Module 11: U of T Emergency Procedure

11.1 Introduction

During the course of normal operations with radioactive materials, a spill may occur that results in contamination of personnel or lab equipment and areas. Also, external irradiation can be encountered from a strong gamma, neutron source, or X-ray instrument inadequately shielded. Appropriate actions must be taken during such incidents to prevent unnecessary doses to personnel and further spread of contamination.

In case of an emergency involving radioactive materials, contact the Radiation Protection Service (weekdays 8 am to 5 pm) at 416.978.2028.

After hours, nights, weekends, and holidays contact U of T Campus Police:

Mississauga Campus 905.569.4333
Scarborough Campus 416.287.7333
St. George Campus 416.978.2222

11.2 Basic Emergency Procedures

There are a number of procedures that are common to all types of accidents involving hazardous materials. These procedures should be followed in the initial stages of any incident or accident involving radioactive materials.

In case of a serious injury, medical attention takes precedence over radiological or other concerns. The following actions must be taken immediately in the following order:

  • Alert everyone in the area
  • Clear the area:
    • Remove all persons who are in the immediate vicinity
    • Limit access to the contaminated area by marking the area with warning sings or tape, close the laboratory doors, etc.
  • Dial the numbers above and inform the RPS or U of T Campus Police about the incident, injury, and that radioactive materials are involved
  • Take all reasonable precautions to limit the spread of radioactive contamination or further exposures:
    • Define a large enough restricted area to accommodate cleaning procedures
    • Persons at the edge of the restricted area should not be affected by radiation
    • If the contamination is liquid, use some absorbent material to prevent the spread of contamination outside the restricted area
  • Never risk external or internal contamination to save equipment or an experiment

11.3 Radioactive Spill

In the event of personal contamination:

  • Remove the contaminated lab coat and clothing, and place them in a sealed plastic bag
  • Check for skin contamination with an appropriate contamination meter; determine the location and extent of skin contamination
  • If skin contamination is detected, record the reading, decontaminate the skin by using plenty of water and a mild soap or detergent.
  • Contact the RPS
  • In case of eye contamination, immediately use the eye wash for at least 15 minutes
  • Use the emergency shower in case of skin contamination of a large area of the body

In normal radioisotope laboratory operations, spills of radioactive materials will be the most common form of emergency situation. In the event of any spill of radioactive material it is important that the correct steps be taken promptly to avoid spread of contamination.

The RPS must be notified in the event of a spill involving any one or more of the following situations:

  • When a spill is more than 100 EQ on a bench, floor etc., spill on a person or a spill involving a volatile radioactive material
  • When the radioactive material emits alpha radiation
  • When free radioiodine is involve
  • When inaccessible areas are suspected to be contaminated
  • When all reasonable efforts to decontaminate are unsuccessful in reducing the level of activity to near background levels
  • When there is doubt regarding the correct decontamination procedure
  • When significant contamination of personnel occurs

The RPS may be contacted for advice in the event of a spill of any quantity of radioactive material.

11.4 Procedure in the Event of a Spill

In addition to the actions indicated above (basic emergency procedures), the following steps must be taken in the event of a spill of any quantity of radioactive material:

  • Wash hands in case they were contaminated during the accident
  • Use an appropriate detector to monitor clothing and hands to determine if any skin or clothing contamination has occurred. If personal contamination has occurred, treat this first by washing the affected area
  • Ensure the laboratory coat is worn, properly buttoned up, to prevent contamination of clothing
  • Double-glove. This will protect the hands in the event one pair gets damaged
  • Use a respirator if airborne material is present to reduce the potential for accidental intake of radioactive material
  • Drop dry absorbent material on wet spills (e.g. paper towels). If the spilled material is dry, use water or the appropriate organic solvent to lightly dampen the material
  • Mark the location and probable extent of contamination with a wax pencil or another marker. Radiation warning tape may also be used. Do not use felt tip or other permanent markers
  • Do not track contamination away from the spill area. Do not let anyone leave the contaminated area without being checked for contamination. Remember to check the shoes for contamination
  • Begin the decontamination procedure as soon as possible. Any experiment or procedure in progress must be set aside until the decontamination is complete
  • Start work from the area of lowest contamination, working towards the area of highest contamination
  • Normal cleansing agents or commercial decontamination agents may be used. Before beginning the decontamination procedure, ensure that sufficient materials are available to properly clean the area. This will eliminate the need to leave the clean-up area unnecessarily
  • Gently wash the affected area with water and cleaning agent. If the material is incompatible with water, contact the Radiation Protection Service before beginning any decontamination procedure. The technique involves several washings, each followed by a clean rinse. Change water and cleaning agent solution often
  • Treat all cleaning materials as radioactive waste. Contaminated cleaning agents or water are considered radioactive waste and must be disposed of accordingly. Absorbent materials used for removing liquid contamination must be put in the solid waste container
  • Continue washing until contamination is removed or cannot be reduced further. Monitor the area after each wash and rinse to check progress of decontamination procedures
  • After the procedure has been completed, use a swipe test to check for the presence of residual contamination. If the area is clean, record all results in the room’s logbook. If contamination remains, further cleaning is required. If cleaning is ineffective in removing the contamination, contact the RPS for assistance
  • Be sure to check hands and shoes at the end of the decontamination procedure

11.5 Emergency Involving Strong Gamma or Neutron Sources

Unshielded strong gamma or neutron sources are external hazards. In the event of an emergency, quick and appropriate actions are very important.

In the case of serious injury, medical attention takes precedence over radiological or other concerns. The following actions must be taken immediately, in the following order:

  • Remove the injured person from the area with high dose fields
  • Alert everyone in the area
  • Clear the area :
    • Remove all persons from the immediate vicinity
    • Dial the numbers above and inform the University RPS or U of T Campus Police about the incident, injury, and that radioactive materials are involved
    • With an appropriate instrument, determine the area where dose limits are 2.5 mSv/hr (0.25 mrem/hr). This operation may involve taking measurements in the surrounding rooms or floors
    • Limit access to the high dose area by marking the area with warning sings or tape, close the laboratory doors, etc.
  • Stand outside of the high dose area and wait until an RPS representative arrives

11.6 Emergency Involving X-ray Instruments

In case of emergencies involving radiation-producing instruments (X-ray):

  • Turn off the machine and unplug or shut off the circuit breaker for that particular machine; do ot change the experimental setting
  • In case of injury to personnel, call the RPS at 416.978.2028 or U of T Campus Police
  • Notify the laboratory supervisor
  • Record all information about the incident (e.g., operating voltage and current, exposure time, distance from radiation source) and provide this information to the RPS representative