Methyl 2-naphthyl ether

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

November 24 2020 to April 02 2021

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

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 10,13,16.9,22.0 and 28.6 mg/l
- Sampling method: An aliquot of required volume of sample solutions were taken, placed in a hot air oven for period of about 30 minutes at 120°C. After that collected the eluate sample solutions and final volume made with acetonitrile and injected into HPLC
- Sample storage conditions before analysis: analysis was done immediately

Vehicle:

yes

Remarks:

Acetone

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
Solubility of the test item was performed by weighed 25.2 mg of test item in a glass vial and dissolved in 75 µL of acetone and transferred into the 1000 ml measuring cylinder, and made up to the 750 ml using natural water and the resulting concentration is 33.36 mg/L
- Controls: water control and Solvent control (Acetone in 0.1ml/L)
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): Acetone
- Concentration of vehicle in test medium (stock solution and final test solution(s) or suspension(s) including control(s)): 0.1ml/L

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
- Common name: Zebrafish
- Source: Tarun fish farm india
- Age at study initiation (mean and range, SD): juvenile fish
- Length at study initiation (length definition, mean, range and SD): 1.4 cm
- Weight at study initiation (mean and range, SD): 0.020 grams

ACCLIMATION
- Acclimation period: Fishes were acclimatized to the laboratory test conditions for a minimum period of seven days prior to test start in water.
- Acclimation conditions (same as test or not): yes same as test conditions
- Type and amount of food during acclimation: Fishes were fed with commercial fish food daily, except at least one day prior to the the exposure
- Health during acclimation (any mortality observed): no mortality

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

165 mg/L, CaCO3

Test temperature:

21.7 to 22.8 ℃

pH:

6.9 to 7.9

Dissolved oxygen:

64.2 to 83.0% of air saturation value

Salinity:

Not applicable

Nominal and measured concentrations:

Nominal concentrations

Details on test conditions:

TEST SYSTEM
- Test vessel: glass aquarium
- Material, size, headspace, fill volume: glass, 5 liters,
- Aeration: no
- No. of organisms per vessel: 7
- No. of vessels per concentration (replicates): 01
- No. of vessels per control (replicates): 01
- No. of vessels per vehicle control (replicates): 01
- Biomass loading rate: 0.023g/l


OTHER TEST CONDITIONS
- Photoperiod: 16 hours light
- Light intensity: 540 to 1000 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :

TEST CONCENTRATIONS
- Spacing factor for test concentrations: definitive test 1.3; range finding study: 1.8
- Range finding study : 2.80, 5.04, 9.07, 16.33 and 29.39 mg/L
- Test concentrations: concentrations of 10.0, 13.0, 16.9, 22.0 and 28.6 mg/L
- Results used to determine the conditions for the definitive study:mortality obtained in range finding test

Reference substance (positive control):

not required

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

20.18 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 95% CI -19.32-21.04

Details on results:

- Behavioural abnormalities:
- Mortality of control: No mortality was observed in control
- Other adverse effects control: N adverse effects found in control
- Abnormal responses: No abnormal responses in control,
Loss of equilibrium (Loss of buoyancy control) in 16.9, 22.0 and 28.6 mg/L, Abnormal Swimming behaviour (Corkscrew swimming) in 13.0, 16.9, 22.0 and 28.6 mg/L for a period of 96 hours

Reported statistics and error estimates:

Based on the mortality data, LC50 value was determined statistically by probit analysis using NCSS Software 2019, Version 19.0.3. The 95% confidence Limits were calculated by using the formula: LC50 ± 1.96 × standarad error

Sublethal observations / clinical signs:

1.0            TABLES

Table1: Percentage of Fish Mortality

Concentration (mg/L)	Mortality (%)
	6 hours	24 hours	48 hours	72 hours	96 hours
Range finding test
Control	0	0	0	0	0
Solvent control	0	0	0	0	0
2.80	0	0	0	0	0
5.04	0	0	0	0	0
9.07	0	0	0	0	0
16.33	0	0	0	14.29	14.29
29.39	0	71.43	71.43	100	100
Definitive test
Control	0	0	0	0	0
Solvent control	0	0	0	0	0
10.0	0	0	0	0	0
13.0	0	0	0	0	0
16.9	0	0	0	42.86	42.86
22.0	0	42.86	42.86	42.86	57.14
28.6	0	42.86	42.86	42.86	85.71

 

LC₅₀Value of test item

Parameters	96 hours
LC50	20.18
95% confidence interval- Lower Fiducial limit	19.32
95% confidence interval - Upper Fiducial limit	21.04

