It is possible for microscopic pieces of metal to be created when using a dull kitchen knife, but it is generally not a significant health risk. These small pieces of metal are typically too small to be seen, and it is unlikely that they would be ingested in significant quantities even if they were present in the food being prepared.

In general, the risks associated with using a dull kitchen knife are related to the difficulties of using the knife, rather than any potential health risks. A dull knife can be difficult to control and can require more force to use, which can increase the risk of accidents and injuries in the kitchen. It is therefore important to use kitchen knives safely and to maintain them in good condition, including regularly honing and sharpening them, to help reduce the risk of accidents and injurie