These editable resources are for the Canadian WHMIS 2015 update, and are focused on WHMIS 2015 (GHS). Feel free to adapt them as needed for your own classroom.
WHMIS 2015 slideshow (.pdf)
WHMIS 2015 worksheet (.doc)
Teacher Information & TOU (.pdf)
The slideshow includes a link to and a video from whmis.org. I do not own the rights to this video (it was created by the CCOHS), and include it as a reference that you might find useful.
For senior students, I recommend using the slideshow and worksheet with WHMIS Pictograms and WHMIS Labels posters/handouts, available from whmis.org (links to the files are in the Teacher Information & TOU file).
You might also be interested in WHMIS & HHPS Cards and Quiz