FYI, I stumbled across a well done video set on chrome 6 / hex chrome.  I think I will incorporate into my training this year:  http://www.elcosh.org/document/2149/d001020/Hexavalent%2BChromium%2BExposure%2BControl%2B%2528HexChEC%2529%2BVideo%2BGuideInstructor%2BManual%253A%2BBest%2BPractices%2Bfor%2BWelders.html?show_text=1

From that home page there are 6 or 7 short videos, both for welders, and for supervisors.

There are also questions on each module that could be used for homework assignments.