In our latest installment of Ask the Expert, brought to you by the team of industry experts at EHS Hero®, we look at a recent question from a subscriber asking about the safety of infrared LEDs. See what the experts had to say.
Q: Where can I learn more about the general photobiological safety of infrared LEDs (IRED)? If components are IR-A but datasheets classify them as exempt in accordance with IEC 62471, can these be deemed safe based on their low radiant intensity? Are filtration systems and/or safety glasses still required?
OSHA requires employers to ensure that affected employees use appropriate eye protection when exposed to eye hazards including potentially injurious light radiation. If, pursuant to the International Electrotechnical Commission (IEC) Standard IEC/EN 62471, your IR-A components are classified as exempt, they would not pose an infrared radiation hazard for the eye (EIR) within 1,000 seconds, a retinal thermal hazard (LR) within 10 seconds, or a near-infrared retinal hazard without a strong visual stimulus (LIR) within 1,000 seconds. Consequently, this would imply that the components do not present an eye hazard due to potentially injurious light radiation and eye protection would not be required pursuant to federal regulation. However, eye protection could be required if the components are atypically operated.
As you correctly noted, the IEC/EN 62471 is the most widely referenced standard providing guidance on the photobiological safety of IREDs and would be the best resource. Specifically, IEC 62471 defines the exposure limits, reference measurement technique, and classification scheme for the evaluation and control of photobiological hazards from all electrically powered incoherent broadband sources of optical radiation, including LEDs but excluding lasers, in the wavelength range from 200 nm through 3000 nm.
You may also want to consult ANSI/IESNA RP-27 Photobiological Safety for Lamps – Risk Group Classification and Labeling, which is the original photobiological safety standard for lamp systems in the United States and was the basis for the IEC 62471. This Recommended Practice covers the classification, labeling, and informational requirements for all electrically powered sources of optical radiation that emit in the 200 nm to 3000 nm range except for lasers and for LEDs used in optical fiber communication systems.
Additionally, we recommend consulting the American Conference of Governmental Industrial Hygienists’ (ACGIH) threshold limit values (TLV) for occupational exposure to near-infrared radiation and the International Commission on Non-Ionizing Radiation Protection’s (ICNIRP) Guidelines on Incoherent Visible and Infrared Radiation. However, the ACGIH and the ICNIRP are not regulatory agencies and thus the TLVs and guidelines are not mandated by law. Instead, they represent best industry and scientific practices.
Note: If you determine that eye protection is required due to atypical operation of your components or some other factor, special safety glasses are available for the IR range. Eyewear must be compliant with ANSI Z87.1, which requires markings on eye protection that relate directly to the device’s ability to defend against specific hazards. Eye protection that is Z87.1-compliant is marked with “Z87.” Additionally, the filter lenses must have a shade number appropriate for the work being performed for protection from the injurious light radiation. IR-absorbing full-face shields should be worn in addition to safety glasses or goggles.