In September 2008, Air1, Dureal and Yara announced that they had again been forced to push up prices for their AdBlue packages. Vice President for Environmental and Specialty Products at Yara, John Arne Ulvan, stated, "We are in a situation where raw material prices are constantly on the rise. This pressure is not only on us as a primary source producer but also on all the other players in the AdBlue market." It has been suggested that the increase is due to the consistent rise in raw material costs that are used to produce AdBlue including urea, which has more than doubled in price since September 2007. The price increases will take effect from October 1st 2008.