N,N,N-tri-C8-C10-alkyl-N-methyl-1-aminium sulfate

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 2020-04-02 to 2020-04-24

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test (Carbon and Ammonium Oxidation))

Version / remarks:

2010

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- The test item concentrations were weighed out on bent object slides and were transferred in the test vessels. All concentrations were stirred overnight in 200 mL ultrapure water.

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

- Name and location of sewage treatment plant where inoculum was collected: Municipal sewage treatment plant of 31137 Hildesheim, Germany
- Pretreatment: The sludge was washed twice and adjusted with chlorine free tap water if necessary. The sludge was used within 24 h after sampling.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Test temperature:

Nominal: 18 - 22 °C, measured: 21.2 °C without ATU, 20.4 °C with ATU

pH:

7.5 ± 0.5

Dissolved oxygen:

Aeration was permanent, to keep the dissolved oxygen concentration above 60 - 70 % saturation and to maintain the sludge flakes in suspension.
6.62 - 8.81 mg/L

Nominal and measured concentrations:

nominal 1 - 3.16 - 10 - 31.6 - 100 mg a.i./L

Details on test conditions:

TEST SYSTEM
- Test vessel: 1000 mL laboratory bottles with screw cap, ISO 4796
- Aeration: Permanent, to keep the dissolved oxygen concentration above 60 - 70 % saturation and to maintain the sludge flakes in suspension.
- No. of vessels per concentration (replicates): 5
- No. of vessels per control (replicates): 3 at the beginning of the test, 3 at the end of the test
- No. of vessels per positive control (replicates): 3
- Sludge concentration (weight of dry solids per volume):
Dry solids concentration [g/L] of sludge for test without ATU was 3.09
Dry solid concentration [g/L] in test solution for test without ATU was 1.55
Dry solids concentration [g/L] of sludge for test with ATU was 3.07
Dry solid concentration [g/L] in test solution for test with ATU was1.54

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: synthetic waste water

OTHER TEST CONDITIONS
- Adjustment of pH: not required (within prescribed range)

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
oxygen uptake rate, 3 h

TEST CONCENTRATIONS
- Spacing factor for test concentrations: sqrt(10)
- Range finding study:
- Test concentrations: 1, 10, 100, 1000
- Results used to determine the conditions for the definitive study: -1% inhibition at 1 mg a.i./L, 16% inhibition at 10 mg a.i./L, 91% inhibition at 100 mg a.i./L, 99% inhibition at 1000 mg a.i./L

Reference substance (positive control):

yes

Remarks:

Copper (II) sulphate pentahydrate

Duration:

3 h

Dose descriptor:

NOEC

Effect conc.:

3.16 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

inhibition of total respiration

Duration:

3 h

Dose descriptor:

EC10

Effect conc.:

6.34 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

inhibition of total respiration

Remarks on result:

other: 95% c.i. 5.43 – 7.38 mg/L

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

26.1 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

inhibition of total respiration

Remarks on result:

other: 95% c.i. 24.2 – 28.3 mg/L

Details on results:

- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values:
- Effect concentrations exceeding solubility of substance in test medium:
- Adsorption (e.g. of test material to the walls of the test container):
- Blank controls oxygen uptake rate:
- Coefficient of variation of oxygen uptake rate in control replicates:

Results with reference substance (positive control):

- Results with reference substance valid? Ja
- Relevant effect levels: EC50 = 106 mg/L, 95% Confidence Interval = 103 - 109 mg/L
- valid range: 53 - 155 mg/L

Oxygen Uptake Rates and Inhibition of the Respiration

 

Test item concentration [mg a.i./L]	Replicate	Oxygen Uptake Rate [mg O2/L·h]	Inhibition [%]	Mean inhibition [%]
Control	1 2 3 4 5 6	31.6 31.6 30.4 28.8 29.6 30.4	---	---
10	1 2 3 4 5	30.4 30.4 30.0 30.4 29.6	0 0 1 0 3
32	1 2 3 4 5	26.4 26.4 25.2 26.0 26.0	13 13 17 14 14	14
100	1 2 3 4 5	18.0 18.4 18.8 18.8 18.0	41 39 38 38 41	39

