SINGAPORE - The emissions standard for new motorcycles and scooters has been tightened to the Euro III standard.

An improvement on the previous Euro I standard, the aim is to improve Singapore's air quality, the National Environment Agency (NEA) said in a press statement on Wednesday.

It added that adopting this new standard will lower ground-level levels of ozone, an air pollutant, to meet World Health Organisation (WHO) guidelines of 100µg/m3 by 2020. This would also reduce levels of other pollutant emissions from motorcycles such as hydrocarbons, nitrogen oxides and carbon monoxide.

The NEA reiterated its strict enforcement of these standards and against smoke-emitting motorcycles. Figures show that about 1,800 motorcyclists in each of the past three years and about 800 this year to date have been sanctioned for having smoke emitting from their motorcycles. These were mainly due to inherent engine problems, clogged exhaust systems, or excessive amounts of lubricant oil used. There were about 144,000 motorcycles on Singapore roads in 2012. Drivers and owners of vehicles spotted to be emitting visible smoke can be fined up to $5,000.

The NEA said that it has been working closely with the authorised vehicle inspection centres Vicom, JIC and STA to ensure motorcycles comply with the emissions standards and do not emit smoke.

Emissions from motor vehicles are a key source of urban pollution in Singapore and other major cities worldwide.

The nation adopted WHO guidelines on air quality as a target in 2012. It is aiming to meet these targets by 2020 for air pollutants such as sulphur dioxide, carbon monoxide, ozone, nitrogen dioxide, PM2.5 and PM10.