“High Court issues landmark ruling against BHP over Brazil’s Mariana dam disaster: What it means for cross-border litigation”, 19 November 2025

Last week – ten years after the Fundão Dam disaster, widely described as Brazil’s worst environmental catastrophe – London’s High Court ruled that the global mining company BHP Group is strictly liable. On 5 November 2015, the Fundão Dam in Southeast Brazil collapsed… The disaster killed 19 people and caused immense environmental and socioeconomic damage...

The claim was filed in England in 2018 and was brought against BHP Group (UK) Limited (‘BHP UK’), domiciled in the UK, and BHP Group Ltd (‘BHP Australia’), which … was found to carry on business in the UK… This created a ‘real and substantial’ connection… On that basis, the Court of Appeal held that England was an appropriate forum…

The action has since grown to more than 600,000 individuals... Before the liability trial, the defendants applied to strike out the claim as an abuse of process… Whilst BHP was initially successful in the High Court, this was overturned on appeal. The Court of Appeal emphasised that the potential size or complexity of a claim cannot restrict access to justice… [and] that the English proceedings provide a ‘realistic prospect of a trial yielding a real and legitimate advantage for the claimants’.

At the liability stage, the High Court reviewed a sample of the compensation agreements signed in Brazil… [and] indicated that some of the settlement agreements were adhesion contracts, in other words, standard-form agreements drafted by the party who has greater bargaining power than the other... any ambiguities or conflicts in such agreements must be interpreted in favour of the claimants.

The Court found BHP strictly liable as a matter of Brazilian law, under the ‘polluter pays’ principle and also liable in fault… The Court dismissed BHP’s defence on limitation and on standing… A second phase – addressing causation and quantum – is scheduled… in October 2026, with a potential third phase… BHP has also announced its intention to seek permission to appeal the liability judgment...