Teams of hazardous material specialists are trying to extinguish a smouldering heap of sulphur ash in Brakpan on Friday as it spews a plume of toxic gas over the town and the neighbouring city of Springs.
At least three people have been hospitalised for irritation to their mucous membranes, said Ekurhuleni emergency services spokesperson Sugan Moodley.
The fire apparently started spontaneously at about 10pm on Thursday night, he said.
The sulphur ash — usually used in the making of bricks — had been dumped over a 10 000sq metre area of what appeared to be an old mining site, said Moodley.
It is not known how long it has been there, or who left it there. Emergency workers are damping down the fire with copious amounts of water and using graders to smother it with fresh soil.
Arrangements have also been made to move the chemicals to a waste disposal facility, he said.
Moodley said he did not know how long the fire could continue smouldering.
He advised people who experience coughing, watering eyes and runny noses to visit their local doctor or clinic.
All Ekurhuleni emergency services would disclose on Friday morning was that the chemical fire had released ”a large gas cloud”.
Although it has been reported that toxic smoke is billowing across the N17 highway, affecting motorists, no roads in the area have been closed, said Ekurhuleni metro police spokesperson Wilfred Kgasago.
Metro police are monitoring the situation, he said. – Sapa