1-[(4-chlorophenyl)methyl]-1-cyclopentyl-3-phenylurea

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:

supporting study

Study period:

1983-06-02 to 1983-07-06

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline available

Principles of method if other than guideline:

Although a test guideline was not reported, the results of the test are well in line with other fish studies and therefore the study is acceptable.

GLP compliance:

yes

Specific details on test material used for the study:

The test material is in a white crystal form.

Analytical monitoring:

no

Vehicle:

yes

Remarks:

Acetone

Details on test solutions:

Required amounts of pencycuron were weighed for each level and 7.5 ml of acetone added. This mixture was added to sufficient bioassay water in each of six labeled 19-liter glass jars to produce 15 liters of each of the following nominal concentrations: 0, 150, 220, 320, 470 and 690 ppm. The compound remained visible as a cloudiness in the water column, a precipitate on the bottom of the jar and a film on the water surface. A seventh jar contained no compound or solvent. On day 0 ten fish were introduced into each jar.

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: rainbow trout (Oncorhynchus mykiss)
- Weight at study initiation: 0.3 g

ACCLIMATION
- Acclimation period: 5 days
- Feeding: They were fed Ralston Purina Trout Chow.

FEEDING DURING TEST
During the 96-hour experiment the fish were not fed.

Test type:

static

Water media type:

other: reconstituted water

Limit test:

no

Total exposure duration:

96 h

Hardness:

42 ppm

Test temperature:

10 to 12°C

pH:

6.03 to 7.16

Dissolved oxygen:

4.6 to 9.2 ppm

Salinity:

30 ppm

Nominal and measured concentrations:

Nominal concentrations: 0, 150, 220, 320, 470 and 690 ppm

Details on test conditions:

TEST SYSTEM
- Test vessel: glass jars
- Aeration: No
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1

OTHER TEST CONDITIONS
- Photoperiod: 16 hours light daily

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 0.3 mg/L

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: based on test substance aqueous solubility.

Details on results:

Actual concentrations of the test substance were not determined. Cloudiness in the water column, a precipitate on the bottom, and a film on the ppm; pH values varied between and the test temperature between 10°C and 12°C. No acute mortality or other adverse effects were observed in the control group and in the groups exposed to the test substance. The authors state that the 96h-LC50 and the 96h-NOEC are >690 ppm and =690 ppm, respectively. Concentrations of pencycuron and responses by the test species are presented in Table 1.

Sublethal observations / clinical signs:

There were no clinical signs or death in any of the concentrations.

 

See "Attachments" in "Overall remarks, attachments" for the table.

Validity criteria fulfilled:

yes

Remarks:

The test substance is not toxic to rainbow trout at a level of its aqueous solubility. Chemical analysis is not available, however, the results of the test are well in line with other fish studies and therefore the study is acceptable.

Conclusions:

As adverse effects to the fish were not observed it can be concluded that under the circumstances of the test, the test substance is not toxic at a level of its aqueous solubility. The dissolved oxygen concentration was below the allowed 60%, but as no adverse effects were observed this is not considered to have influenced the results of the test. The amount of solvent was above the allowed amount of 100 mg/L, however, this has not affected the results of the test.
It is not clear to which extent the nominal concentration corresponds with the bio-available fraction of the test substance, as the test concentration was above the solubility of the active ingredient (0.3 mg/L). Un-dissolved material was observed and chemical analysis has not been carried out. The reported 96h-LC50 and 96h-NOEC are based on nominal concentrations, however, it must be assumed that the amount of test substance dosed above the aqueous solubility of the active ingredient is not bio-available and does not contribute to the exposure of fish to the test substance. Therefore, the 96h-LC50 of pencycuron to the rainbow trout based on pencycuron’s aqueous solubility is >0.3 mg a.s./L.

Executive summary:

The acute toxicity of pencycuron to rainbow trout (Oncorhynchus mykiss) was determined. Fish were exposed to nominal concentrations of 150, 220, 320, 470 and 690 ppm, alongside a control. No clinical signs or deaths occurred in any of the concentrations. Taking the behaviour of the test substance into account, it is concluded that the 96h-LC₅₀ of pencycuron to rainbow trout (Oncorhynchus mykiss) in a static test condition is >0.3 mg a.s./L (aqueous solubility level).

Reference 2

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

2001-03-05 to 2001-09-03

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EPA OPP 72-1 (Fish Acute Toxicity Test)

Version / remarks:

1982/1985

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 850.1075 (Freshwater and Saltwater Fish Acute Toxicity Test)

Version / remarks:

1996

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

Version / remarks:

1992

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Version / remarks:

1992

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

The test material is a white solid.

