Methomyl

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:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPP 72-1 (Fish Acute Toxicity Test)

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

Methomyl technical
DPX-X1179-512
Purity: 98.6%

Analytical monitoring:

yes

Details on sampling:

Approximately 40 mL of sample was collected from the approximate center of each test chamber at mid-depth with a class A glass pipette. The samples were placed in 40-mL amber glass vials and transferred to the analytical laboratory. One sample of each test solution was received from each replicate test chamber and the control on day 0 of the definitive study. Final samples were collected at the end of the test. All samples were analyzed on the day of collection or refrigerated prior to analysis (all samples were analyzed within 11 rather than 5 days of collection and this had no impact on the outcome of the study as mean measured concentrations ranged from 100 to 105% of nominal).

Vehicle:

yes

Remarks:

water

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
A 1,000 mg/L stock solution was prepared by the addition of 0.2504 g of test substance to 250 mL of dilution water in a Class A volumetric flask. The stock solution was well mixed by multiple inversions of the volumetric flask. Test solutions were prepared by the addition of an appropriate volume of this stock solution directly to dilution water in test vessels. Test solutions were clear in appearance, with no visible insoluble material present.

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: Rainbow trout
- Strain: Oncorhynchus mykiss
- Source: Thomas Fish Company, Anderson, California
- Age at study initiation: fingerling
- Length at study termination (controls): 3.64 to 4.12 cm. Total length of the longest fish was not more than twice the length of the shortest fish in the control.
- Weight at study termination (controls): 0.33 to 0.48 g in wet weight, blotted dry (mean 0.39 g)
- Loading: Loading in the water control was 0.13 g/L at test conclusion

ACCLIMATION
- Acclimation period: The fish were held under flow-through conditions in an approximately 280-L, fiberglass holding tank for the first 14 days before test start and in a 20-L glass tank for the final three days before test start.
- Type and amount of food during acclimation: The fish were fed Tetramin Staple Food (Lot# TM08) and trout chow (Lot # TC03) once daily on weekdays, weekends, and holidays except during the final two days before test start, when fish were not fed.
- Health during acclimation (any mortality observed): Disease, injury, and abnormalities were not present in fish in the holding tank nor in the fish used for testing.

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

48 mg/L as CaCO3

Test temperature:

11.1 to 13.0°C

pH:

7.3-8.0

Dissolved oxygen:

7.6-10.4

Conductivity:

160 - 210 µmhos/cm

Nominal and measured concentrations:

Nominal: 0, 0.39, 0.65, 1.1, 1.8, and 3.0 mg/L
Measured: 0, 0.408, 0.668, 1.13, 1.0, 3.06 mg/L
The mean measured values of Methomyl ranged from 100 to 105% of the targeted nominal concentrations

Details on test conditions:

TEST SYSTEM
- Test vessel: glass aquaria [40 (length) x 20 (width) x 25 (height) cm] which held 15 L of test solution (20-L maximum volume; 18-cm test solution depth)
- Type: covered with clear glass or plastic sheets to prevent fish from escaping
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water:
- Total organic carbon: 0.45 mg/L
- Particulate matter: not reported
- Metals: less than or equal to 0.0041 mg/L
- Pesticides: not detected
- Chlorine: not detected
- Alkalinity: 29 ,g/L as CaCO3
- Ca/mg ratio: nnot reported

OTHER TEST CONDITIONS
- Adjustment of pH: not reported
- Photoperiod: 16 hours light and 8 hours darkness was employed which included 15 minutes of transitional light preceding and following the 16-hour light interval
- Light intensity: approximately 1,300 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Mortality and behavioral observations were made at test start, every 24 hours thereafter, and at test end. Criteria for death were the absence of opercular movement and lack of reaction to gentle prodding.

TEST CONCENTRATIONS
- Range finding study : The range-finding test was conducted with five concentrations of test substance (0.10, 0.51, 1.0, 5.1, and 10 mg/L) and a dilution water control. After 96 hours of exposure, there was 0% mortality in the control and at 0.10, 0.51, and 1.0 mg/L, and 100% mortality at 5.1 and 10 mg/L. Surviving fish exposed to 1.0 mg/L exhibited lethargy and/or a loss of equilibrium at the end of the test. All test solutions were clear with no visible insoluble material.

