It was not until 1941 that the aerosol spray can was first put to effective use by Americans Lyle Goodhue and William Sullivan of the United States Bureau of Entomology and Plant Quarantine, who are credited as the inventors of the modern spray can. Their design of a refillable spray can dubbed the aerosol bomb or bug bomb, is the ancestor of many commercial spray products. It was a hand-sized steel can charged with a liquefied gas under 75 pounds of pressure and a product to be expelled as a mist or a foam. A public-service patent was issued on the invention and assigned to the Secretary of Agriculture for the free use of the people of the United States. Pressurized by liquefied gas, which gave it propellant qualities, the small, portable can enabled soldiers to defend themselves against malaria-carrying mosquitoes by spraying inside tents and airplanes in the Pacific during World War II. Goodhue and Sullivan received the first Erik Rotheim Gold Medal from the Federation of European Aerosol Associations on August 28, 1970, in Oslo, Norway in recognition of their early patents and subsequent pioneering work with aerosol sprays.