Product Short Description: The methanol wall wash procedure provides a representative sampling of the impurities and contamination present on the sides of the cargo tank. Product Description: The methanol wall wash procedure provides a representative sampling of the impurities and contamination present on the sides of the cargo tank. The test methods used for analysis of the methanol wall wash samples are capable of determining low levels of impurities or contamination in methanol. These tests include appearance, color, hydrocarbons and chloride. The producers of sensitive cargo like polyester grade monoethylene glycol need confirmation of the cleanliness and suitability of the marine vessel’s tanks prior to loading with in-specification material. Cargo tanks that do not pass the wall wash test should not be loaded.