Article 30 of the Road Traffic (Construction, Equipment and Use of Vehicles) Regulations, 1963, requires vehicles to be so constructed as to prevent, as far as is reasonably possible, the emission of smoke, visible vapour, noxious gases or offensive odours. Article 90 of the 1963 regulations prohibits a person from using a vehicle in such a manner as to emit fumes which could be prevented by the exercise of reasonable care. Enforcement of the regulations is primarily a matter for the Garda Síochána.
Heavy goods vehicles, buses and ambulances must be roadworthiness tested annually under the European Communities (Vehicle Testing) Regulations, 1981 to 1986. The roadworthiness test includes pollution-smoke tests on the exhaust systems. Tests are carried out by authorised testers appointed and supervised, at local level, by licensing authorities (motor tax offices). My Department have overall responsibility, at national level, for supervising the vehicle testing scheme.