Benzyldimethylamine

Long-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2011-01-18 to 2011-02-22

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.20 (Daphnia magna Reproduction Test)

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

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

Reagents and Solvents
Diethylether, Acetonitrile, Cyclododecane, potassium hydroxide pellets, Sodium sulphate

Standard Solutions used for Calibration
Internal standard solution:
20.2 mg Cyclododecane were dissolved in acetonitrile and made up with acetonitrile to the mark in a 20 mL volumetric flask to prepare a solution of 1010 mg/L. This solution was used as internal standard solution

Vehicle:

no

Details on test solutions:

Reconstituted water (so-called 'M4 medium' according to OECD 211) was used for both, the maintenance of the test animals and the preparation of stock and test solutions of the test item.

The hardness of the dilution water ranged from 14.2°dH to 15.8°dH (= 253.5 – 282.0 mg/L CaCO3) during the test.

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 (light intensity:
< 20 µE x m-2 x s-1). The culture water (so-called 'M4 medium') was partly renewed once a week. The Daphnia were exclusively fed 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:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Hardness:

14.2°dH to 15.8°dH (= 253.5 – 282.0 mg/L CaCO3)

Test temperature:

20 +/- 1 °C

pH:

between pH 8.8 and 8.9

Dissolved oxygen:

> 3 mg/L

Nominal and measured concentrations:

- nominal: 0.1, 0.316, 1, 3.16 and 10 mg/L
- measured: 0.075, 0.234, 0.789, 2.622 and 8.073 mg/L

Details on test conditions:

Test vessels : 150 mL glass beakers holding 1 neonate in 100 mL of test medium

Experimental design : 5 test concentrations plus 1 control

1 neonate per vessel, 10 replicates per concentration/control

Semi static system (renewal of the test media on Monday, Wednesday and Friday, respectively).

Method of initiation : neonates were placed in prepared media

Photoperiod : 16 h light: 8 h dark

Light intensity : not exceeding 20 µE x m-2 x s-1

Temperature of
incubation unit : 20.2 to 20.7 °C

Aeration : none

Test item
concentration/s : 0.1, 0.316, 1, 3.16 and 10 mg/L

Food source and : Desmodesmus subspicatus
feeding rate: day 0-7: 0.1 mg C / Daphnia / day
day 8-21: 0.2 mg C / Daphnia / day

Duration of exposure : 21 days

Reference substance (positive control):

no

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

0.789 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

reproduction

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

>= 8.073 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

mortality

Details on results:

Young female Daphnia, aged less than 24 hours at the start of the test, were exposed to a range of concentrations, nominally 0.1, 0.316, 1, 3.16 and 10 mg/L of N,N-Dimethylbenzylamin dissolved in water.
After a 21d-exposure period, the total number of living offspring produced per parent animal alive at the end of the test was assessed. The reproductive output of the Daphnia exposed to the test item was compared to that of the control in order to determine the Lowest Observed Effect Concentration (LOEC) and the No Observed Effect Concentration (NOEC) according to Williams Multiple Sequential t-test Procedure). Additionally, the survival of the parent Daphnia and the time to production of first brood was determined using Fisher`s Exact Binomial Test with Bonferroni Correction.

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.

Test vessels were not aerated during the test. A photoperiod of 8 hours darkness and 16 hours light was maintained, the light intensity not exceeding 20 µE x m^-2 x s^-1. Feeding of theDaphniawith living cells ofDesmodesmus subspicatuswas done daily. The ration was 0.1 – 0.2 mg C /Daphnia/ day which was regarded sufficient for achieving the required number of offspring in the controls.

Validity criteria fulfilled:

yes

Remarks:

The mortality rate in the controls did not exceed 20% by the end of the test. Living offspring produced per parent Daphnia surviving at the end of the test was = 60 in the controls.

Conclusions:

The long-term toxicity of benzyldimethylamine to aquatic invertebrates (Daphnia magna) was tested according to EU method C.20 and OECD Guideline 211.

