The following guidance applies to laboratories that are not administering ionizing radiation to humans. If your application involves special circumstances, please consult with Health Physics.

Radiation device Operating Log

Keep a record of results of radiation surveys performed by Health Physics, repair companies, and laboratory staff. When performed by the laboratory staff, specify the date, the person making the survey, the instrument used and the location and levels of radiation.

  1. Use log with energy, current, other parameters, date, and user’s name.
  2. Device calibration records.
  3. Surveys, safety bulletins, accident reports, corrective efforts, repairs, and modifications.
  4. Start‐up, use, and shutdown procedures and precautions.

Operating requirements

Each entrance or access point to a high radiation area must be:

  1. Equipped with a control device that upon entry to the area reduces the deep‐ dose level of radiation to less than 100 millirem per hour at  30 centimeters from the radiation source or from any surface the radiation penetrates;
  2. Equipped with a control device that energizes a conspicuous visible or audible alarm in such a manner that individuals are made aware of the entry; or
  3. Maintained locked, except during periods when access to the area is required, with positive control over each individual entry.

Lead use and Inspection

The recommended apron inspection policy is as follows:

  • Annually perform a visual and tactile inspection

Visual Inspection:

  • Lay the apron flat on a clean surface and carefully examine it for any visible signs of damage, including tears, holes, bumps, or signs of separation at the seams.
  • Check the closures (velcro, buckles, etc.) to ensure they are in proper working order.
  • Check for any thinning of the lead, creases, cracks, lumps, sagging, or signs of separation at the seams.

Tactile Inspection:

  • After the visual inspection, run your hands over the apron’s surface to feel for any abnormalities, such as lumps, cracks, or sagging seams

Dosimetry required

Both federal and state regulations require personal dosimetry for individuals who enter high radiation areas.

Signs and labels

Necessary signs and labels depend on the dose rate around the device. See Table II.2 for more information.

Precautions for analytical x‐ray devices

X‐ray diffraction and x‐ray fluorescence units pose a special radiation hazard. They have a one‐millimeter diameter beam that has a very high dose rate. Some operators who changed or adjusted samples while the beam was on have received so much radiation dose that their fingers had to be amputated.

These accidents are generally attributable to careless work habits and inadequate instruction. An extract from the 1989 Stanford Radiation Safety Manual, http://web.stanford.edu/group/glam/xlab/Safety/SafetyManual.pdf, and a training film entitled “The Two‐Edged Sword” are available for training x‐ray diffraction machine operators.

  1. All operators must be certified by Health Physics and receive operational safety instructions from the project director. Use only procedures approved by the manufacturer or alternate procedures approved in the CMA.
  2. Wear a finger dosimeter.
  3. When aligning the camera by eye, be sure that the machine is turned off or that the viewing is done through a properly designed lead glass viewing window.
  4. Be sure that the machine is turned off before changing samples. Check the kV and mA meters and the warning light.
  5. After turning the unit on, measure the exposure rate at the table edge. It should be less than 0.2 millirem per hour.
  6. Use shielding to ensure that the above limits are satisfied. Do not remove or modify the manufacturer’s shielding
  7. Maintain direct surveillance of the machine, unless the area is secured. Machines should be kept in a locked room.
  8. Check safety apparatus, shutter, warning lights, survey meter, and shields for proper function monthly. Report any malfunction to the PI. Do not operate a machine with a safety defect. Lock out and tag out the device until the problem is corrected.
  9. If any changes are made in the machine that might affect radiation output, call Health Physics for a survey.
  10. Promptly report any accidental exposures or potential injuries to Health Physics and the project director.
  11. Maintain a log of all operations.
  12. Never put any part of your body in the beam. Exposure to the primary beam for even a fraction of a second can cause severe damage to tissue.

Interlocks and warning lights

Interlocks and warning lights are essential safety features. Do not bypass them without Health Physics review and approval of alternate safety measures.