Disulphur dichloride

Basic toxicokinetics

Administrative data

Endpoint:

basic toxicokinetics

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: A guideline test was performed according OECD TG 111 (Hydrolysis as a Function of pH) to verify fast and quantitative hydrolysis in water. For further details see IUCLID chapter 5.1.2.

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: OECD TG 111 (Hydrolysis as a Function of pH) to verify fast and quantitative hydrolysis in water.

Principles of method if other than guideline:

S2Cl2 is reported in the literature to undergo rapid hydrolysis in aqueous conditions. A guideline test was performed according OECD TG 111 (Hydrolysis as a Function of pH) to verify fast and quantitative hydrolysis in water. As the hydrolysis was known to occur rapidly, hydrolysis behaviour of the test item in aqueous solutions was investigated in a Tier 1 test at room temperature instead of 50 °C, at different pH (4, 7 and 9). The main hydrolysis products expected are chloride, sulfide, sulfur dioxide, sulfite, sulfate, thiosulfate and sulfur.
The following analytical methods were used to detect different hydrolysis products: chloride, sulphite, sulphate and thiosulphate were quantified via ion chromatography; sufide was determined iodometrically and precipitable sulphur was identified by Raman-Spectroscopy and determined by ICP-OES analysis.

For further details on the study see IUCLID chapter 5.1.2

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Disulphur dichloride

EC Number:

233-036-2

EC Name:

Disulphur dichloride

Cas Number:

10025-67-9

Molecular formula:

Cl2S2

IUPAC Name:

dichlorodisulfane

Test material form:

other: liquid

Details on test material:

- Purity: 99.9 %
- Empirical formula: Cl2S2
- Molecular mass: 135.0 g/mole

Radiolabelling:

no

Test animals

Species:

other: in vitro hydrolysis in water

Strain:

other: in vitro hydrolysis in water

Administration / exposure

Duration and frequency of treatment / exposure:

in vitro hydrolysis in water

Doses / concentrations

Remarks:

Doses / Concentrations:
in vitro hydrolysis in water

No. of animals per sex per dose / concentration:

in vitro hydrolysis in water

Results and discussion

Main ADME results

Type:

other:

Results:

S2Cl2 is rapidly (t 1/2 < 2 minutes) and quantitatively hydrolysed in water at 23 °C. Hydrolysis products are HCl and sulphur containing molecules in varying amounts including sulphite, sulphate, thiosulphate, sulphide and precipitable sulphur.

Any other information on results incl. tables

As expected, the hydrolysis is rapid and quantitative. Due to the observed rapid and complete degradation of the test item between sample preparation and injection into ion chromatography apparatus, no precise half-life could be calculated. At 23 °C (room temperature) the half-life was calculated to be < 2 minutes for all pH investigated (4, 7 and 9). Recoveries based on the contents of chloride and total Sulphur were in the range of 97.7 to 101.7 %, indicating quantitative hydrolysis.

The total sulphur fraction was further investigated at different time points and dependent on the pH (4, 7 or 9) contained ca. 9.8 – 25% perceptible sulphur; 6.3 - <4.2% sulphite; < 3.5% sulphate; 15.1 – 60% thiosulfate. Based on the mass balance additional volatile sulphur species as sulphur dioxide are also likely to be present, but were not specifically monitored.

The analytical method for determination of sulfide (iodometry) is not a specific method for testing hydrolysis reactions. The performed procedure resulted in an extreme Sulfide concentration (expected influence of equilibrium reaction). Therefore the recovery values reported for sulphide (3.1 – 12.2 %) should be taken as qualitative figures.

For further details on the study see IUCLID chapter 5.1.2.

Applicant's summary and conclusion

Executive summary:

Overall, this guideline study according to the OECD TG 111 (Hydrolysis as a Function of pH) showed that S2Cl2 is rapidly (t 1/2 < 2 minutes) and quantitatively (97.7 - 101.7 %) hydrolysed in water at 23 °C and pH ranging from 4 to 9. The hydrolysis products are HCl and different sulphur containing molecules in varying amounts including sulphite, sulphate, thiosulphate, sulphide and precipitable sulphur.