STANDARD OPERATING PROCEDURES FOR IODINATION

INTRODUCTION:

Iodinations involve the use of relatively high concentrations of I-25 Sodium Iodide which is known to be volatile in air and readily absorbed by the thyroid gland if inhaled or absorbed internally. Uncapped vials of I-125 and laboratory contamination with I-125 may potentially lead to uptake in the thyroid gland and extra precautions are necessary above an beyond the normal Standard Operating Procedures for Unsealed Sources. It is estimated that the absorption of 1 (one) microcurie of I-125 in the thyroid gland produces a dose of 5 Rad.

To ensure that all personnel conducting iodination receive a minimal amount of radiation exposure, the following procedures have been established and approved by the Radiation Safety Committee.

REGULATIONS:

University regulations require that all iodination be conducted during normal working hours in the special fume hood in Room A-679, Medical Science Building. This hood has a charcoal filter attached to trap any airborne I-125 to minimize release to the environment and to personnel.

PURCHASING PROCEDURE

Orders for I-125 much be approved by the Office of Radiation Safety Services (ORSS). Upon delivery to the ORSS, the package will be leak tested for contamination. The investigator will be informed of the availability of the package which will be stored in Room A-679, Medical Science Building.

USE OF ROOM A-679:

Iodination may be scheduled Monday through Thursday during normal University working hours. Reservations must be made to use this hood as there are 5-6 laboratory groups regularly conducting iodination. Call (ext2-5305) at least 48 hours in advance.

All persons conducting iodination must be supervised by ORSS personnel to ensure safety procedures.

Because of space limitations, no more than 2 persons will be permitted in the room during an iodination.

PRE-IODINATION PROCEDURES

The ORSS personnel will check the hood before each iodination to:

1. Ensure an adequate supply of disposable gloves (provided at no charge).
2. Set up the air sampling system.
3. Set up the containers for solid and liquid waste.
4. Place absorbent paper in fume hood and on the benches.

IODINATION PROCEDURES

1. A pre-iodination thyroid burden test on each iodinator will be performed.

2. Vials of I-125 must be opened only while in the fume hood. Any vials containing I-125 brought outside the fume hood must be capped.

3. Film and finger badges must be worn by all persons.

4. At least two pairs of disposable gloves plus one pair of arm length disposable gloves must be worn.

5. All contaminated syringes, glassware, etc. must remain in fume hood. All items must be decontaminated before leaving the room.

6. If the iodinator leaves the room before the end of the procedure, the hands, feet and clothing must be checked for contamination.

7. No smoking, eating or drinking will be permitted in the lab.

POST-IODINATION PROCEDURES

1. Before leaving the iodination lab, the hands, feet, and clothing will be checked for contamination.

2. If the lab coat contains more than background of contamination, the coat will be stored for decay.

3. Iodinator(s) will be reminded of the need to return to the ORSS for a thyroid burden assay within 72 hours post-iodination, preferably within 24 hours.

AT THE COMPLETION OF THE IODINATION, ORSS PERSONNEL WILL:

1. Count the charcoal filters in the air sampling system (breathing zone and effluent) to determine if excessive airborne radiation was present.

2. Conduct a surface contamination check of the fume hood and general lab area.

3. Dispose of waste generated by the iodination and will bill the investigator.

THYROID ASSAY PROCEDURES

1. Prior to the iodination, a thyroid burden test will be performed for each iodinator.

2. Within 24 hours post-iodination, each iodinator will be required to return to the ORSS for a follow-up thyroid burden test. The results will be kept on a permanent record.

3. In the unlikely event of I-125 accumulation, the iodinator will be informed by the ORSS and will be advised of the necessary course of action.

Note: If the iodinator DOES NOT return within 72 hours, preferably 24 hours, he/she will be in violation of the thyroid burden policy (see attached letter) and may be suspended from doing further iodinations.