Which is better infrared or UV rays

  • Infrared rays are not visible. They often occur as thermal radiation together with visible light.
  • Depending on the wavelength, infrared radiation can penetrate human tissue and cause damage there.
  • Heat rays from 500 ° Celsius can damage the eyes.
  • Protect yourself at your workplace with shields and suitable personal protective equipment against the dangers of thermal radiation.

What is infrared radiation?

Infrared radiation (IR radiation) is also often referred to as thermal radiation, as this type of radiation is perceived as heat. Strictly speaking, depending on the temperature, thermal radiation ranges from infrared to visible light (VIS) to ultraviolet (UV). The IR radiation can no longer be perceived by the human eye and extends in the electromagnetic spectrum from 780 nm to 1 mm (1,000,000 nm).

IR radiation is divided into the following three areas

  • IR-A (780 nm -1400 nm)
  • IR-B (1400 nm - 3000 nm) and
  • IR-C (3000 nm - 1 mm)

Heat workplaces are not dealt with on this page.

How does infrared radiation work?

Infrared radiation can penetrate human tissue and cause damage. The longer the wavelength, the smaller the depth of penetration into the tissue. Infrared radiation is divided into three categories:

  • IR-A radiation has the greatest penetration depth and can reach the retina and fatty tissue.
  • IR-B radiation can no longer reach the retina and only penetrates the blood vessels up to the beginning of the fatty tissue.
  • IR-C radiation only reaches the surface of the skin and the cornea.
Thermal damage to the skin

The thermal damage is caused by the increase in temperature of the tissue. Irradiation of the skin by a very intense IR source can lead to burns. A burn is very unlikely, as pain from the heat is felt before a burn, so that one can move away from the source in good time.

Thermal damage to the lens and retina

If the lens of the eye is regularly heated by IR radiation, this can lead to a cataract.

In order for the retina to suffer irreversible damage, a critical temperature of the heated tissue must be exceeded.

Is thermal radiation dangerous?

The risk depends on the temperature:


Color impression


Possible hazard

200 ° C

No visible light

Ovens, IR surface heating element


500 ° C

incipient red heat

Electric grill

incipient danger to lens and cornea

1500 ° C

Blinding white heat

Iron smelting

Beginning danger to the retina, danger to lens and cornea

5500 ° C

Neutral white


Danger to the retina, danger from UV radiation to the skin and lens and cornea

Where is one exposed to thermal radiation?

Different workplaces with heat radiation sources:

Source / jobs


Protective measures

Metal smelting, foundries

The most likely to exceed the limit value for the eyes, the hotter the melt, the more dangerous (iron melt: 1450 ° C, aluminum melt: 750 ° C)

Use of shields, minimize exposure time, use of personal protective equipment (PPE) (IR protective goggles, protective clothing)

Blast furnaces

Limit value for skin and eyes may be exceeded (1600 ° C)

Use of shields, use of visors and appropriate protective clothing

Processing of glass, glassmaker

Limit value for eyes possibly exceeded, v. a. when standing in front of the warm-up drum, glass furnace (the level of exposure depends on the temperature of the radiation source), when processing the glass with gas flames, UV radiation also occurs

Use of shields, wearing of PPE (IR protective glasses without color distortion)

IR radiator for gluing or drying (with a proportion of visible light)

Limit value for eyes may be exceeded (depending on distance and exposure duration)

Use of shielding, wearing PPE (IR protective goggles)

open fire

The limit value for eyes is exceeded if you stare into the fire at close range for a long time

IR safety glasses

IR radiant heater

In the catering sector, powerful IR emitters (2kW) are very often used for heating purposes. With an appropriate proximity to the radiator (20 cm), the limit value for the eyes is already set after a short time (

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Corresponding distance to the heater, no direct staring into it

Infrared radiation without a heat source

If IR radiation is generated without a heat source, but with the help of IR light-emitting diodes or lasers, it is invisible. Even if you don't feel any heat on your skin due to the IR source, the IR radiation can be dangerous to the eye. If high-performance IR light-emitting diodes are used (e.g. as lighting for surveillance cameras), a safety distance must be maintained. You cannot tell from an IR light-emitting diode whether it is switched on. This is why the source must be disconnected from the power supply during maintenance work, for example. For IR lasers, the regulations for the corresponding laser class apply (see below).