Ceramic fiber products can potentially cause allergic reactions or respiratory problems in some individuals. These fibers are made from materials like alumina-silica or calcium-magnesia and can be inhaled as dust. Prolonged exposure to ceramic fiber dust may lead to respiratory issues such as lung fibrosis or other lung diseases. People with pre-existing respiratory conditions or allergies may be more susceptible to these effects. It's important to handle ceramic fiber products with care and use appropriate personal protective equipment to minimize exposure.