Information about UV Wavebands

UVB-Narrowband, UVB-Broadband, UVA (PUVA) & UVA-1

A “waveband” is the spectral profile of a light source; that is, the relative energy at each wavelength, and it is usually expressed as a curve on a graph. In photo-dermatology for skin disorders using fluorescent light sources, there are basically four waveband types in use: UVB-Narrowband, UVB-Broadband, UVA, and UVA-1 as described below. For each different waveband, Philips Lighting assigns a “Color Code”, which always begins with a slash / followed by two numbers, such as /01 for UVB-Narrowband.

The waveband type of a SolRx device can be changed by installing dimensionally interchangeable bulbs of a different waveband, but not all waveband types are available for all SolRx device families, nor are User’s Manuals available for all of these variants. Also, if the waveband type is changed, the device labeling must be changed so that it is not mistaken for something else, which could result in serious skin burns.

UVB Narrowband

(Philips /01, strong 311 nm peak)

Almost all SolRx devices are sold as UVB-Narrowband and for most patients, it should be the waveband that is tried first. It is by far the most common choice for psoriasis, vitiligo, atopic dermatitis (eczema), and Vitamin D deficiency; because it has proven to be very effective for both clinical and home use, and it is theoretically safer than the alternatives. Nearly all phototherapy clinics use UVB-NB as the principal treatment. UVB-Narrowband SolRx devices have a “UVB-NB” or “UVBNB” suffix in the model number, such as 1780UVB-NB.

uv wavebands

 UVB Broadband

(Philips /12, or FS-UVB)

Formerly, the only UVB waveband type available, UVB Broadband is sometimes still used for psoriasis, atopic-dermatitis (eczema), and Vitamin D deficiency; but almost never for vitiligo. UVB Broadband is considered a more aggressive UV-light therapy than UVB-Narrowband, so it is usually reserved for more difficult cases and after first trying UVB-NB. UVB Broadband treatment times are nominally 4 to 5 times shorter than UVB Narrowband because UVB-Broadband has much greater skin-burning potential.

UVB Broadband bulbs are available for all four SolRx device families, but UVB-Broadband User’s Manuals are available only for 1000-Series models 1740UVB and 1760UVB, and the 100-Series Handheld model 120UVB Handheld (UVB Broadband can greatly reduce scalp psoriasis treatment times when using the UV-Brush). UVB Broadband SolRx models have a “UVB” suffix only, such as 1760UVB. For more information comparing UVB Broadband to UVB-Narrowband, please read: Understanding Narrowband UVB Phototherapy.

Solarc Broadband spectral curve UV wavebands


(Philips /09, 350 nm peak, for PUVA)

UVA is used for PUVA phototherapy, which is an older treatment that uses the drug Psoralen to first photo-sensitize the skin, and then the skin irradiated using UVA light (hence the acronym PUVA). PUVA is needed for the most difficult cases and is complex to administer so it is usually only done in phototherapy clinics, and usually only after UVB-Narrowband has failed. UVA bulbs are available for all SolRx devices except the 100-Series Handheld. Solarc does not have any UVA or PUVA User’s Manuals, but we can measure UVA device irradiance and we have access to PUVA protocols.

Solarc UVA spectral curve UV wavebands


(Philips /10, 365 nm peak, for special applications)

UVA-1 is a relatively new and investigative treatment for several challenging skin disorders. Practically, fluorescent devices are useful only for low-dose UVA-1 for possible treatment under physician guidance of scleroderma / morphea and some other skin disorders. Controlled trials for lupus erythematosus have been done using low-dose UVA-1 and the Philips TL100W/10R lamp, but with a special filter to block the shorter wavelengths. High-dose UVA-1 is needed for atopic eczema and some other skin disorders, making metal halide devices with very high irradiance (light intensity) necessary to keep the treatment times reasonable. UVA-1 bulbs are available for all SolRx devices except the E-Series. Solarc does not have any UVA-1 User’s Manuals or filters.

Solarc UVA 1 spectral curve UV wavebands


  1. The spectroradiometric curves shown above are simplified representations for Philips branded lamps. However, the Philips product line is incomplete, so Solarc may in some cases supply substantially equivalent UVB-Broadband, UVA and UVA-1 lamps made by other qualified manufacturers. Our UVB-Narrowband lamps are however always Philips brand, purchased directly from Philips Lighting Canada in Markham, Ontario.
  2. As part of our Quality System, Solarc batch tests all incoming UV lamps: a) for the correct waveband using a spectroradiometer, and b) for acceptable irradiance using a radiometer.
  3. Solarc does not have any devices or lamps for Seasonal Affected Disorder (SAD).
  4. Solarc does not have any devices or Philips /52 lamps for the treatment of infant jaundice (hyperbilirubinemia).

Solarc may also be able to assist with special applications, scientific research, and industrial devices.

We have supplied equipment, components, and expertise to many large companies, governments, and universities.

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