N,N-dimethylbutylamine

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

DIN 38412-8 (Pseudomonas Zellvermehrungshemmtest)

GLP compliance:

no

Remarks:

non-animal study which was already available, pre-REACH

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: A stock solution of 1250 mg/L was prepared in deionised water.

Test organisms (species):

Pseudomonas putida

Details on inoculum:

- Laboratory culture: The used test strain of Pseudomonas putida DSM 50026 is purchased on regular times from DSM (Deutsche Sammlung von Mikroorganismen in Göttingen (German collection of microorganisms in Göttingen)) and cultured further on slant agar in the Laboratory of Ecotoxicology of BASF AG in Ludwigshafen, Germany.
- Method of cultivation: The stock cultures are kept in slant agar culturing tubes of 50 mL. The inoculation density is one smear from an inoculating loop. The culture is transferred weekly.
- Pretreatment: The pre-cultures are kept in Erlenmeyer flasks with a nominal volume of 250 mL. The vessels are filled with 100 mL pre-culture medium and inoculated with a smear from an inoculation loop with 10 TE/F bacteria suspension at 21 ± 1 °C and incubated for 7h while shaking.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

16 h

Test temperature:

20 ± 1 °C

pH:

Uninoculated t = 0 h: 6.92 - 10.05
Uninoculated t = 17 h: 6.92 - 8.32
Inoculated t =17 h: 6.71 - 7.78

Nominal and measured concentrations:

Nominal concentrations: control, 3.9, 7.8, 15.6, 31.3, 62.5, 125, 250, 500, 1000 mg/L
HCl-neutralised stock solution was used to test the nominal concentrations 125 and 1000 mg/L in parallel (neutralised to pH 6.92 - 7.78).

Details on test conditions:

TEST SYSTEM
- Test vessel: Penicillin vessels with flattened bottom, nominal volume 50 mL and air permeable silicon-foam caps
- Fill volume: 10 mL
- No. of vessels per concentration (replicates): 4 inoculated replicates
- No. of vessels per control (replicates): 1 uninoculated replicate
- Biomass loading rate: 5 TE/F (optical density)

TEST MEDIUM / WATER PARAMETERS
- Test medium: AK-Medium according to DIN 38412, Part 8

OTHER TEST CONDITIONS
- Photoperiod: continuous light
- Adjustment of pH: no
- Light intensity: 120 µEinstein/m²s

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
Optical density: With a Zeiss PM 2 DL, 1 cm cuvette at a wavelength of 436 nm. Measurements are made at t = 16 h in all inoculated replicates, whereby the uninoculated replicate of each concentration is used as background measurement.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2
- Test concentrations: control, 3.9, 7.8, 15.6, 31.3, 62.5, 125, 250, 500, 1000 mg/L
- Application method: liquid-dosing from the stock solution

Duration:

16 h

Dose descriptor:

EC10

Effect conc.:

292 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth inhibition

Key result

Duration:

16 h

Dose descriptor:

EC50

Effect conc.:

480 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth inhibition

Duration:

16 h

Dose descriptor:

other: EC90

Effect conc.:

930 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth inhibition

Remark

The neutralised sample (1000 mg/L, pH 6.94) caused no toxic effect compared to the not neutralised sample (1000 mg/L, pH 10.05).

Optical densities of the bacteria cultures at t = 16 h

Concentration (mg/L)	E 436 nm Inoculated	E 436 nm Uninoculated	Difference	(% of controls)
Control	0.908	---
3.9	0.949	0.001	0.948	104.46
7.8	0.963	-0.001	0.964	106.14
15.6	0.949	0.000	0.949	104.57
31.3	0.962	-0.001	0.963	106.11
62.5	0.998	-0.002	1.000	110.16
125	0.996	0.003	0.993	109.39
250	0.901	0.003	0.898	98.93
500	0.412	-0.003	0.415	45.69
1000	0.036	-0.002	0.038	4.19

Optical densities of the bacteria cultures exposed to test solutions prepared with a neutralized stock solution at t = 16 h

Concentration (mg/L)	E 436 nm Inoculated	E 436 nm Uninoculated	Difference	(% of controls)
Control	0.913	---
125 neutr.	0.957	0.000	0.957	104.82
1000 neutr.	0.937	0.001	0.936	102.49

 

pH values

Concentration (mg/L)	Uninoculated 0 h	Uninoculated 17 h	Inoculated 17 h
Control	6.92	6.94	7.42
100	10.05	8.32	6.94
500	9.69	7.99	6.71
250	9.41	7.74	7.34
125	8.25	7.46	7.54
62.5	7.36	7.20	7.50
31.3	7.13	7.08	7.49
15.6	7.01	7.01	7.48
7.8	6.96	6.97	7.66
3.9	6.95	6.95	7.77
1000 neutr.	6.94	6.92	7.37
125 neutr.	6.92	6.92	7.78

Conclusions:

The 16-hour EC50, based on biomass, was 480 mg/L with the free base.

