I had this question posed to me by a customer today. Essentially a safety administrator was wondering if a company is required to have employees acknowledge health and safety policies, as our software is designed to do. The reference to policy communication is hard to find in most jurisdictions, but it is almost aways there. In Alberta it is in the Occupational Health and Safety Act in section 32 "Written health and safety policies", subsection (c) "...as far as reasonably practicable, inform that person's workers of the policy."
The term "reasonably practicable" is certainly open to interpretation. Your organization may believe printing policy binders and making them available on bookshelves in the office or shop will suffice. Our feeling is that a formal acknowledgement, like the one offered in our software will certainly prove due diligence for your policy communication needs.
The topic of policy communication a bit of a concern for organizations that are RAVS certified by ISNetworld. Essentially you've written health and safety policies and submitted them to ISN for approval, yet because they are long, detailed and dry, you may not have plans to communicate the policies to your employees. I believe most auditors and courts would subscribe to the idea that those policies that pertain to each worker's health and safety need to be communicated. Using a couple of examples, only employees working in and around confined space need to be made aware of the confined space policy, and only employees that may be required to work alone need to be made aware of the company's working alone policy. Our software makes this differentiation by role easy; assign policies only to the positions that are exposed to the hazards in question.

SafetySync takes the policy communication element one step further. The system allows workers to decline a policy if they do not accept it or understand it. Our feeling is that it is "reasonably practicable" to allow a worker to take exception to a policy or suggest improvements. Declines happen only very rarely, but the manager or administrator is immediately notified and can follow up on any concerns, rather than simply assuming everyone accepts a policy as it is written. Employee input and regular reviews are important parts of safety program development.