Isopropyl 4-hydroxybenzoate

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 according to the guideline.

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Principles of method if other than guideline:

Study was conducted to access the effect of test chemical on the mortality of fish Danio rerio. Test conducted according to OECD Guideline 203 (Fish, Acute Toxicity Test).

GLP compliance:

no

Specific details on test material used for the study:

- Name of test material (as cited in study report): isopropyl 4-hydroxybenzoate
- Molecular formula : C10H12O3
- Molecular weight : 180.202 g/mol
- Smiles notation : c1(C(OC(C)C)=O)ccc(O)cc1
- InChl : 1S/C10H12O3/c1-7(2)13-10(12)8-3-5-9(11)6-4-8/h3-7,11H,1-2H3
- Substance type:Organic
- Physical state:Solid

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

The test substance was partially soluble in water. Therefore, the stock solution was prepared by dissolving 1 g of the test substance in 1 liters of potable water (passed through reverse osmosis system) with continuous 24 hours stirring, after stirring stock was analytically detected and the concentration found to be 222.61 mg/L. On the basis of stock concentration 222.61 mg/L further test concentrations calculated which was as follows 1.562 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: Unique Aqua Fish Corner
- Length at study initiation (length definition, mean, range and SD): average 1.81 cm
- Weight at study initiation (mean and range, SD): average 0.073 g
-Housing:The fishes were kept in a static tank in tap water passed through reverse osmosis system, under natural conditions along with proper feed and aeration.
-Duration of housing: 15 days
-Photoperiod: 16 hours light and 8 hours dark
-Diet : Standard brand feed, once daily
-Acclimatization: seven days
-feeding frequency: Once in a day

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

145.5 mg of CaCO3

Test temperature:

23 °C

pH:

7.3 to 7.9

Dissolved oxygen:

6.3 to 6.8

Nominal and measured concentrations:

1.562mg/L, 3.125mg/L, 6.25mg/L,12.5mg/L, 25mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Plastic aquaria
- Material, size, headspace, fill volume: 5 liters of plastic aquaria filled with 2 liter of water
- Aeration: Aeration in test vessels was provided 1 day before the start of experiment
- No. of organisms per vessel: 8 fishes

OTHER TEST CONDITIONS
- Photoperiod: 16 hours light and 8 hours dark

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

3.125 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: LC0 was observed at 1.562 mg/l.

Key result

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: Other details not known

Sublethal observations / clinical signs:

Table 1: Mortality and symptoms:

Nominal Concentration (mg/l)	Number of fish		Mortality (cumulated) after
			3hr			6hr		24hr			48hr		72hr			96hr
			V1	V2		V1	V2	V1	V2		V1	V2	V1	V2		V1	V2
Control	4	4	-	-		-	-	-	-		-	-	-	-		-	-
1.562	4	4	-		-	-	-	-		-	-	-	-		-	-		-
3.125	4	4	-		-	-	-	-		-	-	-	-		-	2		2
6.25	4	4	-		-	-	-	4		4	4	4	4		4	4		4
12.5	4	4	-		-	-	-	4		4	4	4	4		4	4		4
25	4	4	4		4	4	4	4		4	4	4	4		4	4		4

Visible Symptoms:

Nominal Concentration (mg/l)	Number of fish		symptom (cumulated) after
			3hr			6hr		24hr			48hr		72hr			96hr
			V1	V2		V1	V2	V1	V2		V1	V2	V1	V2		V1	V2
Control	4	4	NS4	NS4		NS4	NS4	NS4	NS4		NS4	NS4	NS4	NS4		NS4	NS4
1.562	4	4	NS4		NS4	NS4	NS4	NS4		NS4	NS4	NS4	NS4		NS4	NS4		NS4
3.125	4	4	NS4		NS4	NS4	NS4	NS4		NS4	NS4	NS4	NS4		NS4	M2		M2
6.25	4	4	M4		M4	M4	M4	-		-	-	-	-		-	-		-
12.5	4	4	M4		M4	M4	M4	-		-	-	-	-		-	-		-
25	4	4	-		-	-	-	-		-	-	-	-		-	-		-

