KOLKATA: West Bengal Pollution Control Board under the state department has made installation of sound limiters mandatory to hold open-air functions. An order regarding the matter has been issued by the Board. It stated that on failing to obey, the same will lead to penal action. The West Bengal Pollution Control Board has asked all the police and district administration authorities that permission to use microphones in the open air can only be given if the organizers of functions are ready to install sound limiters. The organizers will have to give in writing that they agree to install sound limiters. Copies of the order issued by Rajesh Kumar, member, secretary, West Bengal Pollution Control Board have been sent to the Commissioner of Police, all district magistrates and superintendents of police , assistant police commissioners and all officers in charge of police station. The step has been taken as during Kali Puja and Chhat music are often played flouting the permissible limit. During immersion DJs are often engaged to play music. Sound limiters bring down the noise level.