A state of haze emergency will be declared when the air pollutant index (API) exceeds 500, said the National Disaster Management Agency (NADMA)
The last state of emergency due to the haze was called in 2013 when the API exceeded 500 in Muar and Ledang, Johor
According to records by the Department of Environment, a haze emergency was also declared in August 2005 in Kuala Selangor and Port Klang, Selangor, when the API was 231.
Meanwhile, the earliest case occurred in September 1997, when the API was 650 in Kuching, Sarawak. According to Borneo Post Online, it is believed to be the most hazardous air quality level reached in the country's history.
NADMA also announced that the Malaysian Meterological Department (METMalaysia) will proceed with cloud seeding in Sarawak on or after Thursday, 19 September, to help reduce the haze
However, the cloud seeding will be subject to weather and cloud conditions.
NADMA also advised the public, especially those living in areas with unhealthy air, to reduce their outdoor activities.