Erythema-Effective Irradiance Measurement of Sun Tanning Studios
Concerns over the safety of both commercial and home use sun tanning lamps led to the EU’s Scientific Committee on Consumer Products (SCCP) [1] recommending a limit of 0.3W/m2 erythema effective irradiance for all cosmetic use sun tanning lamps. This level is implemented within legally binding European regulations for both manufacturers and operators. Erythema is the reddening of the skin which is an inflammatory response caused by, for example, the actinic effect of exposure to UV radiation. Erythemal effective irradiance (CIE S 007-1998) [2] is measured over the wavelength range 250 nm to 400 nm.
Regulations for Sun Tanning Studios
Within Europe, sun tanning products must conform to the Low Voltage Directive (LVD) 2014/35/EU in order to be CE marked which requires type-testing against EN 60335-2-27- 2010 [3]. A high quality UV spectroradiometer such as the BTS2048-UV is required to measure the spectral irradiance of appliances, from which erythema effective irradiance is determined over UV-A and UV-B wavelength regions 250 nm - 320 nm (UV-B) and 320 nm - 400 nm (UV-A). Note that these UV ranges differ from standard CIE UV-A (315 - 400)nm and UV-B (280 - 315)nm wavelength ranges. The total UV-A plus UV-B effective irradiance must not be in excess of 0.3 Wm-2. Additionally, the un-weighted irradiance 250 nm - 280 nm must not exceed 0.003 Wm-2. Excellent scattered light rejection is required of the spectroradiometer otherwise products may unnecessarily fail this criterion. The appliance type is then determined using the following table:
| UV Appliance Type | 250 nm - 320nm ery-eff irradiance (W/m2) | 320 nm - 400 nm ery-eff irradiance (W/m2) | Application |
| 1 | < 0.0005 | > 0.15 | Professional use under supervision of appropriately trained persons. |
| 2 | 0.0005 to 0.15 | > 0.15 | Professional use under supervision of appropriately trained persons. |
| 3 | < 0.15 | < 0.15 | Suitable for household use without training. |
| 4 | > 0.15 | < 0.15 | Intended to be used following medical advice. |
Routine Inspection Measurement Equipment
Routine inspection and compliance checking by either the sun tanning studio operator or by local authority inspectors is more conveniently performed with a suitable UV radiometer such as the X1-4 meter. The XD-45-ERYC multi-detector based sensor supplied with the X1-4 meter also incorporates a UV-C irradiance detector for maximum safety compliance testing.
References
[2] CIE S 007-1998 Erythema Reference Action Spectrum and Standard Erythema Dose
[3] EN 60335-2-27:2013 Household and similar electrical appliances. Safety. Particular requirements for appliances for skin exposure to ultraviolet and infrared radiation