Disulfiram

Hydrolysis

Link to relevant study record(s)

Reference

Endpoint:

hydrolysis

Type of information:

(Q)SAR

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Justification for type of information:

1. SOFTWARE
EPI Suite v4.11 Estimation Programs Interface Suite™ for Microsoft® Windows v 4.11. US EPA, United States Environmental Protection Agency, Washington, DC, USA.

2. MODEL (incl. version number)
HYDROWIN v2.00

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
See “Test material information”

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
See attached information on the model provided by the developer.

5. APPLICABILITY DOMAIN
See attached information and information as provided in "Any other information on material and methods incl. tables".

6. ADEQUACY OF THE RESULT
See assessment of adequacy as outlined in the "Overall remarks, attachments" section.

Qualifier:

according to guideline

Guideline:

other:

Version / remarks:

REACH Guidance on QSARs R.6

Principles of method if other than guideline:

- Software tool(s) used including version: EPI Suite v4.11
- Model(s) used: HYDROWIN v2.00
Full reference and details of the used formulas can be found in:
Mill, T., Haag, W., Penwell, P., Pettit, T. and Johnson, H. "Environmental Fate and Exposure Studies Development of a PC-SAR for Hydrolysis: Esters, Alkyl Halides and Epoxides". EPA Contract No. 68-02-4254: SRI International (1987).
- Model description: see field 'Justification for non-standard information', 'Attached justification' and 'any other information on material and methods'
- Justification of QSAR prediction: see field 'Justification for type of information', 'Attached justification' and/or 'overall remarks'

GLP compliance:

no

Estimation method (if used):

- Temperature for which half-lives were calculated: 20-25 °C
- Computer programme: HYDROWIN v2.00

Transformation products:

not specified

Remarks on result:

other: for results please refer to field "Details on results"

Details on results:

Experimental half-lives data measured at 20-25 °C for a variety of dithiocarbamate pesticides (including Mancozeb, Maneb, Thiram, Ziram and Metiram) suggest the following half-lives for disulfiram:
- pH 5: less than one day to several weeks
- pH 7: less than one day to several days
- pH 9: less than one day

For detailed information on the results please refer to the attached report.

Description of key information

Hydrolysis may be a relevant degradation pathway for disulfiram in aquatic systems.

Additional information

Hydrolysis, predicted by HYDROWIN v2.00 is expected to contribute slightly to the overall degradation of disulfiram in the environment (DT50 hydrolysis = several days to several weeks as a function of pH).