Registration Dossier

Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:
toxicity to aquatic algae and cyanobacteria
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2019

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Test material form:
liquid

Sampling and analysis

Analytical monitoring:
yes

Test solutions

Vehicle:
yes
Details on test solutions:
The test substance was calibrated according to purity(100.0%). The test substance in the test water was prepared by WSF(Water Soluble Fraction).The method of preparation was selected to maximize the solubility of the test item under specific test exposure conditions. 0.10013 g of test substance was put into a 1 L capacity glass volumetric flask, filled with 1 L of OECD Medium, stirred at a 200 rpm for 48 hours, and then filtered once with 0.45 ㎛ PVDF filter. Test solution was prepared immediately before test start.

Test organisms

Test organisms (species):
Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)
Details on test organisms:
The test species were supplied from American Type Culture Collection (ATCC, Manassas, VA, USA) after cultured in Environmental toxicology lab, HTRC.

Study design

Test type:
static
Water media type:
freshwater
Limit test:
yes
Total exposure duration:
72 h

Test conditions

Test temperature:
22.4℃
pH:
pH 8.34(7.79 ~ 8.74)
Reference substance (positive control):
no

Results and discussion

Effect concentrationsopen allclose all
Key result
Duration:
72 h
Dose descriptor:
EL50
Effect conc.:
ca. 118.354 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
NOELR
Effect conc.:
25 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
LOELR
Effect conc.:
50 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Details on results:
1. Biomass and inhibition rate
Initiation biomass of algal mean (0.97 ± 0.09)×104 cell/mL.Percent inhibition in average specific growth rate was showed -0.990, -0.736, 1.139, 18.161 and 29.659 to 6.3, 12.5, 25.0, 50.0 and 100.0 mg/L of the test solution at 72 hours (Table 2). Percent inhibition of yield showed -0.912, 0.405, 5.446, 65.881 and 78.546% to 6.3, 12.5, 25.0, 50.0 and 100.0 mg/L of the test solution at 72 hours.
2. Changes of water quality
The mean of pH was 8.34 (min. 7.79 ~ max. 8.74). The mean of intensity of illumination was 5203.5 Lux (min. 4990 Lux ~ max. 5960 Lux). The mean of temperature was 22.4℃ (min. 22.2℃ ~ max 22.9℃).
3. Validity of the test
The biomass in the control group increased exponentially by a factor of 156 times, it was accepted. it was accepted of upper 16 times.The mean coefficient of variation for section-by-section specific growth rates (Days 0–1, 1–2 and 2–3, for 72 hours) was 12.85%, in the control group, which was accepted guideline (did not exceed 35%). The coefficient of variation of average specific growth rates was 1.5445%. It was accepted during a 72 hours test period did not exceed 7% in the replicated control group.
The pH changed in control to a minimum and maximum deviation of 0.08 within a change of 1.5.
Results with reference substance (positive control):
N/A
Reported statistics and error estimates:
EC50 and 95% confidence limits was calculated by probit method. NOEC and LOEC were statistically calculated by Dunnett test (SPSS, Version 23.0).

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The 72 hours ErL50 value of the test substance to Pseudokirchneriella subcapitata was 118.354 mg/L, NOEL was 25.0 mg/L and EyL50 value was 62.289 mg/L, NOEL was 12.5 mg/L.