Using fake fuel in a Zippo lighter can lead to malfunctioning, safety hazards, and reduced performance. Fake fuel often lacks the proper butane composition, causing difficulty in igniting, inconsistent burning, or clogging the fuel jet. Over time, this may result in overheating, mechanical damage, or even spontaneous combustion. Fake fuel may also emit toxic fumes, such as carbon monoxide, and increase the risk of fire or explosion due to improper combustion.

The risks arise because counterfeit fuels do not meet industry standards for safety and efficiency. A 2020 Consumer Product Safety Commission (CPSC) report highlighted that 1,200 incidents involved faulty lighters linked to substandard fuels. The National Fire Protection Association (NFPA) notes that improper fuel mixtures can reduce burn temperature by up to 30%, increasing residue buildup and failure risks. A 2019 study in the Journal of Forensic Sciences found counterfeit lighters using fake fuel had a 40% higher failure rate in controlled tests compared to genuine products. Additionally, impurities in fake fuel can corrode internal components, worsening performance. These factors collectively heighten fire risks and mechanical failure, making counterfeit fuel dangerous for Zippo lighters. The CPSC advises users to only use authentic butane to ensure safety and longevity.