Analytical monitoring:

yes

Details on sampling:

Immediately prior to the test, water samples were taken from the center of the aquaria for analytical determination of the active substance concentration. Analytical determinations of the active substance concentrations were made in the test medium on day 0, on day 1, on day 2 and on day 3. Analysis was by HPLC-UV.

Vehicle:

yes

Remarks:

Acetone 0.1 mL/L

Details on test solutions:

Based on historical data the definitive test concentration was set at 0.30 mg test item/L (nominal). A stock solution was prepared immediately before the start of the test as well as before changing the test medium in order to get the corresponding test concentration. 150 mg test item was filled up with acetone p.a. to 50 ml solution to make the stock solution. 4 ml of the stock solution was then transferred into 40 L test water.

Test organisms (species):

Lepomis macrochirus

Details on test organisms:

TEST ORGANISM
- Common name: bluegill (Lepomis macrochirus)
- Length at study initiation: 4.1 ± 0.13 cm
- Weight at study initiation: 0.80 ± 0.11 g

ACCLIMATION
- Acclimation period: 14 days
- Feeding: During the acclimation period they were fed commercial trout food. They were not fed 48h before and during the study.
- Health during acclimation (any mortality observed): Less than 3% mortality was noted prior to the test initiation and all unsuitable fish (e.g. injured, deformed, etc.) were eliminated from the test prior to the assignment of test groups
There was a prophylactic treatment directly after arriving of the fish with Oxytetracyclin-Hydrochlorid (4 g/100 I water, 3*24h). So, the Bluegills were used in the study 1 month after the end of prophylactic treatment.

Test type:

semi-static

Water media type:

other: Reconstituted water

Limit test:

yes

Total exposure duration:

96 h

Hardness:

40 - 60 mg CaCO3/L

Test temperature:

20.6°C to 23.5°C

pH:

7.3 to 7.4

Dissolved oxygen:

92 to 106% oxygen saturation

Conductivity:

<0.2 µS/cm

Nominal and measured concentrations:

Nominal concentration: 0.30 mg a.s./L
Measured concentration: 0.260 mg a.s./L

Details on test conditions:

TEST SYSTEM
- Test vessel: The aquaria were made of glass and had a size of 32 x 36 x 38 cm (I x d x h). The test volumes amounted to 40 L.
- No. of organisms per vessel: 30 fishes
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- No. of vessels per vehicle control (replicates): 1
- Biomass loading rate: 0.60 g fish/L test medium

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Reconstituted water was used for the test. It was prepared by adding salt stock solutions to demineralized water (conductivity <0.2 µS/cm).
- Intervals of water quality measurement: The test water was periodically analysed for undesired impurities periodically.

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

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 0.3 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: based on test substance aqueous solubility.

Details on results:

The LC50 (96h) of Pencycuron (99.3%) to Bluegill (Lepomis macrochirus) in a semi-static 96-hour-test was determined to be >0.260 mg a.s./L (Table 1), the practical limit of its solubility in water.

In this test, thirty fish were exposed to a nominal (mean measured) concentration of 0.30 (0.260) mg a.s./L. An additional group of thirty fish was exposed to the highest used solvent concentration (4 ml acetone p.a./40 I test water = 100 µl acetone p.a./L test water). A further control group of thirty fish was exposed to untreated test water. There were neither adverse effects nor mortality in the control and the solvent control group (Table 1).

In the tested concentration at 0.260 mg a.s./L all fish showed the following symptoms: were inactive or displayed abnormally low activity, laid inactive on the bottom of the aquarium (Table 1).

The test ran under semi-static conditions. The test media were changed every day. Analytical determinations of the active ingredient concentration were made in freshly prepared test media and in aged test media, respectively. Based on analytical determination of Pencycuron (in water by HPLC) a mean measured value (day 0/day 1) of 87% of nominal was found (Table 6). All reported results refer to the mean measured concentration of the freshly prepared and aged test medium of day 0. The analytical measurements of day 1-3 verify this value.

Dissolved oxygen (DO) concentrations ranged from 92 to 106 percent oxygen saturation in all aquaria (Table 3). pH values ranged from 7.3 to 7.4 in all aquaria (Table 4). The test temperature ranged from 20.6°C to 23.5°C (Table 5).

Sublethal observations / clinical signs:

All fish showed the following symptoms: were inactive or displayed abnormally low activity, laid inactive on the bottom of the aquarium.

