CNN –Days after a blaze at an eastern Indiana plastics recycling plant forced evacuation orders for hundreds, officials are slated to meet Saturday to discuss when it will be safe for them to return to their homes as the fire fizzles out.

The massive fire – which began Tuesday at a recycling facility in Richmond, Indiana – was largely reduced to hotspots and flare-ups by Thursday. People within a half-mile of the plant – about 2,000 of Richmond’s 35,000 residents – have been under evacuation orders since the fire’s first night.

On Saturday, officials are scheduled to review air and water samples, the results of which will help guide the duration of the evacuation order, Richmond Mayor Dave Snow said Friday.

Officials have warned that the fire site itself, at the very least, was dangerous, with the mayor urging people Friday to stay away from the property.

“Because of the nature of the fire and the material it has burned, it is expected to continue smoldering and producing smoke, soot, or burnt plastic smell for several more days,” the city said in an online notice Thursday night.

Now officials are trying to determine where contaminants can be found and how dangerous they are – from the fire zone outward.

The blaze produced columns of dark smoke that were “definitely toxic,” the state fire marshal said Tuesday – smoke that forced not only the evacuation orders but also moved Richmond public school officials to cancel classes through Friday.

Tim Day was among the Richmond residents who left the city after the fire started Tuesday, he told CNN affiliate WRTV, in part out of concerns for his 7-month-old daughter’s safety. His home is about a mile and a half from the plant.

“I started smelling it inside the apartment, with all the door and windows closed,” Day, who went to stay with his mother in a nearby town, told WRTV. “It was like a burning in the nose.”

At the fire zone’s center, the chemicals hydrogen cyanide, benzene, chlorine, carbon monoxide and volatile organic compounds, or VOCs, were detected, the US Environmental Protection Agency said Friday. They were not detected outside the evacuation zone, the agency said.

Potentially harmful VOCs also were found in six air samples – the agency said, without saying where the samples were taken.

Particulate matter also was found inside and outside the half-mile evacuation zone, as expected, the agency said.

Additionally, one of two air samples taken a little more than a mile from the fire site detected chrysotile asbestos in debris, an EPA official said Thursday. Also called white asbestos, chrysotile asbestos can cause cancer and is used in products from cement to plastics to textiles.

How officials have been responding

Firefighters who were called to the site Tuesday first saw a fire in a semitrailer loaded with plastics. The fire then jumped to surrounding piles of recyclables before eventually reaching the facility, which was “completely full from floor to ceiling and from wall to wall,” Richmond Fire Chief Tim Brown said.

“Any type of plastics that you would imagine was in this facility,” Brown said.

The cause of the fire wasn’t immediately clear. But local leaders have shared concerns since at least 2019 that the facility had hazards and building code violations, records show.

Snow, the mayor, has said the plant was a fire hazard and accused the plant’s owner of ignoring a city order to clean up the property.

CNN has sought comment from the plant’s owner, Seth Smith. The attorney who previously represented Smith in a related lawsuit declined to comment.

Since the fire, the EPA has said that any resident who may have fire debris in their yard should not mow their lawns until officials can advise about how to clean it up.

A primary health concern to residents is particulate matter, which could cause respiratory problems if inhaled, said Christine Stinson, who heads the Wayne County Health Department.

N95 masks – the type recommended to protect against Covid-19 – could shield the particles, but people should leave the area if they see or smell smoke or experience symptoms, Stinson said.

CNN’s Sara Smart, Holly Yan, Paul P. Murphy and Caroll Alvarado contributed to this report.