What is OEHS? The Office of Environmental Health and Safety serves to protect the health and safety of the students, faculty and staff of Wayne State University. The Office operates as the University’s extension of the regulatory agencies that monitor use of hazardous materials and ensures that a safe and compliant workplace is maintained. Please call our office any time you have a question or concern about the acquisition, use, storage or disposal of any hazardous substance at the University.
Health Physics / Radiation Safety The Health Physics staff are specialists in radiological health and safety, and are ready to provide assistance so you may work safely with radioactive material. Please contact us if you have questions or concerns about radioactive materials on campus. Lance Franklin Radiation Safety Officer 577-1200 [email_address] Wendy Barrows Health Physics Specialist 577-0019 email@example.com Michael Huberts Health Physics Specialist 577-9505 [email_address] Ryan Boyd Health Physics Assistant 577-9518 [email_address]
Hazardous Materials Staff are specialists in the treatment, management, and disposal
of hazardous wastes. They are available to provide guidance and services to the
university regarding any waste produced on campus. Please fell free to contact them
with questions or comments regarding all types of waste.
Nuclear Regulatory Commission – Type A Broad Scope Radioactive Materials license. Allows researchers to use a wide range of radioisotopes , but requires strict compliance with Federal Laws. NRC regulates reactor produced radioactive materials ie P-32, H-3, C-14, etc Michigan Department of Community Health – Radiation Generating Machine license. Allows researchers to use x-ray producing machines. State of Michigan regulates machines ie XRD, EM, Diagnotsic X-Ray, etc Regulatory Control and Responsibility Governmental
Regulatory Control and Responsibility
Radiation Safety Committee – Group of university faculty and staff providing oversight to OEHS and research community. Review all protocols involving ionizing radiation to ensure safety and regulatory compliance
OEHS Radiation Safety Staff – Act on behalf RSC to safety and compliance issues are being properly addressed in university research labs. Will happily assist with problems or answer questions concerning work with ionizing radiation
Regulatory Control and Responsibility Laboratory
Who is responsible:
for safe practices in the lab?
for the radioactive material in your lab?
for providing lab specific training?
Who is ultimately responsible for compliance?
Who is responsible for reporting unsafe conditions when seen?
The Approval Holder / PI ! You are!
Radiation Worker Rights View the university’s licenses, inspection reports, and copies of the regulations You may contact the US Nuclear Regulatory Commission without fear of retaliation by your Approval Holder or anyone at Wayne State University. Receive adequate training and have • • questions answered satisfactorily •
Worker Training Basic Radiation Safety Training must be taken annually First time - in class Annually - online Radiation Generating Machine Training – Online Special Training by request Lab-specific training is provided by your PI • • •
Basic Radiation Safety Part 1 Radiation Theory
What is Radiation?
The transfer of energy in the form of electromagnetic waves or particles
The Importance of Energy Ionizing radiation has enough energy to remove electrons from atoms E (hv) > E B Non-ionizing radiation may only excite electrons into excited states E (hv) < E B
Sources of Radiation X-Ray - Electron transition from one level to a lower level, or from slowing of a moving electron (bremsstrahlung) Gamma - Radioactive decay emission originating from the nucleus. Alpha – Helium nucleus from decay from massive atom Beta – particle emitted during n p or p n decay Neutron – neutral particle emitted during fission
Gamma and X-ray Radiation Tissue
Very penetrating – no charge
dense material for shielding (Lead)
The higher the energy, the thicker the shielding
125 I (35KeV) – thin lead plating
51 Cr (320KeV) – thick lead bricks
Alpha Particle Radiation (a) Tissue
Doubly charged (2 protons, 2 Neutrons)
No additional shielding is required
241 Am is used in smoke detectors
Alphas are internally highly toxic
Beta Particle Radiation ( Tissue
Electron or Positron emitted from atomic nucleus
Energetic betas require Plexiglas shielding (E > 500 KeV)
32 P (1.7 MeV) max beta range in tissue = 7.6 mm
3 H (10 KeV) max beta range in tissue = 6 um
Lead shielding causes Bremsstrahlung x-ray production
Emitted in fission reactions
No EM interactions, so neutrons are very penetrating
Requires hydrogenous materials to shield
Transition from one atom to another, due to nuclear imbalance (p/n ratio)
Mass energy released as ionizing radiation
Rate of decay is unique to isotope, given by decay constant λ
Radioisotopes are chemically indistinguishable from stable isotopes of the same element.
The time required for a radioisotope to decay to one-half of its original amount.
