There's a risk with almost all foods, especially those containing protein. The difference is that the soy foods are much less likely to be contaminated with pathogenic bacteria. If they did somehow get contaminated (such as cross-contamination in the fridge with meat dripping on them), then leaving them out at room temperature for a long period of time could be dangerous.



When thinking of food safety questions, you first have to think of where pathogenic bacteria come from and then how they grow. These bacteria mostly come from animals (E coli in beef, Salmonella in chicken & eggs, Listeria in milk, etc). It is possible for these bacteria to end up in other places (such as with the recently contaminated spinach). Don't forget about cross contamination at the grocery store: that counter/belt is NOT clean; think of all the leaky meat packages that were there first. Bag your produce, and don't set your food in any suspicious wet spots.



Bacteria grow well from about 40-140F. So either keep the food cold or hot, and don't leave food within this temperature range for more than about 2 hours. Your best bet would be to either thaw your veggie burgers in the fridge, or don't leave them out at room temp for more than 2 hours (you can stick them in the fridge after this time). The chances are pretty low, but you never know what's going on in the processing plant, or after processing before it gets to you.