Analysis of Commercial Hand Sanitisers amid CoViD-19: Are We Getting the Products that We Need?

Abstract

The CoViD-19 pandemic has caused a sudden spike in demand and production of hand sanitisers. Concerns are rising regarding the quality of such products, as the safeguard of consumers is a priority worldwide. We analyse here the ethanolic content of seven off-the-shelf hand sanitiser gels (two biocides and five cosmetics) from the Italian market, using gas chromatography. The WHO recommends that products containing ethanol should have 60-95% (v/v) alcohol. Four of the tested hand gels have ethanolic contents within the recommended range, while three products (all cosmetics) contain < 60% (v/v), i.e. 52.1% (w/w), ethanol. The product with the lowest alcoholic content has 37.1% w/w ethanol. Toxic methanol is not found in any of the hand sanitisers. We show, in addition, that products with the highest ethanolic content have generally greater antibacterial activity. In conclusion, all tested products are complying with the EU regulations, as the three "substandard" products are classified as cosmetics, whose purpose is cleaning and not disinfecting. Nevertheless, if such hand cleaners were inappropriately used as hand disinfectants, they might be ineffective. Thus, consumer safety relays on awareness and ability to distinguish between biocidal and cosmetics hand gels. The obtained results might sensitise the scientific community, health agencies and ultimately consumers towards the risks of using hand sanitisers of substandard alcoholic concentration. If the wrong product is chosen by consumers, public health can be compromised by the inappropriate use of "low-dosed" cosmetic gels as disinfectants, particularly during the period of the CoViD-19 pandemic.

Keywords: CoViD-19; alcohol content; antimicrobial; ethanol-based disinfectants; gas chromatography.

Fig. 1

GC/FID analysis of ethanolic content in the gels. a Calibration curve for the quantification of ethanol. The calibration curve was prepared by analysing Carbopol^® gels with a standard concentration (40–70% w/w) of ethanol. b The concentration of ethanol (% w/w) determined by GC/FID in the analysed hand sanitiser gels (1–7). The red line indicates the lower limit of the range of concentration of ethanol recommended by the WHO for hand sanitisers. “*” indicates products that are biocides

Fig. 2

Vitality reduction (Log cfu/ml) for the model bacteria (E. coli and S. aureus) after contact with diluted (33–75% v/v) hand sanitiser gel (1–7). MRD is the maximum recovery diluent used as negative control