Methanaminium, N,N,N-trimethyl-, 2,2-dimethylpropanoate (1:1)

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

Study period:

June 2017 - December 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Qualifier:

according to guideline

Guideline:

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

Deviations:

not specified

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Lot number: 13AP016
Expiration date: 2018.5.1
Purity: >99%
Appearance: White Solid

Analytical monitoring:

not specified

Vehicle:

not specified

Test organisms (species):

activated sludge, domestic

Details on inoculum:

Activated sludge microorganisms were obtained from a Chengdong waste water treatment plant receiving predominantly domestic sewage.
On arrival at the laboratory, a small amount of the fresh sludge was weighed, oven-dried, and reweighed.
A calculation was made from these results to determine the amount of wet sludge that must be suspended in deionized water in order to obtain an activated sludge with a mixed-liquor suspended solids (MLSS) level of approximately 3 g/L.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Hardness:

NA

Test temperature:

20±2 degrees celcius

pH:

7.02 - 7.85

Dissolved oxygen:

The mixture was sealed and shaken to keep aerobic condition.
After 3h, a standard BOD measuring bottle was filled from the contents of the first beaker and the respiration rate was measured over a period of 10 min, or until the dissolved oxygen level reached 2.00 mg/L.

Salinity:

NA

Conductivity:

NA

Details on test conditions:

Sludge microorganisms were exposed to three concentrations of the test substance at nominal concentration of 10, 100 and 1000 mg/L in range-finding test. The respiration rate, expressed as oxygen consumption by the microbes in mg 0 2 per liter per hour, was measured under defined conditions following the 30min exposure period. Inhibition values were calculated by comparing test respiration rates to negative control rates.

Reference substance (positive control):

yes

Remarks:

3,5-dichlorophenol

Key result

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth inhibition

Details on results:

The result indicated that under valid test conditions, there was no obvious oxygen uptake of abiotic blank of test substance for dissolved oxygen was 8.47 and 8.47 mg 0 2/L at the beginning and end of test.

Results with reference substance (positive control):

The 3h-EC50 value of 3,5-dichlorophenol was 14.0 mg/L, and 95% confidence limit ranging from 11.7mg/L to 16.7mg/L, which was in the range 2 mg/L to 25 mg/L.
The oxygen uptake rates of negative controls were 94.1 and 87.3 mg 0 2/(L·h), which were 62.7 and 58.2 mg 0 2/(g·h) after considering the concentration of sludge of 1.5 g/L, fulfilled the validity criterion of greater than 20 mg 0 2/(g·h). Additionally, the coefficient of variation of the two negative control respiration rates was 4.50%, which was within 30% of each other. The validity criteria were fulfilled

Validity criteria fulfilled:

yes

Conclusions:

In an OECD 209 "Activated Sludge, Respiration Inhibition Test" , the 3h-EC50 value of the test substance (Methanaminium, N,N,N-trimethyl-, salt with 2,2-dimethylpropanoic acid (1: 1)) was greater than 1000 mg/L.

The result of range-finding test showed that the 3h-EC50 of the test substance was great than 1000 mg/L, there was no need to launch the definitive test.

Executive summary:

In an OECD209"Activated Sludge, Respiration Inhibition Test" , sludge microorganisms were exposed to three concentrations of the test substance at nominal concentration of 10, 100 and 1000 mg/L in range-finding test.

The respiration rate, expressed as oxygen consumption by the microbes in mg 0 2 per liter per hour, was measured under defined conditions following the 30min exposure period. Inhibition values were calculated by comparing test respiration rates to negative control rates.

The result indicated that under valid test conditions, there was no obvious oxygen uptake of abiotic blank of test substance for dissolved oxygen was 8.47 and 8.47 mg 0 2/L at the beginning and end of test. The 3h-EC50 value of 3,5-dichlorophenol was 14.0 mg/L, and 95% confidence limit ranging from 11.7mg/L to 16.7mg/L, which was in the range 2 mg/L to 25 mg/L. The oxygen uptake rates of negative controls were 94.1 and 87.3 mg 0 2/(L·h), which were 62.7 and 58.2 mg 0 2/(g·h) after considering the concentration of sludge of 1.5 g/L, fulfilled the validity criterion of greater than 20 mg 0 2/(g·h). Additionally, the coefficient of variation of the two negative control respiration rates was 4.50%, which was within 30% of each other. The validity criteria were fulfilled.

Under the above valid test conditions, the 3h-EC50 value of the test substance (Methanaminium, N,N,N-trimethyl-, salt with 2,2-dimethylpropanoic acid (1: 1)) was greater than 1000 mg/L.

Reference 2

Endpoint:

activated sludge respiration inhibition testing

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because the substance is found to be readily biodegradable and the applied test concentrations are in the range of concentrations that can be expected in the influent of a sewage treatment plant

Description of key information

In an OECD 209 "Activated Sludge, Respiration Inhibition Test" , the 3h-EC50 value of the test substance (Methanaminium, N,N,N-trimethyl-, salt with 2,2-dimethylpropanoic acid (1: 1)) was greater than 1000 mg/L.

The result of range-finding test  showed that the 3h-EC50 of the test substance was great than 1000 mg/L, there was no need to launch the definitive test.

Key value for chemical safety assessment

EC50 for microorganisms:

1 000 mg/L