News Details

On 10 March 2026, the Bureau of Indian Standards (BIS) released a wide circulation draft for the first revision of the standard on Chlorosulphonic Acid — Code of Safety. The draft was prepared by the Technical Committee on Chemical Hazards (CHD 7) and the draft is now open for review by stakeholders, who are invited to provide comments. 

Background 

Chlorosulphonic acid (CAS No. 7790-94-5; ClSO₃H), also known as sulphuric chlorohydrin, is a slightly cloudy, highly corrosive liquid with a strong penetrating odour. While it is not flammable itself, it reacts violently with water and may ignite combustible materials. This chemical is widely used in the manufacture of detergents, pharmaceuticals, dyes, and other organic chemicals, so ensuring its safe handling is critical. 

Exposure to chlorosulphonic acid can be extremely hazardous: 

• Skin or eye contact: Causes severe burns. 

• Ingestion: Can lead to serious injury or death. 

• Inhalation: Concentrated vapours or mist may damage the lungs. 

Recognizing the risks, the revised code emphasizes accident prevention, noting that industrial accidents cause not only economic and social loss but also compromise workforce productivity. It provides guidance on the proper storage, handling, packing, labelling and waste disposal, as well as on container maintenance, personnel selection, protective equipment, and first-aid procedures. 

Key Changes in the Revision 

The key changes in the 2026 revision include: 

• Updated general properties of chlorosulphonic acid and enhanced safety measures. 

• Detailed information on poisoning symptoms, medical treatment, fire prevention, firefighting, and health monitoring. 

• Revised title: “Chlorosulphonic Acid - Code of Safety.” 

BIS has aligned the clauses of this standard with the formats used for other chemical safety codes. It is important to note that this standard has been prepared in India and that no ISO standard currently exists on this subject. For industrial-grade chlorosulphonic acid, BIS has published IS 7130:1994 on sampling and testing methods. 

Consultation and Timeline 

The draft is now open for stakeholder comments until 9 May 2026, and inputs are to be submitted through the BIS portal. In the absence of comments, approval will be assumed.