Effective July 1st, 2012, all helmets certified with the Economic Commission of Europe (ECE 22.05) standard will now be permitted under the HTA.
http://www.e-laws.gov.on.ca/html/regs/english/elaws_regs_900610_e.htm
http://www.e-laws.gov.on.ca/html/regs/english/elaws_regs_900610_e.htm