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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
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The study was conducted according to O.E.C.D. Test Guideline No. 201, "Algal Inhibiton Test" with concentration verification and GLP compliance.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2010
Report Date:
2010

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
Deviations:
not specified
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Details on test material:
As per IUCLID5 Sections 1.1. - 1.4.

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
At the start of the definitive test, four sample bottles (approximately 35 mL) were completely filled with the freshly-prepared control and test
media. Two of the sample bottles were reserved for analysis on Day 0 and the other two bottles were held under the same conditions as the test vessels until Day 3.

Test solutions

Vehicle:
no
Details on test solutions:
The test media were prepared from an aqueous dilution in which the test substance Crude 1,3-dichloropropene (53.3 μL) was added directly to sterile algal culture medium (2 L) using a gas tight syringe. This primary aqueous solution (32 mg/L) was either used directly at the highest test concentration or was diluted to provide the test media at the four lower concentrations.

Test organisms

Test organisms (species):
Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)
Details on test organisms:
Axenic, uni-cellular, liquid slope cultures of algae were obtained from the Culture Collection of Algae and Protozoa (CCAP), SAMS Research Services Ltd., Dunstaffnage Marine Laboratory, Dunbeg, Oban, Argyll, Scotland. The liquid slope cultures were stored in an illuminated refrigerator. Approximately 100 mL of sterile algal nutrient medium was inoculated with cells aseptically removed from the slope culture. These primary liquid cultures were incubated for approximately three days in an orbital incubator under continuous illumination at nominal temperatures in the range 21 to 25°C with a cell density of approximately 4.5 x 106 cells/mL

Study design

Test type:
static
Water media type:
saltwater
Limit test:
no
Total exposure duration:
72 h
Post exposure observation period:
None

Test conditions

Hardness:
No data
Test temperature:
23.7 - 24.8 degrees C.
pH:
7.6 - 8.8
Dissolved oxygen:
No data
Salinity:
No data, freshwater
Nominal and measured concentrations:
Nominal concentrations were 0.305, 0.977, 3.13, 10 and 32 mg/L. At the start of the test, the measured levels of 1,3-dichloropropene in samples of the tes cultures ranged between 22 and 41% of the nominal test concentrations, confirming that the intended exposure concentrations were adequately achieved given that the test substance contained between 35 and 50% of 1,3-dichloropropene. The overall mean measured levels of 1,3-dichloropropene were 0.0719, 0.204, 0.889, 2.92 and 7.33 mg/L.
Details on test conditions:
The initial agal cell density was approximartely 1 x 104 cells/mL. An aliquot (ca. 65 mL) of the appropriate inoculated test medium was added to each of the test vessels, which were completely filled and sealed leaving no headspace due to the volatility of the test substance. Eighteen flasks (Wheaton vials, total capacity 65 mL) were established for the control group and nine flasks for each test group, plus two additional flasks at nominal concentrations of 0.305 and 32 mg/L, which contained test medium but no algal cells. All of the control and test flasks were incubated.

Each vessel containing control or test culture (65 mL) were placed in an illuminated orbital incubator oscillating at a nominal 150 cycles per minute. The cultures were incubated, without renewal of medium (static conditions) for 72 hours under continuous illumination (nominally 4440 to 8880 lux.) provided by 6 x 30 W “cool white” 1 metre fluorescent tubes. The temperature was maintained between 21.0 and 24.0°C. Samples of the algal cultures were taken from control and test flasks at 24, 48 and 72 hours and the cell densities measured using a Coulter Z Series Particle Count and Size Analyser. The estimate of cell numbers in each sample was based on the mean of three consecutive counts, corrected for background counts of uninoculated dilution medium.
Reference substance (positive control):
no

Results and discussion

Effect concentrationsopen allclose all
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
ca. 8.3 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
other: Area under the growth curve.
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
ca. 3.1 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
not specified
Remarks:
Area under the curve.
Details on results:
After 72 hours of exposure to Crude 1,3-Dichloropropene, the EbC50, ErC50 and EyC50 respectively, were nominal 8.31 mg/L, 12.1 mg/L and 9.37 mg/L).
Results with reference substance (positive control):
Not applicable
Reported statistics and error estimates:
The data were analysed using SAFEStat LD50 application, SAS 9.1.3 (SAS Institute, 2002).

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The algal 72 hr EC50 value based on test substance and Area-Under-The-Curve is 8.3 mg/L. The NOAEC under similar experimental conditions is approximately 3.1 mg/L. Therefore, based on the outcome of this algal screening test, Crude 1,3-dichloropropene is toxic to aquatic organisms.
Executive summary:

The test substance Crude 1,3 -dichloropropene was assessed for acute algal toxicity by an O.E.C.D. Test Guideline No. 201 "Algal Inhibition Test" conducted with GLP compliance. The algal 72 hr EC50 value based on test substance and Area-Under-The-Curve is 8.3 mg/L. The NOAEC under similar experimental conditions is approximately 3.1 mg/L. Therefore, based on the outcome of this algal screening test, Crude 1,3-dichloropropene is toxic to aquatic organisms.