5-methyl-1,3-oxazolidin-2-one

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

Study period:

2015-09-21 - 2015-09-23

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GPL guideline study without restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2015

Report date:

2015

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

5-methyl-1,3-oxazolidin-2-one

EC Number:

810-292-9

Cas Number:

1072-70-4

Molecular formula:

C4H7NO2

IUPAC Name:

5-methyl-1,3-oxazolidin-2-one

Details on test material:

- Name of test material (as cited in study report): 5-methyl oxazolidin-2-one
- Physical state: liquid / colorless, clear
- Analytical purity: 98.0 area-% (GC)

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Sampling method: The test was initiated by impartially distributing 20 neonate (< 24 hours old) Daphnia magna evenly among the 4 test vessels per test group. The neonate daphnids all originated from the same mass culture and were thus genetic clones. The Daphnia were transferred into the test vessels with minimal culture water by capturing each daphnid in a pipette then gently expelling it onto a Teflon mesh (70μm) held by forceps. Each daphnid was then immediately transferred from the mesh into the corresponding test vessel from lowest to highest concentration.
Each test vessel was visually checked for immobilized daphnids after 0, 24 and 48 hours. In addition any abnormal behavior or appearance was documented. Throughout the test, the appearance of the test solutions and dissolution behavior of the test substance was observed and recorded daily. The chemical and physical parameters of the test medium (total hardness, acid capacity, pH, TOC and conductivity) were determined after aeration and prior to use in the test. Dissolved oxygen and pH were measured at the start and at the end of the exposure in replicate 1 of all test concentrations and the control. In addition, temperature was measured continuously during the whole exposure period in a separate vessel filled with water proximal to the test vessels.

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The test substance was homogenized by shaking the container. The stock test solution (120 mg/L) was prepared by directly adding 120.11 mg of test substance to 1L of test medium and stirring for approximately 10 min until visibly dissolved. Before the stock solution was used, the stock solution was checked for complete dissolution of the test substance. The stock solution appeared colourless-clear.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Source: The clone of Daphnia magna STRAUS 1820
used was supplied by the Institut National de Recherche Chimique Appliquée, France, in 1978. From this date on this clone was cultured and bred continuously in the Laboratory of Ecotoxicology of the Experimental Toxicology and Ecology of BASF SE in Ludwigshafen.
- Age at study initiation (mean and range, SD): < 24 hours (at least 3rd brood progeny)
- Acclimatization: The Daphnia are cultured under the identical conditions as the test including test media (Elendt M4), water quality, and temperature (20 ±1°C).

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test conditions

Hardness:

2.36 mmol/L

Test temperature:

19.7 - 20.1°C

pH:

7.8-8.0

Dissolved oxygen:

8.7-9.0 mg/L

Nominal and measured concentrations:

nominal: 0 (control), 120mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass beakers (nominal volume 100 mL)
- Test volume: 50 mL
- Aeration: none
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16:8 light:dark
- Light intensity: About 187 – 804 lux at a wave length of 400 -750 nm

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Results and discussion

Effect concentrations

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 120 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Any other information on results incl. tables

Since the analytically determined concentrations of the test substance in the test solutions were within ±20% of the nominal concentrations, the effect concentration can be expressed relative to the nominal concentration for the evaluation of the test substance.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Executive summary:

In a 48-hour acute toxicity study, neonate Daphnia magna were exposed to 5-methyl oxazolidin-2-one at nominal concentrations of 0 (control) and 120 mg/L under static conditions in accordance with the OECD 202 guideline. The water pH, temperature and dissolved oxygen were within acceptable guideline specifications. Immobilization (mortality) and sublethal effects were observed daily. The 48 hour EC50 values determined in this acute toxicity study were >120 mg/L based on the nominal concentration of the test substance. The test substance had no observable acute effect on Daphnia magna up to 120 mg/L in test media and under test conditions.

The toxicity results presented here are consistent with the results from preliminary tests. The results in this study are consistent with all validity criteria and the test is valid according to the guidelines of this study. No deviations from test guidelines or other incidents occurred during the course of the reported test which may have influenced the results.