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Ecotoxicological information

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:
short-term toxicity to aquatic invertebrates
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Guideline study conducted under GLP

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1997
Report Date:
1997

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
Deviations:
no
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
liquid: viscous
Details on test material:
- Name of test material (as cited in study report): Sucrose Acetate Isobutyrate (SAIB)
- Physical state: Viscous amber liquid
- Lot/batch No.: 4002606

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
The temperature, dissolved oxygen concentration, pH, and analytical concentration verification of each exposure solution were measured at times 0 and 48 hours.

Test solutions

Vehicle:
yes
Details on test solutions:
The stock solution was prepared in the carrier solvent N,N-dimethylformamide (DMF), as the test substance had negligible aqueous solubility. The stock solution was sonicated for approximately 1 hour and l5 minutes prior to use. The concentration of the test substance exposure solution contained the carrier solvent at a concentration of no more than 0.1 mL/1L. The exposure solutions for the test (nominally 0.5, 1, 1.5, 3, and 5 mg/L) were prepared by the addition of the appropriate amounts of the test substance stock solution to each test vessel containing laboratory dilution water. After the addition of the stock solution, each exposure solution was stirred with a glass rod to ensure mixing. The exposure solutions appeared clear throughout the test, with no apparent particulates, surface slicks or precipitates observed.

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
Adult Daphnia magna were reared within 100-L culturing tanks located within the Testing Facility. The gravid daphaids used to produce the test animals for the study were obtained from rearing tanks which had been established for at least two weeks. Prior to the study, approximately 100 gravid daphnids were transferred by net into two 20-cm diameter bowls containing 1 liter of diluent water and 5 mL of food. After 18 hours in these bowls, all adult daphnids were removed by using nets and pipets. Neonate daphnids were collected by pipet and transferred directly into the exposure vessels.
Sequential randomization was accomplished by allocating to each vessel no more than 50% of any one set of test organisms at a time. A total of 10 daphnids were placed into each of the replicate test vessels and replicate control vessels.

Study design

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
48 h

Test conditions

Hardness:
124 mg/L as CaCO3
Test temperature:
19-21 °C
pH:
8.3 - 8.5
Dissolved oxygen:
8.5 - 9.1 mg/L
Nominal and measured concentrations:
Nominal concentrations were 0.5, 1.0, 1.5:. 3.0, and 5.0 mg/L.
The geometric mean of the pooled replicates sampled at test intitiation and end were 0.07, 0.26, 0.31, 0.67 and 1.1 mg/L
Details on test conditions:
The acute aquatic effects test was performed in 250-mL Pyrex glass beakers using two replicates for each of 5 test substance concentrations plus a control and solvent control. Ten test organisms were placed into each of the replicate exposure solutions just after the measurements for physical parameters were performed at time 0. Observations for signs of immobility and stress were made at times 0, 3, 24, and 48 hours.The light/dark cycle of the lighting regime during the test was 16 hours on and 8 hours off, with a 30-minute transition period.

Results and discussion

Effect concentrationsopen allclose all
Duration:
48 h
Dose descriptor:
NOEC
Effect conc.:
>= 1.11 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
mobility
Duration:
48 h
Dose descriptor:
LC50
Effect conc.:
> 1.11 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
mobility

Any other information on results incl. tables

Nominal and measured concentrations, and Daphnia immobility

Nominal Conc. mg/L Measured Conc.* mg/L Number of Daphnids Immobile at
0 hr 3 hr 24 hr 48 hr
Control A ND 0 0 0 0
Control B ND 0 0 0 0
Solvent Control A ND 0 0 0 0
Solvent Control B ND 0 0 0 0
0.50 A 0.07 0 0 0 0
0.50 B 0.07 0 0 0 0
1.0 A 0.28 0 0 0 1
1.0 B 0.23 0 0 1 1
1.5 A 0.37 0 0 0 0
1.5 B 0.25 0 0 0 1
3.0 A 0.63 0 0 0 0
3.0 B 0.71 0 0 0 0
5.0 A 1.19 0 0 0 0
5.0 B 1.03 0 0 1 1

*Test substance concentratiom, as determined gas chromatography with flame ionization detection (GC/FID), were mathematically derived as the geometric mean of the analyzed sample concentration values of the test solutions at times 0 and 48 hours.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Executive summary:

The study report indictes that a definitive test and a limit test had been performed previously that experienced issues related to entrapment of the daphnids due to testing at concentrations above the solubility limit. The current study was designed to reduce the loading closer to the solubility limit to avoid these recognized problems. In this study the acute toxicity of the test substance to Daphnia magna was determined in a 48-hour, static, aquatic effects test. The replicate exposure solutions were prepared by the addition of the appropriate amount of the test substance stock solution to each test vessel containing dilution water at nominal concentrations of 0.5, 1, 1.5, 3, and 5 mg/L. The stock solution was prepared in the carrier solvent N,N-dimethylformamide, as the test substance had negligible aqueous solubility. Samples of the exposure solution containing the test substance, and the controls, were submitted to for chemical analysis. The endpoints reported in this study are based on the geometric mean of the analyzed solutions at times 0 and 48 hours, averaged over the replicates. The analyzed exposure concentration values were determined by gas chromatography with flame ionization detection (GC/FID). The 48-hour EC50 value for Daphnia magna, pooled replicates A and B, was determined to be >1.11 mg/L. The 48-hour No-Observed-Effect Concentration (NOEC) value for Daphnia magna was determined to be ≥ 1.11 mg/L for pooled replicates A and B. The study demonstrates that the test substance does not exhibit toxicity at the limit of aqueous solubility.