MIDDLESEX TWP — The state Department of Environmental Protection is investigating why magnesium cuttings were found in a field off Murray Drive that caught fire Monday afternoon.

Freda Tarbell, DEP spokeswoman, said this morning the problem was detected after emergency services responded to the fire call.

Magnesium, an alkaline metal, ignites when exposed to moisture.

Tarbell the DEP recognizes the dangers posed by the magnesium filings dumped in a field.

She said the DEP investigation began Monday night and continues today.

Butler County Emergency Services, which has a Hazmat specialist, also responded once the magnesium was detected.

Frank Matis, director of county emergency services, said the daughter of property owner Ed Ferree told officials the soil was low in magnesium so her father spread some in the ground to improve the oil quality.

“He was spreading the magnesium with lime,” Matis said.

He said Ferree’s brother used a backhoe to dump dirt onto the fire, which covered a quarter of an acre.

Tarbell said it’s premature to know if there is any environmental violation.

The Middlesex and Penn Township volunteer fire departments were called to the blaze at 4:52 p.m. They left at 8:41 p.m.