P-32 14.3 Days
I-125 60 Days
S-35 87.4 Days
H-3 12.4 Years
C-14 5730 Years
A(t)=A o e – λ t ½ = e – λ t 1/2 ln(2)/ λ = t ½ After n half-lives A = A o 2- n Half –Life Calculation Example: You order 200 uCi of I-125 in January. In June of the same year you decide that you want to use the material. Will you have enough to use? T 1/2 = 60 days t = 6 months ~ 180 days = 3 T 1/2 A = A o 2 -n = A = 200 * 2 -3 = 25 uCi A = Ao *1/2 *1/2 *1/2 = 25 uCi Or λ = ln(2)/ T 1/2 A = Ao e – λ t = 25 uCi
Units of Activity Historical unit defined as the activity of 1 gram of Radium-226. Still used today due to more convenient values Bequerel (Bq) Curie (Ci) SI unit defined as 1 disintegration per second (dps). More useful unit, but very unwieldy values. Designated as official unit . 1 Ci = 3.7 x 10 10 Bq (dps) i.e. 250 microCuries (uCi) = 925 MegaBequerels (MBq)
Units of Exposure Roentgen (R) - The amount of ionization produced in a volume of air by gamma or x-rays Corresponds air at standard temperature and pressure (273K and 760 mm Hg). The usefulness of the Roentgen in the practice of radiation safety is limited, because it is only defined for x-rays and gamma radiation in air.
Units of Dose and Dose Equivalent SI: Gray (Gy) = J/kg rad = 100 erg/g SI: Sievert (Sv) rem Dose (D) is a measure of the absorbed energy per unit mass of material 1 Gy = 100 rad Dose Equivalent (H) is the product of the absorbed dose and the biological efficacy in tissue 1 Sv = 100 rem
Quality Factor / W R
Different types of radiation interact with matter uniquely, causing varying amounts of biological damage to tissue or having different radiobiological effectiveness.
Beta, gamma, x-ray: Q=1
The product of this Quality Factor of the given type of radiation and the dose absorbed results in the dose equivalent .
H = D x Q i.e. 1 Gy dose delivered with neutron radiation; what is dose equivalent? D x Q = 1 Gy x 10 = H = 10 Sv = 1000 rem
Gastrointestinal Syndrome (100-400 Rads) – Irreversible damage to Villi. Death in Weeks in 50%
Central Nervous System Syndrome (>500 Rads) – Coma and death in hours
It is nearly impossible for you to receive these acute doses at Wayne State
Chronic Low-Level Exposure
• No evidence of risk below 10 Rem lifetime exposure
Risk increases 1% for a worker with 10 Rem lifetime exposure
• Exposure exceeding the limit (15 Rem) increases risk
Risk to embryo / fetus
• May be more sensitive to radiation. Women may notify Health Physics for hazard evaluation
Background Radiation Background in Michigan is 360 mRem/year
Basic Radiation Safety Part 2 Radiation Protection
A s L ow A s R easonably A chievable
Making every reasonable effort to maintain exposures to radiation as far below the dose limits as is practical
A L A R A • Time • Distance • Shielding • Contamination Control
Protective Measures Time
The less time spent in the vicinity of radioactive materials, the less dose you will receive. Thus, keep your exposure time as short as possible .
Dose = Dose rate x Time
i.e. A worker performing an experiment in a 300 mrem/hour gamma radiation field completes the work in 20 minutes. What is the dose received by the worker? 300 mrem/hr x 0.33 hr = 100 mrem
Protective Measures Distance Intensity of radiation is inversely proportional to the square of the distance – inverse square law I 1/d 2 I 2 = I 1 x (d 1 /d 2 ) 2 i.e. A worker is 1 meter from a 200 mrem point source. What is the dose at 2 m? 3m? I 1 x (d 1 /d 2 ) 2 = 200 x (1/2) 2 = I 2 = 50 mrem 200 x (1/3) 2 = I 2 = 22.2 mrem I 2 *d 2 2 = I 1 *d 1 2
Protective Measures Shielding Alpha – no shielding Beta – none or Plexiglas, No Pb X, Gamma – Lead, thick or thin Neutron – Concrete, parafin
Protective Measures Contamination Control
Change gloves and wash your hands
Protective equipment, like lab coats, gloves and goggles, provide a contamination barrier between you and the radioactive material
Occupational worker limits
Whole body: Neck to waist 5 Rem/ yr .
Skin: Radiation resistant 50 Rem/yr.
