The department of employment and labour has launched an investigation and issued a prohibition notice after a fire at Sasol’s Sasolburg polyethylene plant left three contractor employees injured, including one who remains in intensive care.

The department’s spokesperson, Teboho Thejane, said a dangerous gas release ignited while contractors were deblocking a pipeline during heat treatment work at the Poly 3 facility on Tuesday, causing the fire.

Thejane said three workers sustained burns. Two of them remained in hospital, one of them in ICU.

He said the third employee was receiving treatment in a surgical ward. However, Sasol later clarified that the worker had sustained only minor injuries and did not require hospital admission.

Thejane said the department started its investigation on Thursday.

“Preliminary findings indicate that the contractor is no longer operating at the site. The investigation is ongoing to establish the circumstances surrounding the incident and determine whether there were any contraventions of occupational health and safety legislation.”

He said an inspector was dispatched to the site on Thursday after the department became aware of and confirmed the incident.

“A prohibition notice has been issued, preventing the continuation of the activities that led to the fire until the department is satisfied that it is safe for work to resume.”

Sasol said the fire broke out at about 1.04pm at its Poly 3 facility on the Midland site in Sasolburg.

“We would like to clarify that there was no explosion associated with this incident. The incident involved a fire, which was promptly responded to and brought under control by Sasol’s emergency response teams.”

Sasol said the affected Poly 3 unit had been shut down while the cause of the fire was investigated. The company said emergency response procedures were activated immediately, all personnel were evacuated safely and there was no risk to employees, neighbouring communities or the environment.

Assessments of the unit and operational impacts of the fire were continuing.

“The wellbeing of the injured individuals remains our primary concern. Sasol is providing support to the injured employees and their families, including ongoing engagement with medical personnel and access to the appropriate employee and contractor support services.”

Sasol acknowledged that it had experienced other process safety incidents at its Sasolburg operations over the past five years. In its 2025 financial year, the group's fires, explosions and releases severity rate increased from 5.4 the previous year to 5.5.

“We actively work to enhance our understanding of risks and continuously improve our risk management and maintenance practices,” it said. “Significant incidents are investigated thoroughly and corrective and preventive actions are implemented where required to address identified causes and strengthen operational safety.”

Sasol denied allegations that employees had been instructed not to discuss the incident, saying workers were routinely reminded that communication with external stakeholders was handled through designated company channels to ensure information released publicly was accurate and consistent.

Sasol said whether its safety, operational and emergency response measures operated as intended and any potential contributing factors would form part of the ongoing investigation. “It would be inappropriate to comment further until the investigation has been concluded.”

Mduduzi Tshabalala of the Vaal Environmental Justice Alliance called for greater transparency after the incident, urging Sasol to publicly disclose the circumstances of the fire, cooperate fully with investigators and engage openly with affected workers and surrounding communities.

He also called on the company to publish a plan outlining immediate containment measures and longer-term safety improvements to prevent a similar incident.

Tshabalala said companies operating near residential areas had a responsibility to protect people’s health, safety and the environment.