Under Clause 90 (1) of the OHS Regulation 2001, designers of plant must ensure that guarding is designed:

• to be a permanent fixed physical barrier or an interlocking type physical barrier if access to the danger point or area is required during normal operation, maintenance or cleaning;
• to make it as difficult as reasonably possible to by-pass or defeat the guard (whether by accident or deliberately);
•  to be of solid construction and securely mounted to resist impact and shock; and
• not to cause a risk itself.

The designer must ensure that any guards that are intended to provide protection from parts of the plant or work pieces that may break, disintegrate or be ejected, are designed to contain effectively the parts, work pieces or any fragments of them. (Clause 90(3)).