Residents in parts of Ohio were instructed to leave their homes on Wednesday after a leak of a toxic chemical that can irritate the skin, eyes, nose, and mouth, while nearby communities were advised to shelter in place indoors.

An evacuation order for individuals within a 1-mile (1.6-kilometer) radius of the “hazardous materials release” was issued around 10::green-background[50] p.m. Tuesday. Toledo residents in an additional 3-mile (4.8-kilometer) perimeter were instructed to shelter in place.

Thick fog and haze obscured sightlines across the city of roughly 265,000 residents, where local news outlets noted a strong plastic-like scent.

“The release is ongoing, and crews continue to monitor the situation,” the Toledo Fire & Rescue Department confirmed in a statement published online early Wednesday.

Authorities linked the evacuation directive to a location along Progress Avenue, a commercial and industrial zone in northern Toledo. Fire officials did not identify a specific company, though directory records list a steel tube and pipe manufacturer at that address.

Officials emailed requests for comment to that manufacturer and a neighboring business on the street, a transport firm specializing in liquid bulk chemical haulage.

Authorities have not identified the chemical involved. Overexposure can trigger dizziness, headaches, fatigue, vomiting, and nausea, and the department urged anyone believing they are suffering a reaction from exposure to contact a medical professional for advice.

“You can’t tell fog from the release by looking, so please don’t rely on how the air looks,” the department said in the news release. “If you are outside the evacuation or shelter-in-place zones and smell an unusual odor, please stay indoors, close windows and doors and turn off ventilation that draws in outside air.”

Several local schools closed Wednesday while others delayed opening.

An elementary school served as a temporary reception center, and buses were deployed to offer additional shelter for displaced residents.