Hydrogen peroxide-urea

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1978

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Qualifier:

according to guideline

Guideline:

other: German Unified Methods for Investigation of Water, Wastewater and Sludge. L15. Fish test. Vom Wasser 46:291-295(1976)

Deviations:

no

GLP compliance:

no

Analytical monitoring:

not specified

Vehicle:

no

Test organisms (species):

Leuciscus idus melanotus

Details on test organisms:

Leuciscus idus melanotus; golden orfe

Test type:

static

Water media type:

freshwater

Total exposure duration:

48 h

Reference substance (positive control):

not specified

Duration:

48 h

Dose descriptor:

LC0

Effect conc.:

> 10 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Key result

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

> 10 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

48 h

Dose descriptor:

LC100

Effect conc.:

> 10 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Sublethal observations / clinical signs:

The 48 hour LC50 of urea in golden orfe fish is >10000 mg/L. This can also be considered as the NOEC. The results reported by the two laboratories were identical.

Validity criteria fulfilled:

not specified

Conclusions:

The LC50 of urea on golden orfe fish was determined to be >10000 mg/L after 48 h exposure.

Executive summary:

A set of 200 organic substances were tested by two laboratories. On of these substances was urea. The 48-hour LC50 of urea with Golden orfe fish was determiend to be >10000 mg/L. This can also be considered as the NOEC. The results reported by the two laboratories were identical. It can be concluded that urea is not acutely toxic to freshwater fish.

Reference 2

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1988

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Qualifier:

no guideline followed

Principles of method if other than guideline:

Acute toxicity test to freshwater fish

GLP compliance:

no

Analytical monitoring:

not specified

Vehicle:

not specified

Test organisms (species):

other: Barilius barna (Barna baril)

Details on test organisms:

Specimens were collected from the dtream Khandagaad, India, and were acclimatized under laboratory conditions for 15 days.
Fish were fed daily with rice bran.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Nominal and measured concentrations:

2500, 10000, 15000 and 20000 ppm (mg/L) plus control

Details on test conditions:

The test was conducted in experimental glass troughs. An initial range finding test was performed to assess the effective doses to be used in the main assay. Ten fish were tested per concentration. The fish were not fed during the test. Controls were not exposed to urea.

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

4 961 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

9 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

24 h

Dose descriptor:

LC50

Effect conc.:

18 600 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

17 860 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

72 h

Dose descriptor:

LC50

Effect conc.:

12 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

The LC50 after 96 h was determined to be 9100 mg/L (ppm). The NOEC was determined to be 4961 mg/L (ppm).

Sublethal observations / clinical signs:

Observations

The test fish, after introducing into different Urea concentrations, showed faster locomotion and opercular movement, surfacing and gulping of air. In the lethal concentration, the fish lost their sense of equilibrium, move vertically for sometime and finally turned with their belly upward before death. The profuse mucous secretion was also observed around the fish. Such secretions and mortality was not observed in the control set of the experiment.

Validity criteria fulfilled:

not specified

Conclusions:

The 96 hour LC50 of urea to B. barna was determined to be 9100 mg/L. The NOEC was determined to be 4961 mg/L.

Executive summary:

A study on Barilius barna hill stream freshwater fish was performed to test the acute toxicity of urea to fish. 10 acclimated fish were exposed to urea concentrations from 2500 to 20000 mg/L (ppm). The LC50 after 96 h of exposure was determined to be 9100 mg/L and the NOEC to be 4961 mg/L, respectively. In conclusion, urea is not acutely toxic to freshwater fish.

Reference 3

Endpoint:

short-term toxicity to fish

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

Please refer to section 13 for "Read-Across justification".

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

9 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: species: Barilius barna (Barna baril)

Key result

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

> 10 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: species: Leuciscus idus melanotus

Reference 4

Endpoint:

short-term toxicity to fish

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

Please refer to section 13 for "Read-Across justification".

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Key result

Duration:

7 d

Dose descriptor:

LC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: species: Oncorhynchus tschawytscha

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

37.4 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: species: Ictalurus punctatus

Reference 5

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1982

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

GLP compliance:

no

Analytical monitoring:

not specified

Details on sampling:

Water samples were taken initially and at 24 and 48 h for chlorophyll determination.