Eyes: Cataract susceptible 15 Rem/yr.
Organs: Selective uptake 50 Rem/yr.
Extremities: No Organs 50 Rem/yr.
The NRC utilizes the Linear, No-Threshold Theory, which assumes all exposure to radiation above natural background will have some detrimental health effect . Risk for radiation workers is equivalent to risk associated with any other hazardous material worker
Pregnant Workers Declared Decision is up to woman May be temporarily assigned non-radiation duties until end of gestation May un-declare her pregnancy at any time Limits: Employer may not limit occupational exposure below worker • • • Undeclared 500 mRem over gestation <50 mRem per month • •
Personal Dosimeters TLD
Are not used for
Monitoring outside of work
Sharing among workers
Are used for
Monitoring one person
Monitoring occupational exposure
Dosimetry records (Form 5) are available for review at the Office of Environmental Health and Safety.
Dosimetry for users of beta emitting isotopes
High energy emitters (energies > 0.5 MeV)
Extremity (ring) badge for persons handling less than 10 mCi per container
Body and extremity (ring) badges for persons handling 10 mCi or more per container
Examples: 32 P, 36 Cl, 90 Sr
Dosimetry for users of beta emitting isotopes
Low energy emitters (energies < 0.5 MeV)
No dosimeter required
Examples: 35 S, 14 C, 3 H
Dosimetry for users of gamma emitting isotopes
Low energy emitters
body badge for persons handling more than 100uCi per container
No dosimeter for persons handling less than 100uCi per container
Example: 125 I
Dosimetry for users of gamma emitting isotopes
High energy emitters
Body and ring badges required
Examples: 111 In, 51 Cr, 22 Na
Proper use of Dosimeters
Must be worn at all times when working with or near radiation
Store away from radiation sources such as heat, light, or radioisotopes
Do not take home
Wear badge between the collar and waist outside clothes, lab coat, etc.
Wear ring on assigned hand inside glove facing the palm
Return TLD’s in timely manner. Your lab will be restricted if your badges are not returned
Sources of inhalation hazards
Protein labeling techniques ( 125 I, and 35 S)
Generation of aerosols
Heating of reagents
Generation of gases
Sources absorption or injection hazards
Cuts in skin – double glove if a cut is present
Absorbed through skin or mucous membrane
Injection with syringe or other delivery device
Use fume hood Be cautious with sharps
Ingestion WSU Food Policy
No consumption in areas where hazardous materials are used, stored or disposed
No food storage or disposal
No cosmetics ie lotion
No mouth pipetting
Floor to ceiling enclosures must separate food areas from hazardous materials areas
Bioassays are required when using:
100 mCi or more of 3 H
1 mCi or more of free 125 I
10 mCi or more of 32 P
10 mCi or more of 35 S
Because many radioisotopes are only internal radiation hazards, external dosimetry is not an effective method for monitoring occupational exposure. For this reason, you may be asked to provide a urine sample for bioassay. Individuals working with unbound 125 I, must come between six and seventy-two hours after each radioiodonation for a thyroid bioassay. • •
Basic Radiation Safety Part 3 Radiation Detection Equipment
Survey Meters Ludlum Model 3 Geiger Counter with pancake and LEG probes Required in most labs ( 32 P 125 I) Detects contamination quickly Indicates the effectiveness of shielding Must be calibrated annually Geiger-Mueller (GM) Crystal Scintillation (LEG) Ion Chamber (QT Pie) • • • • Not for 3 H or 35 S
Pancake and End Window Probes Ion chamber - Volume of gas with biased electrodes. Radiation creates ion which induces “current” to show up as an event Survey Meters
Gamma and X ray Survey Probes (LEG) Low energy gamma 1x1 gamma probe Low energy gamma (LEG) scintillation detectors - Sodium iodide (NaI) crystal encased in a metal cylinder, mounted on a photomultiplier tube. These are more sensitive and will have a higher background than other probes Recommended for detection of 125 I. http:// www.uos.harvard.edu/ehs/radsafety/sur_how.shtml Survey Meters
Ion Chamber Survey Meter
Measuring radiation fields
Measures exposure in mR/hr
Not sensitive enough for detecting contamination
Only a few areas on campus where they are needed
Highly used in Nuclear Medicine
Using a Meter: BCBS
B atteries C alibration B ackground S ource
Reading Your Meter
Use proper scale ie 0.1x, 1x, 10x
Read only in CPM not mR/hr
Meters are calibrated by Health Physics staff annually. If your meter is out of date call us at 577-1200 Survey Meters
Aud On/Off – toggle the audible counting
