Captan

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

November 1980

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: ASTM method, 1980. (American Society for Testing and Materials)

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

- Name of test material: Captan, N-(trichloromethylthio)cyclohex-4-ene-1,2-dicarboximide
- Molecular formula: C9H8Cl3NO2S
- Molecular mass: 300.59- Purity: 90.5 %
- Physical state: white powder
- Date of arrival: 30 October 1980
- Storage conditions:-10°C

Analytical monitoring:

yes

Vehicle:

yes

Test organisms (species):

Daphnia magna

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

255 mg CaCO3 ppm

Test temperature:

20 °C

pH:

8.2

Dissolved oxygen:

9.3 ppm

Conductivity:

50 µmhos/cm

Nominal and measured concentrations:

nominal concentrations : 5, 10 mg/L in 0.5/1.0 ml acetone;
measured concentrations 5 mg/L in 0.5 ml acetone: 3.18 mg/L;
measured concentrations 5 mg/L in 1.0 ml acetone: 3.07 mg/L;
measured concentrations 10 mg/L in 0.5 ml acetone: 7.27 mg/L;
measured concentrations 10 mg/L in 1.0 ml acetone: 6.91 mg/L

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 7.1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

> 7.1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Analysis of solutions: Measured concentrations of captan in the test media were 3.18 and 3.07 mg/L (mean 3.1 mg/L) for the 5 mg/L nominal rate dissolved in 0.5 and 1.0 mL of acetone, respectively, and 7.27 and 6.91 mg/L (mean 7.1 mg/L) for the 10 mg/L nominal rate dissolved in 0.5 and 1.0 mL of acetone, respectively. The measured concentrations therefore ranged from 61 to 73% of nominal and the results are presented as measured values.

Toxicity: No mortality was recorded during the study.

Validity criteria fulfilled:

yes

Conclusions:

The 48-hour EC50 of captan to Daphnia magna under static conditions was higher than 7.1 mg/L. The NOEC was equal to or greater than 7.1 mg/L based on the absence of mortality recorded at the highest dose tested in the study.

Executive summary:

Daphnia magna were exposed for 48 hours to nominal Captan concentrations of 5 mg/L and 10 mg/L in a solubility study. The procedures for static bioassays, as described in Standard Methods for Examination of Water and Wastewater (1) and Methods of Acute Toxicity Tests with Fish, Macroinvertebrates and Amphibians (2) , were used in the experiment.

Captan Technical material of 5 and 10 mg each in both 0.5 ml and 1.0 ml acetone were prepared in triplicate for their respective bioassay. The measured concentrations for the 5 mg/L and 10 mg/L nominal concentrations were 3.18 mg/L and 7.27 mg/L using 0.5 ml acetone and 3.07 mg/L and 6.91 mg/L using 1.0 ml acetone. Solubility in one liter of water was not enhanced by varying the amount of carrier solvent from 0.5. to 1.0 ml.

No daphnia mortality was observed at any of the test concentrations. The 48-hour LC50of Captan Technical was estimated to be higher than 7.1 mg/l.

(1) American Public Health Association. 1975. Standard Methods for the Examination of Water and Wastewater. 14th ed., New York

(2) Methods of Acute Toxicity Tests with Fish, Macroinvertebrates and Amphibians. Stephan, C. E., Chairman. 1975. Committee on Methods for Toxicity Tests with Aquatic Organisms. U.S. EPA, Ecol. Res. Ser. 660/3-75009.

Description of key information

Short-term toxicity to aquatic invertebrates (Daphnia magna): EC50 (48h): > 7.1 mg/L , ASTM method, 1980.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

7.1 mg/L

Additional information

Based on ASTM method 7806 (Methods of Acute Toxicity Tests with Fish, Macroinvertebrates and Amphibians) up to a concentration of 7.1 mg/L toxicity on Daphnia has been tested. No mortalities were observed.

The test was limited by the low solubility of captan. In consequence the 48-hour EC50 values for Daphnia are estimated to be above the limit of water solubility.