Equivalency coding


Published 03.07.2015, updated 31.12.2018 12:29

Keywords: Sun beds

From 1 May 2014, only fluorescent UV lamps (tubes) with equivalency codes are permitted, and all solariums must have equivalency code ranges. The lists of tubes allowed for each model, including the lists of so-called replacement tubes, have been removed from the Norwegian Radiation and Nuclear Safety Authority's (DSA) website and each model is now specified with equivalency code ranges and names of any high-pressure lamps (high-pressure lamps are not covered by the equivalency coding).

Equivalency codes on tubes

All fluorescent UV tubes produced today must be stamped with a code. This code is called an equivalency code and tells us how strong the UV radiation emitted from the tube is and how high the proportion of short wave radiation is. The code is given in the form

    Wattage – Reflector type code – UV code (X/Y)

The reflector type code is one of four different values (letters), of which the two most common are

    R for tubes with a regular reflector and 
    O for non-reflector tubes

The UV code is written in the form X/Y where

    X denotes the strength of the UV radiation from the tube (erythema-weighted irradiance), given in W/m2 and rounded to the nearest integer

    Y denotes the ratio of (Non Melanoma Skin Cancer (NMSC) Weighted) UVB to UVA radiation from the tube, rounded to the nearest first decimal

Example of sunbed tube with equivalency code

Example of sunbed tube with equivalency code

The image above shows the label of a tube with equivalency code (in the red circle). In this case the code shows that the tube is a 100W reflector tube with a total erythema-weighted UV irradiance of 29 W/m2 and with 2.4 times as much NMSC-weighted UVB as UVA.

Equivalency code ranges on solariums

All solariums equipped with low-pressure fluorescent tubes that are put on the market today must be labelled with an equivalency code range, given by the equivalency code of the tube with which the solarium was measured and classified. Then all types of tubes, i.e. regardless of manufacturer and tube name, can be used in the solarium, as long as the equivalency code of the tube is within the given range for the part of the solarium in question (bench, canopy, facial, shoulder and so on)
Equivalency code ranges are given in the form

Wattage – Reflector type code – UV code range (Xmin-Xmax/Ymin-Ymax)

Wattage and reflector type code are the same as for the tube used during type testing/measurement of the solarium. The UV code range is given by the X and Y value of the tube as follows:

        Xmax = X
        Xmin = 0,75 x Xmax
        Ymax = 1,15 x Y
        Ymin = 0,85 x Y

An example: a solarium measured and classified as UV type 3 with a tube with the equivalency code 100-R-29/2.4 will have an equivalency code range 100-R-(22-29)/(2.0-2.8).

How to get equivalency code ranges for existing solarium models

Existing solarium models should be remeasured with the desired tube types (with equivalency code). A notification must be sent to the NRPA with measurements attached showing that the solarium satisfies the UV type 3 requirements. See “Notification requirement –new solarium models or lamp combinations”. Solarium models that had not been remeasured with tubes with equivalency code by 1 May 2014 were given equivalency code ranges based on weak lamps predefined by NRPA and known to give UV type 3 in all accepted models. It is still desirable that these models are remeasured, and submitted notifications are continuously processed.


According to the Radiation Protection Regulations, Section 36, all solariums must be in compliance with harmonised standard EN 60335 with annex;
Household and similar electrical appliances - Safety - Part 2-27: Particular
requirements for appliances for skin exposure to ultraviolet and infrared radiation. This standard says that all solariums equipped with fluorescent tubes must be labelled with an equivalency code range identifying the tubes allowed in the solarium.