Registration Dossier

Ecotoxicological information

Short-term toxicity to aquatic invertebrates

Currently viewing:

Administrative data

Link to relevant study record(s)

Reference
Endpoint:
short-term toxicity to aquatic invertebrates
Type of information:
experimental study
Adequacy of study:
key study
Study period:
January 14, 2002 - September 6, 2002
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to guideline
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
Qualifier:
according to guideline
Guideline:
EU Method C.2 (Acute Toxicity for Daphnia)
GLP compliance:
yes
Analytical monitoring:
yes
Details on sampling:
Test concentrations were verified by chemical analysis. Duplicate samples, of 50 ml, were taken from the control and each test concentration at 0 and 24 hours fresh (from main stock solutions), and after 24 and 48 hours expired (replicates pooled) for analysis.

Preliminary trials were conducted on the stability of the test material in aqueous solution. Sealed vessels containing a known concentration of of Oxazolidinyl ethyl methacrylate (OXEMA) were analysed at time 0 and after 24 hours under exposure to both light and dark conditions. Results showed the parent material degraded under both light and dark conditions. This indicated that of Oxazolidinyl ethyl methacrylate (OXEMA) was not stable in aqueous solution.
Vehicle:
yes
Remarks:
diluent water
Details on test solutions:
The test substance was dissolved in diluent water to give an initial stock solution of 100 mgl/. Serial dilutions of this stock solution were prepared with diluent water to complete the nominal test series of 4.6, 10, 22, 46 and 100 mg/l.
Test organisms (species):
Daphnia magna
Details on test organisms:
Daphnia magna (Straus) used in this study were cultured in-house and were obtained from a strain originating from the Institute National de Recherche Chimique Applique (IRChA), France.
Stock cultures of Daphnia magna were maintained in glass vessels containing approximately 500 to 800 ml of Elendt M4 culture medium with a 16 hour light: 8 hour dark photoperiod at 20°C. Cultures were fed daily with a suspension of the unicellular green alga, Chlorella vulgaris. Culture conditions ensure that cultures reproduce by parthenogenesis.
The day before the start of the study, all juvenile Daphnia were removed from the laboratory cultures. The following morning, juveniles produced by the gravid (egg-bearing) adult Daphnia were removed from the culture vessels and held in a separate holding vessel; these animals, which were less than 24 hours old, were used in the test.
Test type:
semi-static
Water media type:
other: a reconstituted medium Elendt M4
Limit test:
no
Total exposure duration:
48 h
Test temperature:
21 +/- 1 degrees C
pH:
7.6-8.1
Dissolved oxygen:
8.1-8.2
Nominal and measured concentrations:
Nominal test concentrations: 4.6, 10, 22, 46 and 100 mg/l
Geometric mean measured test concentrations: 2.3, 5.4, 11, 22 and 46 mg/l
Details on test conditions:
Four replicate vessels were prepared for the control and each test group. The test vessels were 250 ml capacity glass jars.
Five first instar Daphnia were placed without conscious bias into each glass jar, containing 100 ml of prepared test medium to give a loading of 20 ml test solution per organism. The jars were loosely covered with a lid to minimise evaporative losses.

Cultures were maintained at 21+/-1°C and were without supplementary aeration or feeding during the 48 hour exposure period. A photoperiod of 16 hours light: 8 hours dark was employed with a 30 minute dawn/dusk transition period.
The temperature, pH and dissolved oxygen levels were recorded in stock solutions at 0 and 24 hours fresh and in each test vessel at 24 and 48 hours expired.
Daphnia were exposed to the test or control conditions for a period of 48 hours with renewal of testmedia after 24 hours. A semi-static regime was employed because preliminary stability studies indicated that the test material was unstable in aqueous solution.

