Incandescent light bulb granted a Hungarian patent (No. 34541) for a tungsten filament lamp that lasted longer and gave brighter light than the carbon filament. Tungsten filament lamps were first marketed by the Hungarian company Tungsram in 1904. This type is often called Tungsram-bulbs in many European countries. Filling a bulb with an inert gas such as argon or nitrogen slows down the evaporation of the tungsten filament compared to operating it in a vacuum. This allows for greater temperatures and therefore greater efficacy with less reduction in filament life. In 1906, William D. Coolidge developed a method of making "ductile tungsten" from
Phase-out of incandescent light bulbs have banned incandescent light bulbs on 1 January 2014. As specified in Interministerial Ordinance 1,007 of 31 December 2010, incandescent light bulbs must perform according to certain levels of luminous efficacy in order to be produced, imported and sold in Brazil. Non-conforming light bulbs are being gradually phased out. As of July 2013, bulbs ranging from 61 to 100 Watts which do not perform accordingly can no longer be produced nor imported, but until mid-2014 they can still be sold. Since end of June 2016 it has been completely prohibited in Brazil. The Chilean government has prohibited the manufacture, import