Excessive exposure from this type of radiation

Excessive exposure from this type of radiation often produces skin reddening at exposures of approximately 300 rem (300,000 mrem) while severe skin burns can result for exposures above 500 rem. Because some types of analytical x ray systems can produce exposure rates between 1000 and 1,000,000 mrem/hr, even short exposures to the beam are capable of producing damage. For that reason, the primary radiation beam must always be contained in a shield.