A new study by Centre for Science and Environment revealed on Monday that carcinogen is used to make majority of the breads, buns and pizzas bases available in Delhi. Potassium bromate and potassium iodate has been used by bread companies for treating flour.

In 1990s, these substances were already banned across the European Union, and later Canada, Australia, New Zealand, China, Sri Lanka, Brazil, Nigeria, Peru and Columbia.

They are not banned in India, but in 1999, the International Agency for Research on Cancer (IARC) classified potassium bromate as possibly carcinogenic.

Breads made by Britannia, Harvest Gold and Perfect Bread were found with the highest levels in the samples CSE tested.

The potassium bromate/iodate concentration in Britannia's white bread measured 17.12 parts per million (PPM), 2.58 ppm in its whole wheat bread, 5.48 ppm in its brown bread, 15.01 ppm in its pav, 16.74 in its fruit bun.

The levels in Harvest Gold's white bread were 17.32 ppm, its brown bread were 5.48 ppm. Perfect Bread's white bread had 15.01 ppm and its brown bread 8.16 ppm.

According to the study, only Perfect Bread had listed potassium bromate as an ingredient, most of the other companies such as Britannia denied using it at all.

Britania said, "it does not use Potassium Bromate or Iodate as an ingredient in any of its bread recipes. All Britannia Breads products are in 100 per cent compliance to the existing food safety regulations as stipulated by FSSAI."

Britannia does not use the substance at all, and that 50 ppm was the permissible limit set by the Food, Safety and Standards Authority of India.

According to KFC, "they do not use flour treated with Potassium Bromate or Potassium Iodate to manufacture our products".

Several other brand like Domino's, McDonald's, Subway are in line of fire.