This morning the Valhalla Fire Department was dispatched along with the Grasslands Fire Brigade to the Westchester County Labs and Research Facility for two workers who became ill after reportedly coming into contact with an unknown chemical. First arriving crews were told the chemical had an ammonia like odor. Westchester County HAZMAT was on scene and made entry into the building, metering the facility try to locate the release. HAZMAT crews were unable to find the source and the building was vented as a precaution. The two workers were treated by EMS. Units were released and returned to service.