New Delhi, July 21: Acidity in soft drinks is coming under the microscope.

The Bureau of Indian Standards has, for the first time, recommended a range for acidic content in non-alcoholic beverages, including soft drinks.

The proposed limit came as part of a set of draft standards BIS issued for pesticide residues, caffeine, toxic substances like copper and aluminium and alkalinity.

Recognising the harmful and addictive effects of caffeine on children, a prize segment for cola makers, BIS said soft drink manufacturers should follow the global practice of having “caffeine only in brown drinks”.

The draft standards follow last year’s report by the Centre for Science and Environment that exposed pesticide and contaminant levels in soft drinks.

For starters, BIS recommended for soft drinks an acidity (pH) range of 2.5 to 8.5 on a scale of 1 to 14. Seven is the neutral level. While 1 to 7 refers to the acidity range, 8 to 14 refers to the alkaline level.

CSE director Sunita Narain welcomed the inclusion of the range in the draft but added that acidity levels in soft drinks were far from ideal. Narain said a study conducted by the CSE last year had revealed that most of these drinks had an acidity level of 2, which was very high. The lower the pH value, the higher the acidity level.

“It is a beginning, as the fight to residue reform is going to be a long one. Usually, soft drink manufacturers want to keep pH levels low, for the lower it is, the more acidic it is going to be — a factor that ensures a longer shelf life. We do not think a pH level of 2 is right, but setting a standard is a beginning,” Narain said.

The proposal to limit caffeine to only brown drinks means Mountain Dew, which is from the Pepsi stable, may have to lose the label of being the only “non-brown drink to contain caffeine”.

“In the US and the UK, caffeine is an ingredient only in brown drinks. But here we found that PepsiCo’s Mountain Dew was the only non-brown drink that contains caffeine,” Narain said.

Pepsi countered the charge. “We sell the same soft drink in other parts of the world, including in developed countries,” Pepsi officials said.

Environmentalists and health experts have welcomed the draft standards for non-alcoholic beverages as a big victory for public health and food safety in the country. If finalised, it will be the first standard in the world on pesticide residues in soft drinks.

R. Desikan, head of CONCERT, a leading consumer group, said: “Globally, there is rising concern regarding the use of high amounts of caffeine in soft drinks, which is consumed by a vulnerable section of the society. Therefore, it was important for us to set the global best standard for caffeine.”

Nirmal Singh, the director-general of BIS, said the draft standards have been put “in the public domain only for comments” from the people. “We will not be setting the standards, that work is under the purview of the ministry of health,” Singh told PTI.