In Baytown, Texas, there was an explosion and fire at an ExxonMobil oil refinery plant. The explosion and fire released polypropylene, a chemical that creates a type of plastic, into the air and caused the city of Baytown to issue a shelter in place to its residents due to the concern about air quality. Harris County filed a lawsuit against ExxonMobil in response, on the basis that the explosion and fire caused the emission of multiple air pollutants.