Criterion of effect:
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
21 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
mobility
Duration:
48 h
Dose descriptor:
NOEC
Effect conc.:
11 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Basis for effect:
mobility
Details on results:
Measured concentrations ranged from 84 - 90% of nominal at 0 hours (fresh), 22 - 31% of nominal at 24 hour (expired), 94 - 102% of nominal at 24 hour (fresh) and 16 - 30% of nominal at 48 hours (expired). Geometric mean measured concentrations ranged from 46 - 54% of their nominal values in this study. Actual geometric mean measured concentrations were 2.3, 5.4, 11, 22 and 46 mg/l.

The following values are expressed in terms of geometric mean measured concentration based on 0 and 24 fresh, and 24 and 48 hour expired analytical measurements.
Time (hours)              EC50 (mg/l)                     95% confidence limits (mg/l)
24                                   >46                                   -
48                                   21                                   18 - 23
Highest test concentration resulting in 0% immobilisation: 5.4 mg/l
Lowest test concentration resulting in 100% immobilisation: 46 mg/l
"No-observed effect concentration": 11 mg/l*

The following values are expressed in terms of nominal concentrations.
Time (hours)              EC50 (mg/l)                     95% confidence limits (mg/l)
24                                   >l00                                         - 
48                                    44                                      38 - 49
Highest test concentration resulting in 0% immobilisation: 10 mg/l
Lowest test concentration resulting in 100% immobilisation: 100 mg/l
"No-observed effect concentration": 22 mg/l*
Control immobilisation: 0%
* Although one daphnid was immobilised at the nominal test concentration of 22 mg/l (equivalent to geometric mean measured concentrations of 11 mg/l) after 48 hours this was not considered significant. Therefore this concentration is reported as the NOEC. This decision took into consideration the protocol validity criteria for the control mortality of <10%.

Individual pH, temperature and dissolved oxygen values remained within acceptable limits during the study.

Table 1. Cumulative immobilization data for Daphnia magna exposed for 48 hours to OXEMA

Nominal concentration (mg/l)

Geometric mean measured concentration (mg/l)

Cumulative immobilizedDaphnia magna

24 hours

48 hours

R1

R2

R3

R4

Total

%

R1

R2

R3

R4

Total

%

Control

ND

0

0

0

0

0

0

0

0

0

0

0

0

4.6

2.3

0

0

0

0

0

0

0

0

0

0

0

0

10

5.4

0

0

0

0

0

0

0

0

0

0

0

0

22

11

0

0

0

0

0

0

0

0

0

1

1

5*

46

22

0

0

0

0

0

0

4

3

3

2

12

60

100

46

2

2

0

1

5

25

5

5

5

5

20

100

R1– R4: Replicates 1, 2, 3, 4

ND: None detected

*: Within acceptable control mortality (<10%)

Validity criteria fulfilled:
yes
Conclusions:
The 48 hour EC50 (immobilisation) value for Oxazolidinyl ethyl methacrylate (OXEMA) with Daphnia magna based on nominal concentration was determined to be 44 mg/l (equivalent to geometric mean measured concentrations of 21 mg/l).
The 'No-observed effect concentration' (NOEC) based on nominal concentration was 22 mg/l (equivalent to geometric mean measured concentrations of 11 mg/l).
Executive summary:

The acute toxicity of Oxazolidinyl ethyl methacrylate (OXEMA) to Daphnia magna was assessed under static, daily renewal conditions. The study was conducted in accordance with the test guidelines EC Methods for Determination of Ecotoxicity Annex to Directive 92169lEEC (O.J. No. L383A, 29.12.92) Part C, Method 2 and OECD Guideline for Testing of Chemicals No. 202, Part I.

Groups of twenty, first instar Daphnia, less than 24 hours old, were exposed to Oxazolidinyl ethyl methacrylate (OXEMA) dissolved in Elendt M4 medium for 48 hours at nominal concentrations of 4.6, 10, 22, 46 and 100 mg/l. Actual geometric mean measured concentrations were 2.3, 5.4, 11, 22 and 46 mg/l. Measured concentrations ranged from 84 - 90% of nominal at 0 hours (fresh), 22 - 3 1% of nominal at 24 hour (expired), 94 - 102% of nominal at 24 hour (fresh) and 16 - 30% of nominal at 48 hours (expired).

