I was asked about Hazmat and TDG for North America as this falls under the NAFTA trade agreement so I found some links that may help.
phmsa.dot.gov/hazmat/regs/international/nafta
phmsa.dot.gov/portal/site/PHMSA/ … tfmt=print
tc.gc.ca/eng/tdg/clear-tofc-211.htm
tc.gc.ca/eng/tdg/clear-download-372.htm
phmsa.dot.gov/portal/site/PHMSA/ … tfmt=print
tc.gc.ca/eng/acts-regulations/acts.htm
I hope that helps it is everything I could find regarding the cross border regs.