It has come to our attention that there are claims circulating suggesting that an irradiance of 100–150 mW/cm² is "too high" and could "melt your skin"—and that any company reporting irradiance in this range must have tested incorrectly or misreported a high irradiance.
We’d like to address these concerns based on scientific evidence.
What studies actually show about irradiance safety:
According to a meta-analysis [1] (one of the most robust types of scientific papers) by Dr. Michael Hamblin, a leading expert in the field, the levels of irradiance that could potentially cause unacceptable heating (i.e., burning) of the skin are significantly higher than 100–150 mW/cm². Here’s what was reported:
- 750 mW/cm² for wavelengths in the 800–900 nm range (near-infrared light)
- 300 mW/cm² for wavelengths in the 600–700 nm range (red light)
Additionally, a separate paper [2] evaluating the safety of red light therapy concluded:
"LED-RL [LED red light therapy] is safe up to 320 J/cm² for skin of color and up to 480 J/cm² for non-Hispanic Caucasian individuals."
To put this in everyday terms:
At an irradiance of 140 mW/cm², it would take approximately 38–57 minutes of continuous use to reach those energy doses.
For your safety, LUMEBOX has a built-in 12-minute automatic shut-off to ensure users stay well within safe exposure limits.
So, will 100–150 mW/cm² melt your skin? And are companies testing incorrectly if they report an irradiance in that range?
A resounding NO - IF you follow the science.
In fact, irradiance levels of 100–150 mW/cm² are commonly used in published research on photobiomodulation (red light therapy), especially when treating deeper tissues that require greater light penetration.
Here are just a few examples of studies using irradiances of 100 mW/cm² or higher:
How we test LUMEBOX—and why it's reliable:
To accurately verify our irradiance, we selected SGS, a leading provider of independent testing services, with a global network of ISO/IEC 17025-accredited laboratories, to perform our third-party measurements for both irradiance and wavelength.
For added safety validation, LUMEBOX was also independently tested for compliance with IEC 62471 standards and classified as Risk Group 1 (low risk) — confirming that our device meets safety thresholds for photobiological hazards to the skin.
Our Approach to Accurate Irradiance Reporting
- Our testing at 1 cm distance matches how we advise the device to be used for deep tissues like joints. In fact, most handheld red light therapy devices report their irradiance at 0 cm away.
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In our welcome guide, we clearly explain the different usage distances:
- For skin rejuvenation (face): 5 inches away.
- For muscle/joint support: closer, about 1 cm away, and we advise users to start slow, and build up gradually as tolerated.
- For skin use (at a greater distance), we provide lab-tested irradiance results specifically at 15 cm—transparently posted on two of our blogs that relate to skin:
Photobiomodulation is a specialized field that requires careful interpretation of both technical data and research methodology.
We encourage users to rely on information grounded in the best available scientific evidence, supported by third-party testing conducted by leading independent laboratories with expertise in light measurement.
We remain committed to rigorous, science-based methods in the evaluation of our devices.
Citations:
[1] Zein R, Selting W, Hamblin MR. Review of light parameters and photobiomodulation efficacy: dive into complexity. J Biomed Opt. 2018 Dec;23(12):1-17. doi: 10.1117/1.JBO.23.12.120901. PMID: 30550048; PMCID: PMC8355782.
[2] Jagdeo J, Nguyen JK, Ho D, Wang EB, Austin E, Mamalis A, Kaur R, Kraeva E, Schulman JM, Li CS, Hwang ST, Wun T, Maverakis E, Isseroff RR. Safety of light emitting diode-red light on human skin: Two randomized controlled trials. J Biophotonics. 2020 Mar;13(3):e201960014. doi: 10.1002/jbio.201960014. Epub 2019 Dec 8. PMID: 31483941; PMCID: PMC8887049.