Vehicle:

no

Test organisms (species):

Ictalurus punctatus

Details on test organisms:

- Channel catfish, Inctalurus punctatus

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Test temperature:

22 +/- 2 °C

Nominal and measured concentrations:

0.29 mM (field study) = 9.86 mg/L
0, 0.06, 0.12, 0.24, 0.35, 0.47, 0.71, 0.94, 1.41, or 1.88 mM (laboratory study)

Key result

Duration:

48 h

Dose descriptor:

LC50

Remarks:

pond study

Effect conc.:

> 9.86 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: original value: 0.29 mM;

Duration:

96 h

Dose descriptor:

LC0

Remarks:

lab study

Effect conc.:

17 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Key result

Duration:

96 h

Dose descriptor:

LC50

Remarks:

lab study

Effect conc.:

37.4 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Sublethal observations / clinical signs:

Field study

No fish were killed in any tanks.

Laboratory studies on catfish

Channel catfish were exposed to concentrations of H2O2 varying from 0 to 1.88 mM. Fish treated with >0.94 mM H202 appeared irritable within 1 h of treatment, but first mortality did not occur before 12 h. Half of the fish treated with 1.41 and 1.88 mM were dead after 24 h; after 48 h, four fish were dead in the 0.94 mM treatment. After 96 h, no fish had died in any tanks treated with less than 0.94 mM H2O2. Cumulative mortalities after 96 h were 4, 9, and 10 in tanks treated with 0.94, 1.41, and 1.88 mM H2O2, respectively. The 96-h LD50 for H202 on catfish was 1.1 mM, and threshold toxicity (LD0) was approximately 0.5 mM

Validity criteria fulfilled:

not specified

Conclusions:

The LD50 under laboratory conditions was determined to be 37.4 mg/L. Under field study conditions the LD50 was determined to be >9.86 mg/L as no mortality was observed in the treatment group.

Executive summary:

A field and laboratory study were perfomed with Channel catfish, Inctalurus punctatus, to determined the short-term toxicity of hydrogen peroxide to the tested animals. In the field study one treatment of 9.28 mg/L (0.29 mM) was tested. After 48-hour exposure to the test item, no mortality was observed in both the control and the treatment group. Therefore, the LD50 was determined to be >9.28 mg/L. In the laboratory test, catfish were to concentration from 0.06 to 1.88 mM. Fish treated with concentration higher than 0.94 mM H2O2 appeared irritable within 1 h of treatment, but mortality occurred first after 12 hours. After 96 hours no fish were found dead in the treatments below 0.94 mM, while above this concentration dead fish were already observed after 24 and 48 hours. After 96-hour exposure the LD50 was detemine to be 1.1 mM equivalent to 37.4 mg/L

Reference 6

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1995

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Principles of method if other than guideline:

Method: Adult fish from commercial hatchery were distributed in tanks (12-13 °C, flow 45 L/min) and treated three times a wee with H2O2 until the first occurrence of ovulation. 18-22 fish were used in duplicate test at each concentration.

GLP compliance:

no

Test organisms (species):

Oncorhynchus tschawytscha

Details on test organisms:

- Spring chinook salmon Oncorhynchus tshawytscha
- Source: Oregon Department of Fish and Wildlife's Dexter Fonds Facility

Test type:

flow-through

Water media type:

saltwater

Test temperature:

12 - 13 °C

Nominal and measured concentrations:

25, 100, 250 mg/L

Details on test conditions:

About 200 adult spring chinook salmon were delivered to Smith Fairm Experimental Hatchery and distributed among eight 3.05 m circular tanks (water depth, 1.07 m; flow, 45 L/min; water temperature, 12 - 13 °C). Fish were allowed to become naturally infected with fungus. Then they were treated with hydrogen peroxide solutions at concentration levels of 25 and 100 mg/L. Thrice-weekly treatments were discontinued after the first occurrence of Ovulation was detected. Each day, the tanks were checked for fish mortality. The body surface and gills of dead fish were examined for the presence of fungus. Dead fish that had ovulated or spermiated were considered to have reached maturation before death and therefore were not counted as mortalities for the purposes of this study.

Reference substance (positive control):

yes

Remarks:

Malachite green (0.5 mg/L) and formalin (167 mg/L)

Key result

Duration:

24 h

Dose descriptor:

LC100

Effect conc.:

250 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: eggs

Key result

Duration:

7 d

Dose descriptor:

LC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

None of the dead fish treated with hydrogen peroxide at 100 mg/L had any sign of fungal infection, and only two dead fish treated with hydrogen peroxide at 25 mg/L had fungal infections. Treatment of rainbow trout eggs with hydrogen peroxide at 500 or 1,000 mg/L for 1 h was as effective as or more effective than formalin for Controlling fungal infection. The toxicity level for hydrogen peroxide on eggs was 1,500 mg/L. In the study study, adult spring chinook salmon treated at 250 mg/L died within 24 h of treatment, whereas fish treated with 100 or 25 mg/L showed no ill effects during a 1-week toxicity test. Hydrogen peroxide at either 100 or 25 mg/L resulted in fewer deaths with associated fungal infections than occurred among untreated controls.

