Benzyldimethylamine

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:

2010-05-17 till 2010-06-07

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

, 2008

Deviations:

no

Principles of method if other than guideline:

The purpose of this method was to determine that concentration which causes a 50 % immobilisation rate (= EC 50) or, if conducted as a limit test, to determine the acute toxic effects at a maximum test concentration of 100 mg/L or at the limit of water solubility, respectively.
A range-finding test preceded the main test. It provided information about the range of concentrations which were used in the main test.
In the main test, Daphnia were exposed to the test item added to dilution water at a range of concentrations for a period of 48 hours. Defined
concentrations of the test item led to a certain percentage proportion of immobilised Daphnia at the end of the 48 hour study period. Immobilisation rates were recorded at 24-hour intervals. Additionally any abnormal behaviour or appearance of the Daphnia was reported.

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

Sampling schedule:
Control : at 0 and 48 hours
Test concentrations : at 0 and 48 hours

Storage:
Routinely, the samples were analysed immediately. Only in exceptional cases, they were stored overnight deep frozen and protected from
light.

Vehicle:

no

Details on test solutions:

- direct weighing
- 266 µL of the test item were added to 2 litres of dilution water
- Dilution water: Reconstituted water (so-called 'M4 medium') was used for the maintenance of the test animals and the preparation of stock and test solutions of the test item.
- The pH was measured to be 9.3 and adjusted to pH 8.0.

Test organisms (species):

Daphnia magna

Details on test organisms:

- Name: Daphnia magna STRAUS, parthenogenetic females
- Source: Strain of Bundesgesundheitsamt Berlin
- Maintenance and Acclimatisation: A population of parthenogenetic females of synchronized age structure has been maintained for more than 15
years in the test facility under constant temperature conditions (20 +/- 1 °C) at a 16 : 8 hour light-dark photoperiod (illumination: < 1000 lux). The culture water (so-called 'M4 medium') was partly renewed once a week. The Daphnia were exclusively fed with unicellular green algae (Desmodesmus subspicatus) 'ad libitum'. Mortalities of parent Daphnia during the culture period were recorded daily in a semi-quantitative way. The neonates were separated from their parent Daphnia by filtration prior to the acute test.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

14.7 °dH (= 262.4 mg/L CaCO3).

Test temperature:

20.8 - 21.0

pH:

7.9 - 8.0

Dissolved oxygen:

95 - 101 %

Nominal and measured concentrations:

- nominal: control and 100 mg/L
- measured: <0.094 and 95.9 - 99.5 mg/L

Details on test conditions:

Exposure conditions
- Test vessels: BOD bottles with glass stoppers holding 10 neonates in 250-300 mL of test medium
- Experimental design : 5 test concentrations plus 1 control
10 neonates per vessel, 2 replicates per concentration/control
no feeding during the exposure period static system
closed bottle conditions
- Method of initiation : neonates were placed in prepared media
- Photoperiod : 16 h light : 8 h dark
- Temperature of incubation unit: 20 to 21 °C
- Aeration : none
- Test item concentration/s: 6.25, 12.5, 25, 50 and 100 mg/L
- Method of administration: stock solution
- Medium renewal: none
- Duration of exposure : 48 hours
- Criteria of effects: The criterion of adverse effects used in this study was the item-induced alteration of the normal mobility behaviour and the loss of locomotory actions of the neonates, observed at 24 and 48 hours.

Reference substance (positive control):

no

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: Test concentration was analytically confirmed.

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: Test concentration was analytically confirmed.

Details on results:

No toxic effects against daphnia were observed at a limit test concentration of 100 mg/L.
The results are expressed in terms of nominal concentrations (at 24 h and 48 h). Effective concentrations ranged from 97.6 – 99.5 % of nominal
values at 0 hours and from 94.9 – 95.9 % of nominal values at 48 hours, respectively.

During the test a temperature range of 18 - 22 °C was maintained in the test vessels, with a maximum temperature fluctuation of +/- 1°C in each individual test. The pH and oxygen values were measured at the beginning and end of the test. The main test was conducted as a static test with solutions unchanged throughout the duration of the test.

Table of immobilisation: 

	control	6.25 mg/l	12.5 mg/l	25 mg/l	50 mg/L	100 mg/l
0h	0	0	0	0	0	0
24h	0	0	0	0	0	0
48h	0	0	0	0	0	0

 

Table of chemical analysis (GC values in mg/L):

	control	6.25 mg/l	12.5 mg/l	25 mg/l	50 mg/L	100 mg/l
0h	<0.094	6.103	/	/		99.454
48h	<0.094	5.933	/	/	/	95.874

Validity criteria fulfilled:

yes

Remarks:

The immobilisation and other abnormalities in the controls did not exceed 10 % by the end of the test. The dissolved oxygen concentration remained above 3 mg/L throughout the exposure period.

Conclusions:

The acute toxicity of benzyldimethylamine to aquatic invertebrates (Daphnia magna) was tested according to EU method C.2 'Acute Toxicity for Daphnia' (2008). No toxic effects against Daphnia magna were observed during 48 hours exposure at a limit test concentration of 100 mg/L (Currenta, 2010).

Executive summary:

A study was performed to assess the acute toxicity of benzyldimethylamine to Daphnia magna STRAUS under static conditions in a closed bottle system. The study was conducted in accordance with the Council Regulation (EC) No 440/2008, Method C.2 ‘Acute toxicity for Daphnia’ (2008) which is equivalent to OECD Guideline for Testing of Chemicals No. 202 'Daphnia sp., Acute Immobilisation Test' (adopted April 13, 2004). The Daphnia were exposed to a range of concentrations, nominally 6.25, 12.5, 25, 50 and 100 mg/L of benzyldimethylamine dissolved in dilution water.Observations were made on the swimming ability and the immobilisation rate, respectively, after 24 and 48 hours of exposure. The following values were determined:

EC 50 (24,48 h) > 100 mg/L

The results are expressed in terms of nominal concentrations (at 24 h and 48 h). Effective concentrations ranged from 97.6 – 99.5% of nominal values at 0 hours, and from 94.9 – 95.9% of nominal values at 48 hours, respectively. The hardness of the dilution water used was 14.7°dH (= 262.4 mg/L CaCO3).

Description of key information

The acute toxicity of benzyldimethylamine to aquatic invertebrates (Daphnia magna) was tested according to EU method C.2 'Acute Toxicity for Daphnia' (2008). No toxic effects against Daphnia magna were observed during 48 hours exposure at a limit test concentration of 100 mg/L (Currenta, 2010).

Additional information

A study was performed to assess the acute toxicity of benzyldimethylamine to Daphnia magna STRAUS under static conditions in a closed bottle system. The study was conducted in accordance with the Council Regulation (EC) No 440/2008, Method C.2 ‘Acute toxicity for Daphnia’ (2008) which is equivalent to OECD Guideline for Testing of Chemicals No. 202 'Daphnia sp., Acute Immobilisation Test' (adopted April 13, 2004). The Daphnia were exposed to a range of concentrations, nominally 6.25, 12.5, 25, 50 and 100 mg/L of benzyldimethylamine dissolved in dilution water.Observations were made on the swimming ability and the immobilisation rate, respectively, after 24 and 48 hours of exposure. The following values were determined:

EC 50 (24,48 h) > 100 mg/L

The results are expressed in terms of nominal concentrations (at 24 h and 48 h). Effective concentrations ranged from 97.6 – 99.5% of nominal values at 0 hours, and from 94.9 – 95.9% of nominal values at 48 hours, respectively. The hardness of the dilution water used was 14.7°dH (= 262.4 mg/L CaCO3).