Distinguishing Between Ethanol and Isopropanol in Natural History Collection Fluid Storage

Distinguishing Between Ethanol and Isopropanol in Natural History Collection Fluid Storage
Source: Society for the Preservation of Natural History Collections

Natural history specimens in fluid storage are typically maintained in either ethanol (grain or ethyl alcohol) (CH3CH2OH), isopropanol (isopropyl alcohol or propan-2-ol) [(CH3)2CHOH] or formalin (CH2O). If not previously documented, identifying storage fluids can be surprisingly difficult and potentially hazardous especially in a collection where all three fluids are used. This paper discusses how to identify what you have whithcharts and illustrations.