Corrosion Resistance of Aluminum Beer Cans Containing Hand Sanitizer

Abstract

The COVID-19 crisis and ensuing supply chain disruptions prompted many breweries and distilleries to repurpose their facilities for the production of hand sanitizer, with the vast majority following the World Health Organization formulation (80% v/v ethanol, 1.45% v/v glycerol and 0.125% v/v hydrogen peroxide). The long term shift from bottling to canning among craft brewers left canning as the sole scalable option for many facilities to package hand sanitizer. With essential services desperate for hand sanitizer to help protect their staff, patients, and clients, many breweries moved to package these products in cans despite warnings that they are not designed to hold solutions containing high ethanol concentrations or strong oxidizers. The present study explores the resistance of ubiquitous can liners, WB Modified Epoxy and BPANI Gen 2, to WHO formulated hand sanitizer. Shelf life observations and microscopic visualization show the WB Modified Epoxy liner withstands hand sanitizer with little observable disruption at room temperature, while BPANI Gen 2 liners permit package failure and liquid leakage within 30 days. Incubation at 37 °C accelerated the rate of failure sixfold in BPANI Gen 2 lined cans versus room temperature incubation, providing a basis by which to expect an approximately 72 day shelf life for WB Modified Epoxy lined cans. Because of the inherent risk to consumers presented by these data and despite lack of clear guidance from regulatory agencies, manufacturers should strive to cease packaging hand sanitizer in cans and instead find supplies of inert non-beverage containers.

Keywords:

• Aluminum can
• brewery
• aluminum corrosion
• COVID-19
• hand sanitizer

Acknowledgments

The authors wish to thank Charlie Bredo (Troubled Monk Brewing, Red Deer, AB) for sharing information about WB Modified Epoxy cans, and Jonas Hurtig (Cabin Brewing, Calgary, AB) for generous use of alcohol testing equipment. The authors wish to thank Krista Fraser (Troubled Monk Brewing, Red Deer, AB), Thomas Shellhammer (Oregon State University, Bend, OR, U.S.A.), and Dugald Thomson (Canadian Forces, Victoria, BC) for intellectual contributions.