Stability tests indicated the test material was not stable in aqueous solution and therefore accounts for the losses experienced after each 24 hour exposure period between renewal of test medium. The numbers of immobilised daphnids were recorded for each test and control group after 24 and 48 hours. All results are expressed in terms of nominal and geometric mean measured concentration.

The following values are expressed in terms of geometric mean measured concentration based on 0 and 24 fresh, and 24 and 48 hour expired analytical measurements.

Time (hours)              EC50 (mg/l)                     95% confidence limits (mg/l)

24                                   >46                                   -

48                                   21                                   18 - 23

Highest test concentration resulting in 0% immobilisation: 5.4 mg/l

Lowest test concentration resulting in 100% immobilisation: 46 mg/l

"No-observed effect concentration": 11 mg/l*

Environmental conditions, pH, dissolved oxygen and temperature, remained within the ranges specified by the protocol throughout duration of the study.

The following values are expressed in terms of nominal concentrations.

Time (hours)              EC50 (mg/l)                     95% confidence limits (mg/l)

24                                   >l00                                         - 

48                                    44                                      38 - 49

Highest test concentration resulting in 0% immobilisation: 10 mg/l

Lowest test concentration resulting in 100% immobilisation: 100 mg/l

"No-observed effect concentration": 22 mg/l*

Control immobilisation: 0%

* Although one daphnid was immobilised at the nominal test concentration of 22 mg/l (equivalent to geometric mean measured concentrations of 11 mg/l) after 48 hours this was not considered significant. Therefore this concentration is reported as the NOEC. This decision took into consideration the protocol validity criteria for the control mortality of <10%.

Description of key information

The key study is an OECD Guideline 202, EU Method C.2, GLP compliant study with Daphnia magna.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates
Effect concentration:
21 mg/L

Additional information

The acute toxicity of OXEMA to Daphnia magna was assessed under static, daily renewal conditions.

 

Groups of twenty, first instarDaphnia,less than 24 hours old, were exposed to OXEMA dissolved in Elendt M4 medium for 48 hours at nominal concentrations of 4.6, 10, 22, 46 and 100 mg/l. Actual geometric mean measured concentrations were 2.3, 5.4, 11, 22 and 46 mg/l. Measured concentrations ranged from 84 - 90% of nominal at 0 hours (fresh), 22 - 31 % of nominal at 24 hour (expired), 94 -102% of nominal at 24 hour (fresh) and 16 -30% of nominal at 48 hours (expired).

 

Stability tests indicated the test material was not stable in aqueous solution and therefore accounts for the losses experienced after each 24 hour exposure period between renewal of test medium. The numbers of immobilized daphnids were recorded for each test and control group after 24 and 48 hours. All results are expressed in terms of nominal and geometric mean measured concentration.

 

The following values are expressed in terms of geometric mean measured concentration based on 0 ~ and 24 fresh, and 24 and 48 hour expired analytical measurements:

Time (hours)        EC50(mg/l)          95% confidence limits (mg/l)

          24                 >46                                    -

          48                   21                                 18 -23

 

Highest test concentration resulting in 0% immobilization: 5.4 mg/l

Lowest test concentration resulting in 100% immobilization: 46 mg/l

"No-observed effect concentration": 11 mg/l

 

The following values are expressed in terms of nominal concentrations.

 

Time (hours)       EC50(mg/l)          95% confidence limits (mg/l)

24                 >100                 -

48                   44                          38- 49

 

Highest test concentration resulting in 0% immobilization: 10 mg/l

Lowest test concentration resulting in 100% immobilization:  l00 mg/l

"No-observed effect concentration":  22 mg/l

Control immobilization:  0%