Prevention of Infrared-A Radiation Mediated Detrimental Effects in Human Skin

P. Schroeder, PhD; C. Calles, Dipl.-Biol (MSc); J. Krutmann, MD


Skin Therapy Letter. 2009;14(5) 

In This Article

Physics of Infrared (IR) Radiation

Solar radiation in wavelengths of 290nm to 4000nm reaches the earth’s surface after atmospheric filtering. This part of the electromagnetic spectrum is divided into 3 major bands:

  • ultraviolet (UV) radiation (290-400nm)

  • visible light (400-760nm)

  • IR radiation (760-4000nm)

IR is further divided into IRA (760-1440nm), IRB (1440-3000nm), and IRC (3000nm-1mm). Of the total amount of solar energy reaching the human skin, 54% is IR, while only 7% is UV.[1] Roughly 30% of the total solar energy is IRA, which penetrates deeply into the human skin.[1] Most of the IRA radiation load on human skin is of solar origin, but in recent years artificial IRA sources are used increasingly. In addition to therapeutic approaches, the use of IRA for wellness and lifestyle purposes is steadily rising.