I’m commonly asked why many chemistry ‘recipes’ call for vodka or Everclear as opposed to medical-grade ethanol (alcohol). The answer is simple: It’s easy and inexpensive to obtain vodka, while obtaining medical-grade ethanol, even if you have a permit, can be expensive.
Aside from the regulations surrounding ethanol, it’s a flammable substance, so shipping costs can be prohibitive for small institutions. Many projects call for alcohol as an organic solvent. Vodka tends to be used when the alcohol needs to be ethanol, when the presence of water is acceptable, or when the material has medical/biological applications.
Keep in mind, vodka is 80 proof, which means it is about 40% alcohol and 60% water. If you need a higher purity of alcohol, you can distill vodka to get a higher concentration of ethanol in the product.