X-ray generators must be replaced every five to seven years.  In most states, a licensed professional must install the X-ray generator.  The licensed professional who installs the new X-ray generator certifies that it is operating within regulatory and safety guidelines.

Gamma sources rely on naturally generated radiation, thus there are no failure parts. filtec 100mCi Gamma sources are rated for 40 years of continuous use.   The only requirement is that the source must be wipe tested once every three years by a specifically licensed technician.