Disclosed is an apparatus and method for operating powered air-purifying respirators safely in explosive atmospheres. The apparatus and method utilize a current control means for sensing a current flow from a battery to a motor, and stopping the current flow when the current flow exceeds a threshold value for a predetermined amount of time. Upon sensing that the current flow has exceeded the threshold value for the predetermined amount of time, the current control means immediately stops the current flow. The apparatus and method provides sufficient power to properly start and operate the motor by providing a soft start to the motor by limiting the duration of higher than threshold operating current to intervals shorter than the predetermined amount of time. Pulse width modulation is used to ramp-up the motor to speed by supplying pulses of energy to the motor that will not cause the current control means to stop the current flow.