The department of environmental affairs says says Thor Chemicals has agreed in principle to pay more than R300m required to export the waste to Switzerland, where it will be disposed of.

The department says it wants more than 3,000 tons of mercury waste stockpiles at the old Thor Chemicals factory — a British multinational that owned and ran the Cato Ridge plant where drums of toxic sludge are stored — in KwaZulu-Natal to be removed by the end of next year.

In the late 1980s and 1990s, scores of Thor Chemicals workers who were exposed to the hazardous chemical waste were diagnosed with mercury poisoning and died painful deaths.

Others were partially poisoned and are still feeling the effect of this poisoning, decades later.

Mercury is a neurotoxin, which can lead to blurred vision, tremors, brain damage, coma and death.

Thor Chemicals moved its mercury incinerator plant from the UK in the mid-70s. The company then began exporting these chemicals to its Cato Ridge facility.

The plant was forced to shut its doors here in the early 1990s after news that workers poisoned by mercury were dying and others were comatose.

Two recent incidents have shone the spotlight on the plant in recent months. Criminals stole some containers of the toxic substance in the hope of using it in zama-zama mining pursuits and other criminal activities.

A few weeks ago, a fire broke out at the facility, and environmental organisations estimate that more than 30 tons of mercury waste was injected into the environment as a result of the fire.

Hlela Malombo Nxumalo, a councillor for Fredville and other areas near Cato Ridge, said community members want the plant and its dangerous chemicals to be removed from the area as soon as possible.

“These chemicals are very dangerous. We are concerned because of the danger to humans and animals if they spill into local rivers,” he said.