Ziram

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

Study period:

21 May 1990- 3 September 1991

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

a solvent was used in the study, analytical recovery of the tested substance partially low.

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

yes

Remarks:

The water hardness value was slightly higher than recommended in the guideline and the fish used slightly exceed the range recommended in the guideline but these deviations are not considered to have had any significant effects on the results of the test.

Qualifier:

according to guideline

Guideline:

EPA OPP 72-1 (Fish Acute Toxicity Test)

GLP compliance:

yes

Analytical monitoring:

yes

Remarks:

gas chromatograph with flame photometric detector

Details on sampling:

- The sample bottles were shaken and aliquots transferred by bulb pipette to 40 mL vials. The total volume in each vial was made up to 20 mL with dechlorinated water (carbon filtered) followed by the addition of 8.0 mL reducing solution (3% stannous chloride dihydrate in 10 M hydrochloric acid). The vials were sealed and heated in a water bath at 80°C for one hour. The vials were then shaken for 30 seconds and allowed to stand at room temperature for one hour to stabilise.

Vehicle:

yes

Remarks:

Dimethylformamide

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: A preliminary solution of the test material in dimethylformamide was created. 5 separate solvent stock solutions were prepared for automatic dispensing via the multi-channel dosing apparatus
- Controls: yes
- Chemical name of vehicle: dimethylformamide

Test organisms (species):

Lepomis macrochirus

Details on test organisms:

TEST ORGANISM
- Common name: Bluegill sunfish
- Source: SP Inc., Salem, Mass. USA
- Age at study initiation (mean and range, SD): not reported
- Length at study initiation: 3.3 cm
- Weight at study initiation: 1.01 g

ACCLIMATION
- Acclimation period: 17 days
- Acclimation conditions: yes
- Type and amount of food: commercial fish flake to repletion
- Feeding frequency: daily, discontinued 48 hours prior to the test initiation
- Health during acclimation: 3% mortality 7 days prior to test initiation

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

350 mg CaCO3/L

Test temperature:

21°C

pH:

7.5-7.6

Dissolved oxygen:

8.6-8.8 mgO2/L

Nominal and measured concentrations:

Nominal concentrations: 0.0056, 0.01, 0.018, 0.032 and 0.056 mg/L
Measured concentrations: 0.0046, 0.0080, 0.015, 0.022 and 0.025 mg/L (mean of samples collected at 0, 24 and 96 h)

Details on test conditions:

TEST SYSTEM
- Test vessel: glass aquaria containing 20 L test media
- Aeration: no
- Type of flow-through: peristaltic. A continous flow was delivered by a multi-channel variable speed peristaltic pump (diluent) with solvent stock solutions injected by means of a brown syringe pump dispensing at a rate of 0.3553 ml/hr (i.e 50 uL of solvent stock per litre diluent)
- Renewal rate of test solution: 118 mL/min. The stream was divided equally between two replicates to give a renewal rate of 59 mL/min
- No. of organisms per vessel: 10
- 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: 0.51 g bodyweight/L (static volume), 0.1 g bodyweight/L (volume in 24 hours)

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: laboratory tap water, dechlorinated by means of sodium thiosulphate

OTHER TEST CONDITIONS
- Photoperiod: 16 hours light, 8 darkness

EFFECT PARAMETERS MEASURED : mortality at 3, 6, 24, 28, 72 and 96 hours

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 1.7

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

0.01 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 95%CL 0.0086-0.011 mg/L

Duration:

96 h

Dose descriptor:

LC100

Effect conc.:

0.022 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- Other abnormalities: none
- Other biological observations: for details refer to attachment "chronological record of observations"
- Mortality of control: no
- Other adverse effects control: no
- Effect concentrations exceeding solubility of substance in test medium: no

Sublethal observations / clinical signs:

The recovery of the test substance was between 53 and 94% of the nominal values at the beginning of the test and 19 to 127% of nominal values after 96 h. For more details on analytical and biological results please refer to the attachments provided below.