The audible counting should be left “On”
F/S – Fast or Slow Response
Should be left to “F” until contamination is found, when it
should be switched to “S” for more accurate determination of the amount of contamination
Reset – push after each
scale setting change Survey Meters
Performing a Survey
Follow BCBS being sure to test background away from any possible contamination or sources. ie the hallway
Use the correct probe for the given isotope
Remove cap or cover
Begin survey on lowest scale (0.1x)
Move probe slowly (20 cm/s) and close to the surface (1-2 cm)
Immediately decontaminate any contaminated surfaces
Liquid Scintillation Counters (LSC)
Large and heavy equipment
Wipe test required
Detection of low energy beta from 3 H, 14 C, 35 S, 33 P and 45 Ca as well as higher energy beta
Can count large numbers of samples
Radiation Safety Video
Will contribute questions on Exam
Basic Radiation Safety Part 4 Laboratory Application
Performing a Wipe Test Wipe Test – Wipe surface with filter paper, fold wipe-side in, and insert into scintillation vial. Add ~10mL of scintillation cocktail and count the sample in the LSC. Record all results including nil results
For P-32, I-125, Cr-51 use a survey meter or LSC
For H-3, C-14, S-35 use an LSC
A survey is an evaluation of dose potential in a work area based on all aspects of radiation use, not just monitoring for radiation contamination Surveying = Monitoring
Surveyor must follow a room drawing
All benches, hoods, sinks, freezers, etc must be identified
Contamination Surveys A blank copy of this form is available as Appendix M in the Radiation Safety Manual and Lab Guide
Use Log and After-Use Surveys
Must perform wipe test on vial upon receipt
Must record each use of material
Must perform survey of work area when completed
Must record all results – including those when no contamination is found
Must record results in DPM or CPM with Efficiency
H-3 0906B 09/02/06 500 09/08/06 Thymidine 09/02/06 J. Schmoe 500 22 09/04/06 J. Schmoe 250 250 21 30 22 28 H F1 fl 09/04/06 J. Schmoe 250 0 26 20 39 40 H F1 fl A blank copy of this form is available as Appendix O in the Radiation Safety Manual and Lab Guide
Survey Record If a lab has radioactive material, a monthly survey must be completed in at least the storage location Any survey location must be accompanied by a survey of the adjacent floor See form instructions 10/10/06 Science 123 Dr Franklin Schmoe, Joe Grad Asst X 500 uCi 2 mCi IIIIIIIIIII IIIIIIIIIII H-3 P-32 Ludlum 3 / 123 Science Beckman 8600 / 123 Science 25 44 52 106 107 115 12 99 249 100 B1 fl F2 H B1 fl F2 H H-3 contamination in Hood – cleaned, repeat survey performed 56 H Re-wipe Joe Schmoe 44 115 fl fl 55 110 fl fl A blank copy of this form is available as Appendix N in the Radiation Safety Manual and Lab Guide
Calculation of Activity CPM - BKG NRC requires surveys to be written in units of DPM or uCi. CPM is a function of instrument efficiency Instrument efficiency DPM DPM = uCi = 2.22 x 10 6 DPM/uCi CPM CPM CPM CPM
If a survey results in found contamination follow the procedure for a minor spill
If the contamination is found to have spread throughout or outside of the lab, or on any persons or their clothing follow the procedure for a major spill
If unsure contact OEHS / RSO immediately for assistance 577-1200
Contamination results must be recorded
Notify the PI and persons in the area that an incident has occurred.
Contain the spill. Cover with absorbent paper or dike with absorbent.
Isolate the area to prevent unnecessary spread and personnel exposures.
Survey in order to evaluate the presence of contamination on an individual's skin and clothing and on lab equipment.
If skin or clothing contamination is present, a major spill has occurred. Contact the OEHS immediately.
Using disposable gloves, carefully fold up the absorbent paper and pad and deposit in an appropriate radioactive waste container. If necessary wipe up the spill inward toward the center, not out.
Survey the area of the spill to determine the extent.
Decontaminate the spill using decontaminant detergent (available from Science Stores), and resurvey.
Continue previous step until the area is decontaminated completely.
Document spill in radiation survey log book.
Notify all persons in the area that a major spill or incident has occurred and evacuate unnecessary personnel. Notify the principal investigator.
If possible, prevent the spread of the radioactive material by using absorbent paper. Do not attempt to clean it up. Confine all potentially contaminated individuals in order to prevent the further spread of contamination.
