Suspicious material in the back of an unregistered Dodge Caravan on New Avenue ignited a bomb scare that caught the attention of the bomb squad and the FBI.Neighbors say the Caravan had been parked on the street for a week. The material in question was a black leather case marked with hazardous labels.Police initially suspected a biohazard, which prompted the F.B.I. Joint Terrorism Task Force to become involved. The Department of Health ultimately determined the material to be medical waste. Police say there was never a risk of exposure to any residents.Yonkers police have contacted the Caravan?s owner. They say he used to be employed by a company that transported medical waste. Police say he is no longer employed by the company and is not authorized to transport the waste. They have not revealed if he will face any charges.The vehicle has been impounded by police pending further investigation.