People who live near the site of the burning Barwick Mills plant in LaFayette, Ga. are being told to stay indoors tonight.
The Environmental Protection recommended that city officials issue the warning after EPA workers on the site noticed fluctuation in air quality readings.
Residents who are close enough to be affected are receiving reverse 911 calls, city manager David Hamilton said.
The elevated readings indicate that there are increased amounts of particulates in the air.
EPA officials have been on the site all day doing tests in the wake of the fire that engulfed the 50,000-plus square foot facility on Saturday.
Brian Engler, who is managing EPA's operations on the site, said earlySunday evening the readings are due to incomplete combustion, which is occurring because of a portion of fallen roof that is covering part of the fire and preventing it from being extinguished.
Officials had said earlier in the afternoon that early tests indicated were that there was no risk to human health.
Hamilton said the warning would also be posted on the city's social media pages, adding that the concern is largely for those with respiratory issues.
"The unfortunate part is that it's going to create some undue panic," he said. "The wider the call goes out, the more people are going to be concerned, but it's the right thing to do. We need to let people know what's going on."