Can 75% alcohol be used for disinfection?
Oct 31, 2025
Source: Cainiu Health
Dr. Wang Lei
Introduction
In general, 75% alcohol can be used for disinfection. When using, keep away from open flames and high-temperature environments, and avoid spraying into the air to prevent fire hazards. It should not be used on deep wounds, mucous membranes, or other sensitive areas to avoid irritation and damage. After disinfection, ensure adequate ventilation of the area. For storage, keep tightly sealed in a cool place out of reach of children.
Under normal circumstances, 75% alcohol can be used for disinfection. The detailed explanation is as follows:
75% alcohol is effective for disinfection because this concentration allows the alcohol to penetrate the protein coat of bacteria or viruses without forming a coagulated layer on the microbial surface—something that could occur with higher concentrations and hinder penetration. Once inside the microorganism, alcohol disrupts the spatial structure of proteins, rendering them inactive. This prevents microbial reproduction and kills the organisms, achieving the goal of disinfection. Concentrations that are too high or too low will reduce effectiveness; overly high concentrations cannot penetrate deeply into microbes, while concentrations that are too low fail to effectively denature proteins.
When using alcohol, keep it away from open flames and high-temperature environments, and avoid spraying it into the air to prevent fire hazards. It should not be applied to deep wounds or sensitive areas such as mucous membranes to avoid irritation or damage. After disinfection, ensure adequate ventilation. Store in a tightly sealed container in a cool place out of children's reach to prevent evaporation (which could reduce concentration) and potential safety risks.