Table 1: Validity criteria for OECD 203 (2019)

Criterion from the guideline	Outcome	Validity criterion fulfilled
The mortality in the control(s) should not exceed 10% (or one fish if less than ten are used) at the end of the test	No mortalities of the control	yes
The dissolved oxygen concentration must have been at least 60 per cent of the air saturation value throughout the test	8.6-8.8 mgO2/L	yes
There must be evidence that the concentration of the substance being tested has been satisfactorily maintained, and preferably it should be at least 80% of the nominal concentration throughout the test. If the deviation from the nominal concentration is greater than 20 per cent, results should be based on the measured concentration.	Deviation is greater than 20% therefore results are based on measured concentrations	yes

Validity criteria fulfilled:

yes

Remarks:

For details please refer to field "any other information on results incl. tables"

Reference 2

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

19 May 1989 - 3 September 1991

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

semi-static system used

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

yes

Remarks:

Total hardness of the water was slightly higher than the recommended range but is not considered to have had any significant effects on the results of the test

Qualifier:

according to guideline

Guideline:

EPA OPP 72-1 (Fish Acute Toxicity Test)

GLP compliance:

yes

Analytical monitoring:

yes

Vehicle:

no

Details on test solutions:

- Direct dispersion in water. A stock solution of 50 mg/L was prepared by dissolving the test sample in test water with stirring. The test series was prepared by further dilution of this stock with test watet. No precipitate was observed during the preparation of stock or test solutions.

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: Rainbow trout
- Source: Parkwood Trout Farm, Kent, U.K.
- Age at study initiation (mean and range, SD):
- Length at study initiation (mean and SD): 6.1 cm (SD = 0.7 cm)
- Weight at study initiation (mean and SD): 3.22 g (SD = 1.20 g)
- Feeding during test: no

ACCLIMATION
- Acclimation period: 8-19 May 1989
- Acclimation conditions (same as test or not): yes
- Type and amount of food: commercial trout pellets
- Feeding frequency: daily
- Health during acclimation (any mortality observed): no mortality was observed 7 days prior to test initiation

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

350 mgCaCO3/L

Test temperature:

13°C

Dissolved oxygen:

> = 10 mgO2/L

Nominal and measured concentrations:

Nominal: 0.32, 0.56, 1.0, 1.8 and 3.2 mg/L
Measured: 0.17, 0.36, 0.75, 1.4 and 2.7 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 40 L glass aquaria
- Aeration: yes, via narrow bore glass tubes
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2
- No. of vessels per vehicle control (replicates): 2
- Biomass loading rate: 0.8 g bw fish/L

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Laboratory tap water, dechlorinated by die addition of sodium thiosulphate

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

EFFECT PARAMETERS MEASURED: mortality

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

1.7 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 95% CL 1.5-2.0 mg/L

Duration:

96 h

Dose descriptor:

LC100

Effect conc.:

1.7 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Sublethal observations / clinical signs:

Table 1: Validity criteria for OECD 203 (2019)

Criterion from the guideline	Outcome	Validity criterion fulfilled
The mortality in the control(s) should not exceed 10% (or one fish if less than ten are used) at the end of the test	No mortalities of the control	yes
The dissolved oxygen concentration must have been at least 60 per cent of the air saturation value throughout the test	> = 10 mgO2/L	yes
There must be evidence that the concentration of the substance being tested has been satisfactorily maintained, and preferably it should be at least 80% of the nominal concentration throughout the test. If the deviation from the nominal concentration is greater than 20 per cent, results should be based on the measured concentration.	Deviation is greater than 20% therefore results are based on measured concentrations	yes

