Using & Wearing Radiation
This module is intended to provide additional information for those
people who have been issued radiation monitoring badges.
Information about Princeton University's policy for issuing radiation
monitoring badges is provided in the
Radiation Monitoring Badge Program page.
How the Monitoring Badges Work (top)
Luxel Body Badges
body badge contains a sheet of radiation-sensitive aluminum oxide sealed
in a light and moisture proof packet. When atoms in the aluminum oxide
sheet are exposed to radiation, electrons are trapped in an excited
state until irradiated with a specific wavelength of laser light. The
released energy of excitation, which is given off as visible light,
is measured to determine radiation dose.
The packet contains a series of filters designed so that the energy
and type of radiation can be determined. In order for the radiation
type and energy to be determined, the dosimeter must be worn so that
the front of the dosimeter faces towards the source of radiation.
Luxel body dosimeters are among the most sensitive dosimeters
available. The minimum detectable dose is 1 millirem
for x-rays and gamma rays and 10 millirem for energetic beta radiation.
The ring dosimeter contains a small radiation-sensitive lithium fluoride
crystal. When atoms in the crystal are exposed to radiation, electrons
are trapped in an excited state until the crystal is heated to a very
high temperature. The released energy of excitation, which is given
off as visible light, is measured to determine radiation dose. This
phenomenon is called thermoluminescence and dosimeters that use this
principle are often referred to as TLDs (thermoluminescent dosimeters).
TLD dosimeters are slightly less sensitive than Luxel dosimeters.
The minimum detectable dose for TLD ring dosimeters is 30 millirem
and gamma rays and 40 millrem for energetic beta radiation.
Both the body and ring badges do not detect radiation from beta
emitters with energies less than 250 keV. Consequently, dosimetry is
not issued for persons using H-3, C-14, P-33 and S-35.
Wearing Monitoring Badges(top)
If you are issued a Luxel body badge, you will receive a gray plastic
badge holder and a badge packet sealed inside a cellophane-type
plastic bag. Remove the badge from the bag and snap it into the
Wear your body badge on the part of the body between your neck
and waist most likely to be exposed to the greatest amount of radiation.
Wear it so that the name tag faces toward the source of radiation.
Your ring badge should be worn so that the label is facing out
from the side of the hand most likely to receive a radiation exposure.
In most cases, such as when performing radioactive labeling experiments
in a biology lab, this means that the label will face out from the
palm side of your hand. To avoid contaminating your ring badge
open sources, wear your ring under the glove. Additionally, take care
not to dispose of the ring in the trash when you remove your gloves.
Guidelines for Monitoring Badge Use (top)
- Never share your badges or wear another person’s badges.
Each badge is intended to be worn by only the designated person.
- Do not intentionally expose badges to radiation. Intentional tampering
with badges is a very serious matter.
- If you discover that your badges are contaminated, notify EHS
promptly and request replacement badges.
- No matter how curious you are, do not wear your badges when you
receive a medical x-ray or other medical radiation treatment. Your
badges are intended to document occupational dose, not medical
Monitoring Badge Storage (top)
Store your badges in a safe place, at work rather than at home.
Be sure to store badges away from sources of radiation. Be careful
to consider all sources of radiation. For example, if you store your
badges clipped to your lab coat, make sure that your lab coat (or
any other lab coat near it) is not contaminated.
Store your badges away from sources of heat (some badges such
show some sensitivity to environmental factors like heat). For example,
badges left in cars over hot summer weekends may give false exposure
Lost or Damaged Monitoring Badges(top)
If you lose, damage, or contaminate your badge, call EHS immediately
for a replacement. EHS can generally provide you with a replacement
badge within 24 hours of your request. Do not borrow anyone else's
Badge Exchange and Processing (top)
are exchanged quarterly (except for Declared
Pregnant Workers whose badges are exchanged monthly). You should
expect to receive your new badges a day or two before the start
of each calendar quarter. Snap the old Luxel body badge out of
gray holder and return just the badge itself. Keep the gray holder
so that you can snap the new badge into it. Make sure that your
old badges are available for collection on the first working day
of each quarter. Ask your lab manager or your lab radiation safety
person about how to return your badges.
Wearing a monitoring badge is a serious matter, as it can reflect
on your lifetime
recorded dose. Therefore, it is important for EHS to be able to account
for any missing or damaged badges. If your badges are not turned
in on time or are lost, EHS is required to conduct an investigation
to estimate your dose and will ask you to provide an accounting of
activities involving radioactive sources during the period in which
the badges should have been worn.
Emergency Processing (top)
If you believe that you may have received an unusual dose (if you
may have placed your hand in an x-ray beam, for example), notify EHS
Your badges will be returned for rapid emergency processing.
Dose Reports and How To Read Them
you return your monitoring badges, the badges are sent out to
service company for processing. EHS receives the dose reports several
weeks after the end of a monitoring period and reviews the dose reports.
EHS has established investigational levels at doses that are 10% or
less of the federal and state dose limits. If a dose is reported that
exceeds the investigational level, EHS will contact you to to determine
whether the reported dose is likely to be accurate and to investigate
the causes of the dose in an effort to minimize dose in the future.
After EHS finishes its review, a copy of the dose report is forwarded
to each Authorized User. Since the dose reports contain names, birthdates
and social security numbers, we do not recommend that the reports be
posted in the lab. Contact your Authorized User or lab manager to find
out how the information from the monitoring reports is made available.
A summary of your badge results can also be obtained by calling
In the case of body badges, doses are reported as deep or shallow
or as doses to the lens of the eye. Deep dose is due to penetrating
radiations such as x- or gamma radiation. Deep doses are applied against
the whole body dose limit. Shallow dose is due to less penetrating
such as beta radiation and low energy x-rays. Shallow doses are applied
against the skin dose limit. Dose to the lens of the eyes is due to
an intermediate range of radiations and energies and is applied against
the lens of the eye dose limit. In the case of ring badges, dose
is only reported as shallow dose and is applied against the extremities
Doses are reported in millirem. The minimum reportable dose for body
badges is 1 millirem for x-rays and gamma rays or 10 millirem for energetic
beta radiation, and for ring badges is 30 millirem for x-rays and gamma
rays or 40 millrem for energetic beta radiation. If a dose of "M" is
reported, the total dose received was minimal, i.e., less than the
Contact EHS if you change your name, if your name is misspelled, or
if any other information on the dose report is incorrect.
Exposure History (top)
Contact EHS for a copy of your radiation exposure history. EHS maintains
radiation exposure records indefinitely.
If you terminate employment with the University, your radiation exposure
history will be provided to you or your new employer upon request. A
signed release statement must accompany any request from your new employer.
Requests for radiation exposure histories should be mailed to: EHS,
262 Alexander Street, Princeton, NJ 08544
Monitoring Badge Use at Other Institutions (top)
not take Princeton badges to any other institution. Princeton University
badges are intended solely to measure the radiation dose you receive
while working at Princeton University. If you perform radiation work
at another institution, it is the responsibility of that institution
to provide you with monitoring badges.
However, Princeton University must still control the dose you receive
while working at Princeton so that your total occupational dose does
not exceed the state and federal dose limits. If you are issued radiation
monitoring badges at any other institution, notify EHS immediately.
EHS will contact that institution and request copies of your dose records.