Controls should be reviewed regularly to confirm they work as planned and create no new risks, with frequency set by the level of risk: more frequent review may be needed where an exposure has occurred or where likelihood or consequences are high, but a regular schedule matters even where exposure risk is low, since hazards may still be present and improvements possible, for example regular indoor air quality monitoring prompting a review of airborne hazard controls. The WHS Regulations require review when a control does not control the risk so far as reasonably practicable (a needlestick injury despite retractable syringes, or a reported exposure-related illness); before a change at the workplace likely to give rise to a new or different biological risk the current controls may not handle (a mower bought for grass previously grazed by sheep, raising contaminated dust); when a new relevant hazard or risk is identified (Legionella found in cooling tower water); when consultation indicates a review is necessary (workers reporting an ineffective control or a control creating a new hazard); and when an HSR requests a review on reasonable grounds that one of these may affect workers' health and safety and the PCBU has not already reviewed adequately. Review methods include workplace inspection, observing tasks, consultation and analysing records and data, using the same methods as hazard identification; workers and HSRs must be consulted; gathering evidence and data on compliance with controls helps judge effectiveness; and where problems are found the PCBU goes back through identification, assessment, control and implementation.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.