Registration Dossier

Administrative data

stability: thermal, sunlight, metals, other
Migrated from section 'Stability: thermal, sunlight, metals'
Type of information:
experimental study
Adequacy of study:
supporting study
Study period:
2005-07-22 - 2005-10-17
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: No data on GLP-status, according to Pensky Martens method (DIN 51 758)

Data source

Reference Type:
study report
Report Date:

Materials and methods

Test guideline
no guideline followed
Principles of method if other than guideline:
Differential scanning calorimetry (DSC)
Investigations by DSC and differential scanning calorimetry (DSC) provide information on the thermal behavior of materials.
Sample quantities of a few milligrams are used. The sample and a thermally neutral behaving reference substance are heated in an oven at a constant heating rate, and the temperatur is measured in two containers. An ideal thermal symmetry of the sample and reference substance (ie same heat capacity, same heat transfer to the surroundings) is characterized by both substances beeing equally rapidly heated and the temperature difference is equal to zero. If heat is consumed by a reaction or a physical process, ie. as a phase transition in the sample heat (endothermic) is used or released (exothermic), then temperature differences appear between sample and reference, which characterize the current operation.
In the DSC diagram of the heat flow of the sample is shown related to the oven temperature. By integrating this curve the amount of heat releases or consumed in the thermal event is calculated.
This method is used mainly for investigations of the thermal stability of samples as a screening method for determining the temperature at which the onset of decomposition can be detected (onset temperature) and used to determine the heats of decomposition.
GLP compliance:

Test material

Details on test material:
- Name of test material (as cited in study report): 3-mercaptopropanesulfonsaures Natrium
- Substance type: organic salt
- Physical state: solid, white powder

Results and discussion

For thermal stability study

Test substance thermally stable:
Operating temperature
Operating temp.:
> 15 - 430 °C
Remarks on result:
other: Weak exothermic reaction at T>250 °C after an endothermic event. Temperature range of the endothermic event was 216 - 238 and 240-250°C. The enthalpie measured for the events were 33 or 59 J/g, respectively. The second signal was very weak.
Transformation products:
not measured

Any other information on results incl. tables

A weak exothermic reaction was noted at T>250°C after an endothermic event. The temperature range of the endothermic event was between 216 and 238 and 240-250°C. The enthalpie measured for the events were 33 or 59 J/g, respectively. The second signal was very weak.

Applicant's summary and conclusion

A transition from the melting into decomposition was observed in MPS. The melting temperature is above 200 °C. If, on the substance starts to melt and to decompose, MPS has a relatively low heat release (up to -59 J/g).