What Does Optical Radiation Mean?
Optical radiation is a type of electromagnetic (EM) radiation. As with other types of EM radiation, optical radiation is defined according to the wavelength of the energy that it emits. For radiation to be considered optical radiation, it must have a wavelength between 100 nanometers (nm) and 1 millimeter (mm, equivalent to 1,000,000 nm). This range includes the ultraviolet (UV) spectrum (100 nm – 400 nm), the visible light spectrum (400 nm – 780 nm), and the infrared (IR) spectrum (780 nm – 1 mm).
In OHS contexts, safety management related to optical radiation is typically concerned with eye protection.
Safeopedia Explains Optical Radiation
Optical radiation is a ubiquitous part of everyday life—UV radiation, visible light, and IR are all present in our natural environment, as they are all emitted by the sun. IR energy is also emitted by objects as heat, even when that heat is undetectable to humans, which is why IR cameras can see “light” in a dark, room temperature environment.
In addition to its natural emission sources, all three types of optical radiation are emitted by artificial means. These emissions are often intentional—such as the visible light emitted by a lightbulb; however, they may also be emitted as waste products of another process. For example, the purpose of a welding flame is to generate heat; however, a great deal of visible light is also generated in the process.
Optical radiation is often present in high quantities in many workplaces, especially in manufacturing sectors, and can pose a significant safety hazard to workers. Extended exposure to excess visible light, IR and UV, such as from a welding source, can cause potentially permanent eye damage. Excessive UV exposure can also cause skin damage, including cancer.
In addition to the aforementioned, IR radiation can also pose multiple other safety risks, including burns upon direct contact with the source of the IR, worker exhaustion and heatstroke due to extended exposure to a high-temperature environment, and potentially increased risk of fire and explosion if the emitted heat comes into contact with sufficiently flammable material.
Occupational health and safety agencies generally consider optical light hazards in-terms of their potential to cause eye-and-skin damage and treat IR’s heat-related hazards as separate issues. For example, OSHA’s discussions of optical radiation safety focus on eye protection standards, with specific emphasis placed on welding activity and the use of lasers.