Hazardous materials incident sends 33 employees to area hospitals

A failed valve was the cause of last night’s ammonia leak that evacuated a large industrial building in Sterling and sent employees to several local area hospitals.

At approximately 8:36 p.m., on Wednesday, July 31, the Loudoun County Emergency Communications Center received a 911 call reporting a gas leak inside a commercial building at 22445 Sous Vide Lane in Sterling. Fire and Rescue units from Loudoun County, Fairfax County, Prince William County, and the Metropolitan Washington Airports Authority arrived on the scene and confirmed the leak was ammonia and observed numerous patients who had been exposed.

As Ammonia poses a significant inhalation hazard that can cause respiratory issues as well as burns on the skin, fire crews donned their protective equipment to perform a rapid primary search of the structure. The search confirmed that everyone was out of the building. The Loudoun County Fire and Rescue’s Hazardous Materials Response Team began working with a building representative to identify the source. The Hazardous Materials team personnel then donned specialized protective garments and gear to enter the structure to isolate and control the leaking valve.

First responders arriving on scene encountered a large group of approximately 200 employees who had self-evacuated and were gathering on Broderick Drive. Due to the number of potential patients and type of medical conditions presenting, the incident commander requested a Mass Casualty Incident alarm which includes an additional 10 emergency medical services transport units, 10 suppressions units, a mobile ambulance bus, command staff support, and other resources.

EMS providers worked quickly to evaluate and treat the hundreds of potentially injured workers that had evacuated. Of the 287 employees working in the facility at the time of the leak, a total of 33 patients were transported to area hospitals: five in serious condition, 17 in serious but non-life-threatening condition, and 11 with minor symptoms. 

The remaining 254 employees were isolated, evaluated, and did not require transport. The Loudoun County Office of Emergency Management responded and assisted with transportation of those who did not require medical treatment. Inquiries on patient status should be made with the receiving medical facilities, Loudoun Inova Hospital Lansdowne, Reston Hospital Center and Fairfax Hospital.