The credibility of Centre for Science and Environment's testing labs, which detected high levels of pesticide residue in soft drinks, has been challenged by the laboratory that conducts regular tests for the cola firms.
The NGO has however, strongly dismissed such allegations.
While there was no official comment from either PepsiCo or Coca Cola, RK Khandal, the director of Sri Ram Labs, said the CSE laboratory did not have the NABL accreditation, "a must" for any centre conducting tests related to food safety and health standards in India.
"We conduct regular tests for everybody.... Testing for health safety and food require NABL accreditation, which the CSE lab does not have. If you are not NABL accredited it is doubtful if your results are authentic," Khandal said.
However, when contacted, CSE Associate Director Chandra Bhushan admitted the NGO's lab did not have NABL accreditation, but rubbished charges doubting its credibility.
NABL -- National Accreditation Board for Testing and Caliberation of Laboratories -- has been set up by Department of Science and Technology of the Union Government to provide guidelines and set standards for laboratories who conduct third party tests.
"NABL accreditation does not guarantee a fool-proof testing mechanism. There have been cases when accredited labs have messed up findings. However, we do respect NABL's procedures," he said.
Bhushan said their lab had ISO:9001 accreditation and followed the US Environment Protection Agency methodology for conducting tests for organochlorine and organophosphate pesticides in the soft drinks.
He said even in 2003, when the first study conducted by the CSE showed pesticides in soft drinks, the same issues were raised regarding the credibility of its laboratory. But the Joint Parliamentary Committee, set up after the first study, had approved CSE procedures.
"The JPC, however, had told us that we should have used Gas Chromotography and Mass Spectrometry (GCMS) tests to confirm the presence of pesticides, which we did this time," he added.
The new CSE study had found presence of "pesticide cocktail" in 11 brands of soft drink giants Coca Cola and PepsiCo, three years after the same brands were found to have high pesticide residue.
The new findings claimed all the 57 samples examined were a "cocktail of 3-5 different pesticides", which was 24 times above the standards finalised by the Bureau of Indian Standards.