BHP Billiton denies claims waste from Samarco dam burst is toxic

BHP Billiton has hit back at claims that waste from the tailings burst at the Samarco mine in Brazil is toxic.

An investigation carried out by the United Nations concluded that waste from the burst dam was toxic and the measures taken by BHP and its partner Vale to prevent any damage being done were “clearly insufficient”.

The UN Office of the High Commissioner for Human Rights said evidence showed the 50m metric tonnes of iron ore waste released from the dam contained high levels of toxic heavy materials and other toxic chemicals.

However, BHP refuted the claims, saying the tailings were chemically stable.

“The tailings that entered the Rio Doce were comprised of clay and silt material from the washing and processing of earth containing iron ore, which is naturally abundant in the region. Based on available data, the tailings are chemically stable. They will not change chemical composition in water and will behave in the environment like normal soils in the catchment,” it said.

It added that the National Water Agency and Brazilian Geological Service are continuing to collect, analyse and report water and sediment samples in the Rio Doce.

In addition, Samarco issued a statement on Thursday indicating that further tests carried out by SGS GEOSOL Laboratórios after the incident confirm the waste from the Fundão dam is not hazardous to human health.

At 1000 GMT, BHP Billiton shares were down 2.8% at 829.70p.