There are two other mechanisms worth considering. One is the new substances regime. If the activity you're describing actually results in the use of a substance that is new to Canada, there is a mandatory regime that must be followed to authorize the use of that substance.
The second mechanism is that CEPA contains a provision in section 70 that requires anybody who is importing, manufacturing, transporting, processing, or distributing a substance for commercial purposes and who obtains information that would reasonably lead them to believe the substance might meet the test in section 64—that it may pose a risk to environment or health—to provide that information to the minister.