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Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

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Reference
Endpoint:
toxicity to aquatic algae and cyanobacteria
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:
The supporting QMRF report has been attached
Qualifier:
no guideline available
Principles of method if other than guideline:
The prediction is done using QSAR Toolbox version 3.3 with respect to the descriptor log Kow.
GLP compliance:
not specified
Analytical monitoring:
not specified
Vehicle:
not specified
Test organisms (species):
Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)
Test type:
static
Water media type:
freshwater
Total exposure duration:
72 h
Test temperature:
25 degC
Reference substance (positive control):
not specified
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
110.65 mg/L
Nominal / measured:
estimated
Conc. based on:
test mat.
Basis for effect:
growth rate

The prediction was based on dataset comprised from the following descriptors: EC50
Estimation method: Takes average value from the 7 nearest neighbours
Domain  logical expression:Result: In Domain

((((((((((("a" or "b" or "c" or "d" or "e" )  and ("f" and ( not "g") )  )  and ("h" and ( not "i") )  )  and ("j" and ( not "k") )  )  and ("l" and ( not "m") )  )  and "n" )  and ("o" and ( not "p") )  )  and ("q" and ( not "r") )  )  and ("s" and ( not "t") )  )  and ("u" and ( not "v") )  )  and ("w" and "x" )  )

Domain logical expression index: "a"

Referential boundary: The target chemical should be classified as Anilines (Acute toxicity) by US-EPA New Chemical Categories

Domain logical expression index: "b"

Referential boundary: The target chemical should be classified as Radical AND Radical >> Radical mechanism via ROS formation (indirect) AND Radical >> Radical mechanism via ROS formation (indirect) >> Single-Ring Substituted Primary Aromatic Amines AND SN1 AND SN1 >> Nucleophilic attack after metabolic nitrenium ion formation AND SN1 >> Nucleophilic attack after metabolic nitrenium ion formation >> Single-Ring Substituted Primary Aromatic Amines by DNA binding by OASIS v.1.3

Domain logical expression index: "c"

Referential boundary: The target chemical should be classified as SN1 AND SN1 >> Nitrenium Ion formation AND SN1 >> Nitrenium Ion formation >> Primary aromatic amine by DNA binding by OECD

Domain logical expression index: "d"

Referential boundary: The target chemical should be classified as Weak binder, NH2 group by Estrogen Receptor Binding

Domain logical expression index: "e"

Referential boundary: The target chemical should be classified as Anilines (amino-para) AND Anilines (Unhindered) by Aquatic toxicity classification by ECOSAR

Domain logical expression index: "f"

Referential boundary: The target chemical should be classified as Not known precedent reproductive and developmental toxic potential by DART scheme v.1.0

Domain logical expression index: "g"

Referential boundary: The target chemical should be classified as Inorganic chemical OR Known precedent reproductive and developmental toxic potential OR Metal atoms were identified OR Non-steroid nucleus derived estrogen receptor (ER) and androgen receptor (AR) OR Non-steroid nucleus derived estrogen receptor (ER) and androgen receptor (AR) >> Other non-steroidal estrogen receptor (ER) binding compounds (2b-2) OR Not covered by current version of the decision tree OR Piperazine-, dioxane-, morpholine-, tetrahydrothiopyran-like derivatives and cyclohexanamine (17c) OR Toluene and small alkyl toluene derivatives (8a) by DART scheme v.1.0

Domain logical expression index: "h"

Referential boundary: The target chemical should be classified as Halogens AND Non-Metals by Groups of elements

Domain logical expression index: "i"

Referential boundary: The target chemical should be classified as Alkali Earth by Groups of elements

Domain logical expression index: "j"

Referential boundary: The target chemical should be classified as Aminoaniline, para AND Aniline AND Aryl AND Aryl halide AND Precursors quinoid compounds by Organic Functional groups

Domain logical expression index: "k"

Referential boundary: The target chemical should be classified as Phenol by Organic Functional groups

Domain logical expression index: "l"

Referential boundary: The target chemical should be classified as Aminoaniline, para AND Aniline AND Aryl AND Aryl halide AND Precursors quinoid compounds by Organic Functional groups

Domain logical expression index: "m"

Referential boundary: The target chemical should be classified as Naphtalene OR Nitrobenzene by Organic Functional groups

Domain logical expression index: "n"

Referential boundary: The target chemical should be classified as Not calculated by Hydrolysis half-life (Kb, pH 7)(Hydrowin) ONLY

Domain logical expression index: "o"

Referential boundary: The target chemical should be classified as Aliphatic Nitrogen, one aromatic attach [-N] AND Aromatic Carbon [C] AND Chlorine, aromatic attach [-Cl] AND Chlorine, olefinic attach [-Cl] AND Olefinic carbon [=CH- or =C<] by Organic functional groups (US EPA)

Domain logical expression index: "p"

Referential boundary: The target chemical should be classified as Oxygen, one aromatic attach [-O-] by Organic functional groups (US EPA)

Domain logical expression index: "q"

Referential boundary: The target chemical should be classified as Aliphatic Nitrogen, one aromatic attach [-N] AND Aromatic Carbon [C] AND Chlorine, aromatic attach [-Cl] AND Chlorine, olefinic attach [-Cl] AND Olefinic carbon [=CH- or =C<] by Organic functional groups (US EPA)

