What Does Visible Radiation Mean?
Visible radiation, also referred to as visible light or simply “light,” is a form of electromagnetic (EM) radiation characterized by electromagnetic waves with wavelengths between 380 nanometers and 740 nanometers. It exists as part of the larger electromagnetic spectrum. The basic element of visible radiation—and all EM radiation—is the photon.
When visible radiation interacts with the human eye, only a certain portion of the radiation is actually observed as light. As the power (luminous intensity) of the visible radiation increases, so too does the amount of observable light it creates. The amount of power created by a given source of visible radiation is formally described or measured in units called “candela” and informally described or measured in units called “candlepower.”
Safeopedia Explains Visible Radiation
Visible radiation is an important part of numerous occupational health and safety considerations. Access to light is a key function for workplace safety because properly lit areas are important for humans to be able to navigate safely without tripping, as well as because human health declines when humans do not have adequate exposure to light. Various OHS agencies prescribe access to certain levels of light within the work environment as part of standards (e.g., OSHA 1915.82) related to worker health and as part of standards related to housekeeping.
Visible radiation can also provide diagnostic insights into the physical processes occurring in a given workplace. Different colors created by visible radiation correspond to different EM wavelengths and energy levels, and thus an alteration in color reflects an alteration in the radiation and energy being emitted by a process. A change in the visible radiation (color or intensity) emitted by a process is therefore an indication that a property of the process has changed.
OHS agencies also recognize that excessive exposure to visible radiation can cause eye damage. For example, OSHA 1915.153 requires workers involved in certain welding and cutting operations to be provided with appropriate eye protection to avoid damage due to visible radiation exposure. Work that takes place in environments lit by artificial light sources has also been associated with reduced employee health, an issue attributed to differences in the wavelengths emitted by artificial and natural light sources.