Ziram

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

22 August 1990 - 3 September 1991

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

static test system

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Qualifier:

according to guideline

Guideline:

EPA OPP 72-2 (Aquatic Invertebrate Acute Toxicity Test)

GLP compliance:

yes

Analytical monitoring:

yes

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.

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: direct dispersion in water. A stock solution of 50 mg/L was prepared by dissolving the test sample in test water with the aid of ultrasonic disruption. The test series were prepared by further dilution of this stock with test water.
- Controls: yes
- Evidence of undissolved material: no precipitate was observed during the preparation of the stock or test solutions

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Strain: Straus
- Source: laboratory culture originating from a strain supplied by IRCHA, France
- Age at study initiation: < 24 h
- Method of breeding: cultures were kept at 20° +/- 2°C in glass vessels containing 2 L of dechlorinated and aged tap water, and fed daily with a mixture of fry fish food and a suspension of mixed algae

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

350 mgCaCO3/L

Test temperature:

21°C

pH:

8.0

Dissolved oxygen:

8.6-8.9 mgO2/L

Nominal and measured concentrations:

Nominal concentrations: 0.00032, 0.00056, 0.001, 0.0018, 0.0032, 0.0056, 0.01, 0.018, 0.032, 0.056 and 0.1 mg a.i./L
Measured concentrations: 0.0012, 0.0012, 0.0026, 0.0017, 0.0072, 0.0055, 0.0094, 0.015, 0.032, 0.048 and 0.096 mg a.i./L

Details on test conditions:

TEST SYSTEM
- Test vessel: glass jars containing 200 mL test solution
- Aeration: no
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- Biomass loading rate: 1daphnid/20mL solution

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: dechlorinated (with sodium thiosulphate) and aged laboratory tap water.

OTHER TEST CONDITIONS
- Photoperiod: 16h light; 8 h darkness

EFFECT PARAMETERS MEASURED : immobilisation

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 1.7

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.048 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Basis for effect:

other: immobilisation

Remarks on result:

other: 0.034-0.068

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

0.003 mg/L

Nominal / measured:

estimated

Conc. based on:

act. ingr.

Validity criteria fulfilled:

yes

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

4 - 6 Dec 2007

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

a solvent was used

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

2004

Qualifier:

according to guideline

Guideline:

EPA OPPTS 850.1010 (Aquatic Invertebrate Acute Toxicity Test, Freshwater Daphnids)

Version / remarks:

1996 (draft)

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:

Liquid scintillation counting (LSC)

Details on sampling:

- Concentrations: Samples from all concentrations and controls were collected.
- Sampling method: Water samples were collected from one test chamber of each treatment and control group prior to the start of the test after conditioning the diluter for approx. 17 h. Water samples were collected from mid-depth of the chambers and alternating replicate test chambers at test initiation and termination to measure concentrations of the test substance.Samples of the dispensing stock solutions were additionally analyzed prior to the start.
- Sample storage conditions before analysis: No storage due to instability of the substance.

Vehicle:

yes

Remarks:

DMF (Dimethyl formamide)

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: A primary stock solution of non-radiolabelled substance was prepared by dissolving it in DMF at a nominal concentration of 10 mg/mL. The stock was sonicated for 30 seconds and mixed by inversion. After mixing, the stock solution appeared beige and slightly cloudy. 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 5.02 mg of the 14C-ziram to a 50-mL volumetric flask using DMF and inverting the solution to mix. Triplicate 25-µL samples of the stock solution were analyzed by liquid scintillation counting (LSC), resulting in a mean recovery of 107% of the expected radioactivity, corresponding to a concentration of 107 mg/L or 7.24 x 107 dpm/mL. A volume of 0.44 mL of the primary stock was used in the preparation of each 100-mL dispensing stock solution to achieve a nominal radioactivity of 25 dpm/mL in each test solution. Five dispensing stock solutions were injected into the diluter mixing chambers (at a rate of 15.5 µL/minute) where they were mixed with well water (at a rate of 155 mL/minute) to achieve the desired test concentrations
- Differential loading: yes
- Controls: negative control and solvent control
- Chemical name of vehicle: DMF (Dimethyl formamide)
- Concentration of vehicle in test medium or suspension(s) including control(s)): 0.1 mL/L

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Age at study initiation (mean and range, SD): Neonates (<24 h old at test start)
- Source: in-house culture
- Feeding during test : no

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

140 mg/L as CaCO3

Test temperature:

19.8 -.20.0 °C

pH:

8.3

Dissolved oxygen:

8.3 mg/L (>= 92 % saturation)

Conductivity:

310 µmhos/cm

Nominal and measured concentrations:

Nominal: negative control, solvent control, 19, 38, 75, 150 and 300 µg/L
Mean measured: < LOQ, < LOQ, 20, 38, 76, 151 and 307 µg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 25 L Teflon®-lined stainless steel
- Material, size, headspace, fill volume: 25 L Teflon®-lined stainless steel. each test chamber contained one test compartment constructed from a glass beaker approximately 6.5 cm in diameter and 12 cm in height.
- Volume of solution: 22 L
- Aeration: no
- Type of flow-through: A continuous-flow diluter was used to deliver each concentration of the test substance, a solvent control, and a negative (dilution water) control. Two syringe pumps (Harvard Apparatus, South Natick, Massachusetts) were used to deliver the five test substance stock solutions and dimethyl formamide (DMF) for the solvent control into mixing chambers assigned to each treatment and the solvent control.
- Renewal rate of test solution: Five volume additions of test water every 24 h.
- 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

