The release of a huge cloud of chemical smoke from a fertiliser warehouse fire has caused jitters in a southern Brazilian town amid fears that it might be toxic.
The blaze erupted late on Tuesday at a fertiliser depot in the town of Sao Francisco do Sul, causing panic and forcing the evacuation of 800 people.
Local press reports said more than 100 people fell ill and were treated at health centres.
"We said all along that people should not be exposed to this toxic smoke. The population must be protected," Marlene Zannin of Santa Catarina state's Center of Toxicological Information told Globo television.
She said there was no clarity as to what kind of substances were burning.
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Local authorities said it was only ammonium nitrate, which is not toxic.
But Zannin noted that it was unclear whether the substance was pure or mixed with other elements.
Santa Catarina state officials said in a statement that the fertiliser depot contained "nearly 10 tonnes of fertilisers involving ammonium nitrate, which is not toxic".
"There is no risk of intoxication... But the product provokes skin, respiratory and eye irritation," it added.
But information provided by engineers and the firm selling the fertilisers suggests the substance is "moderately toxic", Santa Catarina's Civil Defense Secretary Milton Hobus said.
Authorities declared a state of emergency on Wednesday in Sao Francisco do Sul, located 178km from Floriannopolis, the state capital.
Firefighters have distributed about 5000 gas masks to residents.
