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

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

Samples were collected at the beginning and end of the exposure duration for the definitive tests. Samples were analyzed at treatments surrounding the test endpoint (LC50). Statistical endpoints were based on the measured concentrations

Vehicle:

no

Details on test solutions:

Moderately Hard Reconstituted Water (MHRW) was used for all culturing and testing for this study. Blacksburg, Virginia municipal tapwater was dechlorinated using activated carbon, deionized using mixed bed deionization tanks to a resistivity of > 1 megohm/cm, and polished with a Millipore, Milli Q UV Plus and 0.2 micron filter to a final resistivity of > 18 megohm/cm. This is referred to as BMI DI water and was used to prepare Moderately Hard Reconstituted Water using EPA guidelines (e.g., EPA/600/4-90/027F).

Test organisms (species):

Pimephales promelas

Details on test organisms:

The fathead minnow (P. promelas) was used in this study. The fish acute toxicity test used fathead minnows that were 2.0 + 1.0 cm in length.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Test temperature:

The test temperature was 23 + 2°C.

pH:

8.05-8.13

Conductivity:

301-312

Nominal and measured concentrations:

Nominal (mg/ml) Measured (mg/l)
250 236.9
500 522.6
1000 1025.2

Details on test conditions:

1. Test type: Static non-renewal
2. Renewal of test solutions: Not Renewed
3. Temperature (°C): 23 + 2°C
4. Light quality: Ambient laboratory illumination
5. Light intensity: 50-100 foot candles (ambient laboratory levels)
6. Photoperiod: 16 hr light/ 8 hr dark
7. Size of test vessel: 1000 ml
8. Volume of test solution: >/= 500 ml
9. Length of test organism: 2.0 + 1.0 cm
10. Number of organisms per test vessel: 10
11. Number of replicates per concentration: 2
12. Total number of organisms per conc.: 20
13. Feeding regime: Not fed
14. Aeration: None
15. Dilution Water: MHRW
16. Test duration: 96 hours
17. Test concentrations: Five product concentrations and a control
18. Dilution series: 0.1 dilution series for range-finding test
0.5 dilution series for definitive test
19. Endpoint: Mortality (LC50)
20. Sampling and sample: Fresh solutions prepared for range finding and definitive testing
21. Test acceptability criterion: < 10% organism mortality in controls

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

581.4 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

The range-finding test was initiated on September 21, 2015. Results of this test indicated that the expected endpoint for the definitive test would be between 100 and 1000 mg/L nominal concentration.
The test resulted in a valid endpoint. Physicochemical parameters were within the established guidelines for the test.
A 96h static range-finding test was performed to estimate the range of concentrations for use in the definitive test. The range-finding test was conducted using half the replication and half the number of organisms per chamber of the definitive test. P. promelas 2.0 + 1 cm in length were exposed to a logarithmic series of product concentrations in MHRW. The highest concentration was 1000 mg/L (nominal). Test water physicochemical parameters were recorded during the 96 hour study. Live fish were counted daily and recorded. The fish were considered dead if there was no visible movement and if there was no reaction by the fish to the touching of their caudal peduncle.
Definitive Test
The methods used for the definitive testing conformed to Section 203 of the OECD guidelines. Table 1 contains a summary of the test conditions that were used in this study.

Definitive testing was conducted based on the results of range-finding test. Two replicates of five compound treatments and a control were prepared. Twenty, randomly selected, fish were exposed to each treatment and the control for 96 hours. The test was performed in 1000 ml polyethylene beakers containing 900 ml of test solution. These volumes were selected based upon loading guidelines (1 g fish/liter). P. promelas were not fed for the test duration. The test temperature was 23 + 2°C.

Conductivity was measured in the treatments and the control at the beginning and end of the study. Temperature, dissolved oxygen, pH, and number of live organisms were recorded daily. Alkalinity and hardness was determined for the dilution water at the beginning of the study.

Validity criteria fulfilled:

yes

Conclusions:

Fish Acute Toxicity of Methanaminium, N,N,N-trimethyl-, salt with 2,2-dimethylpropanoic acid (1:1) was determined using Fish Acute Toxicity Test (OECD 203) with Pimephales promelas. The probit method resulted in an LC50 of 581.4 mg/L with 95% confidence intervals of 473.2 and 709.1.

Executive summary:

Fish Acute Toxicity of  Methanaminium, N,N,N-trimethyl-, salt with 2,2-dimethylpropanoic acid (1:1) was determined using Fish Acute Toxicity Test (OECD 203) with Pimephales promelas. The probit method resulted in an LC50 of 581.4 mg/L with 95% confidence intervals of 473.2 and 709.1.  

Reference 2

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

June - December 2017

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

not specified

Principles of method if other than guideline:

testing was was conducted according to: "The guidelines for the testing of chemicals" (HJ/T 153-2004), "The Guidelines for the Testing of Chemicals, Effects on Biotoc Systems" (the 2nd edition) (2013); and with reference to Procedure 203 of the "Guidelines for Testing of Chemicals" of the OECD: "Fish, Acute Toxicity Test" (1992).

GLP compliance:

yes

Specific details on test material used for the study:

Lot: 13AP016
Expiration: 2018-05-01
Purity: >99%
Appearance: White Solid

Analytical monitoring:

yes

Details on sampling:

Samples were taken (at least in duplicate) from each concentration during the limit test at 0, 24, 48, 72 and 96 h. On each occasion, one sample was analysed after certain pre-treatments; the remaining samples were retained in case further analysis would be required. (when necessary)

Vehicle:

no

Details on test solutions:

Good quality tap water which had been dechlorinated for at least 24 hours was used. The total hardness of the test water was 121.6 mg (CaC03)/L and pH was 8.08 at room temperature.

