(Photo: cer.org.za)
The Department of Environmental Affairs is aware of a strong sulfur smell that hangs over several areas in Gauteng, especially Ekurhuleni and Johannesburg.
The department says in a statement that the stench that residents smell is probably caused by hydrogen sulphide (H₂S), (a colourless, but toxic and flammable gas), and assures the public that the matter is receiving attention.
In August 2025, the Minister of Forestry, Fisheries and the Environment published a notice regarding his intention to tighten the permitted release of hydrogen sulphide from coal gasification processes, in terms of art. 21 of the National Environmental Management: Air Quality Act (2004). The proposed amendment seeks to reduce the emission limit of hydrogen sulphide from 3,500 mg per cubic meter to 600 mg per cubic metre. This will significantly reduce pollution released into the environment. The department says comprehensive comments have been received from stakeholders, and the notice will be published for a second round of public consultations. These regulatory provisions are expected to be finalized and implemented this year.
“On Tuesday, the department received reports of the strong sulfurous smell in Gauteng, which showed that levels of sulfur dioxide, although elevated, remained in line with the national ambient air quality standards during the period.”
Monitoring data also shows increased levels at air quality control stations in particular in Secunda, Springs, Irene (Pretoria), Midstream and Buccleugh.
“Although there are currently no national ambient air quality standards for hydrogen sulfide, these pollution levels were all significantly higher than the World Health Organization’s recommended threshold for environmentally objectionable odors of 5.02 parts per billion. Based on these observations, it is highly likely that the odor was caused by elevated hydrogen sulfide levels,” says the department.
Meteorological conditions show prevailing south-easterly winds have made the air pollution from Mpumalanga to Gauteng possible, especially over Ekurhuleni, Johannesburg and Pretoria.
The department says this is not the first time such an event has taken place. In February 2022, similar sulfurous odor incidents were reported across Mpumalanga and Gauteng. “At the time, investigations were carried out by the Department of Environmental Affairs in collaboration with air quality authorities from Mpumalanga, North West and Gauteng. The focus was particularly on Sasol’s Secunda operations, which are a significant contributor to sulfur dioxide and hydrogen sulphide emissions.”
A task force made up of stakeholders in various spheres was established to investigate complaints and develop a proactive long-term plan to improve the management of sulfur dioxide and hydrogen sulphide emissions.
Following the incident in 2022, two important legislative improvements – the tightening of minimum emission standards and the introduction of hydrogen sulphide as a criteria pollutant – were identified. It is currently being implemented.
Investigations at the time revealed that although the Sasol Secunda operations were within the legal emission limits, the existing limits were not sufficient to protect public health, particularly for communities around Secunda.
The department is also currently investigating hydrogen sulphide as a criteria pollutant under the air quality section of the Environmental Management Act. “This will enable South Africa to establish national ambient air quality standards for hydrogen sulphide, in accordance with international health protection guidelines. Discussions with provinces and municipalities on this are currently taking place.”
