Radiation Safety Training
6- Working with Radioactive Materials
Originally created: December 30, 2009
Last revised: May 12, 2010
For more information, refer to the Radiation Safety Manual, 2005, RSP-420
How can I control my Radiation Exposure?
You can protect yourself from an external exposure from the ionizing particles and rays by
using:
1. Shielding – keep between you and the radioactive
material – use different shielding for different
radioisotopes:
Lucite (plexiglass) or wood for mid energy betas
such as P-32
Lead or leaded glass for low energy gammas such as
I-125 or Cr-51
The outer layers of your skin (like paper) will protect you
from low energy betas and alphas and Low Energy Beta
Emitters such as H-3 (no shielding is required).
Tech Talk: Bremsstrahlung and shielding:
Be careful using lead as a shield with P-32!
An x-ray may arise from an ionizing particle that is deflected rapidly by the
Lead causing it to accelerate creating the x-ray.
Shield beta emitters with a layer of lucite or wood
(not lead) closest to the radioactivity.
X-rays can not be shielded by lucite.
At The University of Manitoba, the most commonly used radioisotopes can be
shielded by plastic (Lucite) or wood; or lead:
Isotope
Type of
Energy
Half-life
Shielding
Emission
H-3
Beta
Lowest
12 years
Not required
C-14
Beta
Low
5730 years Not required
S-35
Beta
Low
88 days
Not required
P-32
Beta
Mid
14 days
I-125
Gamma
Low
60 days
Plastic
(Lucite) or
wood
Lead
Cr-51
Gamma
Low
28 days
Lead
Tc-99m
Gamma
Low
6 hours
Lead
2. Time – limit the time you handle the radioactive material by being prepared. That
means:
– preplan
– practice (dry run)
– assemble supplies
– keep source in shielding
– work quickly
3. Distance – by doubling your distance from the radioactive material, you get a quarter
of the exposure. This is the inverse square law. The distance effect can be affected by
the energy level and particle size of the material. A decreasing energy level and
increasing particle size will decrease the distance required to receive a quarter of the
exposure.
eg. mid energy beta P32, so step back
from unshielded sources
How can I protect myself from getting radioactive material inside myself?!
You can protect yourself from an internal exposure (keep radioactive materials outside your
body) by using industrial hygiene barriers:
B
A
R
R
I
E
R
1. Engineering Controls – have a separate work area
- use a fume hood for volatiles & aerosols
- secondary containment for moving & storing the material
- use splash shields
- keep containers closed when not in use
2. Safe Work Practices – read the MSDS and RSDS or the physical data on select
radioisotopes sheets RSP-930 for the radiolabeled chemical
- cover work surface with a plastic backed absorbent pad
- label equipment & area
- tie back long hair
- wash hands
- do not eat & drink in the lab
- keep your personal items out of the lab (coats, backpacks)
- be aware of your personal mannerisms (pushing up glasses, chewing ends of
pens, touching face) to prevent contaminating yourself
- plan for emergency situations (fire alarm, spill)
- working alone plan
- monitor for contamination (area, lab coat)
3. Personal Protective Equipment (gloves, lab coats, masks, eyewear)
- make sure it fits
- use properly (for radioactive work only, don’t cross contaminate)
- wear properly (lab coat buttoned)
- select gloves & masks based on their protective value
- dispose properly (radioactive waste)
- decontaminate non-disposable PPE (eyewear) after use
DO NOT spread contamination, monitor often!
Remember, all personal contamination must be reported to the
Radiation Safety Officer as soon as possible.
How do I set up a Radiation Work Area?
Incorporate shielding, time & distance and engineering controls, PPE & safe work practices.
How is the work area set up in your lab?
First you need to know some properties of the Radioactive material to be used:
• Radioisotope (half-life)
• Emission & energy (shielding)
• Chemical that is labeled with the radioisotope (hazards associated with the chemical)
• Volatility of the material (packaged in ethanol, then evaporation or other solvent)
Then you can choose a work area:
• Will aerosols be created by the work procedure (vortex, pipette, sonicate, homogenize)
• A fume hood should be used for volatiles and aerosol producing procedures
• A bench area should be away from high traffic flow in the lab (not by an entrance,
away from any desks or computer workstations)
• Consider a wall or window on the other side of the area and not open to another bench
(splashes)
• Electrical panels should not be in the work area, consider access by Physical Plant, they
have keys to your room too!
If shielding is required for the work area, remember:
• Mid to high energy betas require lucite (plexiglass) or wood
• Gammas require lead or leaded glass
• Radio-labeled samples and waste (solid, liquid, etc.) require shielding as well
• Work procedure may require splash shields (plexiglass)
What supplies will be required for the work area:
• Absorbent plastic backed pads (absorbent side up)
• PPE (disposable gloves, lab coat must be worn when handling any
radioactive material)
• Dedicated equipment (pipettes, vortex, microfuge, pens)
• Labels for the area and equipment (don’t forget the sink!)
• Waste tags and waste containers
• Survey meter (for any radioisotope greater than 0.5 mCi, except H-3 & C-14).
• C-14 can be detected with a Ludlum 44-9, but only at larger quantities.
• Access to a liquid scintillation counter
(for H-3 & C-14)
• Shielding if required
• Paper towels/kimwipes
Are you prepared for an emergency? What would you do if your pipette
starting to leak radioactive material?
•
•
•
Do you have what you need?
Do you know what you need?
What is your plan?
Review the emergency response procedures on the web at:
http://www.umanitoba.ca/admin/human_resources/ehso/rad_safety/RadERProcedures.html
• Spill kit - see Radiation Safety Manual. 2004 RSP-422