ABC News

The U.S. Environmental Protection Agency is investigating a fire that enveloped a chemical manufacturing plant today in Waxahachie, Texas, causing residents and students at a nearby elementary school to evacuate.

The fire, which started about 11 a.m., erupted at Magnablend Chemical Plant, about 30 miles south of Dallas. Magnablend manufactures agricultural products such as fertilizer, oil field oils and methanol.

Fire chief David Hutchins said during a news conference today that the blaze was 80 percent contained but that it was still unclear what substances were burning. The U.S. Chemical Safety Board also was reviewing the situation and considering whether to dispatch a team to the site.

Thick, black smoke could be seen for 50 miles as four different fire departments teamed up this morning to fight the blazes. All 85 employees were safe, a plant spokesman told ABC News.

Firefighters tackled the blaze wearing hazardous material-retardant suits and officials said there were definitely contaminates in the air, according to ABC News affiliate WFAA-TV.

“The most important thing would be avoidance,” Dr. Gary Weinstein, a pulmonary disease and critical care specialist at Texas Health Resources, told WFAA-TV. “If you have to be outside, you should wear a mask and try to minimize your exposure.”

An elementary school less than a mile from the plant was evacuated about noon because of the threat of possibly dangerous gases or fumes being released. Area residents were told to evacuate or stay inside with their doors and windows shut. The Occupational Safety and Health Administration also was called to the site.

As a precaution, residents living in the nearby Bella Vida gated residential community were asked to evacuate by Texas state troopers.  Residents  living in a small nursing home were also relocated. Ellis County health officials were monitoring air quality.

There were several large explosions at the plant and the fire moved so quickly that it engulfed a fire truck at the scene, according to  WFAA-TV‘s website. The Waxahachie Fire Department reported four different buildings on fire.