LA PORTE, TX --A chemical release at a plant in La Porte caused a brief shelter in place on Tuesday morning. A phosgene leak was detected at PPG Industries on South 16th and Fairmont Parkway around 10am this morning. A shelter in place was issued as a precaution. The source of the leak was found and secured. The all clear was given half an hour later after air monitoring showed the chemical didn't leave the site. Phosgene is used to make plastics and pesticides.