Results with reference substance (positive control):

Fish exposed to malachite green had extremely rare incidences of fungal infection, and most survived to maturity. In tanks treated with formalin at 167 mg/L, none of the dead fish had associated fungal infections.

Conclusions:

At concentration of 25 mg/L two fish died (apparently in fungal disease) and there was no mortality at 100 mg/L. Additional toxicity studies showed that adult salmon treated at 250 mg/L died within 24 hours of treatment.

Executive summary:

A study on saltwater fish Oncorhynchus tshawytscha was conducted to determine the effect of hydrogen peroxide on fish infected with fungus. Hydrogen peroxide was tested at 2 different concentrations - 25 and 100 mg/L. At concentration of 25 mg/L two fish died (apparently in fungal disease) and there was no mortality at 100 mg/L. Additional toxicity studies showed that adult salmon treated at 250 mg/L died within 24 hours of treatment.

Description of key information

The short-term toxicity to fish was determined with respect to H2O2, as this degradation products of the test item showed the most toxic effects on the tested animals. The other degradation product, urea, is not toxic to fish. Therefore, the LD50 was determined to be 37.4 mg/L.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

37.4 mg/L

Additional information

The short-term toxicity to fish of the test item was addressed with a read-across approach to its degradation products - urea and hydrogen peroxide. The test item is not stable and decomposes rapidly to urea and H2O2, therefore, the read-across to both substances is considered acceptable.

Publications reporting the short-term toxicity to freshwater and slatwater fish of urea and hydrogen peroxide were used in a read-across weight of evidence approach.

Urea

In a study, a set of 200 organic substances were tested by two laboratories. On of these substances was urea. The 48-hour LC50 of urea with Golden orfe fish was determiend to be >10000 mg/L. This can also be considered as the NOEC. The results reported by the two laboratories were identical. It can be concluded that urea is not acutely toxic to freshwater fish.

Another study on Barilius barna hill stream freshwater fish was performed to test the acute toxicity of urea to fish. 10 acclimated fish were exposed to urea concentrations from 2500 to 20000 mg/L (ppm). The LC50 after 96 h of exposure was determined to be 9100 mg/L and the NOEC to be 4961 mg/L, respectively. In conclusion, urea is not acutely toxic to freshwater fish.

Hydrogen peroxide (H2O2)

A study on saltwater fish Oncorhynchus tshawytscha was conducted to determine the effect of hydrogen peroxide on fish infected with fungus. Hydrogen peroxide was tested at 2 different concentrations - 25 and 100 mg/L. At concentration of 25 mg/L two fish died (apparently in fungal disease) and there was no mortality at 100 mg/L. Additional toxicity studies showed that adult salmon treated at 250 mg/L died within 24 hours of treatment.

A field and laboratory study were perfomed with Channel catfish, Inctalurus punctatus, to determined the short-term toxicity of hydrogen peroxide to the tested animals. In the field study one treatment of 9.28 mg/L (0.29 mM) was tested. After 48-hour exposure to the test item, no mortality was observed in both the control and the treatment group. Therefore, the LD50 was determined to be >9.28 mg/L. In the laboratory test, catfish were to concentration from 0.06 to 1.88 mM. Fish treated with concentration higher than 0.94 mM H2O2 appeared irritable within 1 h of treatment, but mortality occurred first after 12 hours. After 96 hours no fish were found dead in the treatments below 0.94 mM, while above this concentration dead fish were already observed after 24 and 48 hours. After 96-hour exposure the LD50 was detemine to be 1.1 mM equivalent to 37.4 mg/L.

In conclusion, urea was determined to not be toxic to fish, while hydrogen peroxide H2O2 showed the most toxic effects at lower concentration. As the H2O2 is the degradation product showing the most toxic effects to fish, the short-term toxicity of the test item was based on the effects of H2O2. Therefore, the LD50 of hydrogen peroxide-urea (1:1) was determined to be 37.4 mg/L.