Officials said air monitoring found no readings indicating a public health threat after hydrogen sulfide was released at the chemical facility.
DEER PARK, TX — Deer Park lifted a citywide shelter-in-place late Tuesday after a hydrogen sulfide release at the Lubrizol chemical plant prompted officials to monitor air quality and warn residents to remain indoors.
The city issued the shelter-in-place at about 6:50 p.m. Tuesday while emergency officials monitored what was initially classified as a Level 3 incident at Lubrizol’s Deer Park facility. The order remained in effect for several hours as authorities worked to identify the material involved and verify air-monitoring results. By 10 p.m., officials said the order had been lifted and there was no threat to the surrounding community.
Lubrizol later de-escalated the incident to Level 2 after confirming that hydrogen sulfide had been generated when phosphorus pentasulfide came into contact with water, according to Harris County Public Health. The company said the incident occurred during maintenance on an idled unit at its facility at 41 Tidal Road.
Authorities continued monitoring conditions while the shelter-in-place was active. In an update shortly before the all-clear, Deer Park officials said internal air monitoring was showing normal levels with no readings of concern, but the city was waiting for final third-party verification and confirmation from Lubrizol before ending the precaution.
Harris County Judge Lina Hidalgo said a fire associated with the incident had been extinguished and all employees at the plant were accounted for. No injuries were reported. County hazardous-materials and pollution-control teams also reported no air readings that indicated a public health risk.
As of about 10:35 p.m., crews were still working to seal a hydrogen sulfide leak, according to county officials. Residents in the area reported a rotten-egg odor, which is commonly associated with hydrogen sulfide. The presence of an odor alone did not mean monitors had detected concentrations considered a public health threat.
The incident also prompted precautions at nearby industrial facilities. Intercontinental Terminals Company, Pemex and Shell Chemical Company issued warnings related to the chemical odor or nearby response. La Porte officials monitored conditions along the boundary with Deer Park and reported no readings of concern in that community.
The shelter-in-place followed an initial report of a chemical odor at the Lubrizol facility at about 6:20 p.m. Deer Park officials then told residents to go indoors, close windows and wait for an all-clear while emergency responders gathered information. The order covered the city as authorities assessed whether the release could affect areas outside the plant.
Although the shelter-in-place has ended, officials said the industrial incident remained ongoing when the all-clear was announced. Harris County Public Health said there was no threat to the community at that time and that additional emergency notifications would be issued if conditions changed.
Author note: Last updated November 11, 2026.