Under EU whole vehicle entry into service requirements all new cars marketed within the European Union must comply with specified noise emissions controls. In Ireland, compliance with the requirements is overseen by the Revenue Commissioners at the time of first registration of each new car.
In addition, road traffic regulations require all vehicles to be fitted with a correctly maintained exhaust silencer or other device suitable for reducing to a reasonable level the noise caused by the escape of exhaust gases from the engine. The regulations prohibit the use of a vehicle which causes any excessive noise as a result of a defect in the vehicle. The effectiveness of vehicle silencers is also assessed as part of both the national car test and the roadworthiness tests for goods vehicles.