Unsealed Source Phosphorus 32


Abbreviation: 32P
Physical Half-life: 14.29 days
Radiations: -ß 1709 keV

External Exposure:

The unshielded ß doses from 1 mCi of 32P are 13,778 mRad/hr at 5 cm; 3443 mRad at 10 cm; 141 mRad/hr at 50 cm

Biological Data:

ALI 0.6 mCi(ingestion), 0.9 mCi(inhalation)
Biological half-life 257 days
Effective half-life 13.5 days
Critical Organs Bone and whole body
Bioassay Urinalysis
Shielding: Plexiglass is recommended.
Range of ß in air is 20' and 0.3" in lucite.

Monitoring & Efficiency

LSC (Eff. ~90%)
Thin-window GM (Eff. ~25%)

Special Considerations

  • The dose at contact of a 1 mCi vial of 32P is in the order of 1000 mRad/hr. Avoid handling unshielded stock vials with your hands, use forceps with rubber sleeves, and work at arms length.
  • A microcurie of 32P on a cm2 of skin gives a dose of about 8000 rads per hour. Wear gloves, lab coat and safety glasses when handling radioactive solutions.
  • Wear a radiation badge when handling 1.0 mCi or more of 32P.
  • Monitor hands and work areas during and immediately after work. Document survey results.
  • Utilize shielding; do not put your hands over open containers.

a beta-emitter (1.71 MeV) with a half-life of 14.3 days which is used routinely in life-science laboratories, primarily to produce radiolabeled DNA and RNA probes, e.g. for use in Northern blots or Southern blots. Because the high energy beta particles produced penetrate skin and corneas, and because any 32P ingested, inhaled, or absorbed is readily incorporated into bone and nucleic acids, Occupational Safety and Health Administration in the Unites States, and similar institutions in other developed countries require that a lab coat, disposable gloves, and safety glasses or goggles be worn when working with 32P, and that working directly over an open container be avoided in order to protect the eyes. Monitoring personal, clothing, and surface contamination is also required. In addition, due to the high energy of the beta particles, shielding this radiation with the normally used dense materials (e.g. lead), gives rise to secondary emission of X-rays via Bremsstrahlung. Therefore shielding must be accomplished with low density materials, e.g. Plexiglas, Lucite, plastic, wood, or water.

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