The Use of P-32 in the Laboratory

1.    Data
2.    Monitoring
3.    Facilities
4.    Concerns
5.    Waste

Half-life (T) = 14.3 days
Maximum Beta energy = 1710 KeV (100%)
Maximum range of Beta in air = 20ft.
Maximum range in tissue = 8mm
Percent transmitted through the dead layer of the skin = 95%.
Critical Organ = Bone for transportable compounds. Lung and lower intestine are critical organs for inhalation and ingestion.
Annual limits on intake (ALI) = 0.9 mCi via inhalation, 0.6 mCi via ingestion
Detection = GM with pancake probe (20-35%) efficient, LSC (90-95%) efficient

A. Monitoring

    1.

    Personnel dosimeter badges will be issued to all personnel working in laboratories where P-32 is utilized. TLD finger type extremity monitors will be issued to all personnel handling P-32.

    2.

    Appropriate survey instrumentation will be required of all laboratories working with P-32. (A geiger counter sensitive to beta particles) A tiny drop of contamination of P-32 can be easily detected with a geiger counter. This survey instrumentation must be calibrated on an annual basis. Annual calibration is handled by the EHRS Department.

    3.

    After each use of P-32 in the laboratory, the work area must be surveyed with an appropriate survey instrument to detect any areas of contamination. Check your hands, shoes, clothing, work bench, floor, and laboratory equipment. These surveys need not be logged unless your laboratory is instructed to do so by the Radiation Safety Officer.

B. Facilities

1.

All P-32 should be stored and used behind a beta shield consisting of low density material (i.e., 3/8"-1/2" plexiglas/lucite). When more than one millicurie of P-32 is handled, a sufficient number of x-rays (bremmstrahlung) may be formed to require lead foil to be added to the exterior of the shield. In most cases, the manufacturer's supplied shield is sufficient for stock vials stored in a refrigerator/freezer.

2.

Designate a specific area of the laboratory for P-32 handling. Place the plexiglas shield near a wall (not toward another work area on the other side of the bench) away from the main flow of traffic in the laboratory.

3.

A series of dry runs must be conducted with all new uses or procedures of P-32 in order to preclude unexpected complications.

4.

No individual research laboratory will be permitted to exceed a possession of 10 mCi of P-32. This level will assist in maintaining exposure levels that are as low as reasonably achievable.

5.

Proper eye protection should be worn by all personnel when working with P-32 to shield the lens of the eye against the P-32 betas as well as providing splash protection.

C. Concerns

    1.

    Surface radiation exposure to the skin of the hands is a concern. Use remote handling tools, such as tongs, to reduce doses to the hands. A drop of contamination containing 1 microcurie of P-32 on 1 cm2 area of the skin produces an exposure of 2,000 millirems per hour.

    This means that the quarterly NRC/PaDEP limit of 7500 millirems to the skin would be reached in 3 hours and 15 minutes.

    2.

    Radiation exposure in air over an open vial is a concern. The dose rate at the opening of a vial containing 1 millicurie of P-32 can be as high as 26,000 millirems per hour.

    This means that the quarterly NRC/PaDEP limit of 18,250 millirems for the hands would be reached in 42 minutes.

    3.

    Using lower concentrations is very desirable. Most companies will provide lower concentrations if requested. The cost of using pre-labeled materials or lower concentrations is higher but the return in safety more than offsets the cost.

    4.

    Change gloves frequently, and monitor gloves frequently, during the use of P-32. Wash your hands thoroughly after using P-32.

D. Waste

1.

Plexiglass containers are recommended for P-32 radioactive waste. All P-32 waste must be transferred from each research area to the storage area as soon as possible to prevent any unnecessary exposure. Therefore, call the McNeil Science & Technology Center or the Griffith Hall Stockroom (X3141 or X8843) when the waste is ready for a pick-up. (See Radioactive Waste Procedures)

2.

Check and survey the normal trash container to make sure no radioactive waste has been accidentally placed there.


University of the Sciences in Philadelphia • 600 South Forty-third Street • Philadelphia, PA 19104-4495 • phone: 215-596-8800 • email: safety@usp.edu