Joinville: Acid spill covers Brazil river in thick white foam
Sulfonic acid, which can cause serious harm to human health, has leaked into the Rio Seco in Joinville, southern Brazil.
The substance - used to produce detergents and household cleaning materials - was released when a truck crashed, triggering a local state of emergency.
A treatment station was closed on Monday morning to prevent the intake of contaminated water - potentially affecting dozens of neighbourhoods' access to drinking water.
Video on social media showed people stockpiling bottled water.