Louisiana Governor John Bel Edwards tweeted that the southwestern communities of Westlake, Moss Bluff and Sulphur are all affected by the order.
Edwards urged residents in these areas to shelter in place until further notice with doors and windows closed and air conditioning units turned off.
“Stay inside and wait for additional direction from local officials,” he tweeted.
A long, thick plume of grey smoke began drifting over the Interstate 10 highway in Westlake — about six kilometres west of Lake Charles — sometime Thursday morning, according to local reports.
Video from the scene posted on social media shows cars stopped on the highway as the smoke billows, blackening as the cloud grows.
The Louisiana Department of Environmental Quality confirmed the fire started at the BioLab plant, which produces chlorine-based products for pools and home cleaning, among other chemicals.
Louisiana State Police issued a public safety alert for the area shortly after the fire broke out Thursday. Police said firefighters were at the scene working to extinguish the blaze, adding that the fire was contained to the BioLab site.
No injuries have been reported.
Westlake police are also investigating the incident, Reuters reported. Traffic has been blocked on the interstate and Highway 90 in the meantime.
Hurricane Laura struck land near Cameron, La., at around 2 a.m. ET Thursday as a powerful Category 4 storm. It weakened to a Category 2 about six hours later and was downgraded to a Category 1 storm at around 9 a.m. ET Thursday as it continued to move north.
Despite the weakening, the storm left widespread damage in its wake. Much of the Louisiana-Texas state line is dealing with floodwaters, destroyed buildings and downed power lines.
The hurricane is expected to continue impacting Louisiana before moving to Arkansas, where it is expected to reach tropical storm status.
— with files from Reuters and The Associated Press