As the Chinese New Year draws near, Monetary Authority Chief Executive Joseph Yam calls on the public to help protect the environment by using good-as-new notes, instead of brand-new ones, for lai-see.

With the support of the public and the note-issuing banks, about 162 million - or half - of the notes issued in the run-up to the last Chinese New Year were good-as-new notes, up from 53 million, or 20%, the year before.

Every year, 300 to 400 million new and used notes are issued to cater for Chinese New Year demand. Producing 300 million notes takes 400 tonnes of cotton and occupies 500 cubic metres of storage space that could fill 20 containers. The three note-issuing banks must arrange 500 trips with security escorts to transport these brand-new notes.

Most of Hong Kong's currency notes are quite clean. Dirty or torn ones are removed from circulation when they are returned to the note-issuing banks. Each year about one-third of the notes in circulation are identified as unfit for use and replaced.

The authority also urged people to re-use lai-see packets to reduce waste.