N-[3-(dimethylamino)propyl]methacrylamide

Short-term toxicity to aquatic invertebrates

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:

2008-07-15 - 2008-07-17

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

GLP.

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Sample storage conditions before analysis: Room temperature, protected from moisture and light

Vehicle:

no

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Strain: Straus (Clone 5)
- Source: Institut für Wasser-, Boden- und Lufthygiene (WaBoLu)
- Age at study initiation: 2-24 h old
- Method of breeding:
Culture: In 2 - 3 L glass vessels with approximately 1.8 L culture medium, at 20  2 °C, in an incubator, 16 h illumination, illumination strength max. 20 µE.m-2 . s-1.
-Culture medium: Elendt M4, according to ELENDT (1990), modified to a total hardness of 160 to 180 mg CaCO3/L.
- Feeding during test:
- Food type: mix of unicellular green algae, e.g. Pseudokirchneriella subcapitata, Desmodesmus subspicatus and Chlorella vulgaris
- Amount: , with an algae cell density of > 106 cells/mL.
- Frequency: At least 5 times per week

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

160 to 180 mg CaCO3/L

Test temperature:

The temperature in the test vessels was within the range 21.1 to 22.0 °C

pH:

pH-value: 7.8+/- 0.2

Dissolved oxygen:

The water parameters (dissolved oxygen concentration, pH-value) of test and control groups at the beginning of the test were measured in one replicate per concentration and control. After 48 h water parameters were measured in all replicates of the old media .
The pH-value, oxygen concentration, temperature, conductivity and total hardness of the dilution water were measured prior to test start .

Nominal and measured concentrations:

nominal test concentrations: 62.5; 125; 250; 500 and 1000 mg/l control and pH control (1000 mg/l)
All concentration levels and the control were analysed via LC-MS after 0 h and 48 h. Recoveries of the test item were in the recommended range of ± 20 % of the nominal values in all concentration levels at test start and test end. Therefore, all effect values are given based on the nominal concentrations of the test item Dimethylaminopropyl methacrylamide

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass beakers (4 cm ID x 7 cm H), 50 mL capacity
- Volume of the study: 20 ml

- No. of organisms per vessel: 5 animals per concentration and control
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2


OTHER TEST CONDITIONS
- Adjustment of pH: pH-control (1000 mg/l adjusted to pH 7.0 +/-0.2 with 1 M HCl
- Photoperiod: 16/8 h light/dark cycle
- Light intensity: Diffuse light, illumination strength max. 20 µE . m-2 . s-1


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : the percentage immobility was determined in all test and control groups after 24 h and 48 h. An animal was considered to be immobile, if it was not able to swim within 15 sec after gentle agitation of the test vessel.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2

- Range finding study
- Test concentrations: 10; 100; 1000 mg/l, control, 2 repilcates, 48h, 2 daphnids per dose group (n=20).
- Results used to determine the conditions for the definitive study: no immobilization in the 10 and 100 mg/l dose group; 100 % Immobilization in
the 1000 mg/l dose group

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

48 h

Dose descriptor:

EC10

Effect conc.:

238 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: -

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

272 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 250-500

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

500 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: -

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

125 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: -

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

250 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Results with reference substance (positive control):

- Results with reference substance valid
- EC50: 1.75 (CI 1.65 - 1.85)
The EC50-value of the reference item is also within the recommended range of 0.6 - 2.1 mg/L according to OECD-Guideline 202.

Reported statistics and error estimates:

STATISTICAL METHODS EC100-values after 24 and 48 h were deduced directly from the
OF EVALUATION dose-response-relationships. There was no mathematical calculation.

EC-values and statistical analyses: EC10- and EC50-values after 48 h and the EC50-value for the reference item were calculated by sigmoidal dose-response regression. Calculation of the confidence intervals for EC50 were carried out using standard procedures. The concentration effect relationships are shown graphically. Since only immobilization rates of 0 and 100 % occurred after 24 h, the EC50-value for the test item after 24 h was determined by calculating the geometric mean of the highest concentration causing no immobility and the lowest concentration causing 100 % immobility. The highest concentration causing no effect and the lowest concentration causing 100 % immobility were used as confidence limits.
NOEC : The tested concentration at which the test item is observed to have no significant effect when compared to the control. Immobilization rates of <= 10 % are seen to be not significant.

LOEC :The tested concentration at which the test item is observed to have a significant effect when compared to the control.

