Thanks very much for the responses. I've also found a US OHSA guideline suggesting aisles be a min of 3ft wider than the widest truck required to pass through the aisle.

I raised the issue and the companys response was "it's not a highway, there are no regulations". However,we've recently had a visit from Labour Canada where they had some issues with the forklift safety, so I'm currently searching out as much infomation as I can find to propose a safer more comprehensive policy than the one that is presently being ignored.

Once again thank you very much your responses have been extremely helpful.