HOUSTON — A shelter-in-place order for an area in west Harris County was lifted after being in effect for several hours on Sunday.
The order was issued following a chemical leak at the 99 Cent Only warehouse on Colonial Parkway near the Grand Parkway and Katy Freeway.
According to officials, the chemical that was leaking was anhydrous ammonia, which can cause irritation to the nose and throat and can also make it difficult to breathe.
At a news conference shortly after 1 p.m., officials said the tanks had bled out and the chemical wasn't detected at harmful levels outside the facility. That led to the shelter-in-place being lifted.
Latrice Babin with Harris County Pollution Control said her office will continue to monitor the air and if they do pick anything up, they'll work with Harris County Public Health to get the word out.
An investigation is now underway, and according to the Harris County Fire Marshal's Office, the facility will remain closed for the time being. The company will have to hire a private contractor to monitor the air at the facility and make the necessary repairs.
"There was actually maintenance being performed at the time ... we don’t know the full ins and outs. We're going to be conducting an investigation to try to determine what happened so we can make sure it doesn’t happen again," Harris County Fire Marshal Assistant Chief Chad Shaw said.
Health officials said there may still be the faint smell of ammonia in the area, but they don't believe it's a health danger. Still, they do say if you have symptoms to reach out.
"We would like to hear if anyone feels they are still symptomatic or have any symptoms in general," Dr. Ericka Brown with Harris County Public Health said.
Ammonia air pollution can cause respiratory symptoms, eye irritation, nose and throat irritation, or shortness of breath.
Officials said the leak started Saturday night just before 9 p.m. when crews were performing maintenance on the refrigeration system in the warehouse.
It started in a line that was inaccessible because of where it was. Crews kept it contained to the building and monitored it. Around 1 a.m. Sunday, the leak started to leave the building.
“The line itself is about 16 feet in the air, so when chief (Fire Chief George McAteer) was talking about it being inaccessible, it’s because of how high it is and it is an explosive product," Fire Marshal Laurie Christensen said. "So at the time, our HazMat team could not go in there and do anything about that initially.”
What is anhydrous ammonia?
According to the Centers for Disease Control, anhydrous ammonia is a "colorless, highly irritating gas with a pungent, suffocating odor."
Anhydrous means without water.
The CDC said it's flammable and stored in pressurized containers. Anhydrous ammonia is lighter than air and will rise.
A report from the Mississippi Department of Health said it's mostly used for agricultural purposes, but it's also used for refrigeration.