As far as I know H2S Alive is required on all Oil and Gas sites where there is a possibility for H2S gas. Most if not all of the larger contractors have made it a mandatory for anyone on their jobs sites to have it. It is a good course too and will really open your eyes to some uncommonly known workplace hazards and may in fact save your life one day. Looks like Enform, the governing body (link below) offers this one online too. I have refreshed this course several times and as much as I hate stuffy class time for material I think I know, I always come away from that course with a couple of things that I have forgotten about. They usually have some old salty dog teaching it that has some good if not frightening stories of H2S exposures. You may be able to get a credit for your Aussie course if it was recent enough.
WHMIS is also mandatory on most jobs sites. Easy to do online and pretty much anyone you take is sure to be valid. TDG (Transoprtation of Dangerous Goods) is sometimes included in that one.
CSTS is a very basic construction safety course and is getting to be mandatory on that larger sites in Alberta and I think also BC and Sask are heading that way too. Very easy to do online.
Many of the larger sites have their own in-house in house safety orientations as well as share an OSSA basic site safety course.
http://www.enform.ca/students/courses_calendar/CourseSearch.aspxCheers,
Chris