| 
                                            Appearance
                                         | 
                                            White or almost white, crystalline powder, colourless crystals or granules, efflorescent
                                         | 
		
			| 
                                            Assay (by NaOH titration)
                                         | 
                                            Min 99%
                                         | 
		
			| 
                                            Insoluble matter in water
                                         | 
                                            Max 0.01%
                                         | 
		
			| 
                                            Chloride (Cl)
                                         | 
                                            Max 0.005%
                                         | 
		
			| 
                                            Sulphate (SO4)
                                         | 
                                            Max 0.01%
                                         | 
		
			| 
                                            Oxalate (as C2H2O4)
                                         | 
                                            Max 0.035%
                                         | 
		
			| 
                                            Heavy metal (as Pb)
                                         | 
                                            Max 0.001%
                                         | 
		
			| 
                                            Lead (Pb)
                                         | 
                                            Max 0.001%
                                         | 
		
			| 
                                            Iron (Fe)
                                         | 
                                            Max 0.001%
                                         | 
		
			| 
                                            Zinc (Zn)
                                         | 
                                            Max 0.001%
                                         | 
		
			| 
                                            Arsenic (As)
                                         | 
                                            Max 0.0001%
                                         | 
		
			| 
                                            Calcium (Ca)
                                         | 
                                            Max 0.02%
                                         | 
		
			| 
                                            Barium (Ba)
                                         | 
                                            Max 0.002%
                                         | 
		
			| 
                                            Reaction against H2SO4
                                         | 
                                            Passes test
                                         | 
		
			| 
                                            Water
                                         | 
                                            7.5 - 8.8%
                                         | 
		
			| 
                                            Sulphated ash (at 600°C)
                                         | 
                                            Max 0.05%
                                         |