Ethanol (2207.10) and methanol (2905.11) fail the single use test as these are common chemicals in many synthetic hydrocarbon reactions, in addition to being “green fuels”. Biodiesel is exclusively used for transportation or energy production but is an ex-out 3®(3824.90 ex) as it is categorized under the large subheading of “products, preparations and residual products of the chemical or allied industries”. Solar cells also form part of a large subheading (8541.40), which includes semiconductor devices and light-emitting diodes.