Introduction to Health Physics: Fourth Edition - Ruang Baca FMIPA UB

INTERNAL RADIATION SAFETY 587
Figure 11-2. Glove box for operations with low-intensity radioactive materials that might accidentally
become dispersed into the environment if not handled in an enclosed volume. In use, long rubber
gloves fit over the port flanges; material transferred into or out of the glove box through the air lock
at the right of the glove box. (Courtesy of Innovative Technology, Inc.)
such contamination, and the health physicist should be prepared to account for
this activity in the design and operation of the surveillance program. For maximum
safety, transfer of materials and apparatus into or out of the glove box is always done
through an air lock. The viewing panel may be heat-resistant safety plate glass. Glove
boxes are unshielded when used for handling radioisotopes that do not create high
radiation levels. For radioisotopes that do create high levels of radiation, shielding
must be added. When handling a high-energy, beta-emitting radioisotope, it may be
necessary to use extra-thick gloves.
When we wish to contain substances that have a high degree of toxicity, we must
have a highly effective containment. However, no hood provides absolutely perfect
containment; some very small fraction of the noxious material that is emitted in the
hood will escape to the environment. The effectiveness of a hood is determined by
a number of factors, including its physical construction, face velocity, air currents
in the laboratory, and so on. Several different methods are used to determine the
effectiveness of a hood. All depend on releasing a vapor or a gas in the hood and then
measuring the concentration of the test gas in the breathing zone directly in front of
the hood. In a commonly used method, a test gas or vapor, such as alcohol or acetone,