2-tert-butyl-4-methoxyphenol

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

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Experimental test result performed using standard test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Principles of method if other than guideline:

This study was designed to assess the toxic effects of the test compound on the Zebra fish. A static procedure was used for the study and it was conducted in compliance with the OECD guideline 203.

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

The test substance was soluble in water. Therefore, the test solution was prepared by dissolving 6.24 mg, 12.5 mg, 25 mg, 50 mg & 100 of the test substance in 4 liters of potable water (passed through reverse osmosis system) with continuous stirring for achieving test concentrations of 1.56 mg/L, 3.125 mg/L, 6.25 mg/L, 12.5 mg/L & 25 mg/L, respectively.

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
- Common name:Zebra Fish
- Strain:Danio rerio
- Source:Orange City Aquarium, Sitabuldi, Nagpur, MS (India)
- Age at study initiation (mean and range, SD):3-4 months
- Length at study initiation (length definition, mean, range and SD):average 2.28 cm
- Weight at study initiation (mean and range, SD):0.115 g (average)
- Method of breeding:
- Feeding during test
- Food type:Standard brand feed,
- Amount:
- Frequency: once daily

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Test temperature:

21 °C

pH:

Between 6-7

Dissolved oxygen:

6.5

Details on test conditions:

The test vessels used were all plastic aquaria having the water capacity of 5liters.
Volume of water: 4 liters
No. of animals per vessel: 8 fishes

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

1.56 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: Toxic

Duration:

96 h

Dose descriptor:

LC100

Effect conc.:

6.25 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: LC50 through probit analysis was 1.42 mg/l.

Sublethal observations / clinical signs:

Table 1. Mortality and symptoms

NominalConcentration (mg/l)	Number of fish	Mortality (cumulated) after
		24h	48h	72h	96h
0 (control)	8	-	-	-	-
1.56	8	2	1	1	-
3.12	8	2	1	1	1
6.25	8	3	3	2	-
12.5	8	3	2	3	-
25	8	5	3	-	-

 

Visible Symptoms: Fishes were moving slow as compared to control

 

NominalConcentration(mg/l)	Number of fish	Symptoms after
		24h	48h	72h	96h
0 (control)	8	NS8	NS8	NS8	NS8
1.56	8	M6	M5	M4	M4
3.12	8	M6	M5	M4	M3
6.25	8	M5	M2	-	-
12.5	8	M5	M3	-	-
25	8	M3	-	-	-

Explanation of symptoms:

A: apathy

N: narcotic-like state

C: swimming near water surface

D: swimming at the bottom of bowl

M: Slow movements compared to control

NS: No abnormal symptoms

Number behind symbol for symptom= number of affected fish

Table 2. pH and oxygen content:

Nominal Concentration(mg/l)	pH readings after
	24h	48h	72h	96h
0(Control)	7.4	7.2	7.2	6.5
1.56	6.7	6.5	6.0	6.0
3.12	6.6	6.5	6.4	6.1
6.25	6.6	6.6	6.4	-
12.5	6.7	6.6	-	-
25	6.7	-	-	-

 

NominalConcentration(mg/l)	Oxygen content (mg/l) after
	24h	48h	72h	96h
0(Control)	6.5	6.5	6.2	6.1
1.56	6.5	6.5	6.2	6.1
3.12	6.5	6.5	6.3	6.2
6.25	6.6	6.6	6.2	-
12.5	6.6	6.6	-	-
25	6.7	-	-	-

 

Table 3. Test temperature

NominalConcentration(mg/l)	Temperature (°C) after
	24h	48h	72h	96h
0(Control)	21	21	21	21
1.56	21	21	21	21
3.12	21	21	21	21
6.25	21	21	21	-
12.5	21	21	-	-
25	21	-	-	-

Validity criteria fulfilled:

yes

Conclusions:

Based on the nominal concentrations, the median lethal concentration LC50 (96 h) for test chemical on Danio rerio was observed to be 1.56 mg/L.

