I work in the city in a non jewish office. Am I allowed to place my kosher lpesach lunch in the fridge that is mixed with the chometz food of the rest of the employees in the office?
The only difference I could see there being between your case and putting it there with treif food the rest of the year is that more food items contain chometz than they do treif, and chometz is more likely to get all over. Just contain your food and you’re fine. I’m in the same situation and put my food in a tied plastic bag.