Yes, ceramic fibers can potentially cause allergic reactions in humans. Exposure to these fibers may lead to respiratory issues, including irritation and inflammation of the airways. In some cases, long-term exposure has been associated with the development of hypersensitivity pneumonitis, a condition characterized by an allergic reaction in the lungs. Additionally, there is a risk of skin irritation and allergic contact dermatitis for those who handle ceramic fibers frequently. However, the severity and occurrence of these reactions can vary among individuals, and not everyone exposed to ceramic fibers will experience allergic reactions.