Hong Kong Environmental Protection Department will launch three new measures from Sunday to improve roadside air quality, including complying with Euro IV standard, installing emission-reduction devices, and registration tax cut for "green" cars.

Bringing blue skies back to Hong Kong is at the top of the Hong Kong Special Administrative Region (HKSAR) government's agenda.

The SAR government will provide a one-off grant to encourage vehicle owners to replace their pre-Euro and Euro I diesel commercial vehicles with new commercial vehicles that comply with the Euro IV standard for newly registered vehicles.

The grant will last for 18 months for pre-Euro vehicles and three years for Euro I vehicles.

Replacing all pre-Euro and Euro I diesel commercial vehicles with Euro IV models will reduce the vehicular emissions of respirable suspended particles (RSP) by 74 percent and of nitrogenoxides (NOx) by 38 percent. That will bring marked improvement to roadside air quality by cutting territory-wide RSP emissions by 18percent and NOx emissions by 10 percent.

According to the new measures, buyers of newly registered environment-friendly petrol cars will enjoy a 30 percent reduction in first registration tax, subject to a ceiling of 50,000 Hong Kong dollars per car.

The SAR government also said that pre-Euro diesel concrete mixers, gully emptiers, lorry cranes or pressure tankers that weigh more than four tons must install emission-reduction devices.

Failure to comply with this statutory requirement stipulated under the Air Pollution Control (Emission Reduction Devices for Vehicles)(Amendment) Regulation will lead to cancellation of vehicle licenses in Hong Kong.

In 2005, the SAR government completed a one-off grant program to help owners of these vehicles install emission-reduction devices and 95 percent took advantage of the grant.