 

Oxygen Uptake Rates and Specific Respiration Rates of theTotal Respirationof the Control

	Repl.	Oxygen Concentration*	Oxygen Uptake Rate RT	Specific Respiration Rate Rs
		[mg O2/L]	[mg O2/(L×h)]	[mg O2/g×h]
Control	1	7.04	37.7	24.4
	2	7.07	37.4	24.2
	3	6.66	36.0	23.3
	4	7.56	34.3	22.2
	5	5.80	32.9	21.3
	6	7.53	32.5	21.0
	Mean value		35.1	22.7
	Standard deviation		2.1
	CV [%]		5.8

*) determined at start of the measurement

Repl. = Replicate ; CV = Coefficient of variation

Oxygen Uptake Rates and Inhibition of the Total Respiration of the Test Item Concentrations

 

Test Item Concentration	Rep	Oxygen Concentration*	Oxygen Uptake Rate RT	Inhibition	Mean Inhibition
[mg/L]		[mg O2/L]	[mg O2/(L×h)]	[%]	[%]
1	1	7.30	34.8	1	-1
	2	7.34	36.6	-4
	3	7.00	36.0	-3
	4	7.36	34.6	1
	5	6.58	34.8	1
3.16	1	5.92	34.7	1	1
	2	7.00	37.4	-7
	3	6.83	33.9	3
	4	6.68	34.7	1
	5	5.68	32.6	7
10	1	7.31	27.6	21	20
	2	7.72	29.9	15
	3	6.64	28.1	20
	4	7.44	28.1	20
	5	6.70	26.9	23
31.6	1	8.25	16.3	54	57
	2	8.12	15.1	57
	3	8.18	14.7	58
	4	7.80	16.0	54
	5	7.59	14.0	60
100	1	8.61	4.4	87	87
	2	8.95	4.5	87
	3	8.39	4.8	86
	4	8.38	4.4	87
	5	8.29	3.4	90

*) determined at start of the measurement

Repl. = Replicate

Oxygen Uptake Rates of the Heterotrophic Respiration of the Control Replicates with ATU

	Rep	Oxygen Concentration*	Oxygen Uptake Rate RH
		[mg O2/L]	[mg O2/(L×h)]
Control	1	8.64	16.2
	2	8.20	14.1
	3	8.29	15.5
	4	8.57	13.5
	5	8.38	12.1
	6	8.26	12.2
	Mean value		13.9
	Standard deviation		1.54
	CV [%]		11.1

*) determined at start of the measurement

CV = Coefficient of variation

Oxygen Uptake Rates and Inhibition of theHeterotrophic Respiration

 

Test Item Concentration [mg/L]	Rep	Oxygen Concentration* [mg O2/L]	Oxygen Uptake Rate RH [mg O2/L×h]	Inhibition [%]	Mean Inhibition [%]
1 + ATU	1	8.67	15.7	-13	-13
	2	8.48	16.9	-22
	3	8.27	16.7	-20
	4	8.31	16.1	-16
	5	7.68	13.4	4
3.16 + ATU	1	8.49	15.6	-12	-10
	2	8.12	14.9	-7
	3	7.81	15.7	-13
	4	9.15	15.6	-12
	5	7.84	15.0	-8
10 + ATU	1	8.87	12.5	10	11
	2	8.57	12.4	11
	3	8.36	12.3	12
	4	8.51	12.4	11
	5	8.23	12.2	12
31.6 + ATU	1	8.99	5.4	61	60
	2	8.71	5.7	59
	3	8.11	5.9	58
	4	8.65	6.0	57
	5	8.60	4.8	65
100+ ATU	1	9.32	0.8	94	94
	2	9.20	0.7	95
	3	8.89	1.1	92
	4	8.87	0.6	96
	5	8.80	0.7	95

*) determined at start of the measurement

CalculatedOxygen Uptake Rates of theNitrificationof the Control

	Rep	Oxygen Uptake Rate RN
		[mg O2/(L×h)]
Control	1	21.5
	2	23.3
	3	20.5
	4	20.8
	5	20.8
	6	20.3
Mean value		21.2
Standard deviation		1.0
CV [%]		4.8

