Jitters in Southern Brazil over Chemical Smoke Cloud

The release of a huge cloud of chemical smoke from a fertilizer warehouse fire caused jitters in a southern Brazilian town Thursday amid fears that it might be toxic.

The blaze erupted late Tuesday at a fertilizer 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 centers.

"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.

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 fertilizer depot contained "nearly 10 tonnes of fertilizers 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 fertilizers suggests the substance is "moderately toxic," Santa Catarina's Civil Defense Secretary Milton Hobus said.

Authorities declared a state of emergency Wednesday in Sao Francisco do Sul, located 178 kilometers (110 miles) from Floriannopolis, the state capital.

Firefighters have distributed about 5,000 gas masks to residents.