The short answer to this is "There aren't any" - Part 3.1 (Manual Handling) of the Occupational Health and Safety Regulations (2007) does not have either weight or maximum force limits.
However, the Regulations require the employer to identify any any task which involves hazardous manual handling, and then take actions to either eliminate or reduce the hazard and/or the associated risks. The Regulations include any task requiring the 'application of high force' as hazardous manual handling. The regulations give the following example of "Application of high force":
"The force required to lift or otherwise handle heavy weights, to push or pull objects that are hard to move, to operate tools that require the use of two hands to exert sufficient force but that are designed for one hand or to operate tools that require squeezing of grips that are wide apart.."
Basically, this means that any weight or force may be a risk to a worker, depending on factors such as posture, frequency, duration, actions and movements, and so on.
Obviously, the greater the force exerted, the greater the risk and workers and OHS Reps should raise this as an issue.
For more information, contact your union.
See also:
- More extensive information page on Strains and Sprains.
- The summary of Part 3.1 Manual Handling, on this site
(Last updated February 2008)