(LANXESS) -- Substantial amounts of hydrocarbons leak through the walls of plastic fuel tanks in gasoline engines to the outside and pollute the atmosphere - a phenomenon known as permeation. Lanxess is therefore working on special blow-moldable grades of polyamide 6 that act as an extremely effective barrier against gasoline fuels. One example of such a material is Durethan TP 142-011. ⌠The polyamide 6 is so effective in suppressing fuel permeation that test results are well below the upper limit for motorcycle tanks, which was recently tightened considerably by the U.S. Environmental Protection Agency (EPA). It is also impact-resistant, a quality it lends to the blow-molded tanks it is used to make, said Maik Schulte, a development engineer at LANXESS. The material is an especially good alternative to high-density polyethylene, which has been used to make many plastic tanks for gasoline engines until now. It also has considerable advantages over other tank materials, such as aluminum, sheet steel and multi-layer plastic composites.