It is used in optical materials like lasers and phosphors due to Er pink fluorescence as a catalyst support in ceramics and potentially in antimicrobial coatings.

Its primary purpose is providing stable Er ions for luminescent applications and as an insoluble phosphate matrix for rare-earth doping in photonics.

Erbium phosphate anhydrous (ErPO) is a pinkish-white crystalline powder a rare-earth orthophosphate with xenotime-type structure molecular weight 262.23 gmol (anhydrous basis) insoluble in water and thermally stable with decomposition above 120C.