Experts raise question on water purifiers

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  • Published 31.07.10

New Delhi, July 30: A consumer health organisation has raised questions over the safety of household storage water purifiers sold in India and called for mandatory standards and greater regulatory measures.

Storage water purifiers sold in India may be disinfecting water efficiently, but by using chemicals that can endanger human health, said Bejon Misra of Healthy You Foundation, the consumer health organisation.

The absence of standards and regulatory oversight over water purifiers allows manufacturers to sell products without specifying residual levels of disinfection by-products in the finished water, Misra said, releasing the findings of a survey of some purifiers sold in India. Chlorine, for instance, is a common agent used to disinfect water, but manufacturers do not disclose chlorine levels in the water.

Water purifiers use gravity-based filtration systems, and rely on a mix of filters, chemicals, and resins to disinfect the water. They do not require a power source — unlike purifiers that use ultraviolet radiation or reverse osmosis.

The foundation said it examined five popular brands and found that none of them discloses residual chlorine levels in the finished drinking water. “Manufacturers are not mandated to share information,” Misra said.

The product labels or documents, he said, do not provide sufficient information about the chemicals used to disinfect the water and how the levels of the disinfection byproducts may be monitored or evaluated by household users.

The foundation said one storage water purifier sold in India uses a chemical called trichloroisocyanuric acid (TCCA) which is mainly used to sanitise swimming pools and public water distribution systems. Misra said the US Environment Protection Agency has not approved TCCA for long-term use as a primary water disinfectant for household water purifiers.

The amount of TCCA used in the Indian purifier is also larger than authorised by EPA for public water systems, he said. The TCCA can break down in the water to produce chlorine and cyanuric acid — both can harm human health.

But the manufacturer that uses TCCA in its purifier has said tests have shown that there is no free chlorine residue in the treated water and the level of cyanuric acid in the purified water is “near zero”.

“This is an interesting exercise,” said Kannepalli Chandrasekhar, manager of the India operations of Water Quality Association, an independent agency for certifying water quality, commenting on the study. “Let’s hope it starts a debate and spurs the Bureau of Indian Standards into looking at standards,” he said.