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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:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
data from handbook or collection of data
Justification for type of information:
Data for the target chemical is summarized based on the structurally similar read across chemicals.
Reason / purpose:
read-across source
Reason / purpose:
read-across source
Qualifier:
according to
Guideline:
other: as mentioned below
Principles of method if other than guideline:
WoE report is based on two toxicity study of test chemical on aquatic algae.

GLP compliance:
no
Analytical monitoring:
no
Vehicle:
no
Test organisms (species):
other: 1. Scenedesmus subspicatus, 2. Pseudokirchneriella subcapitata
Details on test organisms:
1. TEST ORGANISM
- Common name: Green Algae

Test type:
static
Water media type:
freshwater
Total exposure duration:
72 h
Details on test conditions:
After pH-adjustment of a parallel group with the highest concentration (= 100 mg/L), 100 mg/L were tolerated without mortality and toxic signs.
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
90 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Remarks on result:
other: WoE 1
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
69 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
test mat.
Basis for effect:
not specified
Remarks on result:
other: toxic
Validity criteria fulfilled:
not specified
Conclusions:
The test chemical is likely to be toxic to auatic algae atleast in the dose range of 69.0 to 90 mg/l.
Executive summary:

Following studies of structurally and functionally similar read across includes data to conclude the toxicity extent of test material towards aquatic algae is summarized as follows:

Objective of this first study was to determine the effect of test chemical on the growth rate of Scenedesmus subspicatus. Test conducetd under the static system for 72 hours. Based on the growth rate inhibition of algae, EC50 was determine at 90 mg/l whereas EC0 at 25 mg/l. Thus on the basis of EC50 value, chemical consider to be toxic and can be consider to be classiifed in aquatic chronic category 3.

Further it is supported by another structurally similar read across 2 also suggests that the toxicity to aquatic algae test was carried out to study the effects of test chemical on aquatic algae. Effective concentration EC50 to 50% Pseudokirchnerella subcapitata when exposed to test chemical is 69 mg/L. It can be concluded from the value that the test chemical is toxic to the aquatic algae and can be considered as “Aquatic chronic 3” as per the classification criteria for aquatic environment.

Thus based on the effect concentrations which is in the range 69 to 90 mg/l gives the conclusion that test chemical  is likely to be toxic to aquatic environment at environmentally relevant concentrations and applying weight of evidence approach it can be considered to be “aquatic chronic 3” as per the CLP classification criteria.

Description of key information

Thus based on the effect concentrations which is in the range 69 to 90 mg/l gives the conclusion that test chemical is likely to be toxic to aquatic environment at environmentally relevant concentrations and applying weight of evidence approach it can be considered to be “aquatic chronic 3” as per the CLP classification criteria.

Key value for chemical safety assessment

EC50 for freshwater algae:
69 mg/L

Additional information

Following studies of structurally andfunctionallysimilar read across includes data to conclude the toxicity extent of test material towards aquatic algae is summarized as follows:

Objective of this first study was to determine the effect of test chemical on the growth rate of Scenedesmus subspicatus. Test conducetd under the static system for 72 hours. Based on the growth rate inhibition of algae, EC50 was determine at 90 mg/l where as EC0 at 25 mg/l. Thus on the basis of EC50 value, chemical consider to be toxic and can be consider to be classiifed in aquatic chronic category 3.

Further it is supported by another structurally similar read across 2 also suggests that the toxicity to aquatic algae test was carried out to study the effects of test chemical on aquatic algae. Effective concentration EC50 to 50% Pseudokirchnerella subcapitata when exposed to test chemical is 69 mg/L. It can be concluded from the value that the test chemical is toxic to the aquatic algae and can be considered as “Aquatic chronic 3” as per the classification criteria for aquatic environment.

Thus based on the effect concentrations which is in the range 69 to 90 mg/lgives the conclusion that test chemical is likely to be toxic to aquatic environment at environmentally relevant concentrations and applying weight of evidence approach it can be considered to be “aquatic chronic 3” as per the CLP classification criteria.