Osmolal gap is the difference between calculated and measured Osmolality. Determination of osmolal gap is a rapid way to detect exogenous, non-ionized osmolutes present in serum. The gap increases when toxins like Ethanol, Methanol, Isopropanol, Ethylene glycol & Acetone are present in significant concentrations. The gap may also be elevated with hyperlipidemia or hyperproteinemia.