MRI environments can be hazardous for firefighters.
Magnetic resonance imaging (MRI) units are hospital units that present a particular challenge to firefighters due to the properties of MRI scanners.
Definition
MRI scanners are machines that use a strong magnet and radiofrequency waves to generate images.
Problem
The magnets can range from 30, 000 to 60,000 times greater than the magnetic field of the earth. The fringe magnetic field extending around the scanner creates an environment where ferromagnetic objects become high-speed, potentially fatal projectiles. Firefighter equipment is ferrous (iron-containing) and therefore not safe.
Further Considerations
MRI magnets are always on, even when not in use. It is possible to perform emergency shutdown of the magnet, but this last resort involves bleeding off cryogenic gas from the magnet housing. If performed incorrectly, the process can create an oxygen-deficient atmosphere and the machine may overheat and ignite.
Basic Precautions
Firefighting should be conducted at a reasonable distance from the MRI suite. If the fire is in the MRI suite, only nonferromagnetic extinguishers should be used. Extinguishers in an MRI environment are labeled and manufactured of appropriate materials for use in the suite, according to the Cook Children's Health Care System document, "MRI Safety for Firefighters."
Significance
MRI unit operational procedures must be thoroughly understood and preplanned, advises Mark A. Brown, Fire Prevention Bureau Chief for the Concord Department of Fire & Life Safety, North Carolina, in an article for Firehouse.com.
Tags: magnetic field