Software: All data were computer generated and rounded for presentation from the full derived data. Consequently if calculated manually based on the given data minor variations may occur from these figures. Calculations were carried out using software:
- GraphPad Prism4, GRAPHPAD SOFTWARE, INC.
- Microsoft® Office Excel, MICROSOFT CORPORATION
See attached document

The test item was clearly dissolved at the concentration levels 62.5 to 500 mg/L and at the pH-control (1000 mg/L) throughout exposure. At the test item concentration 1000 mg/L a white substance film was observed on the surface of the clearly dissolved test solution after 24 and 48 hours.

The percentage immobility was determined in all replicates of the test and control groups after 24 h and 48 hours. The immobilization rates in % after 24 h and 48 h of exposure under static conditions are given in the followig table.

Percentage of Daphnids Incapable of Swimming after 24 and 48 h of Exposure (n = 20, divided into 4 replicates with 5 daphnids each)

Nominal Test Item Concentration	IMMOBILIZATION [%]
	24 h					48 h
	Replicates					Replicates
[mg/L]	1.	2.	3.	4.	MV	1.	2.	3.	4.	MV
1000	100	100	100	100	100	100	100	100	100	100
500	100	100	100	100	100	100	100	100	100	100
250	0	0	0	0	0	20	20	20	20	20
125	0	0	0	0	0	0	0	0	0	0
62.5	0	0	0	0	0	0	0	0	0	0
Control	0	0	0	0	0	0	0	0	0	0
pH-control* (1000 mg/L)	100	80	80	60	80	100	100	100	100	100

MV = Mean value

*) = The pH-value of the concentration level 1000 mg/l (pH 10.1) was outside the recommended range of pH 6 -9. Therefore, the pH was adjusted to pH 7.0 +/- 0.2 with 1 M HCL.

The concentration-effect-relationship after 24 and 448 hours of exposure are graphically illustrated.

The EC50 -values after 24 and 48 hours were calculated.

Validity criteria fulfilled:

yes

Remarks:

Control group: no Daphnia were immobilized , dissolved O2 conc. was > 3 mg/L, pH-value did not vary by ore than 1 unit in control, recoveries of test item were in the range of ± 20 % of the nominal values in all conc. levels at test start and test end.

Conclusions:

In this study Dimethylaminopropyl methacrylamide was found to be toxic to Daphnia magna after 48 h at concentrations of 250 mg/L (LOEC48 h) and higher. The EC50 (48 h) was calculated to be 272 mg/L (271 – 274 mg/L). The NOEC after 48 hours was 125 mg/L.

Executive summary:

The 48–hr-acute toxicity of Dimethylaminopropyl methacrylamide to Daphnia magna was studied under static conditions.  Daphnids were exposed to nominal concentration of 62.5; 125; 250; 500 and 1000 mg /L for 48 hr.  Immobilization effects were observed daily.  The 48– hour EC₅₀ was 272 mg /L.  The 48–hr NOEC based on immobilization adverse effects was 125 mg/L  

Based on the results of this study, Dimethylaminopropyl methacrylamide would  be classified as not toxic to Invertbrates in accordance with the classification system GHS. 

This study is classified as acceptable and satisfies the guideline requirements for an acute toxicity study with freshwater invertebrates.

 

Results Synopsis

Daphnia magna, static, 48 h: 

EC₅₀:  272 mg /L      95% C.I. : 250-500 mg./L

NOEC: 125.mg /L                      

Endpoint effected: mobility

Description of key information

Dimethylaminopropyl methacrylamide was found to be toxic to Daphnia magna after 48 h at concentrations of 250 mg/L (LOEC48 h)

and higher. The EC50 (48 h) was calculated to be 272 mg/L (271 – 274 mg/L). The NOEC after 48 hours was 125 mg/L.

(DR.U.NOACK-LABORATORIEN, 2009)

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

272 mg/L

Additional information

The 48–hr-acute toxicity of Dimethylaminopropyl methacrylamide to Daphnia magna was studied under static conditions.  Daphnids were exposed to nominal concentration of 62.5; 125; 250; 500 and 1000 mg /L for 48 hr.  Immobilization effects were observed daily.  The 48– hour EC₅₀was 272 mg /L. The 48–hr NOEC based on immobilization adverse effects was 125 mg/L. (DR.U.NOACK-LABORATORIEN, 2009)  

Based on the results of this study, Dimethylaminopropyl methacrylamide would  be classified as not toxic to Invertbrates in accordance with the classification system GHS.