 

See "Attachments" in "Overall remarks, attachments" for the tables.

Validity criteria fulfilled:

yes

Conclusions:

The test was carried out as a limit test with one test substance concentration. There were neither adverse effects nor mortality in the control group and the solvent control group. In the tested concentration at 0.260 mg a.s./L all fish showed the following symptoms: were inactive or displayed abnormally low activity, laid inactive on the bottom of the aquarium. Pencycuron caused no acute mortality within the limits of water solubility. The NOEC was =0.3 mg a.s./L based on nominal concentration and =0.260 mg a.s./L based on mean measured concentration. The 96h-LC50 was >0.3 mg a.s./L based on nominal concentration and >0.260 mg a.s./L based on mean measured concentration.

Executive summary:

The acute toxicity of pencycuron to bluegill (Lepomis macrochirus) was determined. Fish were exposed to a nominal concentration of 0.30 mg a.s./L alongside a control and solvent control. Pencycuron caused no acute mortality within the practical limit of its water solubility under conditions of testing. The LC₅₀ (96 hours) of pencycuron to bluegill (Lepomis macrochirus) in a semi-static test was determined to be >0.3 mg a.s./L based on nominal concentration and >0.260 mg a.s./L based on measured concentration.

Reference 3

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

1989-07-03 to 1990-02-23

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

EPA OPP 72-1 (Fish Acute Toxicity Test)

Version / remarks:

October 1982

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

The test material is in an off white powder form.

Analytical monitoring:

yes

Details on sampling:

Immediately before the start of the test, water samples were taken from the centre of the aquaria for analytical determination of active substance concentrations. Analytical determinations of the active substance concentrations were done at day 0, 1, 2 and at the end of the test in a water sample, taken from the center of the aquaria. Analysis was by HPLC-UV.

Vehicle:

no

Details on test solutions:

The test substance was directly applicated into the test water without a solvent and was most uniformly dispensed in the water by vigorous stirring. The nominal concentration tested was 93.6 mg a.s./L. In addition, a control without any additions was included in the test.

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: Rainbow trout (Salmo gairdneri)
- Length at study initiation: 5.0 ± 0.3 cm
- Weight at study initiation: 1.3 ± 0.2 g

ACCLIMATION
- Acclimation period: 14 days
- Feeding during acclimation: During this period they were fed a commercial trout diet. They were not fed 48 hours before and during the study.

Test type:

static

Water media type:

other: Reconstituted water

Limit test:

yes

Total exposure duration:

96 h

Hardness:

40 - 60 mg CaCO3/L

Test temperature:

12 ± 1°C

pH:

7.3 - 7.9

Dissolved oxygen:

8.9 - 11.8 mg/L

Nominal and measured concentrations:

Nominal concentration: 93.6 mg a.s./L
Measured concentration: 0.26 mg a.s./L

Details on test conditions:

TEST SYSTEM
- Test vessel: The aquaria were made of glass and had a size of 32 x 36 x 38 cm (l x d x h). The test volumes amounted to 40 L.
- Aeration: ca. 200 ml air/min
- No. of organisms per vessel: 30 fish
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Reconstituted water aerated to saturation with following ionic concentrations (according to ISO) was used: 0.384 mmole/ Ca2+, 0.096 mmole/L Mg2+, 0.1 48 mmole/L Na+, 0.015 mmole/L K+, 0.783 mmole/ Cl-, 0.148 mmole/L HC03-, and 0.096 mmole/L S042-.
- Intervals of water quality measurement: The test water is analysed for unwanted contaminants at intervals of about 3 months.

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

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 0.3 mg/L

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: based on test substance aqueous solubility.

Details on results:

The test shows, that the lowest lethal concentration (LLC) of pencycuron to rainbow trout is greater than 93.6 mg a.s./L. Therefore, it is not necessary to determine the LC50. All fish exposed to 93.6 mg a.s./L showed symptoms of intoxication (slightly irregular swimming behaviour, swimming mainly at the bottom of the aquaria, and apathy).

There was no mortality or symptoms of intoxication in the control (Table 1).

The solubility of the test substance is much lower than the nominal concentration tested in this experiment. Accordingly, the test substance precipitated, sedimented to the bottom of the aquarium and rose to the water surface. Thus a representative sampling for analysis of the active substance was not possible.

Sublethal observations / clinical signs:

All fish exposed to 93.6 mg a.s./L showed symptoms of intoxication (slightly irregular swimming behaviour, swimming mainly at the bottom of the aquaria, and apathy).

 

See "Attachments" in "Overall remarks, attachments" for the tables.

