Alcohol-Based Hand Sanitizers: Analysis for Content of Ethanol and Contaminants

Background: Alcohol-Based hand sanitizers (ABHS) are used as hand hygiene products because of the broad-spectrum activity of ethanol (and some other alcohols) against pathogenic microorganisms. They are effective in curbing the spread of infectious diseases such as Covid-19 and other viral, bacterial and fungi infections but the ethanol concentration has to be within a specified range. Some ABHS may contain toxic contaminants and the most prevalent ones are methanol and acetaldehyde. There is therefore a need for routine testing of the products for the content of ethanol and contaminants to ensure effectiveness and safety. Methods: Thirteen samples of commonly available ethanol-based hand sanitizers were sourced randomly for shops and supermarkets in the Lagos metropolis of Lagos State, Nigeria. The samples were analysed for the content of ethanol, methanol and acetaldehyde using gas chromatography coupled with flame ionization detector (GC-FID). Values obtained were compared with label claims of the manufacturers for ethanol and with regulatory limits for the contaminants. Results: The study reveals that 69% of the samples were within the WHO recommended range of 60- 95 % v/v of ethanol concentration. Ethanol content was not stated on the labels of two of the samples and seven samples did not have NAFDAC numbers on their labels. One of the samples was contaminated with methanol and the concentration was above regulatory limits. Acetaldehyde was not found in any of the samples. Conclusion: Some of the alcohol-based hand sanitizers in Lagos market are sub-standard, containing ethanol in concentrations below recommended range. There is also a potential toxicity risk posed by a small percentage that contains contaminants like methanol. This indicates a need for more regulatory control of the production, distribution and sale of sanitizer products for effectiveness and public safety.