Explanation of symptoms:

A: apathy

N: Narcotic-like state

C: Swimming near water surface

M: Slow movements compared to control

NS: No abnormal symptoms

S: Surfacing behaviour

L: Loss of equilibrium

SM: Shimming movement

H1: Hyperactivity

H2: Hypo activity

B: Bending behavior

F: Fin rot

IS: Invert Swimming

SB: Swimming behaviour

RF: Respiratory Function

P: Pigmentation

E: Exopthalamos

pH and oxygen content:

		Number of	pH readings after
Nominal	fish		24h		48h		72h		96h
Concentration			V1	V2	V1	V2	V1	V2	V1	V2
(mg/l)
Control	4	4	7.3	7.3	7.3	7.3	7.4	7.4	7.5	7.5
1.562	4	4	7.5	7.5	7.6	7.6	7.7	7.7	7.8	7.8
3.125	4	4	7.7	7.7	7.8	7.8	7.9	7.9	7.9	7.9
6.25	4	4	-	-	-	-	-	-	-	-
12.5	4	4	-	-	-	-	-	-	-	-
25	4	4	-	-	-	-	-	-	-	-

Nominal	Number of		Oxygen content (mg/L) after
Concentrationfish			24h		48h		72h		96h
(mg/l)			V1	V2	V1	V2	V1	V2	V1	V2
Control	4	4	6.8	6.8	6.7	6.7	6.6	6.6	6.7	6.7
1.562	4	4	6.7	6.7	6.6	6.6	6.4	6.4	6.3	6.3
3.125	4	4	6.5	6.5	6.4	6.4	6.4	6.4	6.3	6.3
6.25	4	4	-	-	-	-	-	-	-	-
12.5	4	4	-	-	-	-	-	-	-	-
25	4	4	-	-	-	-	-	-	-	-
8.3. Test temperature
Nominal	Number of		Temperature (°C) after
Concentrationfish			24h		48h		72h		96h
(mg/l)			V1	V2	V1	V2	V1	V2	V1	V2
Control	4	4	23.9	23.9	23.6	23.6	23.7	23.7	23.7	23.7
1.562	4	4	23.9	23.9	23.6	23.6	23.7	23.7	23.7	23.7
3.125	4	4	23.9	23.9	23.6	23.6	23.7	23.7	23.7	23.7
6.25	4	4	-	-	-	-	-	-	-	-
12.5	4	4	-	-	-	-	-	-	-	-
25	4	4	-	-	-	-	-	-	-	-

Validity criteria fulfilled:

yes

Conclusions:

Based on nominal concentrations, experimental median lethal Concentrations [LC-50 (96 h)] for isopropyl 4-hydroxybenzoate on Zebra Fish Danio rerio was determine to be 3.125 mg/l.

Executive summary:

Study was conducted to assess the effect of test chemical isopropyl 4-hydroxybenzoate on the mortality of fish Danio rerio. Test conducted according to OECD Guideline 203 (Fish, Acute Toxicity Test). The test substance was partially soluble in water. Therefore, the stock solution was prepared by dissolving 1 g of the test substance in 1 liters of potable water (passed through reverse osmosis system) with continuous 24 hours stirring, after stirring stock was analytically detected and the concentration found to be 222.61 mg/L. On the basis of stock concentration 222.61 mg/L further test concentrations calculated which was as follows 1.562 mg/L, 3.125 mg/L, 6.25 mg/L,12.5 mg/L, 25 mg/L respectively and Zebra Fish Danio rerio were exposed to these concentration for 96 hours. Bowl aquaria containing 2 liters of potable water (passed through reverse osmosis system) were loaded with 8 fishes. A static procedure was used for the study and it was conducted in compliance with the OECD guideline 203. Based on nominal concentrations, experimental median lethal Concentrations [LC-50 (96 h)] for isopropyl 4-hydroxybenzoate on Zebra Fish Danio rerio was determine to be 3.125 mg/l. Based on the LC50 value, chemical consider to be toxic but on the basis of readily biodergradability criteria of test chemical, chemical consider to be nontoxic and not classified as per the CLP classification criteria.