Validity criteria fulfilled:

yes

Conclusions:

The test was carried out as a limit test with one test substance concentration. No acute mortality was observed in the control or dose group. However, in the dose group, all surviving fish showed a slight irregular swimming behaviour, apathy, or were swimming mainly at the bottom of the aquaria. It is not clear to what extent the nominal concentrations correspond with the bio-available fraction of the test substance, as the test concentration was above the solubility of the active ingredient (0.3 mg/L) and un-dissolved material was observed.
The reported 96h-LC50 and 96h-NOEC are based on nominal concentrations. It must be assumed that the amount of test substance dosed above the aqueous solubility of the active ingredient is not bioavailable and does not contribute to the exposure of fish to the test substance. Adverse effects to the fish were observed, however, there was no acute mortality. Taking the behaviour of the test substance into account, it is concluded that the 96h-LC50 is >0.3 mg a.s./L (aqueous solubility level) and the 96h-NOEC for mortality and condition (behaviour) =0.3 mg a.s./L and <0.3 mg a.s./L, respectively.

Executive summary:

The acute toxicity of pencycuron to rainbow trout (Salmo gairdneri) was determined. Fish were exposed to a nominal concentration of 93.6 mg a.s./L alongside a control. Adverse effects to the fish were observed, however, there was no acute mortality. Taking the behaviour of the test substance into account, it is concluded that the 96h-LC₅₀ of pencycuron to rainbow trout (Salmo gairdneri) in a static test is >0.3 mg a.s./L (aqueous solubility level) and the 96h-NOEC for mortality and condition (behaviour) ≥0.3 mg a.s./L and <0.3 mg a.s./L, respectively.

Reference 4

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2001-06-25 to 2001-10-31

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Version / remarks:

1992

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPP 72-1 (Fish Acute Toxicity Test)

Version / remarks:

1982/1985

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 850.1075 (Freshwater and Saltwater Fish Acute Toxicity Test)

Version / remarks:

1996

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

Version / remarks:

1992

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

The test material is a colorless crystal.

Analytical monitoring:

yes

Details on sampling:

Analytical determinations of the active ingredient concentrations were made in the test medium on day 0, on day 1, on day 2 and on day 3.

Vehicle:

yes

Remarks:

Acetone 0.1 mL/L

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Controls: Control and solvent control
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): Acetone
- Other relevant information: A stock solution was prepared immediately before the start of the test as well as before changing the test medium in order to get the corresponding test concentration. The test medium was changed every day.
Stock solution: 150 mg test item filled up with acetone p.a. to 50 mL stock solution. 4mL of the stock solution was transferred into 40L test water to make a nominal test concentration of 0.30 mg a.s./L.
The aquaria were made of glass and had a size of 32 x 36 x 38 cm (I x d x h). The test volumes amounted to 40 L. For the concentration tested one aquarium was used. At the start of the test, thirty fish were randomly introduced into the aquarium using a randomization table.

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: Rainbow Trout (Oncorynchus mykiss)
- Strain: lot F 2/01
- Length at study initiation (Mean + SD): 4.5 + 0.33 cm
- Weight at study initiation (Mean + SD): 0.90 ± 0.28 g
- Biomass loading: 0.675 g fish/L test medium

ACCLIMATION
- Acclimation period: 14 days
- Feeding frequency during acclimation: During the acclimation period they were fed commercial trout. They were not fed 48h before and during the study.
- Health during acclimation (any mortality observed): Less than 3 % mortality was noted prior to the test initiation and all unsuitable fish (e.g. injured, deformed, etc.) were eliminated from the test prior to the assignment of test groups.

FEEDING DURING TEST
- Food type: They were not fed during the study.

Test type:

semi-static

Water media type:

other: Reconstituted water

Limit test:

yes

Total exposure duration:

96 h

Test temperature:

10.4 - 11.9°C

pH:

7.1 - 7.4

Dissolved oxygen:

99 - 105 %

Nominal and measured concentrations:

Nominal (mean measured) concentration of 0.30 (0.267) mg a.s./L.

Details on test conditions:

TEST SYSTEM
- Test vessel: 40 L glass aquaria
- Aeration: The water was than aerated to reach the oxygen saturation point
- No. of organisms per vessel: 30 fish
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- No. of vessels per vehicle control (replicates): 1
- Biomass loading rate: 0.675 g fish/L test medium

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Reconstituted water was used for the test. It was prepared by adding salt stock solutions to demineralized water (conductivity < 0.2 uS/cm) to yield the following ionic concentrations (according to ISO): 0.384 mmole/L Ca2+, 0.096 mmole/L Mg2+, 0.148 mmole/L Na+, 0.015 mmole/L K+, 0.783 mmole/L Cl-, 0.148 mmole/L HCO3-, and 0.096 mmole/L SO42-.

