or a log Kow higher than the maximum for this model. A comparative result of 5.68 mg/L was obtained with good confidence from the trend-analyses performed for the endpoint “Acute growth for Chlorophyceae” in the OECD Toolbox (version 4.1). The primary grouping selected was “Aquatic toxicity classification by ECOSAR” and the subsequent sub-categorisation based on “Chemical elements”, structure similarity” and US-EPA New Chemical Categories”.

Assessment of the quality of predictions: The ECOSAR model gave an effect level for green algae that was inside the water solubility values of 1,5-dinitronapthalene. The analyses performed in both ECOSAR software (version 1.11) or in the Danish QSAR database gave the same result and equally valid prediction that was considered acceptable for the proposes of regulatory classification. Further trend-analyses performed in the OECD Toolbox with the endpoint “Acute growth for Chlorophyceae, EC50(96h)”, estimated a valid EC50 obtained from N=9 point data with an R2 of 0.778.

General follow-up procedure: Overall, there is strong evidence that 1,5-dinitronapthalene is an aquatic toxicant and according to the CLP criteria, this substance should be classified as Chronic Toxic category 3 (for aquatic algae).
Executive summary:

Green algae acute toxicity model in ECOSAR predicted that 1,5-dinitronapthalene has an EC50(96h) of 21.03 mg/L. This valid result was considered in the evaluation. Additionally, this substance is not flagged as having water solubility lower than the effect level or a log Kow higher than the maximum for this model. A comparative result of 5.68 mg/L was obtained with good confidence from the trend-analyses performed for the endpoint “Acute growth for Chlorophyceae” in the OECD Toolbox (version 4.1). The primary grouping selected was “Aquatic toxicity classification by ECOSAR” and the subsequent sub-categorisation based on “Chemical elements”, structure similarity” and US-EPA New Chemical Categories”.

Assessment of the quality of predictions: The ECOSAR model gave an effect level for green algae that was inside the water solubility values of 1,5-dinitronapthalene. The analyses performed in both ECOSAR software (version 1.11) or in the Danish QSAR database gave the same result and equally valid prediction that was considered acceptable for the proposes of regulatory classification. Further trend-analyses performed in the OECD Toolbox with the endpoint “Acute growth for Chlorophyceae, EC50(96h)”, estimated a valid EC50 obtained from N=9 point data with an R2 of 0.778.

General follow-up procedure: Overall, there is strong evidence that 1,5-dinitronapthalene is an aquatic toxicant and according to the CLP criteria, this substance should be classified as Chronic Toxic category 3 (for aquatic algae).