In the range-finding test, test solutions of the test substance were prepared by directly dissolving appropriate amount of test substance in dilution medium and then facilitating its dispersion by stirring for 30 min. The test substance was dissolved in water completely, and the test solution was clear and transparent.
In the limit test, test solutions of the test substance were prepared by directly dissolving 1.0005g test substance into 1OL dilution medium and then facilitating its dispersion by stirring for 30 min. A volume of 9L test solution obtained was then evenly distributed to 3 test tanks.

Test organisms (species):

other: Gobiocypris rarus

Details on test organisms:

The Rare minnow, Gobiocypris rarus, was used in the test on the basis of such important practical criteria as, for example, their ready availability throughout the year, ease of maintenance, convenience for testing and any relevant economic, biological or ecological factors. The test species of Rare minnow, Gobiocypris rarus (Batch No.: F20170615G), were bred by our own lab. A population of a single stock was used in the test.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

The total hardness was in the range of 142 mg (CaC03)/L to 147 mg (CaC03)/L

Test temperature:

The temperature of the test mediums was maintained in the range of 23.0 °C to 23.2°C

pH:

The pH values of the control mediums and test mediums were between 7.64 and 7.77

Dissolved oxygen:

The Dissolved Oxygen (DO) values varied from 76 % to 95 % of the air saturation at the test temperature

Reference substance (positive control):

yes

Remarks:

Potassium dichromate, K2Cr20 7, CAS: 7778-50-9; Purity: 99.8%

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC0

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

During the test period, all fish in the control groups and treated groups were alive and appeared normal. The results showed that under valid static test conditions, the 96 h-LC50 of test substance to fish (Rare minnow, Gobiocypris rarus) was greater than the nominal concentration of 100mg/L (mean measured concentration 86.7 mg/L), while the maximum concentration causing no mortality (96 h-LC0) was equal to the nominal concentration of 100 mg/L (mean measured concentration 86.7 mg/L).

Results with reference substance (positive control):

With the conditions maintained as before, K2Cr20 7 was used as the test substance and the resulting 24 h-LC50 was 323 mg/L.

The test with the reference substance is performed at least once each batch of fish as a means of assuring that the laboratory test conditions are adequate and have not changed significantly. The resulting 24 h-LC50 should be in the range of 200 mg/L to 400 mg/L to ensure study validity.

Validity criteria fulfilled:

yes

Conclusions:

96 h-LCso > 100 mg/L (mean measured concentration 86 .7 mg/L);
96 h-LCo = 100 mg/L (mean measured concentration 86. 7 mg/L).

Executive summary:

The acute toxicity of the test substance of Methanaminium N,N,N-trimethyl-, salt with 2,2-dimethylpropanoic acid (1 :1) to Rare minnow (Gobiocypris rarus) was conducted according to: "The guidelines for the testing of chemicals" (HJ/T 153-2004), "The

Guidelines for the Testing of Chemicals, Effects on Biotoc Systems" (the 2nd edition) (2013); and with reference to Procedure 203 of the "Guidelines for Testing of Chemicals" of the OECD: "Fish, Acute Toxicity Test" (1992), under static conditions.

A range-finding test and then a limit test were performed respectively. Nominal concentrations of 1.00, 10.0 and 100 mg/L were used in the range-finding test, while the nominal concentration of 100 mg/L was used in the limit test. Water samples taken from the control and the treatments in

the limit test were analysed. The mean of the measured concentrations was 86.7 mg/L, ranging from 85.2 mg/L to 90.9 mg/L during the test period. The analytical results indicated the test substance was consistent in the test medium throughout the 96-hour test period (deviation within

20%). Thus a static procedure was reasonable.

Five fish per treatment with no replication were tested in the range-finding test while three replicates of seven fish each were tested in the control and limit concentration of the limit test. The test fishes were exposed for 96 hours to the test solution.

During the test period, the pH values of the control mediums and test mediums were between7.64 and 7.77 the Dissolved Oxygen (DO) values varied from 76 % to 95 % of the air saturation at the test temperature; the total hardness was in the range of 142 mg (CaC03)/L to 147 mg

(CaC03)/L; the temperature of the test mediums was maintained in the range of 23.0 °C to 23.2°C and all fishes in the control group were normal. With the same conditions, K2Cr20 7 was used as the positive control substance, and the resulting 24 h-LC50 was 323 mg/L. So the study met the

acceptability criteria prescribed by the protocol and Test Guidelines, and is considered valid.

During the test period, all fish in the control groups and treated groups were alive and appeared normal. The results showed that under valid static test conditions, the 96 h-LC50 of test substance to fish (Rare minnow, Gobiocypris rarus) was greater than the nominal concentration of 100

mg/L (mean measured concentration 86.7 mg/L), while the maximum concentration causing no mortality (96 h-LC0) was equal to the nominal concentration of 100 mg/L (mean measured concentration 86.7 mg/L). i.e.:

96 h-LCso > 100 mg/L (mean measured concentration 86 .7 mg/L);

96 h-LCo = 100 mg/L (mean measured concentration 86. 7 mg/L).

Description of key information

Fish Acute Toxicity of  Methanaminium, N,N,N-trimethyl-, salt with 2,2-dimethylpropanoic acid (1:1) was determined using Fish Acute Toxicity Test (OECD 203) with Pimephales promelas. The probit method resulted in an LC50 of 581.4 mg/L with 95% confidence intervals of 473.2 and 709.1.  

Testing the acute toxicity of the test substance of Methanaminium N,N,N-trimethyl-, salt with 2,2-dimethylpropanoic acid (1 :1) to Rare minnow (Gobiocypris rarus) resulted in a 96 h-LCso > 100 mg/L (mean measured concentration 86 .7 mg/L);

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Dose descriptor:

LC50

Effect concentration:

581.4 mg/L