Validity criteria fulfilled:

yes

Reference 3

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

March 20, 2007 to September 27, 2007

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

a vehicle was used

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Version / remarks:

adopted in 1992

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

adopted in 1996

Qualifier:

according to guideline

Guideline:

other: ASTM Standard E729-96

Version / remarks:

adopted in 1996

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Samples from each treatment and control group were collected 3 days prior to the start of the test after conditioning the diluter for 48 hours. Samples were additionally collected at 0, 48 and 96 hours in order to measure test substance concentrations. Sampling from the 0.90 and 1.5 mg/L treatment groups was discontinued after 48 hours due to 100% mortality in both treatment groups

Vehicle:

yes

Remarks:

dimethyl formamide

Details on test solutions:

- Dispensing stock solutions were prepared by combining an appropriate amount of 14C ziram primary stock solution with non-radiolabelled ziram
stock solution. A primary stock solution of 14C ziram was prepared by transferring 2.00 mg of the 14C ziram to a 25-mL volumetric flask. A calculated volume of 2.60 mL of the primary stock was used in the preparation of each 300mL dispensing stock solution to achieve a nominal radioactivity of
50 dpm/mL in each test solution.
- A primary stock solution of non-radiolabelled ziram was prepared by dissolving ziram in dimethylformamide (DMF) at a nominal concentration of 18 mg/mL. Dispensing stock solutions at nominal concentrations of 1.9, 3.2, 5.4, 9.0 and 15 mg/mL were prepared in DMF using calculated volumes of the radiolabelled and non-radiolabelled ziram primary stock solutions.

Test organisms (species):

Lepomis macrochirus

Details on test organisms:

TEST ORGANISM
- Common name: Bluegill sunfish
- Source: Northeastern aquatics, New York
- Age: juveniles
- Length at study termination (mean): 3.8 cm
- Weight at study termination (mean): 0.51 g
- Feeding during test: no


ACCLIMATION
- Acclimation period: 14 days
- Acclimation conditions (same as test or not): similar to test conditions
- Type and amount of food: commercial preparation
- Feeding frequency: daily
- Health during acclimation (any mortality observed): < 2% mortality observed, no signs of disease or stress (7 days prior test initiation)

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Test temperature:

22 +/- 1°C

pH:

8.0-8.2

Dissolved oxygen:

> 76% oxygen saturation

Nominal and measured concentrations:

Nominal: 0.19, 0.32, 0.54, 0.9 and 1.5 mg/L
Measured: 100-103% nominal concentrations

Details on test conditions:

TEST SYSTEM
- Test vessel: 25 L aquaria containing approx. 15 L test solution
- Type of flow-through: continuous flow-through diluter. Each test vessels received approx. 10 volume additions of test water every 24 hours
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2
- No. of vessels per vehicle control (replicates): 2
- Biomass loading rate: 0.035 g fish/L

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: The water used for culturing and testing was freshwater obtained from a well approximately 40 meters deep located on the Wildlife International, Ltd. site. The well water is characterized as moderately-hard water. Filtration was performed prior to testing.

OTHER TEST CONDITIONS
- Photoperiod: 16 hours light/8 hours darkness
- Light intensity: approx. 193 lux

EFFECT PARAMETERS MEASURED : mortality

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

0.57 mg/L

95% CI:

>= 0.33 - <= 0.93

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Basis for effect:

mortality (fish)

Remarks on result:

other: 95% CL 0.33 -0.93 mg/L

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

0.33 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Basis for effect:

mortality (fish)

Remarks on result:

other: 95% CL 0.33-0.93 mg/L

Sublethal observations / clinical signs:

Table 1: Validity criteria for OECD 203 (2019)

Criterion from the guideline	Outcome	Validity criterion fulfilled
The mortality in the control(s) should not exceed 10% (or one fish if less than ten are used) at the end of the test	No mortalities	yes
The dissolved oxygen concentration must have been at least 60 per cent of the air saturation value throughout the test	> 76% oxygen saturation	yes
There must be evidence that the concentration of the substance being tested has been satisfactorily maintained, and preferably it should be at least 80% of the nominal concentration throughout the test. If the deviation from the nominal concentration is greater than 20 per cent, results should be based on the measured concentration.	100-103% of radio-labelled nominal concentrations found	yes

