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:
72 hours, performed 2020
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to guideline
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
Version / remarks:
Including analytical verification
GLP compliance:
yes (incl. QA statement)
Specific details on test material used for the study:
Purity: 90.8 % Non-volatiles at 130 °C
Physical State/Appearance: Viscous brown liquid
Analytical monitoring:
yes
Details on sampling:
Analysis of the test preparations at 0 hours showed measured test concentrations to range from 0.0012 to 0.37 mg/L. Analysis of the test preparations at 72 hours showed measured test concentrations to range from 0.00074 to 0.29 mg/L.
Given this decline in measured test concentrations it was considered justifiable to base the results on the geometric mean measured test concentrations in order to give a "worst case".
Vehicle:
no
Details on test solutions:
0Nominal concentrations of 0.0010, 0.0032, 0.010, 0.032, 0.10 and 0.32 mg/L
(three replicate flasks per concentration)
Test organisms (species):
other: Raphidocelis subcapitata
Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
72 h
Hardness:
Not specified, but stated to be to OECD standard test media
Test temperature:
Temperature was maintained at 24 ±1 ºC throughout the test
pH:
The pH value of the control cultures was observed to increase from pH 7.7 at 0 hours to pH 9.0 at 72 hours.
Nominal and measured concentrations:
Nominal concentrations of 0.0010, 0.0032, 0.010, 0.032, 0.10 and 0.32 mg/L
Mean measured test concentrations 0.00093, 0.0030, 0.010, 0.033, 0.11 and 0.33 mg/L.
Reference substance (positive control):
no
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
ca. 0.15 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
ca. 0.071 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Validity criteria fulfilled:
yes
Conclusions:
The substance is considered toxic to the aquatic environment.

Description of key information

Three studies are reported.  The most sensitive result suggests inhibition of growth rate IC50 0.15 mg/l

Key value for chemical safety assessment

EC50 for freshwater algae:
0.47 mg/L
EC10 or NOEC for freshwater algae:
0.02 mg/L

Additional information

The acute toxicity of MK92K to freshwater green algae was determined in accordance with OECD Guideline 201 (Alga, Growth Inhibition Test) under static conditions.