Alcohol wetting concentration, the general choice of alcohol concentration is 20% to 30%. Now clinically applied oxygen wetting bottle volume is 240ml, need to fill the wetting bottle by 1/2, wetting solution is 120ml. clinically used alcohol is concentration 75% ethanol, configure 20% alcohol wetting solution as follows: distilled water 88ml + 75% ethanol 32ml. configure 30% alcohol wetting solution as follows, distilled water 72ml + 75% ethanol 48ml.