A fire at the Owl Metals recycling facility that caused the Peninsula Expressway to shut down last week is still causing an air quality alert, according to the Maryland Department of the Environment.

Normal air quality levels are considered to be between 0 and 50 on the Air Quality Index — this is known as the “good” category, according to the U.S. Environmental Protection Agency.

While the MDE didn’t specifically provide a number for the recycling site in Dundalk, on Saturday the air quality around the Baltimore region was “moderate,” which was just below the “good” range, and above the “unhealthy-sensitive groups” category.

“MDE is continuing to monitor the recycling plant fire in Dundalk as it undergoes periods of flare-ups and smoldering,” the MDE said in its Air Quality Forecast Saturday. “We continue to urge those who are in the neighborhoods immediately adjacent to Lynch Cove and Peninsular Highway by the recycling plant to take precautions. People should take steps to limit their exposure to smoke. Sensitive groups in that area should avoid outdoor activities and everyone in proximity to the fire or within drifting smoke should limit strenuous outdoor activities.”

MDE said the guidance will likely continue until the fire at Owl Metals is extinguished and there is no more smoke. Fire personnel first responded to a three-alarm fire at the Owl Metals Inc. recycling center at 1936 Rettman Lane in Dundalk on Jan. 18.

Because several portions of the building had collapsed, firefighters were attempting to subdue the blaze from outside, Baltimore County Fire Department Cpt. Len Stewart said after fighting the blaze.

“It’s a large warehouse,” Stewart said, “and because the recyclables are stacked up, hotspots keep breaking out.”

No injuries were reported, though one man was taken to a local hospital as a precautionary measure after inhaling some smoke. The Peninsula Expressway reopened Sunday.

“We know that deep-seated fire takes days to extinguish and often do rekindle,” Baltimore County Fire Department spokesperson Travis Francis said last week.

As a result, the Maryland Department of the Environment advised sensitive groups to limit their outdoor activities near the recycling facility due to air quality samples taken Thursday near the scene of the fire, the fire department said.

Francis said the cause of the rekindling is unknown but that it could be combustibles still burning below the debris. The weather can also affect it, he said.

Baltimore Sun reporters Glynis Kazanjian, Mary Carole McCauley and Matt Hubbard contributed to this article. Have a news tip? Contact Todd Karpovich at tkarpovich@baltsun.com or on X as @ToddKarpovich.