Laboratories and clinics throughout the University of Washington use radioactive materials or radiation producing equipment.
Radiation Safety has developed this radiation safety training module to help ancillary personnel recognize
radioactive materials, and identify the hazards and the safeguards one should use when working around
these materials. Ancillary personnel include maintenance and housekeeping workers, students, community
safety officers, telecommunications and networking personnel, and others.
While these safeguards should protect you from unsafe conditions in most situations, there is no substitute
for your personal knowledge and vigilance when working in areas where radioactive materials are used. The
guiding principle of radiation protection is to avoid all unnecessary exposures. The UW promotes the principles
of ALARA and is obligated to keep radiation exposure to all employees As Low As Reasonably Achievable.
This module shall be reviewed upon your employment and biannually thereafter.
Radiation is probably the most feared and least understood of all the hazards we encounter in our
lives. We cannot see, hear, smell, or feel it. However, radiation is actually one of the simpler hazards
to measure and control. Unsafe amounts of radiation are also the least frequently encountered; the
dangers from common chemicals, fire hazards, and physical accidents are much more common.
Radiation is simply a form of energy. The energy may be in the form of particles or electromagnetic
waves, similar to light, microwaves, lasers, radio and television waves. It is all around us every
day. No matter what we do or where we live, we have exposure to “background radiation.” Background
radiation comes from the sun, stars, rocks, soil, and food we eat. These doses are quite small.
In addition to background radiation, you may have exposure to radioactive materials in certain laboratories
on campus; at UWMC; Harborview Medical Complex; and the many off campus facilities owned or leased by the University of Washington.
The following information will help you:
- Recognize where these materials are stored and used.
- Know what to do when you work in a room that contains radioactive materials.
- Understand general restrictions for working in these rooms.
- Control your exposure to radioactive materials should problems occur.
Recognizing Radioactive Materials
The University of Washington Radiation Safety Program strives to ensure the safety of all employees. Both
state and federal guidelines provide a framework for this program.
The University of Washington depends on you to recognize the posted signs, identify hazards and safeguards, and
to report any problems to your supervisor, and subsequently to the Radiation Safety Officer at 206-543-0463.
Warning signs indicate the presence of radioactive materials. These signs have a magenta, red or
black symbol, called a trefoil, on a yellow background.
Packages used to transport radioactive materials also have labels. These will have the number 7 at
the bottom of the diamond.
there is also a third type of label or sign for equipment that produces x-rays.
Hazards and Control
You can think of radiation like a sun lamp or tanning bed. Skin will burn if exposed to a sun lamp too long,
or is too close, or is not protected by sun block. Similarly, we can use three basic radiation safety
techniques to control exposures. They are Time, Distance, and Shielding.
- Time: Limit your time around the area.
- Distance: Maximize your distance from the area to at least 6 feet.
- Shielding: Keep a wall or door between you and the radiation area.
Radiation is measured using several units. The most common of these, the rem,
measures the biological damage caused by radiation. As mentioned previously, doses encountered in every
day life are typically
very small. In fact, we use millirem (mrem) or thousandths of a rem to measure it.
The average person
in the United States receives about 200 to 400 millirem every year. This dose is mostly from natural
sources of radiation.
Some Typical Annual Exposures
||mrem per year
|Natural sources (=82%)
|Food, water, air that we ingest or inhale
|Human-made sources (=18%)
||1 mrem/ 2500 miles of driving
||Stone or concrete
|Sleeping with partner or other
*Regularly smoking cigarettes adds about 1300 mrem/year to one’s exposure.
Very few authorized users of radioactive materials wear personal monitoring
devices(dosimeters) to track their exposure while working due to the small amounts of materials used
and the very small chance of exposure to ionizing radiation. Ancillary personnel will have a much less possibility
of exposure so no personal monitoring is required. Safety during pregnancy should not be a serious concern;
however, any employee may request to consult with the Radiation Safety Office for additional information.
Work areas containing radioactive materials or machines have added safety measures. The primary
users and radiation safety staff routinely sample these areas by monitoring the area with a radiation detector (frisk) or swiping
the area with filter paper and analyzing
it for radioactivity. For example, active labs take wipes and or frisk areas:
- daily after use in areas where they use radioactive materials
- Monthly in all areas)
- Every six months for sealed sources
- Every three months for alpha emitters (>10 microcuries)
Caution Radiation Area
- Routine cleaning occurs in rooms where there are radiation-producing machines or radioactive
materials. Safeguards are in place to ensure the machines are not turned on and that the materials
are stored safely. Trash disposal in this area is authorized, if not labeled radioactive.
- Never eat, drink, or smoke in rooms where radioactive materials are used.
Caution Radioactive Materials
- Do not handle, move, or remove bags or containers labeled “Radioactive Material.”
- Do not handle or dispose of trash in this area unless requested or authorized by the Radiation
- Do not clean floors or counter tops unless requested by the Radiation Safety Office.
There are many areas where instruments produce x-rays. A label or plate will identify
such rooms. If you are asked to work in a room with this equipment:
- Contact the authorized user for safety instructions prior to entry. Some experiments run
If you encounter a liquid or solid spill in an area posted as “Radioactive Materials,” close
the door and notify your supervisor and/or the Radiation Safety Office.
Emergency telephone numbers
|Radiation Safety Office (RSO)
|Health Sciences Radiation Safety Office
|Hospital Radiation Safety