A draft revised standard for Glauber salt is open for consultation in India

On 6 July 2023 the Bureau of Indian Standards (BIS) published a draft revised standard for Glauber salt (sodium sulphate, decahydrate). The last date for comments is 7 September 2023. 

In 1950, the BIS published a draft for Glauber salt involving the maximum acceptable limits for some heavy metals.  

Glauber salt also known as mirabilite is used in textiles, glass, paper and pulp, dyestuff, leather, and metallurgical industries. In these sectors, it is for example used in the manufacture of plate and sheet partially glass, it serves as an agent to promote even distribution of dye of common salt in curing hides, and is also used for separation of nickel from copper. 

The draft standard was eventually revised in 1972. The first revision involves the limit values for sodium sulphate and zinc.  

• For sodium sulphate the defined minimum limit was 98.5 percent. 

• For zinc: the maximum limit was given to be 0.4 percent.  

The current second revision involves test methods for chloride and iron determination. The draft consists of following two annexes: 

• Annex A: provides method of testing for Glauber salt 

• Annex B: contains details on sampling of Glauber salt 

Also, a subsection for packing and marking is mentioned in the draft. The product must be marked with the BIS standard mark and the packages must be marked with the following details: 

a) Name and grade of the material; 

b) Net weight of contents;  

c) Year of manufacture;  

d) Manufacturer’s name and/or his recognized trade-mark, if any; and  

e) Batch number to enable the lot of manufacture to be traced from records 

Further details on the methods, packing and marking can be found here: 

https://www.services.bis.gov.in/tmp/WCCHD17022844_06072023_1.pdf