Executive summary:

A study was performed to assess the effects of N,N-Dimethylbenzylamine on the reproductive output of Daphnia magnaSTRAUS under semi static conditions. The study was conducted in accordance with Council Regulation (EC) No 440/2008, Method C.20 Daphnia magna Reproduction Test (2008), which equals in all relevant parts to the OECD Test guideline 211 (Daphnia magna Reproduction Test; adopted: Oct. 03, 2008). Young female Daphnia, aged less than 24 hours at the start of the test, were exposed to a range of concentrations, nominally 0.1, 0.316, 1, 3.16 and 10 mg/L of N,N-Dimethylbenzylamine dissolved in water. After a 21d-exposure period, the total number of living offspring produced per parent animal alive at the end of the test was assessed. The reproductive output of the Daphnia exposed to the test item was compared to that of the control in order to determine the Lowest Observed Effect Concentration (LOEC) and the No Observed Effect Concentration (NOEC) according to Williams Multiple Sequential t-test Procedure). Additionally, the survival of the parent Daphnia and the time to production of first brood was determined using Fisher`s Exact Binomial Test with Bonferroni Correction.

  

Results [mg/L]

 

21d-NOEC_{(reproduction)}(t_a0.05)                 :   0.789

 

21d-LOEC_{(reproduction)}(t_a0.05)                  :   2.622

 

21d-NOEC_(mortality)(t_a0.05)                      :=8.073

 

21d-LOEC_(mortality)(t_a0.05)                      : > 8.073

 

1^stbrood on day                                      :   9

 

The results are expressed in terms of time-weighted mean measured concentrations. Effective concentrations ranged from 70.0% to 88.2% of the nominal values in the freshly prepared media and from 68.4% to 84.1% in the media after 48 hours, or 72 hours of exposure.

The hardness of the dilution water used ranged from 14.2°dH to 15.8°dH (= 253.5 – 282.0 mg/L CaCO₃)during the test.

Description of key information

The long-term toxicity of benzyldimethylamine on aquatic invertebrates was tested in a study according to EU Method C.20 and OECD Guideline 211 in Daphnia magna. Based on the results a NOEC (21d) of 0.789 mg/L was determined for effects on reproduction and a NOEC (21d) of > 8.073 mg/L for effects on mortality.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

NOEC

Effect concentration:

0.789 mg/L

Additional information

A study was performed to assess the effects of N,N-Dimethylbenzylamine on the reproductive output ofDaphnia magnaSTRAUS under semi static conditions. The study was conducted in accordance with Council Regulation (EC) No 440/2008, Method C.20 Daphnia magna Reproduction Test (2008), which equals in all relevant parts to the OECD Test guideline 211 (Daphnia magna Reproduction Test; adopted: Oct. 03, 2008). Young female Daphnia, aged less than 24 hours at the start of the test, were exposed to a range of concentrations, nominally 0.1, 0.316, 1, 3.16 and 10 mg/L of N,N-Dimethylbenzylamine dissolved in water. After a 21d-exposure period, the total number of living offspring produced per parent animal alive at the end of the test was assessed. The reproductive output of the Daphnia exposed to the test item was compared to that of the control in order to determine the Lowest Observed Effect Concentration (LOEC) and the No Observed Effect Concentration (NOEC) according to Williams Multiple Sequential t-test Procedure). Additionally, the survival of the parent Daphnia and the time to production of first brood was determined using Fisher`s Exact Binomial Test with Bonferroni Correction.

  

Results [mg/L]

 

21d-NOEC_{(reproduction)}(t_a0.05)                 :   0.789

 

21d-LOEC_{(reproduction)}(t_a0.05)                  :   2.622

 

21d-NOEC_(mortality)(t_a0.05)                      :=8.073

 

21d-LOEC_(mortality)(t_a0.05)                      : > 8.073

 

1^stbrood on day                                      :   9

 

The results are expressed in terms of time-weighted mean measured concentrations. Effective concentrations ranged from 70.0% to 88.2% of the nominal values in the freshly prepared media and from 68.4% to 84.1% in the media after 48 hours, or 72 hours of exposure.

The hardness of the dilution water used ranged from 14.2°dH to 15.8°dH (= 253.5 – 282.0 mg/L CaCO₃)during the test.