Key:LC₅₀- Median Lethal Concentration

Concentration (mg/L)	Number of fish	Mortality (number)
		2.5h	5h	24h	30h	48h	54h	72h	78h	96h
Range finding test
Control	7	0	0	0	0	0	0	0	0	0
Solvent control	7	0	0	0	0	0	0	0	0	0
2.80	7	0	0	0	0	0	0	0	0	0
5.04	7	0	0	0	0	0	0	0	0	0
9.07	7	0	0	0	0	0	0	0	0	0
16.33	7	0	0	0	0	0	0	0	1	0
29.39	7	0	0	0	5	0	0	0	2	NA
Definitive test
Control	7	0	0	0	0	0	0	0	0	0
Solvent control	7	0	0	0	0	0	0	0	0	0
10.0	7	0	0	0	0	0	0	0	0	0
13.0	7	0	0	0	0	0	0	0	0	0
16.9	7	0	0	0	0	0	0	2	1	0
22.0	7	0	0	0	3	0	0	0	0	1
28.6	7	0	0	0	3	0	0	0	0	3

 

Range Finding Test
Hours	Parameters	Concentration (mg/L)
		Control		Solvent control		2.80		5.04		9.07		16.33		29.39
0	pH	6.9		7.0		6.8		7.1		7.2		7.2		7.4
	Temperature	22.2		22.4		22.3		22.5		22.1		22.3		22.4
	Dissolved oxygen	8.8		8.8		8.2		8.1		8.0		8.1		8.3
24	pH	7.0		7.0		6.7		6.8		6.9		7.0		7.1
	Temperature	22.4		22.5		22.6		22.4		22.4		22.3		22.4
	Dissolved oxygen	8.5		8.5		8.2		8.1		8.3		8.0		8.0
48	pH	6.9		6.9		7.0		6.7		6.8		6.9		6.9
	Temperature	22.2		22.4		22.1		22.3		22.4		22.5		22.4
	Dissolved oxygen	8.2		8.0		8.1		7.9		8.0		7.8		6.8
72	pH	7.0		6.9		7.0		6.6		6.7		6.9		6.8
	Temperature	22.1		22.3		22.2		22.4		22.3		22.3		22.2
	Dissolved oxygen	8.0		7.8		8.0		7.6		7.5		7.2		6.8
96	pH	6.9		6.9		6.8		6.6		6.7		6.8		NA
	Temperature	22.2		22.4		22.3		22.5		22.2		22.4		NA
	Dissolved oxygen	7.9		7.7		7.8		7.4		7.3		7.0		NA
Definitive test
Hours	Parameters	Concentration (mg/L)
		Control	Solvent control		10.0		13.0		16.9		22.0		28.6
0	pH	7.0	7.0		7.5		7.6		7.4		7.7		7.8
	Temperature	22.1	22.8		22.7		22.4		22.3		22.2		22.2
	Dissolved oxygen	8.2	8.4		8.3		8.5		8.2		8.2		8.4
24	pH	6.9	7.0		7.2		7.4		7.0		7.5		7.3
	Temperature	22.3	22.2		22.2		22.0		21.9		21.8		21.8
	Dissolved oxygen	8.1	8.3		8.2		8.3		8.0		8.1		8.2
48	pH	7.0	7.1		7.0		7.3		7.2		7.3		7.2
	Temperature	22.2	22.8		22.7		22.2		22.1		22.1		22.3
	Dissolved oxygen	8.4	8.2		8.0		8.4		7.8		7.0		7.7
72	pH	7.9	7.9		7.5		7.6		7.6		7.5		7.6
	Temperature	22.2	22.1		22.1		22.0		21.7		21.9		21.9
	Dissolved oxygen	7.0	7.1		7.6		7.8		7.0		7.3		7.5
96	pH	7.7	7.7		7.7		7.6		7.7		7.5		7.5
	Temperature	22.5	22.4		22.2		22.1		22.0		21.9		21.9
	Dissolved oxygen	7.0	6.9		6.9		7.2		6.9		7.2		7.0

 

Validity criteria fulfilled:

yes

Remarks:

No mortality in control group, air saturation values were greater than 60%, analytical range was within 80-120%

Conclusions:

The effect of test chemical was studied on fresh water fish danio rerio, for the period of 96 hours, the median lethal concentration was found to be 20.18 mg/l.

