China's standardization authority announced stricter quality standards for gasoline on December 18, in an effort to reduce vehicle emissions.

The higher standard marks a step toward accelerating the use of greener fuel in the world's largest auto market, where vehicle exhausts are blamed as a major factor in worsening air conditions.

The new standard, known as China 5, limits sulphur content for gasoline to no more than 10 ppm (parts per million), whereas the previous standard allowed up to 50 ppm.

Petrol meeting the new China 5 standard will be available nationwide by January 1, 2018.

According to government data, one fifth of airborne particulate matter smaller than 2.5 microns in diameter, commonly referred to as PM2.5, comes from vehicle emissions. PM2.5 readings are considered a major indicator of air quality.

Under the new standards, the maximum allowable content of manganese, an element that is harmful to humans, will be lowered to 2 mg/L from the previous 8 mg/L. Alkene content will also be reduced to mitigate photochemical smog.

Ding Jizhu, Director of the Industrial Standards Department under the Standardization Administration of China, said that the China 5 standard has been made in accordance with emission control standards in Europe.

Ding estimates that the new standard will cut nitrogen oxide emissions by 300,000 metric tons annually.