I occasionally have Photographer's Formulary ship stuff to my brother-in-law's parents who live in Oregon (they drive up here twice a year). The last time I got stuff shipped to them, the Canadian Customs people wanted to look at the package very carefully and inspected every single item in the box, but were very friendly and chatty while doing it, presumably since the story they were told made sense. Keep stuff in original packaging so that any Customs people who have issues with the chemicals can have a clearer idea of what you are bringing. The packaging will tell them what the chemicals are for.
The only possible problem you might have is that Canada Customs and Revenue Agency might charge you taxes on the product, if they believe that you will be leaving it in Canada (gifts up to $50 are allowed but above that, you have to pay taxes as Canadians would). However, you're allowed to bring in any reasonable amount of personal effects (there are limits on alcohol and tobacco, and we have more stringent firearms laws than the US does, but for normal things, you're pretty unrestricted).
I wouldn't worry about it too much really. You have a legitimate reason for bringing it. The only reason that can cause you grief with border crossings is employment.