According to the notice issued by the office sighted by Harian Metro, schools are required to seek approval before resuming outdoor activities.

School heads have been advised to closely monitor the health of their students and staff.

The district education office also ordered all schools to report any unusual odour or stench immediately to the 24-hour emergency task force.

State education and information committee chairman Aznan Tamin said the directive was a precautionary measure.

He added that parents had been urged to seek medical attention if their children exhibited symptoms of dizziness, nausea and vomiting.

“This directive was issued to alleviate the worries of residents who fear another occurrence of the 2019 Sungai Kim Kim pollution incident,” he was quoted as saying.

On March 7, 2019, more than 2,000 residents experienced dizziness, with 947 being hospitalised, after toxic waste was discovered in Sungai Kim Kim. A total of 111 schools were also closed.

Pasir Gudang is located 20km away from Sungai Pandan, where the high levels of ammonia gas were detected. However, the air quality readings returned to normal at 1am today.