Executive summary:

This study was designed to assess the toxic effects of the test compound on the Zebra fish. A static procedure was used for the study and it was conducted in compliance with the OECD guideline 203. Test conducted under the static system for 96 hrs under the static system. The test substance was soluble in water. Therefore, the test solution was prepared by dissolving 6.24 mg, 12.5 mg, 25 mg, 50 mg & 100 of the test substance in 4 liters of potable water (passed through reverse osmosis system) with continuous stirring for achieving test concentrations of 1.56 mg/L, 3.125 mg/L, 6.25 mg/L, 12.5 mg/L & 25 mg/L, respectively. Based on the nominal concentrations, the median lethal concentration LC50 (96 h) for test chemical on Danio rerio was observed to be 1.56 mg/L. Thus based on the LC50 value, chemical consider to be toxic and classified as aquatic chronic 2 as per the CLP classification criteria.

Description of key information

This study was designed to assess the toxic effects of the test compound on the Zebra fish. A static procedure was used for the study and it was conducted in compliance with the OECD guideline 203. Test conducted under the static system for 96 hrs under the static system. The test substance was soluble in water. Therefore, the test solution was prepared by dissolving 6.24 mg, 12.5 mg, 25 mg, 50 mg & 100 of the test substance in 4 liters of potable water (passed through reverse osmosis system) with continuous stirring for achieving test concentrations of 1.56 mg/L, 3.125 mg/L, 6.25 mg/L, 12.5 mg/L & 25 mg/L, respectively. Based on the nominal concentrations, the median lethal concentration LC50 (96 h) for test chemical on Danio rerio was observed to be 1.56 mg/L. Thus based on the LC50 value, chemical consider to be toxic and classified as aquatic chronic 2 as per the CLP classification criteria.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

1.56 mg/L

Additional information

Summarized result for the toxicity of test chemical on the mortality of fishes were reviewed and mention as below:

This study was designed to assess the toxic effects of the test compound on the Zebra fish. A static procedure was used for the study and it was conducted in compliance with the OECD guideline 203. Test conducted under the static system for 96 hrs under the static system. The test substance was soluble in water. Therefore, the test solution was prepared by dissolving 6.24 mg, 12.5 mg, 25 mg, 50 mg & 100 of the test substance in 4 liters of potable water (passed through reverse osmosis system) with continuous stirring for achieving test concentrations of 1.56 mg/L, 3.125 mg/L, 6.25 mg/L, 12.5 mg/L & 25 mg/L, respectively. Based on the nominal concentrations, the median lethal concentration LC50 (96 h) for test chemical on Danio rerio was observed to be 1.56 mg/L. Thus based on the LC50 value, chemical consider to be toxic and classified as aquatic chronic 2 as per the CLP classification criteria.

 

Above experimental study was supported by the second supporting data from authoritative database. Short term toxicity of test chemical were studied on the mortality of fish. Test conducted under the static system for 96 hrs. The 96 hour LC50 value of test chemical in fish was determine to be 5.8 mg/L. Thus based on the LC50 value, chemical consider to be toxic and classified as aquatic chronic 2 as per the CLP classification criteria.

 

Similar acute toxicity of fish were determine on the mortality rate of fishes Lepomis macrochirus. Juvenile Lepomis macrochirus were used in the study. Test conducted under the static system for 48 hrs. After the 48 hrs of incubation effects on the mortality rate of fishes were observed. Based on the mortality the 48 hour LC50 value of test chemical in fish (Lepomis macrochirus) was determine to be 4.8 with 95 % CI of (4.5-5.0) mg/L. Hence on the basis of LC50 value, chemical consider to be toxic and classified as aquatic chronic 2 as per the CLP classification criteria.

 

In the fourth acute toxicity of test chemical were determine on the mortality rate of fish Ictalurus punctatus. Based on the mortality of fish (Ictalurus punctatus) by the chemical exposure for 48 hrs, the LC50 value was determine to be 1.5 mg/L.

 

Similar short term toxicity of test chemical on the mortality of fish were studied. Test conducted under the static system for 24 hrs. The 24 hour LC50 value of test chemical in Oryzias latipes was observed to be 5.6 mg/L at 20°C and 5.5mg/L at 10°C on the basis of mortality. These values indicate that the chemical will exhibit short term toxicity to fish. As per the CLP criteria, the substance will be classified in Aquatic Chronic Category 2.

 

Objective of this sixth study was to determine the effect of test chemical on the mortality of fish Oryzias latipes. Test conducted under the static system for 48 hrs. The 48 hour LC50 value of test chemical in fish (Oryzias latipes) was observed to be 5 mg/L at 20°C.

 

Thus based on the overall studies for the test chemical, it was concluded that the chemical was toxic and classified as aquatic chronic 2 as per the CLP classification criteria.