The radiation produced by a microwave oven is non-ionizing. It therefore does not have the cancer risks associated with ionizing radiation such as X-rays and high-energy particles. Long-term rodent studies to assess cancer risk have so far failed to identify any carcinogenicity from microwave radiation even with chronic exposure levels (i.e. large fraction of life span) far larger than humans are likely to encounter from any leaking ovens. However, with the oven door open, the radiation may cause damage by heating. Microwave ovens are sold with a protective interlock so that it cannot be run when the door is open or improperly latched.