A chlorine gas leak on May 20 at Olin Corp.’s Plant B in Freeport, Texas, prompted emergency response and shelter-in-place orders across multiple cities in Brazoria County.
According to The Houston Chronicle, Brazosport CAER, a community alert system, reported the incident around 9 a.m. The leak activated on-site emergency procedures and prompted workers to shelter in place while response teams began containment efforts.
Within minutes, the Lake Jackson Police Department confirmed a Level 3 chlorine release, indicating that gas had escaped the plant’s perimeter and was detectable off-site. Authorities advised residents in the nearby cities of Clute and Lake Jackson to stay indoors, close all doors and windows and turn off air conditioning systems.
According to Olin, the leak was stopped by 9:46 a.m., and all community shelter-in-place orders were lifted at 10:40 a.m. The shelter-in-place at the plant remained in effect past 11:30 a.m. as safety evaluations continued. The company reported that all personnel had been accounted for and those potentially exposed were being assessed by medical professionals.
Olin declined to confirm reports that several workers were treated following the release, but according to the International Union of Operating Engineers Local 564, four members received medical attention. Three of those individuals were later released, while one remained hospitalized in stable condition.
The chlorine leak was one of the few incidents in recent years in the region to be categorized as a Level 3 event. The hydrogen sulfide leak at the PEMEX Deer Park refinery in 2024 that killed two workers was rated as Level 1.
In a statement, Olin, a major North American chlorine producer, said it is cooperating with local authorities in ongoing investigations and emphasized that “the safety of our employees, the community and our environment is always our top priority.”
