There is a voltage level translation on the PCB, so it is definitely safe to use.
Viewing post in Blazing Rangers / 炎のレンジャーマン comments
Awesome, thanks for confirming!
I would've liked to find this info on the game's page on the First Press Games website. It's often a concern these days with all the new releases and reproduction cartridges coming out for classic consoles. It's pretty common that they don't have correct voltage unfortunately.