Sulphur Odour in Gauteng Linked to Hydrogen Sulphide: DFFE

According to the department, the unpleasant odour reported by residents is likely caused by elevated levels of hydrogen sulphide (H₂S) in the atmosphere.

South Africa’s Department of Forestry, Fisheries and the Environment (DFFE) has assured the public that it is actively investigating reports of a strong sulphurous smell detected across parts of Gauteng, particularly in Ekurhuleni and Johannesburg.

According to the department, the unpleasant odour reported by residents is likely caused by elevated levels of hydrogen sulphide (H₂S) in the atmosphere.

Elevated Hydrogen Sulphide Levels Detected

The DFFE said it first received complaints about the odour on 10 March 2026 and immediately began monitoring air quality data through the South African Air Quality Information System (SAAQIS).

While sulphur dioxide levels were slightly elevated, they remained within the country’s National Ambient Air Quality Standards.

However, hydrogen sulphide readings showed notable spikes across several monitoring stations, including:

• Secunda

• Springs

• Irene (Pretoria)

• Midstream

• Buccleuch

Although South Africa does not currently have national air quality standards for hydrogen sulphide, the recorded levels were significantly higher than the World Health Organisation’s recommended nuisance odour threshold of 5.02 parts per billion.

Officials said this strongly suggests that the public complaints were triggered by elevated hydrogen sulphide concentrations.

Pollution Likely Transported from Mpumalanga

Meteorological data indicates that south-easterly winds during the period transported polluted air from Mpumalanga into Gauteng, affecting major urban centres including Ekurhuleni, Johannesburg and Pretoria.

Authorities are continuing to analyse possible emission sources.

Health Risks Associated with Hydrogen Sulphide

Hydrogen sulphide exposure can irritate the eyes and respiratory system, and may cause several health symptoms.

Possible effects include:

• Headaches and dizziness

• Nausea and stomach discomfort

• Weakness and irritability

• Breathing difficulties

In severe cases, high levels of exposure may lead to convulsions, loss of consciousness or serious respiratory complications.

Children are considered particularly vulnerable because their faster breathing rates may result in higher exposure levels relative to body size.

Public Advisory Issued

The DFFE has urged residents in affected areas to report persistent strong odours to environmental health or local health authorities.

Members of the public are advised to:

• Avoid prolonged exposure where strong odours are present

• Seek medical attention if experiencing persistent respiratory irritation or discomfort

The department said it will continue monitoring the situation and coordinate with provincial and municipal authorities to identify emission sources and ensure compliance with environmental regulations.

Government Moves to Tighten Emission Regulations

Following a similar sulphur odour incident in 2022 affecting Mpumalanga and Gauteng, the government has begun implementing legislative measures to strengthen pollution control.

Key reforms include:

• Tightening minimum emission standards for hydrogen sulphide in coal gasification processes

• Introducing hydrogen sulphide as a criteria pollutant under the National Environmental Management: Air Quality Act

Once designated as a criteria pollutant, South Africa will be able to establish national ambient air quality standards for hydrogen sulphide, aligned with international health guidelines.

Consultations with provincial and municipal governments on these standards are currently underway.