Catalase

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:

05 August 2010 to 07 October 2010

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The study was conducted according to the OECD Guideline 203 but is not in compliance with GLP.

Justification for type of information:

For industrial enzymes, the PNEC (predicted no effect concentration) value for enzymes in general is considered the highest dose tested for a given endpoint in studies conducted and published by the enzyme industry. The one exception is for proteases and oxidoreductases, where effects may be observed at lower concentrations. Similarly, although the acute fish study with catalase was not conducted GLP, the 96-hour median lethal concentration (LC50) for catalase was greater than the limit dose of 100 mg/L. The weight-of-evidence indicates that enzymes in general are not ecotoxic.

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

GLP compliance:

no

Remarks:

See 'Justification for type of information'

Analytical monitoring:

no

Vehicle:

yes

Remarks:

(dilution in water)

Test organisms (species):

Pimephales promelas

Details on test organisms:

Experimental Organism
- Source: Stillmeadow Inc.
- Age ans size: Juvenile; Range finding: 0.0133-0.02659 g and 11-13 mm; Limit: 0.0160-0.0455 g and 11-15 mm
- Quantity: Range finding: 10 per test concentration and control; Limit: 30 per test concentration and control. The organisms were randomized into containers containing the appropriate concentration of test substance

Organism Husbandry
- Test Chambers: Range finding: 1 L glass beakers filled with 1000 mL of the appropriate solution. Limit: 1 L glass beakers filled with 1000 mL of the appropriate solution
- Loading: Maximum loading of 1.0 g fish/liter
- Holding: All fish were held in the laboratory at least 14 days before they were used for testing. The fish were held in water of the quality used in the test for at least seven days immediately before testing. No signs of disease, injury, stress or mortality were observed during acclimation.

Environmental Controls:
- Set to Maintain: Temperature Range of 23 ± 2°C; 16-hours light/8-hours dark cycle
- Actual Temperature: 21-24°C
- Food: Fish were fed daily until 48 hours before the test was dosed. Fish were not fed during the test.

Test type:

static

Water media type:

other: moderately hard synthetic freshwater

Limit test:

yes

Total exposure duration:

96 h

Test temperature:

24°C

pH:

7.8

Dissolved oxygen:

94% in 0 mg/L 95% in 100 mg/L

Conductivity:

311 µmhos/cm in 0 mg/L, 352 µmhos/cm in 100 mg/L

Nominal and measured concentrations:

Nominal: 0 and 100 mg/L (equivalent to 3.48 mg active enzyme protein/L)

Details on test conditions:

Range-finding Test: A preliminary range-finding test was conducted using concentrations of 0.1, 1.0, 10, 50, and 100 mg/L of the test substance. Following randomization, ten organisms were placed into each test beaker containing the appropriate concentration of test substance. Ten organisms, which were not exposed to test substance, served as controls to demonstrate the condition of the test population. At 0, 24, 48, 72, and 96 hours following dosing, each container was examined for mortality and the number of live fish was recorded.

Limit Test: A limit test was conducted using a concentration of 100 mg/L of the test substance. The test level consisted of three replicates often fish. Three replicates containing ten fish each were not exposed to test substance and served as controls to demonstrate the condition of the test population. At 0,6,24,48, 72 and 96 hours following dosing, each of the aquaria was examined for mortality and the number of live fish was recorded.

Chemical and Physical Monitoring: The following measurements were recorded daily during testing: dissolved oxygen, temperature, conductivity and pH of control and treated containers.

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: no effetcs observed

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 3.48 mg/L

Nominal / measured:

nominal

Conc. based on:

other: active enzyme protein

Basis for effect:

other: no effects observed

Details on results:

A 73% survival rate was observed in fish treated with 100 mg/L of the test substance. A survival rate of 93% was observed in the control fish respectively. The 96-hour median lethal concentration (LC50) of the test substance was greater than 100 mg/L.

