A head wearable air purifier includes a headgear, an air purifier assembly supported by the headgear, a nozzle assembly and a mask body. The air purifier assembly includes a filter and an airflow generator for generating an airflow through the filter. The nozzle assembly is configured to extend in front of a face of a wearer in use. The nozzle assembly includes an inlet aperture configured to receive a filtered airflow from the air purifier assembly, and an air outlet for emitting the filtered airflow from the nozzle assembly. The mask body detachably connects to the nozzle assembly and defines a cavity for receiving a mouth and/or nose of the wearer. The cavity is in fluid communication with the air outlet.