Will patching an opsak compromise its odor proof qualities?

Duct tape is great for so many things, so maybe it would work? If it's a small hole, perhaps a patch of tape on the inside and outside. It might get you through until you can pick up a replacement. Of course, either way, an appropriate hang is always a good thing.

They are intended to be semi expendable items. Is squeezing a little extra use out of a three dollar plastic bag worth risking your food supply, potentially not enjoying your trip, and even risking your own personal safety?

I would replace the thing and not worry about it.

I'd replace it if you use your OPSAKS as a way to avoid bear bagging (ie. sleeping with your food). Even if a patch pretty much works, you're not going to be able to sleep well worrying about bears crawling into your tent for a snack. And that's worth $5 or so for your next trip.

I'm sure you leave more smells with your handling than a duct tape patch of a small puncture would "leak".

I have a theory that habituated animals are as attracted by the smell of humans as they are by the food— for example, where there are smelly socks, there is food. Then again, part of the process is preventing the habituation of animals in the first place, as well as protecting our food supply.

OPSAKs replace bear hanging? I must be uber paranoid to rinse with everclear after eating, place smellys back in OPSAK, and then hang…