We are spoiled today. Finding Ontario regulations is much easier than it used to be. For an up-to-date version of a regulation, we have the e-Laws website. To see the text of a regulation as it was when first enacted, there is the “Regulations as Filed” option under the “Source Law” bullet on e-Laws, or the PDF version of the Ontario Gazette. Of course, there is always a catch.
These free online sources only reach back to 2000. If you need a regulation prior to this period, you must use the print-format Ontario Gazette or the Revised Regulations of Ontario. And when determining a point-in-time reading of a regulation, you can either create your own using these sources, or try to find one in a commercial publication from that year.
But wait, it gets harder. Prior to 1944, Ontario regulations were not required to be published, making the task of finding whether a specific one existed a real needle in the haystack search. You will need to make your way to a law library and comb through the indexes of pre-1944 issues of the Ontario Gazette. The Great Library has the full set available, reaching right back to Volume 1.
With the enactment of The Regulations Act, 1944, S.O. 1944, c.52, (in force July 1, 1944), Ontario regulations had to be filed and published in the Ontario Gazette.
Just for interest: currently, it is the Legislation Act, 2006, S.O. 2006, c. 21, Sched. F, Part III, which provides that regulations must be filed with the Registrar of Regulations and published on e-Laws and in the Ontario Gazette. The Legislation Act, 2006, also stipulates when regulations come into effect.