As used in this part, “commission” means the Commission on Fire Prevention and Control; “municipality” means town, city, consolidated town and city, consolidated town and borough, borough, school district, fire district, fire and sewer district, sewer district, lighting district or any other municipal corporation or taxing district upon which is placed the duty of, or which has itself assumed the duty of, protecting its inhabitants from loss by fire; “fire fighting duties” means and includes duties performed in connection with the suppression and prevention of fires, fire training and rescue, fire investigation, arson investigation, details and assignments to protect the public safety against fire and other related work; “firefighters” means any person who is regularly employed and paid by any municipality or by a contractor which is a nonprofit corporation for the purpose of performing fire fighting duties for a municipality on an average of not less than thirty-five hours per week or any volunteer who performs fire fighting duties and who elects to cooperate with the commission in accordance with § 7-323m.