Fenamiphos

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:

2001-04-02 to 2001-07-18

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:

EPA-FIFRA § 72-1/SEP-EPA-540/9-85-006 (1982/1985)

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

Public Draft, 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:

rev.1992

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

- Name: Fenamiphos
- CAS No.: 22224-92-6

Analytical monitoring:

yes

Details on sampling:

- Sampling method: medium taken at the beginning of the test, on day 2 and at the end of the test
- Sample storage conditions before analysis: stored frozen until analysis

Vehicle:

yes

Remarks:

dimethylformamide

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: preparation of stock solution (40 mg test item filled up with dimethylformamide p.a. to 50 mL solution), treatments were prepared by sequential dilution of the stock solution to obtain nominal test item concentrations of 40.0, 20.0, 10.0, 5.0 and 2.5 µg test item\L
- Controls: negative control (test water only), solvent control (50 µl dimethylformamide/L test water)
- Chemical name of vehicle: dimethylformamide
- Concentration of vehicle in test medium: 50 µl dimethylformamide/L test water
- Test concentration separation factor: 2
- Evidence of undissolved material: no

Test organisms (species):

Lepomis macrochirus

Details on test organisms:

TEST ORGANISM
- Common name: bluegill fish
- Lot: F 3/00 E
- Source: Osage Catfisheries, Inc., Lake Road 54-56, Osage Beach, Mo 65065, USA
- Age at study initiation: not specified
- Length at study initiation: not specified
- Weight at study initiation: not specified
- Maintenance of the brood fish: culture tanks, 16/8 hour light/dark photoperiod

ACCLIMATION
- Acclimation period: at least 14 days prior to testing
- Acclimation conditions: primarily acc. to Brauhn et al.
- Type and amount of food during acclimation: not specified
- Feeding frequency during acclimation: not specified
- Health during acclimation: 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: no

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

none

Hardness:

40 - 60 mg CaCO3/L

Test temperature:

21.3 °C - 22.5 °C

pH:

7.1 - 7.4

Dissolved oxygen:

92 % - 102 %

Salinity:

not applicable

Conductivity:

not specified

Nominal and measured concentrations:

Nominal: 2.50, 5.00, 10.0, 20.0 and 40.0 µg a.s./L; Measured: 1.75, 3.38, 7.03, 14.0, 32.4 µg a.s./L (mean measured)

Details on test conditions:

TEST SYSTEM
- Test vessel: aquaria
- Type: not specified
- Material, size, headspace, fill volume: glass, 32 x 36 x 38 cm (I x d x h), 40 L fill volume
- Aeration: no active aeration
- No. of organisms per vessel: 10
- No. of vessels per concentration: 1
- No. of vessels per control: 1
- No. of vessels per vehicle control: 1
- Biomass loading rate: not specified

TEST MEDIUM / WATER PARAMETERS
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):

Ca++: 0.384 mmole/L
Mg++: 0.096 mmole/L
Na+: 0.148 mmole/L
K+: 0.015 mmole/L
Cl-: 0.783 mmole/L
HC03-: 0.148 mmole/L
SO4--: 0.096 mmole/L

The water was than aerated to reach the oxygen saturation point.

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16/8 hour light/dark
- Light intensity: not specified

EFFECT PARAMETERS MEASURED: mortality and behavioral observations (inactive or displayed abnormally low activity, laboured respiration, laid inactive on the bottom of the aquarium, weaker coloration, laid on their sides or backs) 4, 24, 48, 72 and 96 hours after test initiation

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2
- Range finding study: no, concentrations were derived based on historical data

Reference substance (positive control):

not required

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

9.3 µg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

act. ingr.

Basis for effect:

mortality (fish)

Remarks on result:

other: measured mean (not further specified); 95% confidence interval: 6.85 -12.8

Details on results:

- Other abnormalities: at the test item concentration level 7.03 to 32.4 µg a.i./L fish were inactive or displayed abnormally low activity, showed laboured respiration, laid inactive on the bottom of the aquarium, showed weaker coloration, laid on their sides or backs
- Observations on body length and weight: no
- Other biological observations: not reported
- Mortality of control: no
- Any observations that might cause a difference between measured and nominal values: not reported

Results with reference substance (positive control):

not applicable

Reported statistics and error estimates:

Whenever possible, the LC50 values and the 95%-confidence intervals were calculated every 24-hour using a computer program which estimated the LC50 using one of three statistical techniques: moving average, binomial probability or probit analysis. The appropriate method was determined according to the data characteristics.

Sublethal observations / clinical signs:

At the test item concentration level 7.03 to 32.4 µg a.i./L fish were inactive or displayed abnormally low activity, showed laboured respiration, laid inactive on the bottom of the aquarium, showed weaker coloration, laid on their sides or backs,

Validity criteria fulfilled:

yes

Conclusions:

In a static acute toxicity fish with bluegill fish (Lepomis macrochirus) according to OECD TG 203 the 96-hour LC50 of the test item was determined to be 9.3 µg a.i./L (mean measured).