If possible, shield the source, but only if it can be done without significantly increasing your radiation exposure.
Leave the affected room and lock the doors in order to prevent entry. Attempt to prevent further contamination or spreading to unrestricted areas. (Hallways, non-radiation laboratories, etc., are unrestricted areas.)
Contact the Radiation Safety Officer if the spill occurs during normal work hours. Call the Department of Public Safety, (57)7-2222, after normal working hours.
Remove all contaminated clothing and wait for instructions concerning cleanup from the Radiation Safety Officer.
If skin contamination has occurred, measure levels of contamination with a survey meter, record, and begin decontamination by gentle washing with warm water and soap, washing downwards towards extremities, not upwards.
Fire or Explosion – Evacuate immediately, pull fire alarm, and call 577-2222 and inform the dispatcher of the hazardous materials involved
Medical Emergency – Call for medical assistance immediately, providing all hazardous material information to dispatcher. Provide any appropriate assistance to the victim without regard to radioactive contamination .
Radioactive material has been released, and one or more of the following has occurred: No University lab possesses enough radioactive material to cause immediate harm to a first responder
Radiation Lab Postings Warning Placard with radiation sticker – outside lab NRC-3 Form – visible in lab Radioactive materials sticker – on all storage, use and waste areas and containers ie Refrigerators, freezers, cabinets, sinks, benches, hoods, centrifuges, etc. • • Three postings must be clearly visible in or at the entrance to your lab If you cannot locate any of these call OEHS immediately for a replacement at 577-1200 * •
Changing RAM Location Use/Storage
Labs may not post or de-post any labs, or storage locations.
If you need to begin using another storage location ie a freezer, you must contact Health Physics
If you are no longer using a storage unit you must contact Health Physics to remove the radioactive materials posting.
If you wish to begin use or storage in an unposted lab, you must contact Health Physics to obtain RSC approval for the use of the new space and posting for radioactive materials use.
Labeling and Identifying
Samples (tray, rack, etc)
Temporary waste containers
Any radioactive material or waste must be labeled as such and identified. ie radionuclide, lot number, assay date etc. If there is radiation above background in or on something, it must be labeled or decontaminated. It is not acceptable to label items known to be free of contamination with a radioactive warning
Moving Radioactive Material
All radioactive orders, transfers, or shipments must be pre-approved by OEHS
Ordered material is delivered to OEHS, where the box and pig are surveyed and will be delivered to your lab by the health physics staff.
You are responsible
for surveying the inner
vial for contamination
All radioactive material must be secured from tampering or removal by unauthorized persons. Material Security Lock the lab door in your absence Loss of material must be reported to the RSO immediately • •
Radioactive waste is defined as any type of radioactive material that is no longer useful or needed.
To disposed of decayed waste, we must store it for 10 half-lives, so minimize volume
Material that is not contaminated with radioactive material should be disposed of as conventional waste.
Radioactive waste must be completely labeled at all times , from the time it is deposited into a container until final disposal. Records of radioactive waste disposal must be maintained by the University for NRC review, so this labeling or “manifesting” is critical.
Radioactive Waste Tag
Radionuclide and activity
Radioactive Waste Pick-up
• Do not fill more than ¾ full
• Ensure completion of required manifests
• You must wipe test the outside of the waste container
• Go to www.oehs.wayne.edu under Hazardous Materials to request waste pick-up and new containers or tags
Both radioactive and chemically hazardous. This includes scintillation vial waste that contains flammable cocktail or liquids that contain more than 15% of a hazardous chemical waste.
Must have a green Hazardous Waste Disposal Tag in addition to the yellow Radioactive Waste Tag, and the proper name of the waste chemical (no chemical formulas, please) must appear on the green tag as soon as the first drop of waste is placed in the container.
Radioactive Waste Do’s
Fill out waste tags immediately
Record isotope, activity and initials each time waste is added
One isotope per waste container
Separate solids and liquids
Use secondary containment for liquid waste
Ensure proper seal on all containers
Deactivate potential pathogens with bleach
Wipe containers for contamination before pick up
Radioactive waste Don’ts Do NOT mix potentially dangerous chemicals Do NOT discard sharps into regular waste Do NOT dispose of liquid waste into solid waste boxes Do NOT dump liquid waste down the drains Do NOT overfill waste containers (>¾) Do NOT mix incompatible chemicals Do NOT mix isotopes Do NOT remove radioactive waste without OEHS approval • • • • • • • •