Occupational Safety and Health Administration officials are looking into an explosion at an Edmond, Okla., piping company that injured four on Thursday.

The morning explosion sent three of the injured workers to two nearby hospitals. One victim suffered third-degree burns and was sent to an intensive care unit. The other three, one of whom was sent home without hospitalization, suffered first-degree burns. No significant property damage was reported.

The Occupational Safety and Health Administration investigates any workplace incident that results in the hospitalization of two or more workers or that results in fatality. They have six months to complete their investigation. NOV Tuboscope’s parent company, National Oilwell Varco, says they will cooperate with the investigation.

Edmond Fire Maj. Kelly Lewis told the  Edmond Sun that no secondary fire resulted from the explosion at the facility. A kerosene space heater  ignited a cloud of  polymer dust that was released while workers were working on machinery resulting in the explosion.

OSHA regulations demand temporary space heaters in the workplace be approved for commercial use by a recognized safety testing laboratory. Further, they should be placed away from combustible materials, and have a tip-over switch to ensure it will turn off automatically if knocked over.

As the year begins, it is a good time to review the safety precautions and procedures of your business. A thorough risk assessment of a work site involves the identification of hazards like space heaters around flammable material or where flammable material may. Safety Services Company manuals walk thorough hazard identification and risk assessment to help ensure any work site is safer than the standards.