At least five people are reported to have been treated in hospital and by emergency workers after hydrochloric acid spilt from a truck, generating a cloud of noxious gas fumes on the busy N3 freeway just outside Durban around 7am on 14 June.

The emergency incident led to major traffic snarl-ups around the city, with both east and west-bound lanes closed for several hours while paramedics, police, the fire brigade and specialist personnel from a hazardous waste spill company contained the situation. It also coincided with heightened public security concerns in KwaZulu-Natal linked to political conflict.

Sources at the scene reported that "a few hundred" litres of hydrochloric acid (concentrated swimming pool acid) spilt onto the city-bound lane of the N3 freeway shortly before the Spaghetti Junction with the N2 freeway.

Because there was early-morning moisture on the road, some of the liquid acid reacted with the wet road and was transformed into a gaseous form.

According to ALS Paramedics spokesperson Gareth Jamieson, who attended the emergency scene, his staff transported three people to hospital after they inhaled gas fumes -- two SA Police Services officers and a road construction worker who were busy trying to keep motorists away from the scene.

It is understood that at least two other people were treated for breathing difficulties after inhaling the powerful fumes.

The acid spilt from two of several plastic 'flow bins' being transported on a truck with a trailer. Each flow bin...