Chemboys Hexane –- High Purity Solvent for Botanical Oil Extraction - Industrial Non Polar Solvent for Cements, Ink - Made in USA - 1 Pint (16 fl oz)

Arrived in 4 quarts which is fine. Used one quart and the product is great. I stored the remaining three quarts in a dark cool and dry place unopened. When I needed to use some, the unopened bottles had somehow evaporated down to less than half of quart... Unopened. Is this normal? How can it evaporate out of a sealed container? I think this should be stored in glass containers. But I am not sure. All I know is the product evaporated.