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Freshwater obtained from a well approx. 40 m deep located on the site of the laboratory (for more details on water parameters refer to attachment "Rep.No.602A-108_Attachment 3_Analyses of Pesticides, Organics and Metals in Well Water"). Well water was passed through a sand filter to remove particles greater than approximately 25 µm, and pumped into a 37,800 L storage tank where the water was aerated with spray nozzles. Prior to use, the water was filtered to 0.45 µm to remove fine particles and was passed through an ultraviolet sterilizer.
- Culture medium different from test medium: no
- Alkalinity: 174 mg/L as CaCO3
- TOC: <1 mg C/L
- Intervals of water quality measurement: prior to test

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 h light / 8 h darkness (30 min transition period)
- Light intensity: 220 lux

EFFECT PARAMETERS MEASURED :
Mobility, signs of toxicity were observed after 2, 24 and 48 h.

VEHICLE CONTROL PERFORMED: yes

RANGE-FINDING STUDY
- Test concentrations: not mentioned in report

Reference substance (positive control):

not specified

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

206 µg/L

95% CI:

> 151 - < 307

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Other biological observations: please refer to attachment "Rep.No.602A-108_Attachment 2_Biological results"
- Mortality of control: yes, but ≤10%
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: no
- Effect concentrations exceeding solubility of substance in test medium: no

Measure concentrations of the substance in water samples collected during the test ranged from approximately 97 to 108 % of nominal. Samples of the dispensing stock solutions ranged from 101 to 103 % of nominal, confirming that the correct concentrations were being delivered to the diluter system.

Table 1: Validity criteria for OECD 202 (2004)

Criterion from the guideline	Outcome	Validity criterion fulfilled
In the control, including the control containing the solubilising agent, not more than 10% of the daphnids should have been immobilized.	7.5 % of the control daphnids had been affected	yes
The dissolved oxygen concentration at the end of the test should be ≥ 3 mg/L in control and test vessels.	≥8.6 mg/L	yes

Validity criteria fulfilled:

yes

Remarks:

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

Reference 3

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

a solvent was used

Qualifier:

according to guideline

Guideline:

EPA OPPTS 850.1035 (Mysid Acute Toxicity Test)

Version / remarks:

1996 (draft)

GLP compliance:

yes

Analytical monitoring:

yes

Remarks:

Liquid scintillation counting (LSC)

Vehicle:

yes

Remarks:

dimethyl formamide

Test organisms (species):

Americamysis bahia (previous name: Mysidopsis bahia)

Test type:

flow-through

Water media type:

saltwater

Limit test:

no

Total exposure duration:

96 h

Nominal and measured concentrations:

Nominal: negative control, solvent control, 30, 60, 120, 240 and 480 µg/L
Mean measured: < LOQ, < LOQ, 28, 66, 134, 272 and 517 µg/L

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

140 µg/L

95% CI:

>= 111 - <= 175

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

> 517 µg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: retrospectively calculated based on results in study report

Results of analyses to measure concentrations of [14C] ziram in water samples collected prior to the test to verify the operation of the diluter ranged from l 02 to 110 % of nominal. Results of analyses to measured concentrations ziram in water samples collected during the test ranged from 102 to 120 % of nominal.

Validity criteria fulfilled:

not specified

Description of key information

EC50 (48 h) = 206 µg/L (mean measured, Daphnia magna, OECD 202)

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

206 µg/L

Additional information

Three studies are available assessing the short-term toxicity of zinc bis dimethyldithiocarbamate (CAS No. 137-30-4) to aquatic invertebrates.

The key study (2008) was performed according to the OECD Guideline No. 202, EPA Guideline OPPTS 850.1010 and GLP. The acute toxicity of the substance to Daphnia magna, was investigated within 48 h in an unaerated, flow-through system. A 14-C radiolabeled test item was used and was analytically monitored via liquid scintillation counting. Treatments consisted of a negative control, a solvent control and the nominal concentrations of 19, 38, 75, 150 and 300 µg/L. DMF (dimethyl formamide) was used as a vehicle. The mean measured concentrations had been determined to be 20, 38, 76, 151 and 307 µg/L. Based on the mean measured concentrations the 48-h EC50 value was calculated to be 206 µg/L (95 % confidence limits: 151 - 307 µg/L). This study was selected as key study since it bears the most appropriate test system and the lowest 48-h EC50 value.

In the supporting study (1991) the acute toxicity of zinc bis dimethyldithiocarbamate (CAS No. 137-30-4) to Daphnia magna was investigated according to OECD Guideline No. 202, EPA Guideline OPP 72-2 and GLP. After 48 h of exposure to the test substance within a semi-static water regime, daphnids immobilization was observed. The study resulted in an EC50 (48 h) of 480 µg/L (mean measured). 

A further study (2008) assessed the acute effects of the substance to marine invertebrates according to the EPA Guideline OPPTS 850.1035 and GLP. The acute toxicity of the substance to Americamysis bahia was determined in a 96-h test under flow-through conditions. Saltwater mysids were exposed to a negative control, a solvent control (dimethylformamide) and nominal test item concentrations of 30, 60, 120, 240 and 480 µg/L (corresponding to mean measured concentrations of 28, 66, 134, 272 and 517 µg/L). The determined 96-hour LC50 value was 140 µg/L (mean measured). Based on the reported raw data, the retrospectively estimated 48 h LC50 value is > 517 µg/L (geom. mean measured, the highest tested concentration).