2-methylenepropane-1,3-diyl diacetate

Short-term toxicity to fish

Administrative data

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Experimental start date: Oct 09, 2019. Experimental completion date: Oct 26 2019

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2020

Report date:

2020

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

2-methylenepropane-1,3-diyl diacetate

EC Number:

223-225-8

EC Name:

2-methylenepropane-1,3-diyl diacetate

Cas Number:

3775-29-9

Molecular formula:

C8H12O4

IUPAC Name:

2-[(acetyloxy)methyl]prop-2-en-1-yl acetate

Specific details on test material used for the study:

Test substance: MPDAc
Chemical Name: 2-methylenepropane-1,3-diyl diacetate
CAS: 3775-29-9
Molecular formula C8H12O4
Molecular weight: 172-18
Purity: 99.5 %
Water solubility: 28.9 g/L
Batch Number: 805003
Expiry date: Aug 30, 2020
Appearance: Colorless transparent liquid

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

no

Details on test solutions:

The stock solution of 100 mg/L for Range-finding test was prepared by dissolving 0.0104 g test substance into 100 mL test water. The stock solution of 100 mg/L for Definitive test was prepared by dissolving 0.0256 g test substance into 250 mL test water. The test solutions were agitated with speed of 500 rpm for 30 min at 25 °C. The stock solution was colorless and clear, and the test item was completely dissolved. Other concentration groups were obtained by dilution of the stock solution

Test organisms

Test organisms (species):

other: Rare minnow, 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.: F201903 15G), were bred by the laboratory.

Domestication of test fish
Fish to be used in the test were acclimated for 7 days in water of the quality and temperature to be used in the test. During the acclimation, the following conditions were maintained:
- Light: 12 hours photoperiod daily, intensity 935 to 957 Lux;
- Water Quality: the water quality is the same as the test water;
- Temperature: :23.0°C to 23.1°C:
- Oxygen concentration: 104.9% to 106.2% of the air saturation value;
- Feeding: Brine Shrimp twice daily during the holding period, until approximately 24 hours before being placed into the test vessels.

Selection criteria for test fish
During the acclimation period (7 days), no mortality was observed. So the batch of fish (Batch No.: F20 I 90315G) was accepted. The average wet-weight and the length of the fish used in the definitive test was 0.2597 g and 3.291 cm, with the relative standard deviation (RSD) of 7.14% and 5.66%, respectively

Study design

Test type:

static

Water media type:

other: Good quality tap water which had been dechlorinated for at least 24 hours was used. Characteristics of the dilution water were measured by Jiangsu Yanlan Detection Technology Co., Ltd.

Limit test:

no

Total exposure duration:

96 h

Test conditions

Hardness:

150 mg (CaCO3)/L

Test temperature:

22.9 °C to 23 .1 °C

pH:

7.58 - 7.62 at 0 hours to 7.21 - 7.59 at 96 hours

Dissolved oxygen:

73.8% to 105.2% the air saturation; No aeration.

Nominal and measured concentrations:

Range finding test
Nominal: 0.0200, 0.100, 0.500 mg/L

Definitive test
Nominal: 0.205, 0.256, 0.320, 0.400, 0.500 mg/L
Mean Measured: 0.167, 0.211, 0.265, 0.338 and 0.416 mg/L

Details on test conditions:

Range-finding Test
Static method was adopted in the range-finding test, groups of fish (5 per group) were exposed to the test solutions with nominal concentration of 0.0200, 0.100 and 0.500 mg/L. One control group was also included in the study using test water without the test substance. Each test tank contained 10 L of test solution. No replicate was used.
The test fish were randomly chosen and put in appropriate test solutions after the temperature had been adjusted to the required value. This was done within 30 min.
Test duration was 96 hours. If dead fish were observed, dead fish were removed at least once daily and discarded. The mortalities of the fish were recorded at 24, 48, 72 and 96 h, and then the maximum concentration causing no mortality (LC0) and the minimum concentration causing I 00% mortality (LC100) were determined.

Definitive Test
Static method was adopted m definitive test. The stability of the test solution in 96 h was confirmed (deviation within 20%).
The concentration of 0.205, 0.256, 0.320, 0.400 and 0.500 mg/L were assigned in definitive test with no replicate. One control group was also included in the study using test water without the test substance. Each group contained 10 L of test solution and 10 fish. The test fish were randomly chosen and put in appropriate test solutions after the temperature had been adjusted to the required value. This was done within 30 min.
At 24, 48, 72 and 96 h, the mortalities of the fish were recorded, and observations on individual behaviour were performed. Meanwhile, measurements of pH, dissolved oxygen, temperature and light intensity were carried out and recorded daily.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

96 h

Dose descriptor:

LC100

Effect conc.:

0.5 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Effect concentrations 2

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

0.32 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Effect concentrations 3

Duration:

96 h

Dose descriptor:

LC0

Effect conc.:

>= 0.32 - <= 0.34 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

All fish in the control group were alive and appeared normal. Effects (Fish fin damage) occurred at 0.400 mg/Land the higher concentrations. All Fish were dead after 96 h-exposure at the concentration of 0.500 mg/L.

