Authorities are also investigating a separate incident involving suspected chemical fumes at Umbilo Secondary School, south of Durban.
At least 20 pupils and one teacher were treated for breathing difficulties, panic attacks and seizures after a strong chemical odour spread across the school grounds.
Six pupils were taken to hospital for further treatment.
The incident prompted the evacuation of more than 1,000 learners and the temporary closure of the school.
Preliminary investigations by fire and environmental health officials traced the odour by monitoring wind direction and conducting checks around the school perimeter.
Officials identified a nearby company where a container-cleaning operation involving the chemical Ethyl acrylate was taking place.
Authorities believe fumes from the operation may have drifted towards the school due to windy conditions.
The eThekwini Municipality says it is verifying the company’s compliance documentation and operating procedures.
Municipal Fire Regional Commander Sibusiso Mkhulisi says a full compliance investigation is underway and legal action could follow if violations are identified.
“We are conducting a full probe into the company’s practices, and if non-compliance is confirmed, we will act decisively with stricter legal measures,” Mkhulisi said.
He added that response teams remained on site until conditions stabilised and continued working with the school to monitor the situation.
Classes have since resumed after safety checks confirmed that the chemical odour had dissipated.
The municipality says environmental inspections and sampling are continuing in the surrounding industrial area while authorities fast-track enforcement measures depending on the outcome of the investigation.