• As many as 11 out of 30 samples of fish species purchased from Chinthadripet and Kasimedu, the two major fish markets in Chennai, on two different days, have tested positive for formalin, a cancer-inducing chemical used illegally to preserve fish.

• Formalin is used widely as a preservative and disinfectant. Formalin causes irritation in the eyes, throat, skin and stomach. In the long run continued exposure causes harm to the kidneys, liver and can even cause cancers.

• Food Safety and Standards Authority of India (FSSAI) officials have been undertaking tests at fish markets and harbours across the State to test for formalin following a scare in neighbouring Kerala that fish sourced from here were chemically contaminated.

• Fish industry experts said that formalin or formaldehyde is sprayed on the fish or injected into the fish or the fish is dipped into the solution. This helps keep the fish fresh for a longer time. Usually, people who buy fish check the gills for freshness, if it is red it denotes freshness, when formalin is used the gills remain red for longer periods. In some cases, fishermen also apply kumkum to retain redness.

The Hindu