Executive summary:

The inhibitory effect of N,N-Dimethylbutylamine on cell proliferation of Pseudomonas putida was determined according to an acknowledged national test method, DIN 38412 Part 8. The EC50 (16 h) based on biomass was 480 mg/L with the free base (BASF AG, 1991).

Reference 2

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

ISO 8192 (Water quality - Test for inhibition of oxygen consumption by activated sludge for carbonaceous and ammonium oxidation)

Version / remarks:

(draft, 1984)

GLP compliance:

no

Remarks:

non-animal study which was already available, pre-REACH

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Stock solution: 2000 mg test substance in 1000 mL; DOC = 1256 mg/L

Test organisms (species):

activated sludge, industrial

Details on inoculum:

- Laboratory culture: activated sludge from a wastewater plant treating industrial wastewater (BASF AG)
- Concentration of dry substance: 1 g/L

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

30 min

Test temperature:

ambient (20 ± 2 °C)

Nominal and measured concentrations:

nominal: 400 and 800 mg/L

Details on test conditions:

A mean reference value of 41 mg/L*h was used instead of running a blank.

Reference substance (positive control):

no

Duration:

30 min

Dose descriptor:

other: EC20

Effect conc.:

> 800 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Concentration (mg/L)	Conc DOC-Test substance (mg/L)	Respiration rate (mg O2/L*h)	Change of respiration rate (%)
400	251	45	11
800	502	43	5

 

- blank (mean value): 41 mg O2/L*h

- Increase in respiration rate at 400 and 800 mg/L

- The inhibition of the degradation activity of activated sludge is not anticipated when introduced in appropriate low concentrations

Conclusions:

Respiration of microorganisms contained in activated industrial sludge was not affected at concentrations up to 800 mg/L.

Executive summary:

The inhibitory effect of N,N-Dimethylbutylamine on cell respiration of activated industrial sludge was determined according to an acknowledged national test method, ISO 8192 (Draft, 1984). At concentrations of 400 and 800 mg/L the respiration rate (45 and 43 mg O2/L*h) was slightly increased compared to the blank (mean: 41 mg O2/L*h). Thus, respiration of microorganisms contained in activated industrial sludge was not affected at concentrations up to 800 mg/L (BASF AG, 1986).

Description of key information

DIN 38412-8 (Pseudomonas Zellvermehrungshemmtest)

The EC50 (16 hrs), based on biomass, was 480 mg/L with the free base (BASF AG, 1991).

ISO 8192 (Water quality - Test for inhibition of oxygen consumption by activated sludge for carbonaceous and ammonium oxidation)

Respiration of microorganisms contained in activated industrial sludge was not affected at concentrations up to 800 mg/L (BASF AG, 1986).

Key value for chemical safety assessment

EC50 for microorganisms:

480 mg/L

Additional information

DIN 38412-8 (Pseudomonas Zellvermehrungshemmtest)

In the key study, the inhibitory effect of N,N-Dimethylbutylamine on cell proliferation of Pseudomonas putida was determined according to an acknowledged national test method, DIN 38412 Part 8. The EC50 (16 hrs), based on biomass, was 480 mg/L with the free base (BASF AG, 1991).

ISO 8192 (Water quality - Test for inhibition of oxygen consumption by activated sludge for carbonaceous and ammonium oxidation)

In the supporting study, the inhibitory effect of N,N-Dimethylbutylamine on cell respiration of activated industrial sludge was determined according to an acknowledged national test method, ISO 8192 (Draft, 1984). At concentrations of 400 and 800 mg/L the respiration rate (45 and 43 mg O2/L*h) was slightly increased compared to the blank (mean: 41 mg O2/L*h). Thus, respiration of microorganisms contained in activated industrial sludge was not affected at concentrations up to 800 mg/L (BASF AG, 1986).