StructureTetrakis(hydroxymethyl) phosphonium sulfate (THPS)
CAS No. 55566-30-8
EC No. 259-709-0
Synonyms Octakis(hydroxymethyl)diphosphonium sulfate; Tetrakis(hydroxymethyl) phosphonium sulfate; tetrakis (hydroxymethyl) phosphonium sulfate (2:1); THPS

Tetrakis(hydroxymethyl) phosphonium sulfate (THPS)

Tetrakis(hydroxymethyl)phosphonium sulfate (THPS) is an organophosphorus compound . Connect Chemicals is worldwide leader for the usage of THPS in the leather industry.


  • precursors in flame retardant manufacture process
  •  biocide in water system
  • Tanning agent in the leather industry

One of the main application within Connect Chemicals Group is to use THPS as Tanning agent in the leather industry.

In this case THPS can be used as chrome-free (metal free) tanning system in the wet white process and give

can give the benefits of a lower allergology phenomena and a better biodegradability

Advantage of the wet white tanned leathers, using THPS offers:

  • a light color and pastel shades
  • They can reach shrink temperatures of at least 70 grad C
  • High softness
  • Good lightness
  • Feeling of naturalness
  • Pleasant to the touch
  • Beauty that lasts for a long time
  • Can be burned without the risk of hexavalent chromium formation

Shelf Life

Under proper storage conditions, the shelf life is 12 months.

Health & Safety

Detailed information on the product described can be found in our relevant Health and Safety Information (Material Safety Data Sheet).