CV = Coefficient of variation

             Oxygen Uptake Rates and Inhibition of theNitrification

 

Test Item Concentration [mg/L]	Rep	Oxygen Uptake Rate RN [mg O2/L×h]	Inhibition [%]	Mean Inhibition [%]
1	1	19.0	10	8
	2	20.8	2
	3	20.2	5
	4	18.8	11
	5	19.0	10
3.16	1	19.3	9	9
	2	22.0	-4
	3	18.5	13
	4	19.3	9
	5	17.2	19
10	1	15.2	28	26
	2	17.5	17
	3	15.7	26
	4	15.7	26
	5	14.5	31
31.6	1	10.7	49	54
	2	9.5	55
	3	9.1	57
	4	10.4	51
	5	8.4	60
100	1	3.6	83	83
	2	3.7	82
	3	4.0	81
	4	3.6	83
	5	2.6	88

 

Validity criteria fulfilled:

yes

Conclusions:

The 3 h NOEC of Quarternary ammonium compounds, tri-C8-C10-alkylmethyl, Me sulfates is 3.16 mg a.i./L. The 3 h EC10 is 6.34 mg a.i./L, and the EC50 is 26.1 mg a.i./L.

Executive summary:

In a 3 hour toxicity study conducted according to OECD Guideline 209 (2010), the cultures of activated sludge of a predominantly domestic sewage treatment plant were exposed to Quarternary ammonium compounds, tri-C8-C10-alkylmethyl, Me sulfates at nominal concentrations of 0 (control), 1, 3.16, 10, 31.6, and 100 mg a.i./L mg/L under static conditions.

The batch of activated sludge was checked for sensitivity by testing the reference substance Copper (II) sulphate pentahydrate.

The respiration rates of the control, reference and test item replicates were measured after a contact time of three hours, and the inhibitory effects of the test and reference item were determined in comparison to the controI respiration rates. The mean inhibition of respiration for the test item replicates ranged from -1% to 87%

The 3 h NOEC of Quarternary ammonium compounds, tri-C8-C10-alkylmethyl, Me sulfates is 3.16 mg a.i./L. The 3 h EC10 is 6.34 mg a.i./L, and the EC50 is 26.1 mg a.i./L.

 

Results Synopsis

Test Organism: activated sludge from a sewage treatment plant treating predominantly domestic sewage

Test Type: Static 

3 h NOEC: 3.16 mg/L

3 h EC10: 6.34 mg/L, 95% c.i. 5.43 - 7.38 mg/L

3 h EC50: 26.1 mg/L, 95% c.i. 24.2 – 28.3 mg/L

Endpoint effected: Inhibition of respiration

Description of key information

3 h EC10 = 6.34 mg a.i./L, EC50 = 26.1 mg a.i./L (OECD TG 209; RL1; GLP)

Key value for chemical safety assessment

EC50 for microorganisms:

26.1 mg/L

EC10 or NOEC for microorganisms:

6.34 mg/L

Additional information

In a 3 hour toxicity study conducted according to OECD Guideline 209 (2010), the cultures of activated sludge of a predominantly domestic sewage treatment plant were exposed toQuarternary ammonium compounds, tri-C8-C10-alkylmethyl, Me sulfatesat nominal concentrations of 0 (control), 1, 3.16, 10, 31.6, and 100 mg a.i./L mg/L under static conditions.

The batch of activated sludge was checked for sensitivity by testing the reference substance Copper (II) sulphate pentahydrate.

The respiration rates of the control, reference and test item replicates were measured after a contact time of three hours, and the inhibitory effects of the test and reference item were determined in comparison to the controI respiration rates. The mean inhibition of respiration for the test item replicates ranged from -1% to 87%

The 3 h NOEC of C12-18 alkyldimethyl ammonium chloride is 3.16 mg a.i./L. The 3 h EC10 is 6.34 mg a.i./L, and the EC50 is 26.1 mg a.i./L.