How long should I cook pork for (at 100° C)? I have a pork shoulder cooking in the oven right now at 100° C (212° F). I was planning on roasting it for 7 hours, will this be long enough to cook it safely?

I saw the FDA chart about minimum internal temperatures - but am not sure how to translate that to oven temperature/time.
100°C seems a little low. I've done a bone-in pork shoulder at 120 for 8 hours before now, I think the norm is 2 hours a pound (450 g) at that temperature.

To be safe you should really use a meat thermometer, trichinosis is not something you want to have.