为半透明无色晶体或结晶性白色粉末；无臭，味咸；加热至 350-400 ℃失去全部结晶水即为无水硼砂（ Na2B4O7 ），密度 1.72g ／ cm3 ；易溶于水，也溶于甘油，不溶于醇。其水溶液呈弱碱性，熔融时呈无色玻璃状。有杀菌作用，口服对人体有害。

GB/T 632-93
99.99% metals basis:


外观Appearance                                               White Powder
X-射线衍射X-Ray Diffraction                            Conforms to Structure
纯度Purity                                                          ≥99.99% Based on Trace Metals Impurities
ICP Major Analysis                                          Confirms Boron component
痕量金属杂质total metallic impurities         ≤200ppm by ICP Atomic emission

项目Item                                                     优级纯     分析纯    化学纯
                                                                      (GR)       (AR)      (CP)
含量(Na2B4O7·10H2O)Assay,%            ≥99.5       99.5      99.0
澄清度试验Clarity                                           合格       合格      合格
盐酸不溶物Insiluble matter 
in hydrochloric,%                                        ≤0.003     0.005      0.02   
氯化物(Cl)Chloride,%                                ≤0.0005    0.002      0.005
硫酸盐(SO4)Sulfate ,%                              ≤0.005     0.01       0.015
磷酸盐(PO4)Phosphate,%                       ≤0.001     0.002      0.005 
钙(Ca)Calcium,%                                     ≤0.001     0.005      0.02 
铁(Fe)Iron,%                                              ≤0.0001    0.0003     0.0005
铜(Cu)Copper,%                                      ≤0.0005    0.001      0.002
铅(Pb)Lead,%                                           ≤0.0005    0.001      0.002

危险品标志  Xn 
    
危险类别码  62 
    
安全说明  22-24/25-36/37 
    
危险品运输编号  UN 1458  
    
海关编码  28401990 
    
WGK Germany  1 
    
RTECS  VZ2275000

硼砂的用途很广，可用做洗衣粉和肥皂的填料，也是制造光学玻璃、珐琅和瓷釉的原料，也可制造人造宝石、焊药等。经提炼精制后可做清热解毒药，性凉、味甘咸，可治咽喉肿痛、牙疳、口疮、目生翳障等症。
密封保存