Validity criteria fulfilled:

yes

Reference 4

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

13 - 24 June 2014

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

a vehicle was used

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Version / remarks:

adopted in 1992

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

adopted in 1996

GLP compliance:

yes

Remarks:

laboratories in the USA are not certified by any governmental agency, but are subject to official inspections

Analytical monitoring:

yes

Remarks:

HPLC/MS

Vehicle:

yes

Remarks:

0.1 mL/L Dimethylformamide

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Test temperature:

11.6 - 12.7 °C in test chambers

pH:

8.1 - 8.2

Dissolved oxygen:

≥8.1 mg/L (≥75% of saturation)

Nominal and measured concentrations:

Nominal: Negative control, vehicle control, 57, 97, 169, 293, 507 µg/L
Measured:

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

318.6 µg/L

95% CI:

>= 246 - <= 461

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: retrospective re-calculation of study results based on measured analytical data

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

145 µg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: retrospective re-calculation of study results based on measured analytical data

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

355 µg/L

95% CI:

>= 293 - <= 507

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: as reported in study

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

169 µg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: as reported in study

Details on results:

- Other biological observations: no
- Mortality of control: no
- Other adverse effects control: no
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: Test solutions were clear and colorless, with no evidence of precipitation during the test, in the negative control, solvent control, 57, 97, 169, 293, and 507 µg test item/L test chambers, and in the negative control, solvent control, 57, 97, and 169 µg test item/L diluter mixing chambers that delivered test solution for these concentrations. The solutions in the diluter mixing chamber that delivered test solution for the 293 and 507 µg Ziram technical/L test concentration also appeared clear, but a white ring of precipitate was noted around the mixing cup.

Sublethal observations / clinical signs:

At the start of the test the measured concentrations of ziram were between 71 % and 98 % of the nominal concentrations. After 96 hours measured test item concentrations were between 70 % and 84 % of the nominal concentrations.

Table 1: Cumulative mortality of fish.

Nominal Concentration (µg Ziram technical/L)	Rep.	No. of exposed fish	Cumulative No. of dead fish
			24 h	48 h	72 h	96 h
Negative Control	A	10	0	0	0	0
	B	10	0	0	0	0
Solvent Control	A	10	0	0	0	0
	B	10	0	0	0	0
57	A	10	0	0	0	0
	B	10	0	0	0	0
97	A	10	0	0	0	0
	B	10	0	0	0	0
169	A	10	0	0	0	0
	B	10	0	0	0	0
293	A	10	0	1	1	1
	B	10	0	1	1	2
507	A	10	10	10	10	10
	B	10	10	10	10	10

Table 2: Validity criteria for OECD 203 (2019)

Criterion from the guideline	Outcome	Validity criterion fulfilled
The mortality in the control(s) should not exceed 10% (or one fish if less than ten are used) at the end of the test	No mortalities	yes
The dissolved oxygen concentration must have been at least 60 per cent of the air saturation value throughout the test	≥8.1 mg/L (≥75% of saturation)	yes
There must be evidence that the concentration of the substance being tested has been satisfactorily maintained, and preferably it should be at least 80% of the nominal concentration throughout the test. If the deviation from the nominal concentration is greater than 20 per cent, results should be based on the measured concentration.	Measured concentrations were between 70% and 84% after 96 h. Results are based on measured values.	yes

Validity criteria fulfilled:

yes

Remarks:

For details please refer to field "any other information on results incl. tables"

Reference 5

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:

comparable to guideline study with acceptable restrictions

Remarks:

a vehicle was used for the study, 10% mortality of fish was observed in control and solvent control treatments

Qualifier:

equivalent or similar to guideline

Guideline:

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

GLP compliance:

yes

Analytical monitoring:

yes

Remarks:

