Ditolyl 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:

1984

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

other: UBA test protocol: Letale Wirkung beim Zebrabaerbling Brachydanio rerio, (LC 0, LC 50, LC 100; 48 - 96h) Stand Mai 1984

Deviations:

yes

Remarks:

The recommended test temperature was not met in all experiments.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

Principles of method if other than guideline:

The purpose of this method was to determine that concentration which causes a 50 % mortality (= LC 50) or, if conducted as a limit test, to determine the acute toxic effects at a maximum test concentration of 100 mg/L or at the limit of water solubility, respectively.
In the main test, fishes are exposed to the test item added to water at a range of concentrations for a period of 96 hours. Defined concentrations of the test item will lead to a certain percentage of dead fish at the end of the 96 hour study period.
Mortalities are recorded at 24-hour intervals. The LC 0 and the LC 100 are determined directly from the test results. During the test a temperature range of 20 - 24 °C is to be maintained in the test vessels, with a maximum temperature fructuation of +/- 1 °C in each individual test. pH and oxygen values are measured at the beginning of the test and every 24 hours thereafter.
The test is conducted as static test in which no flow of test solution occurs and solutions remain unchanged throughout the duration of the test.

GLP compliance:

no

Analytical monitoring:

no

Details on sampling:

- Concentration of the test item 0.5 to 50 mg/L (nominal)

Vehicle:

no

Details on test solutions:

Test item concentration/s : 0.5, 1, 3, 6, 5, 10, 15, 20 and 50 mg/L

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

Test species:
Name: Zebra fish (Danio rerio)
Source: West Aquarium GmbH (Germany)

Maintenance:
Temperature: 20-24°C
Dissolved oxygen: > 5 mg/L
Holding water: dechlorinated tap water: hardness 15° dH, acidity: 0.1 +/- 0.02 mmol/l; Ca/Mg: 4:1; pH: 6.3-6.8; oxygen: >= 90 % of saturation
Mortalities during acclimatisation period: none
Medication: none

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

not applicable

Hardness:

approx. 15 °dH

Test temperature:

16.4 - 21.7 °C measured at 0, 24, 48, 72 and 96 hours at each test vessel

pH:

6.4 - 7.1 measured at 0, 24, 48, 72 and 96 hours at each test vessel

Dissolved oxygen:

8.1 - 10.2 mg/L measured at 0, 24, 48, 72 and 96 hours at each test vessel

Salinity:

not reported

Nominal and measured concentrations:

Nominal concentrations in mg/L: 0.5, 1, 3, 5, 6, 10, 15, 20 and 50

Details on test conditions:

- Test vessels: glass aquaria holding 5 L of test media covered with glass plates
- Experimental design: 9 test concentrations plus 1 control; 10 animals per test concentration; no feeding during the exposure period
- Method of initiation: animals were placed in prepared media
- Photoperiod: 16 h light, 8 h dark
- Medium renewal: none
- Duration of exposure : 96 hours
- Criteria of effects : The criterion of death used in this study was the absence of response to physical stimulation. In addition to observations an mortality at 0, 24, 48, 72 and 96 hours, type and incidence of sub-lethal effects compared with control fish were observed.

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

2.62 mg/L

Nominal / measured:

nominal

Basis for effect:

mortality (fish)

Details on results:

The analysis for the mortality data with control, 0.5, 1, 3 and 6 mg/L was performed by probit analysis.

Sublethal observations / clinical signs:

The test organisms were inspected 24h, 48h, 72h and 96h after test start. In the following table the number of dead fish and the number of fish showing abnormal behaviour after 48h and 96h exposure period are presented:

 

Test concentration [mg/L]	48 h		96 h
	Mortality for zebra fish	Abnormal behaviour*	Mortality for zebra fish	Abnormal behaviour*
Control	0	0	0	0
0.5	0	0	0	0
1.0	0	0	1	0
3.0	0	0	4	0
5.0	6	4	9	1
6.0	8	2	10	0
10.0	0	0	4	0
15.0	10	0	-	-
20.0	9	1	10	0
50.0	9	1	-	-

Comments: * Fish with effects

 

Validity criteria fulfilled:

yes

Conclusions:

The toxicity to fish was determined at LC50 of 2.62 mg/L after 96 hours.

Executive summary:

A study on the acute toxicity of the substance to Danio rerio was conducted in accordance with the UBA test protocol: Letale Wirkung beim Zebrabaerbling Brachydanio rerio, (LC 0, LC 50, LC100; 48 - 96h) Stand Mai 1984, which is comparable to the OECD Guideline for Testing of Chemicals No. 203 "Fish, Acute Toxicity Test". The test was performed under static conditions and the mortality and the abnormal behaviour were obsevered after 24, 48, 72 and 96h.

Groups of ten fishes were exposed to test concentration of 0.5 to 50 mg/L (nominal concentration) of the substance.

A LC50 (96h) was calcutated to be 2.62 mg/L (determined by probit analysis).

Description of key information

The toxicity to fish was determined at LC50 of  2.62 mg/L after 96 hours.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Dose descriptor:

LC50

Effect concentration:

2.62 mg/L

Additional information

A study on the acute toxicity of the substance to Danio rerio was conducted in accordance with the UBA test protocol: Letale Wirkung beim Zebrabaerbling Brachydanio rerio, (LC 0, LC 50, LC100; 48 - 96h) Stand Mai 1984, which is comparable to the OECD Guideline for Testing of Chemicals No. 203 "Fish, Acute Toxicity Test" . The test was performed under static conditions and mortality and abnormal behaviour were assessed after 24, 48, 72 and 96h. Groups of ten fishes were exposed to test concentration of 0.5 to 50 mg/L (nominal concentration) of the substance. The LC50 (96h) was calcutated to be 2.62 mg/L.