| Description | 
                                
                                    A very fine, light, white powder. 15 g occupies a volume of about 150 ml
                                 | 
	
                            
                                Identification | 
                                
                                    The solution gives the reactions of magnesium salts
                                 | 
	
                            
                            
                                
	
                                | Appearance of solution | 
                                
                                    Solution 'A' is not more intensely colour than reference solution BS2
                                 | 
	
                            
                                Arsenic | 
                                
                                    NMT 4 ppm
                                 | 
	
                            
                            
                                
	
                                | Soluble substance | 
                                
                                    NMT 2.0%
                                 | 
	
                            
                                Substance insoluble in acetic acid | 
                                
                                    NMT 0.1%
                                 | 
	
                            
                            
                                
	
                                | Loss on ignition (at 900°C) | 
                                
                                    NMT 8.0%
                                 | 
	
                            
                                Assay                                                                                                | 
                                
                                    NLT 98.0% and NMT 100.5% of MgO, calculated on the ignited basis
                                 |