How Impurities Responsible for Recalls Emerge in Hand Sanitizers

The global pandemic has created an unprecedented demand for alcohol-based hand sanitizers. This stimulated the entry of many new producers of hand sanitizers, both to provide a new business during the general shutdowns, and to meet the needs of society. Similarly, this created a need for alcohol sources well beyond what had been produced for the consumer market. This has led to numerous recalls of formulations in both the United States and Canada for exceeding the limits of several key impurities, arising from oxidized forms of alcohols, that could risk consumers’ health. Some of these recalls likely arise from the use of substandard ingredients, but others are less easily explained. However, the inclusion of hydrogen peroxide, and the possibly introduction of metal salts from processing could explain the levels of oxidative impurities. This study investigates these questions experimentally using the standard WHO formula as the base formulation, and finds that these impurities do readily arise in the presence of metal salts.