The vibrant dye spread through the water, colouring the stream and leaving geese and ducks with stained feathers. Several dead, blue-tinged fish were also found.
Environmental teams from the São Paulo State Environmental Company (CETESB) are analysing the water to assess the level of contamination.
Local and state authorities, along with NGOs, are working to rescue affected animals and mitigate further damage.
Officials say the dye contains an organic compound based on acetic acid, a substance known to be corrosive and environmentally hazardous.
