Shielding
Glass and plastic are the best shields for beta particles from P-33.
Detection
A tiny drop of contamination from P-33 can be easily detected with a wipe test from a Liquid Scintillation Counter. Most Geiger Counters will not efficiently detect the presence of P-33.
Equipment/Supplies
The following equipment and supplies must be available:
- A Liquid Scintillation Detector
- Disposable latex or plastic gloves
- A full-length lab coat
- Radioactive waste receptacle
- Pipettes dedicated to the use of P-33
- Commercial decontaminate
Safety Rules
If the following safety precautions are used, personnel radiation exposure will be as low as reasonably achievable.
- Designate a specific area of the lab for P-33 handling
- Full-length lab coats must be worn by all persons who handle P-33
- Protect your hands from becoming contaminated from spills by wearing two pairs of disposable gloves
- Never pipette P-33 by mouth
- Only use pipettes which have been dedicated to your specific use of P-33
- Pipettes will easily become contaminated and therefore, should not be shared with others
- If you have reason to believe that your gloves are contaminated, immediately dispose of them in the radioactive waste container
Post-Use Procedures
- Conduct a wipe test and count the wipes in a Liquid Scintillation counter
- Check all equipment, centrifuges, water baths for contamination
- If any contamination is found, use a commercial radiation contamination remover with paper towels to clean up the equipment
- Place the towels in the radioactive waste receptacle
- If contamination cannot be removed, place a "radiation" label on the equipment indicating that it is P-33, maximum cpm found, and the date you measured the level
- Check the work bench and floor
- If contamination is found, it can usually be removed easily
- If it cannot be removed, contact the RSO at rso@wpi.edu to obtain shielding materials
- Inform your fellow lab workers if any unremovable contamination is found
- Check the normal trash container to make sure no radioactive waste has been accidentally placed there
- Store the waste temporarily in containers marked with labels "Radioactive Waste-Do Not Empty"
- Wash your hands thoroughly
Other Information
Physical Data
- Beta energy: 0.249 keV (maximum, 100% abundance)
- 0.085 keV (average)
- Physical half-life: 25.4 days
- Biological half-life: 19 days (40% of intake; 30% rapidly eliminated from body, remaining 30% decays)
- Effective half-life: 24.9 days (bone)
- Specific activity: 1,000 - 3,000 Ci/millimole
- Maximum beta range in air: 89 cm
- Maximum range in water/tissue: 0.11 cm
- Maximum range in plexiglas/lucite/plastic: 0.089 cm
- Half-Value Layer (HVL): 0.30 mm (water/tissue)
Radiological Data
- Critical organ (biological destination) (soluble forms): Bone marrow
- Critical organs (insoluble forms or non-transportable P-33 compounds): Lung (inhalation) and G.I. tract/lower large intestine (ingestion)
- Routes of intake: Ingestion, inhalation, puncture, wound, skin contamination (absorption)
- Internal exposure and contamination are the primary radiological concerns
- Committed Dose Equivalent (CDE): 0.5 mrem/mCi (inhalation)
- Skin contamination dose rate: 2,910 mrem/hr/uCi/cm2 (7 mg/cm2 or 0.007 cm depth in tissue)
- Fraction of P-33 beta particles transmitted through the dead skin layer is about 14%
- Tissues with rapid cellular turnover rates show higher retention due to concentration of phosphorus in the nucleoproteins.
- P-33 is eliminated from the body primarily via urine
- Phosphorus metablolism: 30% is rapidly eliminated from body
- 40% has a 19-day biological half-life
- 60% of P-33 (ingested) is excreted from body in first 24 hrs
Shielding
Not required; however low density material is recommended, e.g., 3/8" thick plexiglas, acrylic, lucite, plastic or plywood
Survey Instrumentation
- GM survey meter with a pancake probe
- Liquid scintillation counting of wipes may be used to detect removable surface contamination
Dosimetry
- Not required, since they do not detect this low energy nuclide
- It is recommended, however, that dosimetry should be worn when handling radioisotopes of any nature
General Precautions
- Inherent volatility (STP): Insignificant
- Skin dose and contamination are the primary concerns.
- Drying can form airborne P-33 contamination.
- Monitor work areas for contamination, using smears or wipes to check for removable contamination.