Executive summary:

The objective of this study is to assess the Acute Toxicity of test chemical in Freshwater Fish (Danio rerio).The study was performed in compliance with OECD 203 Guideline for the testing of chemicals; Fish, Acute Toxicity Testing, (18th June, 2019). Solubility of the test item was performed by weighing 25.2 mg of test item in a glass vial and dissolved in 75 µL of acetone and transferred into the 1000 ml measuring cylinder, and made up to the 750 ml using natural water and the resulting concentration is 33.36 mg/L. Stability of the test item in natural water determined by analyzing the test concentrations of 1 and 30 mg/L at 0 hour, 24 hour, 48 hour, 72 hour and 96 hour showed that the test item concentration remained 80% to 120% (between97.83% and 99.27% for 1 mg/L and between97.45% and 99.24% for 30 mg/L) with respect to initial measured concentration and hence the dose verification for definitive test was performed at the beginning and at the termination of the test. Range finding test was conducted with test concentration of 2.80, 5.04, 9.07, 16.33 and 29.39 mg/L along with a control groups without test item by static method. Each concentration contained seven fish. Test item was first formulated in acetone (not exceeding 0.1 ml /L) follwed by natural water. No mortality (percent) observed in control groups and in the tested concentrations of 2.80, 5.04 and 9.07 mg/L whereas, 14.29% and 100% in 16.33 and 29.39 mg/L for a period of 96 hours. No clinical sign observed in control groups and in all the tested concentrations for a period of 96 hours. Based on the results of range finding test, the definitive test was conducted with test concentrations of 10.0, 13.0, 16.9, 22.0 and 28.6 mg/L along with a control groups without test item by static method. Each concentration contained seven fish. Test item was formulated in (not exceeding 0.1 ml /L) follwed by natural water. No mortality (Cumulative mortality percent) observed in control groups and in the tested concentration of 10.0 mg/L and 13.0 mg/L whereas, 42.86%, 57.14%, and 85.71% in 16.9, 22.0 and 28.6 mg/L for a period of 96 hours. No clinical signs observed in control groups and in the tested concentration of 10.0 mg/L whereas, Loss of equilibrium (Loss of buoyancy control) in 16.9, 22.0 and 28.6 mg/L, Abnormal Swimming behaviour (Corkscrew swimming) in 13.0, 16.9, 22.0 and 28.6 mg/L for a period of 96 hours. The test item available in the test medium (natural water) was determined by a validated HPLC method. The test item concentration oftest itemin the test medium at the initiation (0 hour) and 96 hours was 94.79% to 96.23 % for 10.0 mg/L, 94.08 % to 95.02 % for 16.9 mg/L, 95.07% to 95.56 % for 28.6 mg/L % of the nominal test concentrations. As the measured concentrations were within 80 to 120% of the nominal concentration during the definitive test period. Based on the results of the study, the test item,2-methoxynaphthaleneLC₅₀value at 96 hours was found to be 20.18 mg/Lwith 95% confidence limits between19.32 mg/Land21.04 mg/l. Based on the 96 hours LC50 value the test chemical can be categorised in chronic category 3 as per CLP classification criteria.

.

Description of key information

The objective of this study is to assess the Acute Toxicity of test chemical in Freshwater Fish (Danio rerio).The study was performed in compliance with OECD 203 Guideline for the testing of chemicals; Fish, Acute Toxicity Testing, (18th June, 2019). Solubility of the test item was performed by weighing 25.2 mg of test item in a glass vial and dissolved in 75 µL of acetone and transferred into the 1000 ml measuring cylinder, and made up to the 750 ml using natural water and the resulting concentration is 33.36 mg/L. Stability of the test item in natural water determined by analyzing the test concentrations of 1 and 30 mg/L at 0 hour, 24 hour, 48 hour, 72 hour and 96 hour showed that the test item concentration remained 80% to 120% (between97.83% and 99.27% for 1 mg/L and between97.45% and 99.24% for 30 mg/L) with respect to initial measured concentration and hence the dose verification for definitive test was performed at the beginning and at the termination of the test. Range finding test was conducted with test concentration of 2.80, 5.04, 9.07, 16.33 and 29.39 mg/L along with a control groups without test item by static method. Each concentration contained seven fish. Test item was first formulated in acetone (not exceeding 0.1 ml /L) follwed by natural water. No mortality (percent) observed in control groups and in the tested concentrations of 2.80, 5.04 and 9.07 mg/L whereas, 14.29% and 100% in 16.33 and 29.39 mg/L for a period of 96 hours. No clinical sign observed in control groups and in all the tested concentrations for a period of 96 hours. Based on the results of range finding test, the definitive test was conducted with test concentrations of 10.0, 13.0, 16.9, 22.0 and 28.6 mg/L along with a control groups without test item by static method. Each concentration contained seven fish. Test item was formulated in (not exceeding 0.1 ml /L) follwed by natural water. No mortality (Cumulative mortality percent) observed in control groups and in the tested concentration of 10.0 mg/L and 13.0 mg/L whereas, 42.86%, 57.14%, and 85.71% in 16.9, 22.0 and 28.6 mg/L for a period of 96 hours. No clinical signs observed in control groups and in the tested concentration of 10.0 mg/L whereas, Loss of equilibrium (Loss of buoyancy control) in 16.9, 22.0 and 28.6 mg/L, Abnormal Swimming behaviour (Corkscrew swimming) in 13.0, 16.9, 22.0 and 28.6 mg/L for a period of 96 hours. The test item available in the test medium (natural water) was determined by a validated HPLC method. The test item concentration oftest itemin the test medium at the initiation (0 hour) and 96 hours was 94.79% to 96.23 % for 10.0 mg/L, 94.08 % to 95.02 % for 16.9 mg/L, 95.07% to 95.56 % for 28.6 mg/L % of the nominal test concentrations. As the measured concentrations were within 80 to 120% of the nominal concentration during the definitive test period. Based on the results of the study, the test item,2-methoxynaphthaleneLC₅₀value at 96 hours was found to be 20.18 mg/Lwith 95% confidence limits between19.32 mg/Land21.04 mg/l. Based on the 96 hours LC50 value the test chemical can be categorised in chronic category 3 as per CLP classification criteria.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

