AVALON, Pa. -- A strong-smelling chemical by-product of sewer line work in the area forces the evacuation of an Avalon apartment building on Friday.

Firefighters were called a three-story apartment building at South Birmingham Avenue and Taylor Street after a resident reported a strong odor in the building around 10 a.m.

Avalon firefighters, using handheld meters, detected what they thought was dangerous hydrogen cyanide gas on the third-floor of the apartment building.

“It was like spilt fingernail polish,” said resident Ebony Garland. “That’s what it smelled like to me.”

However, four hours into the evacuation, hazmat crews discovered that the source of the smell was not deadly cyanide, but rather styrene, a strong-smelling chemical by-product of sewer line work that was taking place nearby.

“Crews are realigning the sewer system,” said hazmat’s chief cmdr. John Krauland. “The odor came into the house through a crack in the floor.”

Officials said styrene is usually found in a liquid form and is used to make plastic and fiberglass products. However, the chemical wafted as a gas into the apartment building after crews were heating metals inside the sewer line.

Exposure to high levels of styrene can cause headache, fatigue, dizziness, confusion and drowsiness.

All residents and pets were evacuated from the 19-unit building.

No injuries were reported.