PORT NECHES, Texas — One of the major questions we've been getting today -- what's on fire at the TPC Group Plant in Port Neches?

According to Mike White, the Jefferson County Emergency Management coordinator, there are a couple of chemicals housed at the facility.

The early morning explosion happened in the area of the plant that manufactures or processes butadiene, which is used to make synthetic rubber and other products, like tires, plastics and other chemicals

Butadiene is a colorless gas with a gasoline-like odor.

Long-term exposure has been associated with cardiovascular disease and cancer. That's why the air quality will continue to be monitored.

RELATED: All employees accounted for, 3 injured after explosion, fire at Port Neches plant early Wednesday

RELATED: Mandatory evacuations in place after TPC Group plant explosion, fire in Port Neches

White says  the TCEQ is on scene to monitor air quality. We'e reached out to them, but haven't heard back. He does say the wind is working in the favor of response crews.

Because there are still questions about the air quality, there is a shelter in place. 

According to a spokesperson for the plant, their focus is safety and also minimizing any impact to the environment.