Using old aluminum foil facing as a cutting board is not recommended. Aluminum foil is not designed to withstand the sharp edges of knives and can easily tear or puncture, posing a risk of injury. Additionally, the foil can transfer aluminum particles to the food, which may not be safe for consumption. Instead, use a proper cutting board made from materials like wood, plastic, or bamboo that are designed to handle knives and protect both your food and your safety.