In 2024, B10 gasoline, which is 95 gasoline with a bioadditive of up to 10% anhydrous alcohol, was introduced to the market in Poland and the European Union. Fuel transmission systems consisting of pipelines, tanks, flanged valves, and control and measurement equipment are filled with B10 fuel, which can cause faster degradation of seals than 95 gasoline without bio-additives. This article describes durability tests of two selected types of gaskets used in petrochemicals, tested in the environments of PB95E10 gasoline and PB95 E5 gasoline. During the 1000-h tests, weight loss and decreased flange pressure on the seals were measured over time. The test results allow for mathematical analyses, including the prediction of the operational lifespan of gaskets. Durability tests conducted by the Laboratory of Sealing Technology and Fittings enable companies to plan renovations for their installations. The value of biofuel leakage fugitive emissions after the 1000-h test was lower than the allowable limit in the DIN Standard. The main conclusion of this article is that the AFM and AFO gasket materials can be permitted for use in contact with gasoline containing ethanol and diesel fuel with methane esters.