Executive summary:

The acute toxicity of the test item to bluegill fish was assessed in accordance with OECD TG 203 under static conditions. 10 bluegill fish (Lepomis macrochirus) were exposed for 96 hours to nominal active substance concentrations of 2.50, 5.00, 10.0, 20.0 and 40.0 µg a.s./L. Test item concentrations were analytically ,monitored and measured to be 1.75, 3.38, 7.03, 14.0 and 32.4 µg a.s./L (mean measured). The test concentrations were prepared by using dimethylformamide as solvent and stepwise dilution of a stock solution.  The final solvent concentration was 50 µl/L test water. A negative control and a solvent control (50 µl dimethylformamide/L test water) ran in parallel. One replicate with ten fish pre treatment and control was used. All validity criteria of the guideline were fulfilled. There were neither adverse effects nor mortality in the control group and the solvent control group. At test levels > 3.38 µg as/L fish showed the following symptoms: were inactive or displayed abnormally low activity; showed laboured respiration; showed weaker coloration; laid inactive on the bottom of the aquarium; laid on their sides or backs. Based on mortality, the 96-hour LC of the test item was determined to be 9.3 µg a.i./L.

Description of key information

In a static acute toxicity fish with bluegill fish (Lepomis macrochirus) according to OECD TG 203 the 96-hour LC50 of the test item was determined to be 9.3 µg a.i./L (mean measured).

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Dose descriptor:

LC50

Effect concentration:

9.3 µg/L

Additional information

Reliable information from valid guideline studies on the acute toxicity of the test substance to freshwater fish is available and summarized in the table below. The data were submitted in April 2002 according to Directive 91/414/EEC and peer reviewed by the Committee for Risk Assessment and evaluated in the Draft Assessment Reprort (DAR) according to the Commission Regulation (EU) No 1107/2009 (Vol. 3, Annex B, Point 9.2, November 2003). Results from the studies were included in the EFSA conclusion (EFSA Scientific Report (2006) 62, 1-81). 

 

Table: Overview about available study data on the acute toxicity to freshwater fish.

Author(s)	Year	Title Company Report No. Source (where different from company) GLP or GEP status Published or not	Adequacy of study	Result
Dorgerloh, M., Sommer, H.	2001	Fenamiphos - Acute toxicity (96 hours) to bluegill (Lepomis macrochirus) in a static test. Report No. DOM 21021 Bayer AG GLP Unpublished	Key	96-hour LC50 = 9.3 µg a.i./L (mean measured)
Surprenant, D.C.	1988	Acute toxicity of technical grade fenamiphos (trade name Nemacur) to sheepshead minnow (Cyprinodon variegatus) under flow through conditions Report No. 98040 Bayer AG GLP Unpublished	Supporting	96-hour LC50 = 17 µg a.i./L (mean measured)
Lamb and Roney	1972	Acute Toxicity of  NEMACUR Technical and NEMACUR 15 % Granular to Fish Report No.: 34014 CHEMAGRO Div. of Baychem Corporation, Non-GLP Unpublished	Supporting	96-hour LC50 (corrected to 100 % purity) = 14.4 µg/L (bluegill) and 58.4 µg/L (rainbow trout) (nominal)

 

Key information

The acute toxicity of the test item to bluegill fish was assessed in accordance with OECD TG 203 under static conditions. 10 bluegill fish (Lepomis macrochirus) were exposed for 96 hours to nominal active substance concentrations of 2.50, 5.00, 10.0, 20.0 and 40.0 µg a.s./L. Test item concentrations were analytically ,monitored and measured to be 1.75, 3.38, 7.03, 14.0 and 32.4 µg a.s./L (mean measured). The test concentrations were prepared by using dimethylformamide as solvent and stepwise dilution of a stock solution.  The final solvent concentration was 50 µl/L test water. A negative control and a solvent control (50 µl dimethylformamide/L test water) ran in parallel. One replicate with ten fish pre treatment and control was used. All validity criteria of the guideline were fulfilled. There were neither adverse effects nor mortality in the control group and the solvent control group. At test levels > 3.38 µg as/L fish showed the following symptoms: were inactive or displayed abnormally low activity; showed laboured respiration; showed weaker coloration; laid inactive on the bottom of the aquarium; laid on their sides or backs. Based on mortality, the 96-hour LC of the test item was determined to be 9.3 µg a.i./L (Dorgerloh and Sommer, 2001).

 

Supporting information

In addition, results from an acute fish toxicity test with sheepshead minnow (Cyprinodon variegatus) was carried out. The test followed the standard practice for conducting acute toxicity tests with fishes, macroinvertebrates and amphibians (ASTM, 1980). 20 fish in duplicate test aquaria were exposed for 96 h under flow through conditions to five mean measured concentrations of 11, 26, 40, 56 and 96 µg a.i./L, negative control and solvent control. Signs of intoxication were: lethargic, exhibited rapid respiration, loss of equilibrium and darkened pigmentation. There were neither symptoms of intoxication nor mortality in the control group. The 96-hour LC50 of the test item at sheepshead minnow was determined as 17 µg a.i./L. 

 

The study of Lamb and Roney (1972) was conducted when analytical verification of the test concentrations was not required by the test guideline. Due to the uncertainties with exposure an acute toxicity study on the most sensitive fish species identified in the earlier studies (Bluegill sunfish; Lepomis macrochirus) was conducted according to recent guidelines and requirements with respect to analytical verification (Dorgerloh and Sommer, 2001, see above).

 

Conclusion

Based on the most reliable information and in compliance with the Draft Assessment Report, the 96-hour LC50 of the substance is determined to be 9.3 µg/L (measured mean). The LC₅₀ calculated from the results of this study (9.3 µg/L) was in the same order of magnitude as the LC₅₀ values derived in 1972 (14.4 µg/L) on basis of nominal concentrations. The results of this comparison allows to conclude that in the earlier study the actual test concentrations are well comparable to the nominal the test substance concentrations and that a repetition of these studies is not justified from an animal welfare perspective. Additional data are not necessary to cover the data requirement according to Regulation (EC) No 1907/2006 (REACH), Annex VIII, section 9.1.3.