白色结晶。置空气中失去部分氨。易溶于水，微溶于稀氨水，不溶于醇、丙酮。

    
CP /  SP  /  4N
    项目Item                                                                分析纯                                  化学纯
    
                                                                                (AR)                                     (CP)
    
    
含量［(NH4)3PO4
    
    
·3H2O)Assay,%                                                 ≥ 98.0                                   95.0
    
    
铁(Fe)Iron,%                                                         ≤ 0.001                                 0.003
    
    
砷(As)Arsenic,%                                                   ≤ 0.0001                               0.0003
    
    
重金属(以Pb计)Heavy metals,%                         ≤ 0.001                                  0.002 
    
碱金属(以磷酸盐计)Alkali metals,%                    ≤ 0.1                                       0.3
    
    
澄清度试验Clarity                                                  合格                                        合格
    
    
水不溶物Insoluble matter in water,%                   ≤ 0.005                                  0.01
    
    
氯化物(Cl)Chloride,%                                           ≤ 0.001                                  0.002
    
    
硫化合物(以SO4计)Sulfur compounds               ≤ 0.01                                     0.02
    
 

    
分析试剂、掩蔽剂，木材等防火剂。
    
密封保存