The three level system reflects the increasing risk to life and the decreasing amount of time people have until the fire reaches them.

FESA chief operations officer Craig Hynes said the public information system would be used by all fire management agencies including FESA, Department of Environment and Conservation and local governments.

"People need to know what actions they need to be taking at all levels," Mr Hynes said.

"An advice will provide information when a fire is not threatening lives or property but may be causing smoke near homes such as a small controllable fire.

"People need to note where the fire is, avoid the area if possible and keep up to date with any changing conditions.

"A watch and act message tells you the fire conditions are changing and there is potential for lives and property to be threatened.

"This is when you will leave for a safer place or activate your bushfire survival plan.

"It may start with a siren sound called the Standard Emergency Warning Signal (SEWS) to get your attention as the fire is about to arrive."

The SEWS may be broadcast immediately before major emergency announcements on radio, television and other communication systems.

* For information about the public information system visit www.fesa.wa.gov.au