Thought some folks would be interested to know as here in Canada we seem obsessed by DOT approved helmets. (American standard).
It is actually legal in Canada to wear any helmet with the following approved sticker, this comes from the official Highway Traffic Act. I have also confirmed this with a phone call and an email. Here is an extract, the whole thing can be read on my website at www.topendz.com.
1. A helmet worn by a person,
(a) riding on or operating a motorcycle; or
(b) operating a motor assisted bicycle,
on a highway shall,
(c) have a hard, smooth outer shell lined with protective padding material or fitted with other energy absorbing material and shall be strongly attached to a strap designed to be fastened under the chin of the wearer; and
(d) be undamaged from use or misuse. R.R.O. 1990, Reg. 610, s. 1.
2. The helmet referred to in section 1 shall conform to the requirements of the,
(a) Canadian Standards Association Standard D230 Safety Helmets for Motorcycle Riders and shall bear the monogram of the Canadian Standards Association Testing Laboratories;
(b) Snell Memorial Foundation and shall have affixed thereto the certificate of the Snell Memorial Foundation;
(c) British Standards Institute and shall have affixed thereto the certificate of the British Standards Institute; or
(d) United States of America Federal Motor Vehicle Safety Standard 218 and shall bear the symbol DOT constituting the manufacturer's certification of compliance with the standard. R.R.O. 1990, Reg. 610, s. 2.