A wearable air purifier

A wearable air purifier 101 comprising a helmet 102, a fan assembly 103 mounted to the helmet to generate an airflow, a duct assembly to duct the airflow, a nozzle 105 to receive airflow from the duct assembly and bring it downward from the upper helmet toward a lower region of the wearer's face, and a transparent eye shield 106 connectable to the helmet, wherein the nozzle and the eye shield are each movably mounted to the helmet by connections such as hinges 501 for movement between a non-mating position and a mating position in which the nozzle and the transparent eye-shield mate with one another such that they form an air resistant seal. The wearable air purifier may comprise a sensor detecting whether the eye shield is in the mating position, where the rate of airflow delivered by the fan can be linked to the sensed state.