Guwahati, Dec 19: A day after three journalists were severely injured during an unprovoked “rolling-in” of tear gas shells at a massive protest organised by the Congress near Raj Bhavan in Kharguli, speculation has emerged that expired tear gas canisters might have been used by the police.

Sources within Assam Police revealed to The Assam Tribune that the use of expired tear gas canisters is a "routine" practice, not just in Assam but in other major cities, including Delhi.

“Even Delhi Police sometimes use expired tear gas canisters during protests to disperse gatherings. The use of such canisters is quite common during these exercises. If individuals exposed to heavy doses of tear gas experience prolonged symptoms, it is likely the canisters were expired,” said a highly placed source.

Guwahati Commissioner of Police Diganta Barah, however, refuted all speculations stating that Assam Police doesn’t use expired tear gas shells.

“We don’t use expired stock. As per protocol, all expired stocks are destroyed time to time and new stock included,” he told The Assam Tribune.

Meanwhile, medical experts have raised alarms about the potential dangers of expired tear gas canisters, adding that similar methods were reportedly employed during the Hong Kong protests.

“Tear gas canisters have an expiry date for two key reasons. First, the potency of their explosion can increase if they are expired. Second, expired canisters may form cyanide-containing compounds and release harmful chemicals like phosgene,” explained a GMCH doctor, speaking anonymously.

The doctor added, “While 24 hours is usually not considered a long-lasting period for tear gas effects, if symptoms such as dizziness, vomiting, and nausea persist, it is likely the individuals were exposed to excessive or expired tear gas smoke. This can harm the mucous membranes of those exposed. Reports indicate that expired tear gas canisters were used for riot control during the Hong Kong protests.”

The three journalists—Amarendra Deka, Raju Bora, and Ajay Sarma—who were exposed to heavy doses of tear gas on Wednesday, reported severe symptoms, including prolonged dizziness, nausea, and vomiting. Their condition forced them to seek medical attention at GMCH late in the evening.

Despite treatment, many journalists, including a reporter from The Assam Tribune, continue to battle lingering symptoms and are expected to return to the hospital for further evaluation today evening.

Experts agree that while studies on the long-term effects of expired tear gas canisters are limited, the potential harm cannot be ruled out.

The incident has sparked concerns over police protocols and the safety of protest management tools, especially in light of the severe impact on journalists covering events from the ground.