Residents in Wentworth and in Johannesburg, have complained about strange smells in the air.
The City of eThekwini Municipality launched an investigation into the odour in Wentworth.
The City’s Sibusiso Mkhulisi, Fire Regional Commander, said compliance checks were intensified this week, following Thursday’s toxic fumes incident, which affected learners and teachers at a school in Wentworth.
The school had to be evacuated on Thursday, and affected learners and teachers, transported to Hospital for treatment.
The Department of Forestry, Fisheries and the Environment (DFFE) said it is acting on reports of a sulphurous odour in Johannesburg and Ekurhuleni.
The Department suspects hydrogen sulphide (H₂S) is the main cause of the smell in two of Gauteng’s main cities.
The Department also said reports of the odour were received on 10 March 2026.
The South African Air Quality Information System showed that levels of sulphur dioxide, while elevated, remained in compliance with National Ambient Air Quality Standards, during this period.
Higher than normal amounts of Hydrogen sulphide, were in Secunda, Springs, Irene (Pretoria), Midstream and Buccleuch air quality monitoring stations.
These levels were higher than those stipulated by the World Health Organisation (WHO), of a threshold of 5.02 parts per billion.
The Department also said Meteorological conditions show prevailing south-easterly winds enabled the transportation of air pollution from Mpumalanga into Gauteng, particularly over the cities of Ekurhuleni, Johannesburg and Pretoria.
Effects of Hydrogen Sulphide (H₂S) vary from irritation to the eyes and respiratory system, to dizziness, headaches, nausea and stomach upset weakness and irritability and breathing difficulties.
In severe cases, high exposure may lead to convulsions, loss of consciousness, or respiratory complications.
Children and the elderly are most vulnerable.
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