It's a sad day for public protection and for Ontario's engineers, for sure. We're the only province in Canada with an industrial exemption. Thanks to the business lobby and a provincial government with no backbone, now we're stuck with it.
The exemption applies only to engineering done for an employer on their means of production by their employees, i.e. design work done by a millwright or an electrician on their own employer's production line, plant etc. However, from an enforcement perspective, it is treated as if it were the same general exemption for engineering done in industry (rather than for the general public) that exists in many US states.
For some reason, the Ontario government continue to think that an employee is more willing to be injured by incompetent engineering work done on their employer's production equipment than any other member of the general public. Of course they also assume that the consequences of the incompetent engineering won't be felt beyond the plant gate. As a chemical engineer, the fact that my mistakes may have consequences well beyond the plant gate is never lost on me.
Licensing engineers may not be 100% effective at ensuring that all engineering work done is done competently. One thing is certain, though: it is more effective at that sort of protection than allowing employers to be the sole judge of an engineer's competence.