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

2.49 mg/L

Nominal / measured:

meas. (arithm. mean)

Basis for effect:

mortality (fish)

Key result

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

0.408 mg/L

Details on results:

No mortality or sublethal effects were seen in any water control fish at any time. Two surviving fish exposed to 0.668 mg/L exhibited loss of equilibrium or lethargy, and all surviving fish exposed to 1.13, 1.80, and 3.06 mg/L exhibited lethargy, loss of equilibrium, erratic swimming, immobility, change in coloration, and/or a body deformity at the end of the study.

Reported statistics and error estimates:

The 96-hour LC50, based on mean, measured concentrations, was 2.49 mg/L, with a 95% confidence interval of 1.98 to >3.06 mg/L.

Sublethal observations / clinical signs:

Mean Measured Concentration (mg/L)	Replicate	Cummulative Mortality (%)
		0 hr	24 hr	48 hr	72 hr	96 hr
Control	A	0	0	0	0	0
	B	0	0	0	0	0
0.408	A	0	0	0	0	0
	B	0	0	0	0	0
0.668	A	0	0	0	0	0
	B	0	0	0	0	0
1.13	A	0	0	0	0	0
	B	0	20	20	20	20
1.80	A	0	0	0	0	0
	B	0	0	0	0	0
3.06	A	0	60	80	80	80
	B	0	60	80	80	80

 

Mean Measured Concentration (mg/L)	Replicate	Number of Fish with Effects/Number of Fish Alive(a)
		0 hr	24 hr	48 hr	72 hr	96 hr
Control	A	0/5	0/5	0/5	0/5	0/5
	B	0/5	0/5	0/5	0/5	0/5
0.408	A	0/5	0/5	0/5	0/5	0/5
	B	0/5	0/5	0/5	0/5	0/5
0.668	A	0/5	0/5	0/5	2/5	2/5
	B	0/5	0/5	0/5	0/5	0/5
1.13	A	0/5	5/5	5/5	5/5	5/5
	B	0/5	4/4	4/4	4/4	4/4
1.80	A	0/5	5/5	5/5	5/5	5/5
	B	0/5	5/5	5/5	5/5	5/5
3.06	A	0/5	2/2	1/1	1/1	1/1
	B	0/5	2/2	1/1	1/1	1/1
(a) = Affected fish exhibited one or more of the following effects: lethargy, loss of equilibrium, erratic swimming, immobilization, change in coloration, misshapen bodies.

Validity criteria fulfilled:

yes

Conclusions:

The 96-hour LC50, based on mean, measured concentrations, was 2.49 mg/L, with a 95% confidence interval of 1.98 to >3.06 mg/L.

Executive summary:

The acute toxicity of the test substance to unfed fingerling rainbow trout, Oncorhynchus mykiss, was tested in accordance with the OECD Guideline 203; EC Method C.1; and the US EPA guideline 72-1. The study was conducted under unaerated, static conditions with five concentrations of the test substance and a dilution water control. Two replicate test chambers were used per test concentration with five fish in each chamber (total of 10 fish per concentration).

 

Exposure of rainbow trout to mean, measured concentrations of 0.408, 0.668, 1.13, 1.80, and 3.06 mg/L, resulted in 0% mortality at 0.408 and 0.668 mg/L, 10% mortality at 1.13 mg/L, 0% mortality at 1.80 mg/L, and 80% mortality at 3.06 mg/L at the end of 96 hours. Mean, measured concentrations ranged from 100 to 105% of the nominal concentrations. No mortality or sublethal effects were seen in any water control fish at any time. Two surviving fish exposed to 0.668 mg/L exhibited loss of equilibrium or lethargy, and all surviving fish exposed to 1.13, 1.80, and 3.06 mg/L exhibited lethargy, loss of equilibrium, erratic swimming, immobility, change in coloration, and/or a body deformity at the end of the study. The No Observed Effect Concentration (the highest mean, measured concentration causing no toxicant-related mortality or sublethal effects) at test end was 0.408 mg/L. The 96-hour LC50, based on mean, measured concentrations, was 2.49 mg/L, with a 95% confidence interval of 1.98 to >3.06 mg/L.