OTHER TEST CONDITIONS
- Photoperiod: 16/8 hour light/dark

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): During the test, fish were examined after four hours and then daily for mortalities and signs of poisoning.

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 0.3 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: based on nominal concentration

Details on results:

In this test thirty fish were exposed to a nominal (mean measured) concentration of 0.30 (0.267) mg test item (a.s.)/L. An additional group of thirty fish was exposed to the highest used solvent concentration (4 ml acetone p.a./40 L test water = 100 µL acetone p.a./L test water). A further control group of thirty fish was exposed to untreated test water. There were neither adverse effects nor mortality in the control and the solvent control group (Table 1).

In the test level at 0.267 mg a.s./L all fish showed the following symptoms: were inactive or displayed abnormally low activity, laid inactive on the bottom of the aquarium (Table 1).

The test ran under semistatic conditions. The test media were changed every day. Analytical determinations of the active ingredient concentration were made in freshly prepared test media and in aged test media, respectively. Based on analytical determination of Pencycuron (in water by HPLC) a mean measured value (day 0/day 1) of 89% of nominal was found (Table 6). All reported results refer to the mean measured concentration of the freshly prepared and aged test medium of day 0. The analytical measurements of day 1 - 3 verify this value.

The LC50 (96h) of Pencycuron (99.3%) to Rainbow Trout (Oncorhynchus mykiss) in a semi-static 96-hour-test was determined to be >0.267 mg a.s./L (Table 1), the practical limit of its solubility in water under conditions of testing. The 96h-NOEC values for mortality and condition (behaviour) are =0.3mg a.s./L and <0.3 mg a.s./L, respectively.

Sublethal observations / clinical signs:

In the test level at 0.267 mg a.s./L all fish showed the following symptoms: were inactive or displayed abnormally low activity, laid inactive on the bottom of the aquarium.

 

See "Attachments" in "Overall remarks, attachments" for the tables.

Validity criteria fulfilled:

yes

Conclusions:

The test was carried out as a limit test with one test substance concentration. No acute mortality was observed at any of the exposure concentrations, however, in the dose group, all surviving fish showed inactivity or laid inactive on the bottom of the aquarium. Therefore, the 96h-LC50 is >0.3 mg a.s./L and the 96h-NOEC values for mortality and condition (behaviour) are =0.3mg a.s./L and <0.3 mg a.s./L, respectively based on nominal concentration.

Executive summary:

The acute toxicity of pencycuron to rainbow trout (Oncorhynchus mykiss) was determined. Fish were exposed to a nominal concentration of 0.30 mg test item (a.s.)/L alongside a control and solvent control. Pencycuron caused no acute mortality within the practical limit of its water solubility under conditions of testing. The LC₅₀ (96 hours) of pencycuron to rainbow trout (Oncorhynchus mykiss) in a semi-static test was determined to be >0.3 mg a.s./L based on nominal concentration and >0.267 mg a.s./L based on measured concentration.

Description of key information

An acute 96-h toxicity test was conducted to estimate the toxicity of Pencycuron Rainbow Trout (Oncorhynchus mykiss). Based on nominal concentrations of Pencycuron the 96-h LC₅₀ was determined to be >0.3 mg/L.

 

Test species	Result	Assessment	Reference
Rainbow trout (Oncorhynchus mykiss)	96-h LC50 > 0.3 mg a.s./L (nominal)	Key study	Dorgerloh & Sommer (2001)
Bluegill sunfish (Lepomis macrochirus)	96-h LC50 > 0.3 mg a.s./L (nominal)	Supporting study	Dorgerloh & Sommer (2001)
Rainbow trout (Salmo gairdneri)	96-h LC50 > 0.3 mg a.s./L	Supporting study	Grau (1990)
Bluegill sunfish (Lepomis macrochirus)	96-h LC50 = 127 mg a.s./L	Study is considered as not acceptable due to major deviations from the current OECD 203 guideline and no clear dose-response relationship.	Carlisle & Roney (1983)
Rainbow trout (Oncorhynchus mykiss)	96-h LC50 > 0.3 mg a.s./L	Supporting study	Carlisle & Roney (1983)

 

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Dose descriptor:

LC50

Effect concentration:

> 0.3 mg/L