Melamine Quality Standard: Purity: 99.8% min. Appearance: White crystal powder without impurity Water content: 0.1% max. Ph Value: 7.5-9.5 Ash content: 0.03% max. Through the test of formaldehyde solubility turbility (China -Clay): 20% max. Chroma <Hzaen> Unit colourity: (Pt-Co):20 max. Kaolin nephelometer: 20 max.