(CNN) Harris County, Texas, filed a lawsuit against ExxonMobil on Thursday, one day after an explosion and fire at the company's Baytown plant.

The lawsuit said Wednesday's fire "resulted in the emission of multiple air pollutants, including propylene, LPG, propane, and associated products of combustion." The county says the company violated the state's clean air act and asks for orders to prevent a recurrence.

The fire began late Wednesday morning at ExxonMobil's Baytown Olefins Plant at a unit that contains polypropylene material.

Residents were urged to shelter in place for hours because of concern about the air quality. The advisory was lifted after monitoring didn't detect any "levels of concern," Baytown officials said Wednesday afternoon.

Officials said 66 employees and contractors were examined at a health clinic Wednesday.

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