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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:
Preliminary Test (Pre-test): 2019-08-12 to 2019-08-15
Main test: 2019-08-26 to 2019-08-29
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
Guideline:
OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)
Version / remarks:
2011
Deviations:
no
GLP compliance:
yes

Test material

Constituent 1
Chemical structure
Reference substance name:
(1S,4R)-1-methyl-4-(prop-1-en-2-yl)cyclohex-2-en-1-ol
Cas Number:
22972-51-6
Molecular formula:
C10H16O
IUPAC Name:
(1S,4R)-1-methyl-4-(prop-1-en-2-yl)cyclohex-2-en-1-ol
Test material form:
liquid
Details on test material:
Test item: (1S,4R)-1-Methyl-4-(prop-1-en-2-yl)cyclohex-2-enol
CAS number: 22972-51-6
Physical state: Liquid
Storage: Room temperature
Specific details on test material used for the study:
Test item: (1S,4R)-1-methyl-4-(prop-1-en-2-yl)cyclohex-2-en-1-ol
CAS number: 22972-51-6
Physical state: Liquid
Storage: room temperature

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
study. Algal biomass in each flask was measured by under microscope at 0, 24 ± 2, 48 ± 2, 72 ± 2 hours aft er treatment, measured the pH

Test solutions

Vehicle:
no
Details on test solutions:
The test article “Menthadienol (PMDOL)” solution were prepared and 10 mL of the test article so solutions were added to reaction mixture contains 80 mL growth medium, 10 mL algae (1 x 10^5 cells/mL) solution in each treatment group, and the growth medium is used as control in this study.

According to the results of the preliminary test, the highest concentration of main test was determined as 100 mg/L and was further taken 2-fold serial dilution of test article solutions and mad e to 50 mg/L, 25 mg/L, 12.5 mg/L and 6.25 mg/L to apply in other treatment groups.

Test organisms

Test organisms (species):
Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)
Details on test organisms:
Test species: Pseudokirchneriella subcapitata
Source: Freshwater Bioresource Center of National Chiayi University Controls
The algae were cultured 7 days in advance until the test starts.
Initial cells density: 10,000 cells/mL

Study design

Test type:
static
Water media type:
other: Growth medium
Total exposure duration:
72 h

Test conditions

Test temperature:
23 ± 2°C, in study period, the algae is cultured in the algae incubator.
pH:
t=0h: 7.5-7.6
t=72h: 7.4-7.6
Nominal and measured concentrations:
Main test:
Nominal test concentrations: 100mg/L, 50 mg/L, 25 mg/L, 12.5 mg/L and 6.25 mg/L
Measured test concentration:
at day 0: 90.79 mg/L, 47.12 mg/L, 23.17 mg/L, 10.82 mg/L, 5.99 mg/L
at day 3: 80.05 mg/L, 42.65 mg/L, 21.99 mg/L, 10.24 mg/L, 5.59 mg/L
Details on test conditions:
TEST SYSTEM
- vessel: 250 mL glass flasks and test article solution is 100 mL/vessel
-Temperature: 23 ± 2°C, in study period, the algae is cultured in the algae incubator.
-Light intensity: 4440~8880 lux; continuous illumination.
-Type of test: Incubation with rotary shaking approximately 100 rpm.
-Duration: 72 ± 2 hours.
GROWTH MEDIUM: Preparation according to the OECD 201 Guideline

Measurements:
-pH was measured at the beginning and at the end of the test. Temperature was continuously measured in a control vessel.
-Analysis of all test concentrations at the beginning and at the end of the test were recommended to measure and should be remained within 80-120 % of nominal concentration.
-At the end of the final test microscopic observations were performed on all test concentrations to observe for any abnormal appearance of the algae.
Reference substance (positive control):
no

Results and discussion

Effect concentrationsopen allclose all
Key result
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
57.03 mg/L
Conc. based on:
test mat.
Basis for effect:
growth rate
Key result
Duration:
72 h
Dose descriptor:
EC20
Effect conc.:
2.47 mg/L
Conc. based on:
test mat.
Basis for effect:
growth rate
Key result
Duration:
72 h
Dose descriptor:
EC10
Effect conc.:
0.48 mg/L
Conc. based on:
test mat.
Basis for effect:
growth rate
Key result
Duration:
72 h
Dose descriptor:
LOEC
Effect conc.:
6.25 mg/L
Conc. based on:
test mat.
Basis for effect:
growth rate
Key result
Duration:
72 h
Dose descriptor:
NOEC
Remarks on result:
not determinable

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
PMDOL is hazardous to the aquatic environment and classified into GHS Acute aquatic hazard Category 3 – 72 h EC50 (for algae or other aquatic plants) > 1 0mg/L but ≤ 100 mg/L.