The survey was a part of the society's ongoing testing programme of various items of daily consumption about 25 loose tea samples were gathered at random from all over.

Managing committee member of CGSI NG Wagle in a statement here said, "The test report of the loose tea samples has confirmed in a conclusive manner that food items sold loose are grossly adulterated, tea is no exception.''

Typical adulterants used in the Indian loose tea trade as revealed under the microscopic test carried out by CGSI include sawdust, sand, stone, stalk and used tea leaves, Wagle said.

He said a minimum 32 per cent was a clear benchmark for detecting adulteration as per PFA specification of water - soluble extracts of tea and analysis of the samples of loose teas has shown clearly that the water - soluble extract was significantly lower than 32 per cent, which indicated that there was adulteration with external materials.

Wagle said a second analysis was conducted to determine the ash content. The loose tea samples that were tested did not fulfill the desired norm of below four per cent or above eight per cent ash content and clearly showed that the tea had been mixed with other contaminants, he said.

Another simple test carried on the samples was a check on adulteration by colouring agents. The samples collected particularly from the south showed that artificial colouring agents were added to the dry tea. Several colouring and dyeing agents were proven carcinogens and their use for adulteration in tea could be extremely dangerous for human consumption, he added.