The TCEQ said regional staff used handheld air monitoring and stationary monitors overnight, which did not detect any issues of concern.
K-Solv, the company that controls the facility of yesterday's massive fire, said late Thursday morning that leaders were given access of the scene. They were still looking into what exactly was on fire and what caused the inferno.
Harris County is now able to monitor air quality in real time.
Harris County's Pollution Control Services Department shows real-time air quality monitoring on their website.
Massive flames shot out of the K-Solv warehouse on Lakeside Drive in Channelview around 4 p.m. At the height of the blaze, the smoke was so thick it was even visible on doppler radar.
RELATED: Shelter order lifted after massive fire at K-Solv facility in Channelview
Shelter order lifted after massive fire in Channelview
After several hours, fire officials were able to snuff out the flames.
The company provides environmental protection, disaster services and chemicals to the petrochemical industry.
WATCH: Officials update the cause of the fire at press conference
What we know about fire at K-Solv in Channelview
According to the fire marshal's office, known chemicals on site include, but are not limited to, hydrochloric acid, acetone, ethanol, ethylene dichloride, and other acids.
"We had a drum transfer operation, and during the operation, we had an ignition source. At that time, our employees activated our response plan, called for evacuation and notified 911 immediately," a K-Solv official detailed. "The fire department was deployed. We rapidly had an intensification of a fire situation. Resources were pulled in to mitigate that."
"We rolled down the window and you could feel the actual heat from the fire, from the flames," one witness recalled. "It was kind of scary so we just did a U-turn and took off."
One person went to the hospital for minor respiratory irritation from the fire. A shelter-in-place order was lifted for Lakeside Park Estates and Lakeview Homes, according to Harris County Judge Lina Hidalgo.
SEE ALSO: Residents say industrial facility fire in Channelview sounded like explosion
Residents say fire in Channelview sounded like explosion