Abstract: An accessory intended to be worn by a user, including a case and an element for carrying the case, the accessory also including a pad that is able to release an active substance by gradual evaporation, the case being equipped with a housing that has a lateral slot through which the pad can be reversibly inserted, the housing being arranged for providing a force for holding said inserted pad, at least one wall of the housing having a grille the openings of which are arranged to allow the evaporation of the active substance through the grille.

Abstract: The invention relates to a method providing a diffusion procedure where diffusion is controlled in order to confer a diffusion desired for the composition, and, before the execution of the diffusion procedure, a previous procedure of treatment of the air of the environment occurs. The previous treatment procedure measures at least one physico-chemical parameter of said air; compares the measured parameter to a threshold; and, if the threshold is exceeded by the measured parameter, activates a device for treatment of the air that is arranged in order to modify the parameter in compliance with the threshold.