Processed cheese slices, like other perishable dairy products, should not be left out at room temperature for an extended period. The general rule for perishable foods is the "2-hour rule," which states that perishable foods should not be left at temperatures between 40°F (4°C) and 140°F (60°C) for more than 2 hours.
Processed cheese slices contain dairy products and additives that can support the growth of harmful bacteria when left at room temperature. If processed cheese slices are left out for more than 2 hours, there is an increased risk of bacterial contamination, which can lead to foodborne illnesses.
To ensure food safety and maintain the quality of the processed cheese slices, it's best to keep them refrigerated at all times. Once you take the cheese slices out of the refrigerator for serving or preparation, they should be consumed or returned to the fridge promptly.
If processed cheese slices have been left out at room temperature for more than 2 hours, it is advisable to discard them to avoid the risk of foodborne illnesses. Proper food handling and storage are essential to prevent food contamination and keep yourself and others safe from foodborne diseases.