20.18 mg/L

Additional information

The objective of this study is to assess the Acute Toxicity of test chemical in Freshwater Fish (Danio rerio).The study was performed in compliance with OECD 203 Guideline for the testing of chemicals; Fish, Acute Toxicity Testing, (18th June, 2019). Solubility of the test item was performed by weighing 25.2 mg of test item in a glass vial and dissolved in 75 µL of acetone and transferred into the 1000 ml measuring cylinder, and made up to the 750 ml using natural water and the resulting concentration is 33.36 mg/L. Stability of the test item in natural water determined by analyzing the test concentrations of 1 and 30 mg/L at 0 hour, 24 hour, 48 hour, 72 hour and 96 hour showed that the test item concentration remained 80% to 120% (between97.83% and 99.27% for 1 mg/L and between97.45% and 99.24% for 30 mg/L) with respect to initial measured concentration and hence the dose verification for definitive test was performed at the beginning and at the termination of the test. Range finding test was conducted with test concentration of 2.80, 5.04, 9.07, 16.33 and 29.39 mg/L along with a control groups without test item by static method. Each concentration contained seven fish. Test item was first formulated in acetone (not exceeding 0.1 ml /L) follwed by natural water. No mortality (percent) observed in control groups and in the tested concentrations of 2.80, 5.04 and 9.07 mg/L whereas, 14.29% and 100% in 16.33 and 29.39 mg/L for a period of 96 hours. No clinical sign observed in control groups and in all the tested concentrations for a period of 96 hours. Based on the results of range finding test, the definitive test was conducted with test concentrations of 10.0, 13.0, 16.9, 22.0 and 28.6 mg/L along with a control groups without test item by static method. Each concentration contained seven fish. Test item was formulated in (not exceeding 0.1 ml /L) follwed by natural water. No mortality (Cumulative mortality percent) observed in control groups and in the tested concentration of 10.0 mg/L and 13.0 mg/L whereas, 42.86%, 57.14%, and 85.71% in 16.9, 22.0 and 28.6 mg/L for a period of 96 hours. No clinical signs observed in control groups and in the tested concentration of 10.0 mg/L whereas, Loss of equilibrium (Loss of buoyancy control) in 16.9, 22.0 and 28.6 mg/L, Abnormal Swimming behaviour (Corkscrew swimming) in 13.0, 16.9, 22.0 and 28.6 mg/L for a period of 96 hours. The test item available in the test medium (natural water) was determined by a validated HPLC method. The test item concentration oftest itemin the test medium at the initiation (0 hour) and 96 hours was 94.79% to 96.23 % for 10.0 mg/L, 94.08 % to 95.02 % for 16.9 mg/L, 95.07% to 95.56 % for 28.6 mg/L % of the nominal test concentrations. As the measured concentrations were within 80 to 120% of the nominal concentration during the definitive test period. Based on the results of the study, the test item,2-methoxynaphthaleneLC₅₀value at 96 hours was found to be 20.18 mg/Lwith 95% confidence limits between19.32 mg/Land21.04 mg/l. Based on the 96 hours LC50 value the test chemical can be categorised in chronic category 3 as per CLP classification criteria.