Assay (iodometric, SO₂): 5 - 6 %

Chloride (Cl): ≤ 5 ppm

Ag (Silver): ≤ 0.02 ppm

Al (Aluminium): ≤ 0.05 ppm

As (Arsenic): ≤ 0.5 ppm

Ba (Barium): ≤ 0.05 ppm

Be (Beryllium): ≤ 0.02 ppm

Bi (Bismuth): ≤ 0.1 ppm

Ca (Calcium): ≤ 1 ppm

Cd (Cadmium): ≤ 0.05 ppm

Co (Cobalt): ≤ 0.02 ppm

Cr (Chromium): ≤ 0.02 ppm

Cu (Copper): ≤ 0.02 ppm

Fe (Iron): ≤ 0.5 ppm

Ge (Germanium): ≤ 0.05 ppm

K (Potassium): ≤ 0.1 ppm

Li (Lithium): ≤ 0.02 ppm

Mg (Magnesium): ≤ 0.1 ppm

Mn (Manganese): ≤ 0.02 ppm

Mo (Molybdenum): ≤ 0.02 ppm

Na (Sodium): ≤ 0.5 ppm

Ni (Nickel): ≤ 0.02 ppm

Pb (Lead): ≤ 0.02 ppm

Sr (Strontium): ≤ 0.02 ppm

Ti (Titanium): ≤ 0.1 ppm

Tl (Thallium): ≤ 0.05 ppm

V (Vanadium): ≤ 0.05 ppm

Zn (Zinc): ≤ 0.05 ppm

Zr (Zirconium): ≤ 0.1 ppm

Residue on ignition (as sulfate): ≤ 0.002 %