LSC (Liquid Scintillation Counting) and HPLC-ELSD

Vehicle:

yes

Remarks:

Dimethylformamide

Test organisms (species):

Cyprinodon variegatus

Test type:

flow-through

Water media type:

saltwater

Remarks:

filtered seawater

Limit test:

no

Total exposure duration:

96 h

Test temperature:

22 - 23 °C

pH:

8 - 8.1

Dissolved oxygen:

5.6 - 7.2 mg/L (corresponding to 77 - 100% of saturation)

Salinity:

31 - 32%

Nominal and measured concentrations:

Nominal: 260, 430, 720, 1200, 2000 µg a.i./L
Measured: 310, 560, 810, 1200, 2200 µg a.i./L

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

840 µg/L

95% CI:

>= 720 - <= 1 100

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

310 µg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Sublethal observations / clinical signs:

Table 1: Validity criteria for EPA Guideline OCSPP 850.1075

Criterion from the guideline	Outcome	Validity criterion fulfilled
All test vessels were identical	Were identical	yes
Treatments were randomly or indiscriminately assigned to individual test vessel locations, or individual test organisms were randomly or indiscriminately assigned to test vessels.	Test organisms were randomly assigned to test vessels	yes
A dilution water control (and vehicle (solvent) control, if a vehicle was used) was included in the test.	Was included	yes
More than 10% of the organisms in either the dilution water or vehicle (solvent) controls showed signs of disease, stress (e.g., discoloration, unusual behavior, immobilization), and/or death.	10% mortality in control and solvent control treatments after 72 h	yes
Fish were not fed during the test.	Not fed	yes
No surfactant or dispersant was used in the preparation of a stock or test solution. (However, adjuvants may be used when testing pesticide typical end-use products.)	No surfactant or dispersant was used	yes

Validity criteria fulfilled:

yes

Description of key information

LC50 (96 h) = 9.7 µg/L (arithm. mean measured, Lepomis macrochirus, OECD 203)

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Dose descriptor:

LC50

Effect concentration:

9.7 µg/L

Additional information

The acute toxicity of zinc bis dimethyldithiocarbamate (CAS No. 137-30-4) to fish species has been investigated in several studies.

The key study (1991) was conducted according to the OECD Guideline No. 203, EPA OPP Guideline 72-1 and GLP. Lepomis macrochirus was exposed for 96 h within a flow-through water regime, to nominal concentrations of 0.0056, 0.01, 0.018, 0.032 and 0.056 mg test item/L as well as a negative and a vehicle control (corresp. to mean measured concentrations of <LOQ, <LOQ, 0.0046, 0.0080, 0.015, 0.022 and 0.025 mg/L). Dimethyl formamide was used as a solvent for the preparation of the test solutions. The recovery of the test substance was between 53 and 94% of the nominal values at the beginning of the test and 19 to 127% of nominal values after 96 h. Therefore, effect results are based on measured data. Mortality and other sub-lethal effects could be observed in Lepomis macrochirus at concentrations higher than 4.6 µg/L. The study resulted into an LC50 (96 h) value of 9.7 µg/L (arithm. mean measured). This study was chosen as key study since it bears the most sensitive effect data for this endpoint.

Additional studies using the freshwater organisms Lepomis macrochirus or Oncorhynchus mykiss and flow through or semi-static conditions, exhibited lower toxicity values, resulting in LC50s between 0.318 and 1.7 mg a.i./L. A solvent was used in most of these studies.

Furthermore, one study (1995) is available with a marine organism (Cyprinodon variegatus).The study was conducted according to the OECD Guideline No. 203 and GLP. Fish were exposed for 96 h to the nominal concentrations of 260,430, 720, 1200 and 2000 µg [ 14C] ziram/L (corresp. to mean measured concentrations of 310, 560, 810, 1200 and 2200 µg [14C] Ziram/L). An LC50 (96 h) value of 0.84 mg/L (mean meas.) was determined.