Reference 2

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: EPA OPP 72-3

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

methomyl technical
INX-1179-394
Purity: 98.35%

Analytical monitoring:

yes

Details on sampling:

- Sampling method: Was performed on individual samples from each test vessel collected at initiation and termination of the test. Samples were filtered through a 0.5 micron filter into a sample vial and analyzed via direct injection using a high performance liquid chromatograph equipped with an autosampler, reverse phase column, UV detector and a data reduction system.
- Sample storage conditions before analysis: Samples were stored in 40 mL glass vials with Teflon lined caps and immediately transferred to the analytical laboratory at Resource Analysts Inc.

Vehicle:

yes

Remarks:

dilution water

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: An initial stock solution was prepared by combining 1.0200 grams of test substance and dilution water and adjusting the mixture to a final volume of 1000 mL. Appropriate amounts of stock solution were added directly to each test vessel (no solvent used) and thoroughly mixed.

Test organisms (species):

Cyprinodon variegatus

Details on test organisms:

TEST ORGANISM
- Common name: Sheepshead minnow
- Strain: Cyprinodon variegatus
- Source: commercial supplier (Multi Aquaculture Systems, Amagansett, New York)
- Age at study initiation: juvenile
- Length at study initiation (length definition, mean, range and SD): not reported
- Weight at study initiation (mean and range, SD): not reported

ACCLIMATION
- Acclimation period: 42 days
- Type and amount of food during acclimation: newly hatched Artemia salina nauplii and a commercial fish food
- Feeding frequency during acclimation: once or twice daily before the test, except for 24 hours preceeding the test
- Health during acclimation (any mortality observed): free of apparent sickness, injuries, and abnormalities

FEEDING DURING TEST : Fish were not fed during the test.

Test type:

static

Water media type:

saltwater

Limit test:

no

Total exposure duration:

96 h

Test temperature:

21.0-22.2 degC

pH:

7.5-8.1

Dissolved oxygen:

6.3-8.1 mg/L

Salinity:

16.2 - 17.6 ppt

Nominal and measured concentrations:

Nominal: 0, 0.4, 0.6, 1.0, 1.5, 2.5, 4.0 mg/L
Measured: 0, 0.53, 0.77, 1.30, 1.65, 2.82, 4.02 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 19.6 L glass aquaria (approximately 20 cm in width, 40 cm in length and 25 cm in height) that contained 15 L of test solution
- Aeration: not required
- No. of organisms per vessel: 10 (20 minnow were randomly and equally distributed among 2 replicates of each treatment)
- No. of vessels per concentration (replicates): 2

TEST MEDIUM / WATER PARAMETERS :
pH: 7.8
Salinity: 16.2 ppt
Organocholorine pesticides: Not detected
Organophosphorus: Not detected
Polychlorinated biphenyls: Not detected


OTHER TEST CONDITIONS
- Photoperiod: 16 hour light/8 hour dark
- Light intensity: 10 uEs-1m-2

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :

TEST CONCENTRATIONS
- Range finding study : Yes
- Test concentrations: 0.098, 0.49, 0.98, 4.9, 9.8 mg/L
- Results used to determine the conditions for the definitive study: 100% survival at 0.098 and 0.49 mg/L. 70% survival at 0.98 mg/L and 0% survival at 4.0 and 9.8 mg/L

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

1.16 mg/L

Nominal / measured:

meas. (not specified)

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

0.77 mg/L

Nominal / measured:

meas. (not specified)

Reported statistics and error estimates:

96-hr LC50 = 1.16 mg/Ll 95% confidence limit 1.02 - 1.3 mg/L

Sublethal observations / clinical signs:

Mean Measured Concentration (mg/L	Replicate	Number Alive
		0 hr	24 hr	48 hr	72 hr	96 hr
Control	1	10	10	10	10	10
	2	10	10	10	10	10
0.53	1	10	10	10	10	10
	2	10	10	10	10	10
0.77	1	10	9	9	9	9
	2	10	10	10	10	10
1.30	1	10	4	2	2	2
	2	10	7	3	3	2
1.65	1	10	2	1	1	1
	2	10	7	3	3	3
2.82	1	10	0	0	0	0
	2	10	0	0	0	0
4.02	1	10	0	0	0	0
	2	10	0	0	0	0

 

Mean Measured Concentration (mg/L	Replicate	Number Affected
		0 hr	24 hr	48 hr	72 hr	96 hr
Control	1	0	0	0	0	0
	2	0	0	0	0	0
0.53	1	0	0	0	0	0
	2	0	0	0	0	0
0.77	1	0	9b	9b	0	0
	2	0	10b	10b	0	0
1.30	1	10a	4b	2b	2b	2b
	2	10a	7b	3b	3b	2b
1.65	1	10a	2b	1b	1b	1b
	2	10a	7b	3b	3b	3b
2.82	1	10a	-	-	-	-
	2	10a	-	-	-	-
4.02	1	10a	-	-	-	-
	2	10a	-	-	-	-
a = Affected organisms exhibited a loss of equilibrium, erratic swimming and color change. b = Affected organisms exhibited a loss of equilibrium, erratic swimming, color change and lethargy.

Validity criteria fulfilled:

yes

Conclusions:

96-hr LC50 (sheepsheaad minnow) = 1.16 mg/L

Executive summary:

The acute toxicity to sheepshead minnow was tested according to EPA OPP 72-3 at nominal dose levels of 0, 0.4, 0.6, 1.0, 1.5, 2.5, 4.0 mg/L. The number of surviving organisms and the occurrence of sublethal effects (loss of equilibrium, erratic swimming, loss of reflex, excitability, discoloration or change of behavior) were determined visually and recorded at 24, 48, 72, and 96 hours.

The 96-hour LC50 was calculated to be 1.16 mg/L. The 96-hour NOEC was determined to be 0.77 mg/L.

Reference 3

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

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:

EU Method C.1 (Acute Toxicity for Fish)

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

Batch 16RLMX99
Purity: 100%

Analytical monitoring:

yes

Details on sampling:

- Concentrations: Water samples were taken from the control and all surviving test groups at 0 (fresh media), 24 (old media) and 96 (old media) hours for quantitative analysis. Duplicate samples and samples at 24 (fresh media), 48 and 72 hours (fresh and old media) were taken and stored frozen (approximately -20°C) for further analysis, if necessary.
- Sampling method: A volume of test sample was extracted with three portions of dichloromethane and each extract filtered through anhydrous sodium sulphate. The combined extracts were evaporated to dryness and the residue re-dissolved in dichloromethane to five final theoretical test material concentrations of approximately 25 mg/L.

Vehicle:

yes

Remarks:

dechlorinated tap water

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: 200 mg of test material was dissolved in dechlorinated tap water with the aid of ultrasonication for approximately 1 minute and the volume adjusted to 2 L to give the 100 mg/L stock solution. Aliquots of this stock solution were each separately dispersed in dechlorinated tap water and the volume adjusted to 20 L to give the 0.32, 0.56, 1.0, 1.8 and 3.2 mg/L test concentrations.

Test organisms (species):

Lepomis macrochirus

Details on test organisms:

TEST ORGANISM
- Common name: Bluegill sunfish
- Strain: Lepomis macrochirus
- Source: Aquatic Research Organisms, Hampton, New Hampshire, USA
- Length at study termination: 3.6 cm (sd = 0.1)
- Weight at study termination: 0.89 g (sd = 0.08)

ACCLIMATION
- Acclimation period: 12 days
- Feeding frequency during acclimation: Fish were fed commercial Tetramin flake food which was discontinued 24 hours prior to the start of the definitive study
- Health during acclimation (any mortality observed): There was <1% mortality in the 7 days prior to the start of the test.

