Everyone who has some involvement from design through to use, has responsibilities.  In summary:

• The designer must identify any foreseeable hazard and design plant with regard to eliminating or controlling risk.  This would include design of effective guarding as required
• the manufacturer must undertake risk management in relation to plant and ensure that faults (e.g. a guard that creates risk) are not incorporated into the manufacturing process
• the manufacturer must also, where reasonably practical, consult with the designer to rectify any faults by altering design
• the supplier must ensure that risks arising from the sale or transfer of new plant are eliminated or controlled
• for used plant, they must provide, in writing before the sale or transfer, all relevant information about the plant including any identified faults (e.g. guards working only intermittently)
• the employer must identify any hazards associated with plant and ensure that risk controls are in place to eliminate or reduce the risk.  This may be ensuring the guards are in place and are effective
• the employer must also provide appropriate instruction, training and supervision in relation to guarding
• the employee must not interfere with or misuse anything that is required for safety.  This includes machine guarding
• employees must also co-operate with their employer, which includes following safe work methods and reporting problems in relation to guarding.

Note:  The above is a summary only and does not cover all obligations.  More detailed information about obligations can be found in the OHS Regulation 2001, Chapter 5 – Plant.