Abstract The new coronavirus pandemic (COVID-19) is a global problem that is having severe impacts on health systems worldwide. One particular characteristic of this virus is its high transmission rate, which has led to a high demand for personal care materials such as masks, gloves, and alcohol for asepsis. Seventy percent is the ideal concentration for the ethanol used in hand sanitizers; however, this concentration can be expressed in different ways, and, consequently, the different solutions will have different antiseptic activity. In this manuscript we comment on some characteristics of alcohol-based preparations and the different ways of expressing the concentrations.