Animals were not fed during exposure.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Test temperature:

21°C

pH:

7.7-8.2

Dissolved oxygen:

8.2-8.9 mg/L

Nominal and measured concentrations:

Nominal: 0, 0.32, 0.56, 1.0, 1.8, and 3.2 mg/L
Analysis of test solutions showed that the measured test concentration ranged from 85-115% of nominal values with the exception of the 1.0 and 1.8 ng/L concentrations at 24 hours which showed measured values of 122 and 121% of nominal respectively.

Details on test conditions:

TEST SYSTEM
- Test vessel: 20 Lglass tank, with a "single pass" (once through) water renewal system, covered with a perspex lid to reduce evaporation
- Aeration: Aerated via narrow bore glass tubes
- No. of organisms per vessel: 10

TEST MEDIUM / WATER PARAMETERS
- Total organic carbon: 1 mg/L
- Particulate matter: not reported
- Metals: <36 µg/L
- Pesticides: < 0.02 µg/L
- Chlorine: 0.12 mg/L
- Alkalinity: 134 mg/L
- Ca/mg ratio: not reported

OTHER TEST CONDITIONS
- Adjustment of pH: not reported
- Photoperiod: 16 hours light/ 8 hours dark with 20 minute dawn and dusk transition periods
- Light intensity: not reported

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Any mortalities or sublethal effects of exposure were recorded at 3, 6, 24, 48, 72, and 96 hours after the start of exposure. The criteria for death were taken to be the absence of both respiratory movement and response to physical stimulation.

TEST CONCENTRATIONS
- Range finding study : No mortalities at 0.010 an d0.10 mg/L. However, 33% and 100% mortalities were observed at 1.0 and 3.2 mg/L.

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

0.63 mg/L

Nominal / measured:

nominal

Basis for effect:

mortality (fish)

Key result

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

0.32 mg/L

Nominal / measured:

nominal

Details on results:

Sub-lethal effects were observed at 1.0 mg/L and above. These responses were swimming at the bottom of test vessels, the presence of moribund fish and moribund fish with arched bodies. Due to animal welfare implications, all fish with were moribund with arched bodies were killed in extremis and were classified as mortalities for the purpose of calculating LC50 values.

Reported statistics and error estimates:

The 96-hour LC50, based on nominal concentrations, was 0.63 mg/L with 95% confidence limits of 0.53-0.74 mg/L

Sublethal observations / clinical signs:

Nominal Concentration (mg/L)		Cumulative Mortality (initial population = 10)						% Mortality
		3 hr	6 hr	24 hr	48 hr	72 hr	96 hr	96 hr
Control		0	0	0	0	0	0	0
0.32		0	0	0	0	0	0	0
0.56		0	0	1	1	2	3	30
1.0		0	0	7	10	10	10	100
1.8		0	0	10	10	10	10	100
3.2		0	0	10	10	10	10	100

 

Nominal Concentration (mg/L)	Time (hours)						Sub-lethal effects
	3	6	24	48	72	96
Control	10/10	10/10	10/10	10/10	10/10	10/10	None detected
0.32	10/10	10/10	10/10	10/10	10/10	10/10	None detected
0.56	10/10	10/10	9/9	9/9	8/8	7/7	None detected
1.0	10/10	10/10					None detected
			3/3	A/D			Swimming at bottom
1.8		2/10	A/D				Moribund with arched body
							None detected
3.2	7/10		A/D				Moribund
	3/10	6/10					Moribund with arched body
		4/10					Swimming at bottom
A/D = All fish dead

Validity criteria fulfilled:

yes

Conclusions:

The 96-hour LC50, based on nominal concentrations, was 0.63 mg/L with 95% confidence limits of 0.53-0.74 mg/L

Executive summary:

Bluegill sunfish were exposed, in groups of 10, to an aqueous solution of the test material over a range of concentrations of 0.32, 0.56, 1.0, 1.8, and 3.2 mg/L for a period of 96 hours under semi-static conditions. The number of mortalities and any sub-lethal effects of exposure in each test and control vessel were determined 3 and 6 hours after the start of exposure and then daily throughout the study until termination at 96 hours. The 96-hour LC50, based on nominal concentrations, was 0.63 mg/L with 95% confidence limits of 0.53-0.74 mg/L. The No Observed Effect concentration was 0.32 mg/L.