Domain logical expression index: "r"

Referential boundary: The target chemical should be classified as Tertiary Carbon by Organic functional groups (US EPA)

Domain logical expression index: "s"

Referential boundary: The target chemical should be classified as Aliphatic Nitrogen, one aromatic attach [-N] AND Aromatic Carbon [C] AND Chlorine, aromatic attach [-Cl] AND Chlorine, olefinic attach [-Cl] AND Olefinic carbon [=CH- or =C<] by Organic functional groups (US EPA)

Domain logical expression index: "t"

Referential boundary: The target chemical should be classified as Fluorine, aliphatic attach [-F] by Organic functional groups (US EPA)

Domain logical expression index: "u"

Referential boundary: The target chemical should be classified as Amine AND Aromatic compound AND Aryl chloride AND Aryl halide AND Halogen derivative AND Primary amine AND Primary aromatic amine by Organic functional groups, Norbert Haider (checkmol)

Domain logical expression index: "v"

Referential boundary: The target chemical should be classified as Secondary amine by Organic functional groups, Norbert Haider (checkmol)

Domain logical expression index: "w"

Parametric boundary:The target chemical should have a value of log Kow which is >= -0.612

Domain logical expression index: "x"

Parametric boundary:The target chemical should have a value of log Kow which is <= 1.14

Validity criteria fulfilled:
not specified
Conclusions:
A study was predicted using OECD QSAR toolbox version 3.3 (2017), to assess the toxicity effect of 2-chloro-p-phenylenediamine on algae in a 96 hours of exposure. The median effective concentration (EC50) for the test substance, 2-chloro-p-phenylenediamine, in algae (Desmodesmus subspicatus) on a growth rate effect was estimated to be 110.65 mg/L in a 72 hour study.
Executive summary:

A study was predicted using OECD QSAR toolbox version 3.3 (2017), to assess the toxicity effect of 2-chloro-p-phenylenediamine on algae in a 96 hours of exposure. The median effective concentration (EC50) for the test substance, 2-chloro-p-phenylenediamine, in algae (Desmodesmus subspicatus) on a growth rate effect was estimated to be 110.65 mg/L in a 72 hour study. Thus on the basis of EC50 value and by considering the CLP criteria for aquatic classification of the substance, it is concluded that the substance ‘2-chloro-p-phenylenediamine (CAS No. 615-66-7)’ does not exhibit toxicity to aquatic algae.

Description of key information

A study was predicted using OECD QSAR toolbox version 3.3 (2017), to assess the toxicity effect of 2-chloro-p-phenylenediamine on algae in a 96 hours of exposure. The median effective concentration (EC50) for the test substance, 2-chloro-p-phenylenediamine, in algae (Desmodesmus subspicatus) on a growth rate effect was estimated to be 110.65 mg/L in a 72 hour study. Thus on the basis of EC50 value and by considering the CLP criteria for aquatic classification of the substance, it is concluded that the substance ‘2-chloro-p-phenylenediamine (CAS No. 615-66-7)’ does not exhibit toxicity to aquatic algae.

Key value for chemical safety assessment

EC50 for freshwater algae:
110.65 mg/L

Additional information

Various studies including predicted results from the validated model and experimental study from a peer-reviewed journal for toxicity to aquatic algae with the target substance 2-chloro-p-phenylenediamine (CAS No. 615-66-7) and to its relevant read across substance 2-chloroaniline (CAS No. 95-51-2) by considering its structure-activity relationships, were summarized as follows:

 

A study was predicted using OECD QSAR toolbox version 3.3 (2017), to assess the toxicity effect of 2-chloro-p-phenylenediamine on algae in a 96 hours of exposure. The median effective concentration (EC50) for the test substance, 2-chloro-p-phenylenediamine, in algae (Desmodesmus subspicatus) on a growth rate effect was estimated to be 110.65 mg/L in a 72 hour study.

 

In addition, based on the Ecological Structure Activity Relationships (ECOSAR) Predictive Model version 1.11 (2017), the median effective concentration (EC50) for the test substance, 2-chloro-p-phenylenediamine, in a green algae was estimated to be 801.51 mg/L on the basis of growth rate effect in a 96 hour study.

Moreover, the test was carried out by Kuhn,R. et al. (Water Res.24(1): 31-38, 1990) on Scenedesmus subspicatus with the substance 2-chloroaniline (CAS No.- 95-51-2) in a 72 hours of exposure. The effective concentration to 50% of test organisms was determined. The median effective concentration (EC50) for the test substance, 2-chloroaniline, in aquatic green algae Scenedesmus subspicatus was determined to be 150.0 mg/L on the basis of population effect in a 72 hours study.

 

Based on the above predicted and experimental studies for target substance 2-chloro-p-phenylenediamine (CAS No. 615-66-7) and to its read across substance 2-chloroaniline (CAS No. 95-51-2), the effective concentration EC50 value was found to be in the range of 110.65 mg/L and 801.51 mg/L. Thus, on the basis of this EC50 value and according to CLP Criteria for aquatic classification of the substance, it is concluded that 2-chloro-p-phenylenediamine (CAS No. 615-66-7) does not exhibit toxicity to aquatic algae.