Although an unlikely event, Fire Departments may have to respond to an emergency involving Class 7 radioactive materials. Many larger departments have Hazmat teams that are fully equipped and trained to manage this type of incident. This article is being provided to assist rural departments that do not have the in-house Hazmat teams available to manage an emergency involving Class 7 radioactive materials. All responders should adhere to internal Fire Departmental policies and procedures when responding to an incident involving radioactive materials. The 2020 Emergency Response Guidebook should be utilized as a guidance document for all hazmat incidents.
The Basics
Emergency responders may not be regularly dispatched to incidents involving radioactive substances, however; radioactive materials are present in most of our communities.
Radiation occurs both naturally and in man-made forms and is omnipresent in our civilian and working lives. There are three types of naturally occurring radiation: cosmic, terrestrial, and internal. Cosmic radiation is emitted by the sun and other stellar sources. Our annual dose from cosmic radiation amounts to approximately 0.40 mSv. Terrestrial sources include ground, rocks, building materials, and radon. These radiological sources amount to a dose of 1.70 mSv annually. Finally, our bodies contain natural radionuclides that amount to an annual dose of approximately 0.30 mSv. The above dose rates are worldwide averages; Canadian-specific information may be obtained from the Canadian Nuclear Safety Commission.
Manmade radiation is also present in our daily lives and can be found in televisions, tobacco, ionization smoke detectors, medical x-rays, and diagnostics utilizing medical isotopes, to name a few. Examples of industrial or commercial applications include gamma-rays used in the irradiation processing of food, radiography to test welds, and security equipment now common at airports.
For the purpose of this article, only ionizing radiation from radioactive decay will be discussed. Ionizing radiation is categorized into three main types: alpha, beta, and gamma. While other forms of radiation exist, they are unlikely to be encountered in vehicle accidents that municipal fire departments would be responding to.
An alpha particle (α) is made up of two protons and two neutrons and has a positive charge. Alpha particles have a relatively high ionization effect. If an alpha-emitting material is inhaled or ingested, it can cause severe damage. However, alpha particles themselves can be stopped by a sheet of paper or a person’s skin. Emergency responders can effectively protect themselves against alpha-emitting materials by wearing proper PPE including SCBA and following general radiation protection precautions such as minimizing their time exposed to the source of the radiation.
A beta particle (β-) is an energetic electron (negative charge) or positron (positive charge). Beta particles have a much lower ionizing effect than alpha particles. Like alpha particles, beta particles do not travel very far (~2 meters) but do travel farther than alpha particles. Beta particles are typically stopped by a few millimetres or about an eighth (1/8 of an inch of skin tissue; higher-energy beta particles will be stopped by approximately a centimetre or about a third (1/3) of an inch of skin tissue. An emergency responder can protect against beta-emitting materials by wearing proper PPE including SCBA and following general radiation protection precautions such as minimizing the time exposed to radiation.
Gamma (γ) and x-rays are waves of energy that travel at the speed of light. They can travel much further than Alpha or Beta radiation and have a moderate-to-high penetrating power, which is capable of penetrating deep into the human body. To protect tissue from Gamma rays, shielding such as lead or concrete, or large separation distances, is required.
Note: Emergency responders can limit their exposure to radioactive materials by understanding the following principle: Time/Distance/shielding’ Limiting a responder’s exposure time, maintaining as great a distance from the source as possible, and using dense objects as shielding, can significantly reduce exposures. Don’t forget to use the objects at the scene, such as vehicles, for shielding, i.e. position yourself so a vehicle or other large/massive object is between you and the radiation source.
Emergency Response – General
When emergency responders are challenged by hazardous products, they can safely manage these incidents by understanding them at a fundamental level and dealing with them according to established departmental protocols and procedures. In most cases, other than the provision of scene control, the emergency responders should minimize activities once the scene has been stabilized as the responsibility for all incidents involving hazardous materials, including radioactive materials, rests with the carrier/consignor of the dangerous goods. Only the activities immediately necessary for scene stabilization should be conducted, including but not limited to victim extrication, medical care, suppression activities, and spill control. Once hot, warm and cold zones have been set, response personnel should be stationed to ensure all unauthorized personnel are maintained at a safe distance.
All emergency scenes should be approached with caution. where possible, vehicles should be parked uphill and upwind. Hot, warm and cold zones should be immediately set up with the hot zone starting no less than 25 meters from the accident. Wear placards or packaging labels are visible, the Emergency Response Guide should be used to determine minimum safe distances.
An initial assessment of the situation should be conducted from a safe distance to determine:
- if there are any spills, leaks, fire, electrical or other hazards;
- if there are any victims present, and if they require medical attention or extrication;
- the type of vehicle and/or containers, and any placards and labels;
- if there is any visible damage to the container or shipping packaging;
- if the shipping documents can be easily retrieved;
- if there is a driver or other knowledgeable person available to provide additional information.
If required, recon teams in full PPE and on-air should be tasked to retrieve shipping documents and conduct further investigation. Binoculars should be used to minimize exposure. Radioactive products may not be the only hazard(s) present. Mixed loads can contain multiple dangerous goods and could potentially be more hazardous for responders. Don’t get “tunnel vision” about radiation; it is important to look for spilled fuel, downed power lines, etc. The Emergency Response Guidebook should be used to assist in determining the hazards and what actions can safely be taken to rectify the situation. The hazard from a radioactive source being transported may be insignificant compared to other dangerous goods in a mixed load.
This is part one of a two-part blog. Click here for Part Two.