Description of key information

Study was conducted to assess the effect of test chemical isopropyl 4-hydroxybenzoate on the mortality of fish Danio rerio. Test conducted according to OECD Guideline 203 (Fish, Acute Toxicity Test). The test substance was partially soluble in water. Therefore, the stock solution was prepared by dissolving 1 g of the test substance in 1 liters of potable water (passed through reverse osmosis system) with continuous 24 hours stirring, after stirring stock was analytically detected and the concentration found to be 222.61 mg/L. On the basis of stock concentration 222.61 mg/L further test concentrations calculated which was as follows 1.562 mg/L, 3.125 mg/L, 6.25 mg/L,12.5 mg/L, 25 mg/L respectively and Zebra Fish Danio rerio were exposed to these concentration for 96 hours. Bowl aquaria containing 2 liters of potable water (passed through reverse osmosis system) were loaded with 8 fishes. A static procedure was used for the study and it was conducted in compliance with the OECD guideline 203. Based on nominal concentrations, experimental median lethal Concentrations [LC-50 (96 h)] for isopropyl 4-hydroxybenzoate on Zebra Fish Danio rerio was determine to be 3.125 mg/l. Based on the LC50 value, chemical consider to be toxic but on the basis of readily biodegradability criteria of test chemical, chemical consider to be nontoxic and not classified as per the CLP classification criteria.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

3.125 mg/L

Additional information

In different studies, the given test chemical has been investigated for toxicity of chemical on mortality of fishes to a greater or lesser extent. The studies are summarized as below –

 

The first key study was conducted to assess the effect of test chemical isopropyl 4-hydroxybenzoate on the mortality of fish Danio rerio. Test conducted according to OECD Guideline 203 (Fish, Acute Toxicity Test). The test substance was partially soluble in water. Therefore, the stock solution was prepared by dissolving 1 g of the test substance in 1 liters of potable water (passed through reverse osmosis system) with continuous 24 hours stirring, after stirring stock was analytically detected and the concentration found to be 222.61 mg/L. On the basis of stock concentration 222.61 mg/L further test concentrations calculated which was as follows 1.562 mg/L, 3.125 mg/L, 6.25 mg/L,12.5 mg/L, 25 mg/L respectively and Zebra Fish Danio rerio were exposed to these concentration for 96 hours. Bowl aquaria containing 2 liters of potable water (passed through reverse osmosis system) were loaded with 8 fishes. A static procedure was used for the study and it was conducted in compliance with the OECD guideline 203. Based on nominal concentrations, experimental median lethal Concentrations [LC-50 (96 h)] for isopropyl 4-hydroxybenzoate on Zebra Fish Danio rerio was determine to be 3.125 mg/l. Based on the LC50 value, chemical consider to be toxic but on the basis of readily biodegradability criteria of test chemical, chemical consider to be nontoxic and not classified as per the CLP classification criteria.

 

Similar short-term toxicity to Pimephales promelas was performed for 48 hrs at five nominal concentrations in a temperature-controlled incubator at 24°C with a 16:8 light: dark cycle.500 ml beaker was taken having 250 ml of test chemical. Test solution was prepared by dissolved in high-performance liquid chromatography grade acetone and delivered into RHW at 0.1% acetone. No aeration was used and LD 50 value was determined at 24 and 48 hrs. On the basis of above experiment result, the LD 50 value for Pimephales promelas for isopropylparaben (4191-73-5) was found to be 17.5 mg/L concentrations. Based on this value, it can be concluded that the test chemical Isopropyl 4-hydroxybenzoate can be considered as toxic to aquatic environment. Since the chemical is readily biodegradable in nature, chemical Isopropyl 4 -hydroxybenzoate can be considered as non-toxic to fish at environmentally relevant concentrations and can be considered to be not-classified as per the CLP classification criteria.

 

Thus based on the above both studies, chemical consider to be nontoxic and not classified as per the CLP classification criteria.