Abstract: The present invention relates to improvements to powered air purifying respirators (PAPR). PAPR are known generally for use in polluted environments. A typical PAPR comprises a powered impellor arranged to draw air from the atmosphere, a filter element and a mask to provide the filtered and pressurized air to the user. Embodiments of the present invention place a generator unit, comprising a filter and impellor for pressurizing the air, behind the head of the user, and include components for improving delivery of the air to the user and improving its quality.