Validity of Test
Control group
A control group, comprising the same number of fish as that exposed under the same test condition, was conducted. During the test period, no mortality was observed in the controls and all fish in the control group were normal.
Fish loading
About 0.260 g fish (wet weight) per litre of test medium.
Validity of test result
During the definitive test, the pH values of the control mediums and test mediums were between 7.16 and 7.62, the Dissolved Oxygen (DO) values varied from 73.8% to 105.2% of the air saturation at the test temperature, the temperature of the test mediums were maintained in the range of 22.9 °C to 23.1 °C, the light intensity values were maintained in the range of 837 to 946 Lux, and the total hardness was 150 mg (CaCO3)/L. With the same conditions, K2Cr2O7 was used as the positive control substance, and the resulting 24 h-LC50 was 254 mg/L. So the study met the acceptability criteria prescribed by the protocol (pH: 6.0 - 8.5; dissolved oxygen concentration:> 60% of the air saturation value; light with intensity of 540 - 1000 Lux; total hardness: 40 - 250 mg (CaCO3)/L; temperature: (23±2) °C; 24 h-LC50 of potassium dichromate in the range of 200 to 400 mg/L). Therefore, the test was considered valid.

Results with reference substance (positive control):

With the conditions maintained as designed for this test, potassium dichromate was used as the test substance and the resulting 24 h-LC50 was 254 mg/L.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The results showed that under static test conditions, the 96 h-LC50 of the test substance to fish (Rare minnow, Gobiocypris rarus) was 0.34 mg/L. with 95% confidence limit of 0.32 ~ 0.36 mg/L (based on the mean measured concentration ). The maximum tested concentration causing no mortality (96 h-LC0) was 0.320 mg/L (mean measured concentration was 0.265 mg/L). The minimum concentration causing I 00% mortality (96 h-LC100) was 0.500 mg/L (mean measured concentration was 0.416 mg/L), i.e.:
96 h-LC50 = 0.34 mg/L, 95% CI 0.32 - 0.36 mg/L (based on mean measured concentration);
96 h-LC0 = 0.320 mg/L (mean measured concentration was 0.265 mg/L);
96 h-LC100 = 0.500 mg/L (mean measured concentration was 0.416 mg/L).

Executive summary:

Under static conditions, the acute toxicity of test substance (MPDAc) 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 Biotic Systems" (the 2nd edition. Beijing: China Environment Press. 2013 30-36) and "Chemicals-Fish acute toxicity test" (GB/T 27861-2011 ); with reference to Procedure 203 of the ''Guidelines for Testing of Chemicals" of the OECD: "Fish, Acute Toxicity Test" (2019).

A range-finding test and then a definitive test were performed respectively. Nominal concentrations of 0.0200, 0.100 and 0.500 mg/L were used in the range-finding test, while the nominal concentration of 0.205, 0.256, 0.320, 0.400 and 0.500 mg/L were used in the definitive test. Water samples taken from the control and the treatments in the definitive test at 0, 24, 48, 72 and 96 h were analysed by GC. The analytical results showed that the mean measured concentration of the test substance were 0. 167, 0.211, 0.265, 0.338 and 0.416 mg/L during the definitive test (96 h). The measured concentration of the test substance deviated less than 20% of initial concentration. Thus, a static procedure was reasonable.
In the range-finding test, 5 fish per treatment and no replicates were used. And 10 fish per treatment with no replicates was used in the definitive test. The test fish were exposed for 96 hours to the test solution.

During the definitive test period, the loading rate was 0.260 g (wet weight) fish per litre of test medium, the pH values of the control mediums and test mediums were between 7.16 and 7.62, the Dissolved Oxygen (DO) values varied from 73 .8% to 105.2% of the air saturation at the test temperature, the temperature of the test mediums were maintained in the range of 22.9 °C to 23.1 °C, light with intensity of 837 to 946 Lux, the total hardness was 150 mg (CaCO3)/L, and all fish in the control group were normal. With the same conditions, potassium dichromate (K2Cr2O7) was used as the positive control substance, and the resulting 24 h-LC50 was 254 mg/L. So the study met the acceptability criteria prescribed by the protocol and Test Guidelines (A maximum loading of 0.8 g fish per litre of test medium; the mortality of control :S 10%; pH: 6.0 - 8.5; dissolved oxygen concentration: > 60% of the air saturation value; temperature: (23±2) °C; light intensity: 540 - 1000 Lux ; total hardness: 40 - 250 mg(CaCO3)/L; 24 h-LC50 of K2Cr2O7 in the range of 200 to 400 mg/L). Therefore, the test was considered valid.

During the test period, all fish in the control group were alive and appeared normal. Effects (Fish fin damage) occurred at 0.400 mg/L and the higher concentrations. All Fish were dead after 96 h-exposure at the concentration of 0.500 mg/L. The results showed that under valid static test conditions, the 96 h-LC50 of the test substance to fish (Rare minnow, Gobiocypris rarus) was 0.34 mg/L, with 95% confidence limit of 0.32 - 0.36 mg/L (based on the mean measured concentration). The maximum tested concentration causing no mortality (96 h-LC0) was 0.320 mg/L (mean measured concentration was 0.265 mg/L). The minimum concentration causing 100%mortality (96 h-LC100) was 0.500 mg/L (mean measured concentration was 0.416 mg/L), i.e.:
96 h-LC50 = 0.34 mg/L, 95% CI 0.32 - 0.36 mg/L (based on mean measured concentration);
96 h-LC0 = 0.320 mg/L (mean measured concentration was 0.265 mg/L);
96 h-LC100 = 0.500 mg/L (mean measured concentration was 0.416 mg/L).