Anglo American Platinum (Amplats), the world’s second-biggest source of platinum group metals (PGMs), is scrambling to find spare refining capacity after declaring force majeure on supply contracts and lowered its full-year refined output forecast by a fifth, or 900,000oz.

A company declares force majeure, a clause in all supply contracts with customers, to allow it to interrupt that supply if an extraordinary event happens. It carries with it reputational damage and it is not something companies declare easily...