Sublethal observations / clinical signs:

Limit test:

Concentration (mg/L)	Replicate	Number of Surviving Organisms
		0 Hours	6 Hours	24 Hours	48 Hours	72 Hours	96 Hours	Survival (%)
0	A	10	10	10	10	10	10	93
	B	10	10	10	10	9	9
	C	10	10	10	10	10***	9
100	A	10	10	9*	5**	4	2	73
	B	10	10	10	10	10	10
	C	10	10	10	10	10	10

*One organism found dead with fibrous growth covering all of its body.

**Organisms found dead with fibrous growth covering all of their body

***One organism looks lethargic

Chemical and Physical Monitoring Data :

Table 1. Temperature (degree Celsius) 

Concentration (mg/L)	Limit Test
	0 hours	6 Hours	24 Hours	48 Hours	72 Hours	96 Hours
0	24	21+	21+	21+	21+	21+
100	24

 + -Temperature taken from chamber thermometer

Table2. pH

Concentration (mg/L)	Limit Test
	0 hours	6 Hours	24 Hours	48 Hours	72 Hours	96 Hours
0	7,8	7,4	7,5	7,7	7,4	7,7
100	7,8	7,4	7,6	7,5	7,2	7,6

 

 Table 3. Dissolved Oxygen (%) 

Concentration (mg/L)	Limit Test
	0 hours	6 Hours	24 Hours	48 Hours	72 Hours	96 Hours
0	94	86	85	83	87	86
100	95	86	85	80	81	81

 

Table 4. Conductivity (µmhos/cm)

Concentration (mg/L)	Limit Test
	0 hours	6 Hours	24 Hours	48 Hours	72 Hours	96 Hours
0	311	309	301	317	318	317
100	352	351	346	378	357	369

Validity criteria fulfilled:

yes

Remarks:

(in both range finding and limit test control mortality did not exceed 10%)

Conclusions:

The 96-hour median lethal concentration (LC50) of Catalase was greater than 100 mg/L corresponding to 3.48 mg active enzyme protein/L.

Executive summary:

The study was conducted to assess the toxicity of Catalase to the fathead minnow (Pimephales promelas) in a 96-hour test according to the OECD Guideline 203.

Test concentrations were determined by preliminary range-finding test.A test substance concentration of 100 mg/L was administered to the test system, Pimephales promelas, in moderately hard synthetic freshwater. Three replicates of ten organisms were treated with each concentration of the test substance. A control group containing thirty organisms was not exposed to test substance. Dissolved oxygen, temperature, conductivity and pH measurements were recorded at dosing and daily through study termination. Observations of mortality were made at 0, 6, 24, 48, 72 and 96 hours after treatment. The test was terminated after 96±1 hours of exposure.

The 96-hour median lethal concentration (LC50) of the test substance was greater than 100 mg/L corresponding to 3.48 mg active enzyme protein/L.

Description of key information

Under the conditions of the test, Catalase was not found to be acutely toxic to the fathead minnow (Pimephales promelas). Consequently, the 96-hour LC50 value for Catalase could not be calculated and must be >100 mg/L corresponding to 3.48 mg aep (active enzyme protein)/L.

Additional information

The study was conducted to assess the toxicity of Catalase to the fathead minnow (Pimephales promelas) in a 96-hour test according to the OECD Guideline 203. Test concentrations were determined by preliminary range-finding test.A test substance concentration of 100 mg/L was administered to the test system, Pimephales promelas, in moderately hard synthetic freshwater. Three replicates of ten organisms were treated with each concentration of the test substance. A control group containing thirty organisms was not exposed to test substance. Dissolved oxygen, temperature, conductivity and pH measurements were recorded at dosing and daily through study termination. Observations of mortality were made at 0, 6, 24, 48, 72 and 96 hours after treatment. The test was terminated after 96±1 hours of exposure. The 96-hour median lethal concentration (LC50) of the test substance was greater than 100 mg/L corresponding to 3.48 mg active enzyme protein/L.