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
Study period:
2012
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2012
Report date:
2013

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
other: TCCA(Toxic Chemical Control Act)-Test Guidelines described in Annex 5 of TCCA-Good Laboratory Practice Standards and Test Guidelines” Notification No. 2012-23, National Institute of Environmental Research, Korea (Aug. 22, 2012)
GLP compliance:
yes

Test material

Constituent 1
Chemical structure
Reference substance name:
2-{2-[(2-ethylhexyl)oxy]ethoxy}ethyl prop-2-enoate
Cas Number:
117646-83-0
Molecular formula:
C15H28O4
IUPAC Name:
2-{2-[(2-ethylhexyl)oxy]ethoxy}ethyl prop-2-enoate
Test material form:
liquid
Details on test material:
Test substance name: MI RAMER M1086
Appearance : Clear liquid
Manufacturing date: 2012-03-29
Supplier:Miwon Specialty Chemical Co., Ltd.
Receipt day: 2012-05-23
Deli very amount: 399.223 g(Gross)
Cas No.:117646-83-0
Lot No.:120329JY1
Purit y: 95.55 %
Expiration date: 2013-03-28 (Manufactured after 1 year)
Storage condition: Room temperature [(15 ~ 25)°C

Sampling and analysis

Analytical monitoring:
yes

Test organisms

Test organisms (species):
Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)
Details on test organisms:
The test species (Lot No.: 7403439) were obtained from the American Type Culture Collection (ATCC, U.S.A.) on May 7, 2009.
Sub-culture
Frozen cells, which were stored in a deep freezer (OPR-DFU-657CEV, Operon, Korea, -70±10oC) upon receipt, were thawed and inoculated in culture medium under aseptic conditions, Then, the cells were incubated at a temperature of 23±2oC under continuous illumination (intensity 4,440–8,880 Lux) and constantly shaken at approximately 100 rpm using a shaking incubator for 7 days. After incubation, a biomass (the number of cells per volume) was counted and the suspension was diluted with culture medium to produce a biomass of 1×104 cells/mL. Cells were subcultured under the same conditions at intervals of 3 to 4 days.
Exponentially growing cells, which were sub-cultured for 4 passages, were observed for atypical cell morphology such as flocculation, discoloration, swelling, atrophy and rupture and inoculated in agar medium for long-term storage. They were then incubated at 23±2oC under continuous illumination (intensity 4,440–8,880 Lux). The culture was maintained under refrigeration (2–8oC) until use.
Pre-culture
A colony from algal cells in agar medium for long-term storage was collected in a clean bench and inoculated in a culture medium four days prior to study initiation. A biomass was counted using a particle counter and diluted with culture medium to produce a biomass of 0.5×104 cells/mL. Counted cells were incubated by shaking (at approximately 100 rpm) at 23±2oC under continuous illumination (intensity 4,440–8,880 Lux).

Study design

Test type:
static
Water media type:
freshwater

Test conditions

Test temperature:
During the exposure period, water temperature and illuminance of the test solution were 23.5°C
pH:
The measured pHs were 7.5 and 7.3–7.7 at initiation of the test and 72 hours after exposure, respectively.

Results and discussion

Effect concentrationsopen allclose all
Key result
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
0.245 mg/L
Nominal / measured:
meas. (geom. mean)
Key result
Duration:
72 h
Dose descriptor:
LOEC
Effect conc.:
0.402 mg/L
Nominal / measured:
meas. (geom. mean)

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
Based on the Range Finding Test, the Definitive Test was conducted the control group (including the solvent control group) and a dose level were selected at 5, 11, 23, 48 and 100 mg/L.
No test substance was detected in the test solutions of the control group (including the solvent control group).
The concentration in the test solution in each treatment group was within ±20% of nominal values for solubility at the start of exposure and 24 hours after exposure. But, the concentration in the test solution in each treatment group exceeded ±20% of 0 hour values (at the start of exposure) at 48 and 72 hours after exposure. Therefore, all test results were calculated based on the geometric means of the measured values during the exposure period.
In conclusion, ErC50 (0–72 hours) and EyC50 (0–72 hours) that were obtained under the test conditions with the test substance, MIRAMER M1086, were determined to be 2.1166 mg/L (measured concentration, 95% confidence limits: 1.870–2.446 mg/L) and 0.6595 mg/L (measured concentration, 95% confidence limits: 0.6061–0.7197 mg/L), respectively.
The No Observed Effect Concentration (NOEC) and Lowest Observed Effect Concentration (LOEC) for the results of the average specific growth rate and yield were determined to be 0.2450 and 0.4023 mg/L (measured concentrations), respectively.
Executive summary:

This study was designed to assess the effect of the test substance, MIRAMER M1086, on the growth of the fresh water alga, Pseudokirchneriella subcapitata, during an exposure period of 72 hours under static test conditions and to determine the median effect concentration (EC50) for percent inhibition in growth rate and yield in each group. The desired nominal concentrations were selected at dose levels of 5, 11, 23, 48 and 100 mg/L.

Based on the results of this study, ErC50 (0–72 hours) and EyC50 (0–72 hours) that were obtained under the test conditions with the test substance, MIRAMER M1086, were determined to be 2.1166 mg/L (measured concentration, 95% confidence limits: 1.870–2.446 mg/L) and 0.6595 mg/L (measured concentration, 95% confidence limits: 0.6061–0.7197 mg/L), respectively.

The No Observed Effect Concentration (NOEC) and Lowest Observed Effect Concentration (LOEC) for the results of the average specific growth rate and yield were determined to be 0.2450 and 0.4023 mg/L (measured concentrations), respectively.