The Food Safety and Standards Authority of India (FSSAI) will remove the mandatory Bureau of Indian Standards (BIS) certification for packaged drinking water from January 1 in Tamil Nadu. This will end the need for dual approvals for the 1,600 water bottling units in the state. Instead, manufacturers must follow a stricter testing and compliance framework under FSSAI rules. Nearly 40% of units have already stopped renewing BIS certificates ahead of the change. A. Shakespeare, head of the Greater Tamil Nadu Packaged Drinking Water Manufacturers Association, warned that failing to meet quality tests could lead to license cancellations and legal actions. He also said that the new testing rules will raise operational costs due to extra and frequent microbiological checks. Despite fewer new manufacturers entering the market, demand stays strong at five crore litres daily in Tamil Nadu, with Chennai consuming three crore litres. Consumer groups urged the government to set up more testing labs and step up inspections. T. Sadagopan, president of Tamil Nadu Progressive Consumer Centre, called for simpler licenses and regular third-party checks to enforce FSSAI guidelines effectively. Health officials confirmed all packaged water types fall under high-risk food and undergo private and government quality checks. Meanwhile, BIS still accepts certification applications but sees fewer renewals. BIS said it will continue market surveillance and take action against misuse of the ISI mark.