 

Analysis of test solutions showed that the measured test concentration ranged from 85-115% of nominal values with the exception of the 1.0 and 1.8 ng/L concentrations at 24 hours which showed measured values of 122 and 121% of nominal respectively. 

Reference 4

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods with acceptable restrictions

Qualifier:

according to guideline

Guideline:

other: 1964 USDI fish and wildlife services "procedure for evaluation of acute toxicity to fish and wildlife"

GLP compliance:

no

Specific details on test material used for the study:

Insecticide 1179
Purity: 100%

Analytical monitoring:

no

Vehicle:

yes

Remarks:

acetone

Test organisms (species):

Carassius sp.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Nominal and measured concentrations:

Nominal: 10 - 100 ppb

Details on test conditions:

10 fish per concentration group

Reference substance (positive control):

yes

Remarks:

p,p'-DDT

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 100 other: ppb

Results with reference substance (positive control):

96-hour LC50 for p,p'-DDT = 3.98 ppb with confidence limits of 3.46 - 4.58

Validity criteria fulfilled:

not specified

Conclusions:

96-hour LC50 (goldfish) > 100 ppb

Executive summary:

The acute toxicity to goldfish was tested in a static, unaerated test at nominal dose levels of 1 – 100 ppb. The 96-hour LC50 was > 100 ppb. 

Reference 5

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: Japan 12 NouSan 8147

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

Methomyl technical
Lot Jul06LP276
Purity: 99.4%

Analytical monitoring:

yes

Vehicle:

yes

Remarks:

Dechlorinated water (activated carbon filtered tap water (Iwata city water))

Test organisms (species):

Cyprinus carpio

Test type:

semi-static

Water media type:

other: tap water

Limit test:

no

Total exposure duration:

96 h

Test temperature:

20.4-21.7 degC

pH:

7.5-8.3

Dissolved oxygen:

87-101%

Nominal and measured concentrations:

Nominal: 0.20, 0.44, 0.96, 2.10, 4.60 and 10.0 mg/L
Measured concentrations were < ±20% on nominal

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

3.58 mg/L

Basis for effect:

mortality (fish)

Reported statistics and error estimates:

96-hr LC50 (carp) = 3.58 mg/L; 95% confidence limits were 2.5 - 5.12 mg/L

Validity criteria fulfilled:

yes

Conclusions:

96-hr LC50 (carp) = 3.58 mg/L; 95% confidence limits were 2.5 - 5.12 mg/L

Executive summary:

The acute toxicity to carp was tested according to Japan 12 NouSan 8147 at nominal dose levels of 0.20, 0.44, 0.96, 2.10, 4.60 and 10.0 mg/L. The 96-hour LC50 was calculated to be 3.58 mg/L.

Description of key information

Duration/Value Type	Species	Value	Guideline	Reliability
96 -hr LC50	rainbow trout	2.49 mg/L	OECD 203 EU Method C.1 EPA OPP 72 -1	1
96 -hr LC50	bluegill sunfish	0.63 mg/L	OECD 203 EU Method C.1	1
96 -hr LC50	carp	3.58 mg/L	Japan 12 NouSan 8147	1
96 -hr LC50	goldfish	> 0.1 mg/L	1964 USDI fish and wildlife services procedure	2
96 -hr LC50	sheepshead minnow	1.16 mg/L	EPA OPP 72 -3	1

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

0.63 mg/L

Marine water fish

Marine water fish

Effect concentration:

1.16 mg/L

Additional information

The test substance was tested in 4 freshwater species and one saltwater species. Acute 96 -hour LC50 values in freshwater species ranged from 0.63 mg/L to 3.58 mg/L in bluegill sunfish and common carp respectively.  In the saltwater species, the acute 96-hour LC50 value was 1.16 mg/L in the sheepshead minnow. The most sensitive fish species (bluegill sunfish) had an 96 -hour LC50 < 1 mg/L.