From Harold McGee's On Food and Cooking, page 474:
Cooked rice turns out to be a potential source of food poisoning. . . . If cooked rice is left for a few hours at room temperature, the [dormant spores of bacteria that are almost always in raw rice] germinate. . .
He goes on for a bit about our rice vs. Japanese rice in terms of food safety, but the point is that it shouldn't be held too long at room temp. So if the rice you're asking about has been left on a buffet table, I'd toss it. McGee doesn't go into how long to keep it in the fridge, but I'd be careful not to keep it more than a few days--& then freeze it.
If you're afraid of butter, use cream. ~~ Julia Child
As you cook, you enjoy omniscience about food that no amount of label reading can match. Having retaken control of the meal from the food scientists, you know exactly what is in it. (Unless you start w/cream of mushroom soup, in which case all bets are off.) To reclaim control over one's food, to take it back from industry & science, is no small thing; indeed, in our time, cooking from scratch qualifies as subversive. ~~ Michael Pollan