The mobility required to perform the task should be assessed to see how the RPD selection may be affected. Location of the hazardous area may limit the type of RPD that can be used safely.

For example, if entry into the hazardous area requires movement over several metres, movement between floors or levels within a building or transit through very small openings or tunnels/ducts using ladders or crossing railroad tracks, then class SY RPD may not be suitable because of the possibility of tangling or severing the supplied air hoses. The maximum length of hose permitted by standards may also limit the travel distance of airline respirator wearers. Also, when using class S or combination class SY/S, the distance from the hazardous area to the nearest staging area containing a breathable atmosphere should be known to ensure that the RPD selected will have an adequate supply of breathable gas or that the service life of the auxiliary escape cylinder of the combination class SY/S is adequate for emergency escape.

Confined spaces require special considerations such as hazard and exposure assessment, space limitations, and a means of communication between the respirator wearer and standby personnel.

Where significant body movements are envisaged, e.g. bending, stretching, crawling and manual handling tasks, the impact of these movements should be assessed. It may be necessary to consider both — the possibility of discomfort or musculoskeletal injury to the worker due to the RPD and the possibility that movements may affect the fit and protection of the RPD. The RPD may need to be very carefully selected so that it does not get damaged by the activity and does not unduly impede movement.

Bulky backpacks or pressure vessels could cause problems if the worker needs to work on their back or pass through a small opening. In some cases, it may be necessary to take backpacks off temporarily. In this case, protection has to be maintained. The risk of hoses and tubes becoming snagged should be assessed so the most appropriate RPD can be selected to minimize the risk of protection failure or damage. Mobility limitations caused by RPD having encapsulating suits because of their size or construction shall be considered.

Reference/s for further information and detail:

AS/NZS 1715:2009 – Selection, use and maintenance – Section 4.3.3
SA/SNZ TS ISO 16975.1:2023 – Selection, use and maintenance – Section 7.3.3 & Annex D.3.2