Justin,
It really depends upon who your audience is. Are these going to be employees that have little or no safety experience? If so, then you'll need to go to the basics, make sure they understand what they need to do to get the job done. The tests can be basic but make sure they have lots hands on exercises.
Are these going to be full or part time safety people that have some knowledge? If so, you can make the tests a little more difficult and subject specific.
If they are experts, the test is going to be a formality.
In my opinion, the test whether written or hands on must be able to show that the student has absorbed and retained the information. Give tests that will pass the laugh test (the test isn't so easy that an auditor would bust out laughing)
MikeCJ