ATLANTA (AP) -- Residents east of Atlanta were again warned to take shelter where they are on Tuesday if a chemical cloud moves over their neighborhood, as winds shifted the plume from a fire at a chemical plant.

A shelter-in-place order had just ended Monday evening for more than 90,000 people closest to the chemical plant where a fire sent a huge plume of orange and black smoke into the Georgia sky on Sunday. People complained about a strong chemical smell and haze for many miles around the BioLab plant in Conyers, about 25 miles (40 kilometers) southeast of downtown Atlanta.

"Due to the weather, the plume is banking down and moving throughout the county. If the cloud moves over your vicinity, please shelter in place until the cloud moves out," Rockdale County officials told residents on social media early Tuesday.

The fire was brought under control around 4 p.m. Sunday, officials said, but they were still mopping up hot spots in the wreckage on Monday and the polluting smoke "constantly shifted" before dawn on Tuesday. With relatively little crosswinds to disperse the plume, smelly haze lingered across the Atlanta area.

BioLab's website says it is the swimming pool and spa water care division of Lawrenceville, Georgia-based KIK Consumer Products. Residents around the area expressed frustration that company officials in their public statements didn't specify what "products" were burning. Atlanta's fire department said it was testing for the presence of chemicals including chlorine, hydrogen sulfide and carbon monoxide.

Federal officials are investigating what led to the fire and how it has been handled. The sprinkler system showered water onto water-reactive chemicals around 5 a.m. Sunday, Rockdale County Fire Chief Marian McDaniel said. There were employees inside the plant, but no injuries were reported.

"We are sending investigators to the site to determine the cause of this dangerous incident and the safety gaps at the facility that allowed this huge fire to occur," Steve Owens, chairman of the U.S. Chemical Safety and Hazard Investigation Board, said in a statement Monday. "Tens of thousands of people have been put potentially at risk by this catastrophe."

While the chemical smell remained in many places on Monday, "no immediate life safety issues have been identified," Atlanta Fire Rescue reported.

Many residents weren't reassured. The foggy air "slapped you in the face" northeast of Atlanta, where Arynne Johnson took her Great Danes outside in Suwanee on Monday morning.

"I used to work at a water park, and it felt like walking into a pool house," Johnson said. Breathing it gave her a headache, made her cough and "my upper chest and throat have been tight all day," she said.

Nearer to the plant in Rockdale County, residents north of Interstate 20 were ordered to evacuate on Sunday, while others were told to shelter in place. But residents of Atlanta's densely populated eastern suburbs in DeKalb and Gwinnett counties also reported seeing a haze or the strong smell of chlorine.

Hours passed Sunday before DeKalb emergency management authorities said data suggested the air pollution was "unlikely to cause harm to most people." The DeKalb statement said anyone concerned about breathing the chemicals could stay inside with their homes sealed up and air conditioners turned off.

Multiple school districts canceled outdoor activities on Monday, and were monitoring developments Tuesday before deciding whether to extend the closures.

There have been other destructive fires at the Conyers complex, which opened in 1973.

In May 2004, multiple explosions in a warehouse led to a huge fire that prompted the evacuation of 300 people as a chlorine-laden cloud rolled through the area, The Associated Press reported, sending up a plume of green, gray and white smoke that stretched 10 miles (16 kilometers) long. At least nine people went to hospitals with complaints of burning eyes and lungs.

In June 2015, six Rockdale County firefighters were hurt in a fire at the complex, and another fire in 2016 prompted some voluntary evacuations near the plant, the Rockdale Citizen reported.

In September 2020, a chemical fire prompted authorities to shut down Interstate 20 during the morning rush hour. Biolab workers tried to isolate decomposing chemicals to prevent the catastrophe, but their forklifts were sliding on the wet floor amid the fumes, and firefighters were hindered by poorly stacked pallets of materials, the Chemical Safety and Hazard Investigation Board later determined. Nine firefighters were evaluated at hospitals after inhaling hazardous vapors.