A laboratory test is yet to take place to determine the quality of the teargas being used by the police to disperse protestors.
A research by the Centre for Peace and Religion has found that expired teargas had been used in 2022, including teargas manufactured in 2000 onward.
Teargas canisters numbering 40,000 imported between 2012 and 2019 are expired, with 8,265 of them used by July 20, 2022.
Despite advice by manufacturers against using teargas near the presence of firearms, that had been totally disregarded in 2022.
Amid a financial crisis, police used 6,722 teargas canisters worth Rs. 26 million in 84 instances between March 31 and July 20 last year.
President of the Young Journalists Association Tharindu Jayawardena said the police mostly used expired and highly toxic teargas in complete violation of internationally-accepted norms.
Meanwhile, lawyer Suren D. Perera has told BBC Sinhala Service that it was unfortunate the police was using teargas against the citizens despite its promise not to use teargas even against a foreign military.
There are several complaints before the Human Rights Commission over the use of teargas, and legal action will follow, he said.