Diesel-powered machines may impact environmental conditions, and related health and safety in underground mines through tailpipe emissions. This spurs opportunities for alternative technologies such as battery electric, diesel-electric, and hydrogen-fuel-cell-electric equipment. These alternative technologies have the potential to reduce carbon emissions and provide cleaner working environments. However, they also introduce new health and safety hazards to the underground mining environment, including but not limited to high-pressure gas handling and storage, explosion hazards, high voltage equipment that can lead to electric shock and thermal runaway which can then produce off-gas and potential fire. 

To reduce these hazards, the CSA Group revised its underground mine mobile machine standards to incorporate elements pertaining to alternative technologies and added a new standard, M424.4 to the M424 standard series in 2022. This presentation highlights the content of the M424.4 standard which includes the base system configuration of the alternative technologies and addresses technical measures for eliminating or reducing risks arising from hazards during commissioning, operation, and maintenance. Also, a focus on machine design requirements that shall be met for self-propelled, electrically driven machines for use in non-gassy underground mines will be presented.