The U.S. Department of Labor Occupational Safety and Health Administration is investigating the explosion that injured three workers Feb. 16 at Broadcom Ltd., formerly CyOptics Inc., at Tek Park, 9999 Hamilton Blvd., Breinigsville.

“The employees were changing out canisters containing what is believed to be the chemical trimethylindium when the explosion took place,” OSHA Spokeswoman Joanna Hawkins emailed The Press on Feb. 21.

CyOptics Inc., has no prior OSHA history, she said.

Hawkins noted OSHA has up to six months to complete its investigation.

Upper Macungie Township Fire Commissioner and Emergency Management Coordinator Grant Grim also recently spoke with The Press about the explosion.

Volunteer firefighters from Upper Macungie Township’s Station 56 and Good Will, Trexlertown, were dispatched shortly after 10 a.m. last Thursday for an explosion at the facility, Grim said, adding the three employees injured in the explosion at the back of the Broadcom building were taken to Lehigh Valley Hospital.

He said Upper Macungie police and Cetronia Ambulance Corps personnel were dispatched earlier than the 30 volunteer firefighters who responded.

“Once they were dispatched, then the fire departments were dispatched,” Grim stated.

“I then dispatched the Lehigh Valley HazMat Unit and Lehigh Valley Hospital’s decontamination trailer.”

Grim said seven employees helping the injured, and one paramedic were decontaminated.

One Upper Macungie police officer was decontaminated and sent to the hospital, Grim added.

Upper Macungie Police Chief Edgardo Colón emailed The Press about the officer’s condition.

“He is fine,” Colón wrote. “He was not directly exposed to any dangerous substances.

“Because he went in to render aid and was in the area where an injured person was. I made the decision to send him to the hospital as a precaution.”

Upper Macungie Deputy Police Chief Joseph B. Wilson also emailed The Press concerning the officer.

“The officer was decontaminated and transported to the hospital strictly as a precautionary measure,” Wilson stated. “This was due to his proximate to the area of concern. He showed no injuries and had no complaint of pain. He returned to work the next day.”

Grim said once everything was finished between 1:30-2 p.m. and all proper decontamination procedures were followed then Elk Environmental Services, Reading, took over.

“They did the clean up and then they turned the building back to the company,” Grim said. “Everybody did a great job, between the hospital, Lehigh Valley HazMat, the two fire companies, Cetronia Ambulance Corps and Upper Macungie Township Police.”

According to the company’s website, Broadcom Ltd., a semiconductor supplier, purchased CyOptics Inc. in 2013.