Registration Dossier

Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Currently viewing:

Administrative data

Link to relevant study record(s)

Reference
Endpoint:
toxicity to aquatic algae and cyanobacteria
Type of information:
experimental study
Adequacy of study:
key study
Study period:
55 days
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
comparable to guideline study
Qualifier:
according to
Guideline:
OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)
Deviations:
no
GLP compliance:
yes
Specific details on test material used for the study:
Batch 135214 of Disperse Blue 359 was a dark blue powder with a purity of 99%.
Analytical monitoring:
yes
Details on sampling:
2 mL samples were taken a t=0, t=24h and t=72 h
Vehicle:
no
Details on test solutions:
Insoluble in water. Solutions containing 1.0, 10 and 100% of the Saturated Solution (SS) prepared at a loading rate of 100 mg/L.
6 replicates of the control and the limit concentration, 3 replicates of lower test concentrations, 1 or 2 replicates of each concentration without algae, 1 or 2 replicates of each test concentration for sampling purpose at 24 hour of exposure.
Test organisms (species):
Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)
Details on test organisms:
Pseudokirchneriella subcapitata, strain: NIVA CHL 1
Source: In-house laboratory culture.
Reason for selection: This system is an unicellular algal species sensitive to toxic items in the aquatic ecosystem and has been selected as an internationally accepted species.
Test type:
static
Water media type:
freshwater
Limit test:
yes
Total exposure duration:
72 h
Hardness:
0.24 mmol/L
Test temperature:
21-24°C
pH:
8.1 ±0.2
Reference substance (positive control):
yes
Remarks:
Potassium dichromate
Key result
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
> 3.6 µg/L
Nominal / measured:
not specified
Conc. based on:
test mat. (dissolved fraction)
Basis for effect:
growth rate
Key result
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
> 3.6 µg/L
Nominal / measured:
not specified
Conc. based on:
test mat. (dissolved fraction)
Basis for effect:
cell number
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
> 3.6 µg/L
Nominal / measured:
not specified
Conc. based on:
test mat. (dissolved fraction)
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
> 3.6 µg/L
Nominal / measured:
not specified
Conc. based on:
test mat. (dissolved fraction)
Basis for effect:
cell number
Duration:
72 h
Dose descriptor:
EC20
Effect conc.:
> 3.6 µg/L
Nominal / measured:
not specified
Conc. based on:
test mat. (dissolved fraction)
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC20
Effect conc.:
> 3.6 µg/L
Nominal / measured:
not specified
Conc. based on:
test mat. (dissolved fraction)
Basis for effect:
cell number
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 3.6 µg/L
Nominal / measured:
not specified
Conc. based on:
not specified
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 3.6 µg/L
Nominal / measured:
not specified
Conc. based on:
test mat. (dissolved fraction)
Basis for effect:
cell number
Validity criteria fulfilled:
yes
Conclusions:
Under the conditions of the present study with Pseudokirchneriella subcapitata, no inhibition of growth rate or inhibition of yield was recorded at the limit concentration prepared at a loading rate of 100 mg Disperse Blue 359 per litre.
Both the EC50 for growth rate inhibition (72h-ERC50) and the EC50 for yield inhibition (72h-EYC50) were beyond the range tested, i.e. exceeded the maximum solubility of Disperse Blue 359 in test medium (estimated to be 3.6 µg/L).
The 72-NOEC for both growth rate inhibition and yield inhibition was the maximum solubility of test item in medium (estimated to be 3.6 µg/L).
Due to the very low solubility of Disperse Blue 359 in water, concentration levels that might be toxic for algae could not be reached.
Executive summary:

Under the conditions of the present study with Pseudokirchneriella subcapitata, no inhibition of growth rate or inhibition of yield was recorded at the limit concentration prepared at a loading rate of 100 mg Disperse Blue 359 per litre.

Both the EC50 for growth rate inhibition (72h-ERC50) and the EC50 for yield inhibition (72h-EYC50) were beyond the range tested, i.e. exceeded the maximum solubility of Disperse Blue 359 in test medium (estimated to be 3.6µg/L).

The 72-NOEC for both growth rate inhibition and yield inhibition was the maximum solubility of test item in medium (estimated to be 3.6µg/L).

Due to the very low solubility of Disperse Blue 359 in water, concentration levels that might be toxic for algae could not be reached.

Description of key information

Under the conditions of the present study with Pseudokirchneriella subcapitata, no inhibition of growth rate or inhibition of yield was recorded at the limit concentration prepared at a loading rate of 100 mg Disperse Blue 359 per litre.

Both the EC50 for growth rate inhibition (72h-ERC50) and the EC50 for yield inhibition (72h-EYC50) were beyond the range tested, i.e. exceeded the maximum solubility of Disperse Blue 359 in test medium (estimated to be 3.6µg/L).

The 72-NOEC for both growth rate inhibition and yield inhibition was the maximum solubility of test item in medium (estimated to be 3.6µg/L).

Due to the very low solubility of Disperse Blue 359 in water, concentration levels that might be toxic for algae could not be reached.

Key value for chemical safety assessment

Additional information

Under the conditions of the present study with Pseudokirchneriella subcapitata, no inhibition of growth rate or inhibition of yield was recorded at the limit concentration prepared at a loading rate of 100 mg Disperse Blue 359 per litre.

Both the EC50 for growth rate inhibition (72h-ERC50) and the EC50 for yield inhibition (72h-EYC50) were beyond the range tested, i.e. exceeded the maximum solubility of Disperse Blue 359 in test medium (estimated to be 3.6µg/L).

The 72-NOEC for both growth rate inhibition and yield inhibition was the maximum solubility of test item in medium (estimated to be 3.6µg/L).

Due to the very low solubility of Disperse Blue 359 in water, concentration levels that might be toxic for algae could not be reached.