The present invention relates to a system for increasing the safety of a portable electrical tool (10), comprising: a generator (40) of a radio-electric signal, which generator is electrically coupled to said user (1) so as to inject into the body of the user (1) said radio-electric signal (s(t)), said radio-electric signal (s(t)) then being emitted by said user (1) in the form of an electromagnetic signal; and the portable electrical tool (10), which is arranged to be borne by a member of the user and comprises: a machining member (4); a holding member (2); an actuator connected to the machining member (4); an antenna fastened to the machining member (4) and/or the holding member (2) and arranged to receive a radio-electric signal corresponding to the electromagnetic signal emitted by the user (1). A computing module (30) determines a distance between the user and the machining member and/or holding member on the basis of the electromagnetic signal received by the antenna, and modifies accordingly the speed of the actuator.