Disodium sulphide

Endpoint summary

Additional information

The majority of data on the physical and chemical properties of sodium sulfide (commercial form, type ca. 60 %) were provided by new testing in accordance with GLP: melting point, boiling point, density, particle size (and dustiness testing), water solubility, auto flammability, flammability, phyrophoric properties, and pH testing (without GLP). DSC analysis was also performed with sodium sulfide, anhydrous.

Additional available data on the physical and chemical properties of sodium sulfide, anhydrous was taken from public domain reviews and handbooks including the CRC (2008), Merck (2006), and Gmelin database (2009): appearance, melting point, density, water solubility. It is noted here thathandbook data for physico-chemical properties are considered to be from a trusted source acc. to "ECHA, Guidance on information requirements and chemical safety assessment – Chapter R.7a: Endpoint specific guidance" and therefore, theses data could be regarded as valid.

Waivers are proposed for boiling point (anhydrous form), vapour pressure, partition coefficient, surface tension, flash point, flammability in contact with water, explosiveness, oxidizing properties, stability in organic solvents, dissociation constant and viscosity , based on intrinsic properties of the substance oron the criteria as laid down in regulation (EC) 1907/2008 as described above.

If available, the values for the anhydrous form and the hydrated, commercial form (type ca. 60 %) are presented.

Summary of results:

Property	Value for sodium sulfide(commercial form, type ca. 60 %)	Value for sodium sulfide (anhydrous)
Substance type	Inorganic substance	Inorganic substance
Appearance/physical state/colour	Yellow flakes under atmospheric pressure and room temperature	Solid crystals, granules, lumps or flakes, colour description: between clear, white, yellow, pink and red
Melting/freezing point	69 to 93 °C	>600 °C
Boiling point (at 1013 hPa)	No boiling point; test item oxidises after melting	Not required if melting point is above 300 °C
Density at 20⁰C	Relative density is 1.64 at room temperature	Relative density is 1.9 at room temperature
Particle size distribution	D50: 3,500 µm (sieving analysis) MMAD: 33.93 µm	no data
Vapour pressure	Not required if melting point is above 300 °C. The lower MP of the hydrate is only based on the crystal water.	Not required if melting point is above 300 °C
Partition Coefficient	Not required for inorganic substances	Not required for inorganic substances
Water solubility at 20⁰C	178 g/L at 20 °C and pH 12.8	Between 124 – 290 g/L (at between 0 – 40 °C)
Surface Tension at 25⁰C	Not expected to be surface active	Not expected to be surface active
Flash point	Not required for inorganic solid substances	Not required for inorganic solid substances
Self ignition temperature	No self-ignition was observed up to 430 °C	no data
Flammability	Non-flammable and no pyrophoric properties; no flammability in contact with water expected	no data
Explosiveness	Not expected to possess explosive properties	no data
Oxidising properties	No oxidising properties expected	no data
Stability in organic solvents and identity of relevant degradation products	Not considered critical for an inorganic substance	Not considered critical for an inorganic substance
Storage stability	May be corrosive to carbon steel and aluminium	-
pH	12.9 (1 % solution) 13.1 (saturated solution)	no data
Dissociation constant	No relevant functional groups, thus considered not required	No relevant functional groups, thus considered not required
Viscosity	Not required for solids	Not required for solids