ICNIRP GUIDELINES

1 INTERNATIONAL COMMISSION ON NON-IONIZING RADIATION PROTECTION ICNIRP PUBLICATION 2004 ICNIRP GUIDELINES ON LIMITS OF exposure TO ultraviolet RADIATION OF WAVELENGTHS BETWEEN 180 nm AND 400 nm (INCOHERENT OPTICAL RADIATION) PUBLISHED IN: HEALTH PHYSICS 87(2):171-186; 2004 ICNIRP GuidelinesGUIDELINES ON LIMITS OF exposure TO ULTRAVIOLETRADIATION OF WAVELENGTHS BETWEEN 180 NM AND 400NM (INCOHERENT OPTICAL RADIATION)The International Commission on Non-Ionizing Radiation Protection*INTRODUCTIONSINCE THEpublication of the ICNIRPG uidelines on UVRadiation Limits( ICNIRP 1996), recent research hasmade it appropriate to update the GUIDELINES for protec-tion. While no significant changes are made in the values,the biological basis can be strengthened, and the limita-tions on use can be document titledEnvironmental Health Criteria160, ultraviolet Radiation(UNEP 1994), was publishedin 1994 under the joint sponsorship of the United NationsEnvironment Programme (UNEP), ICNIRP , and theWorld Health Organization (WHO).

2 The document con-tains a review of the biological effects reported fromexposure to ultraviolet radiation (UVR) and serves as thescientific rationale for the development of these guide-lines. In addition, the International Agency for CancerResearch (IARC) published a monograph on UVR in1992 (IARC 1992) and published a monograph onsunscreens more recently (IARC/WHO 2001). Further-more, the National Radiological Protection Board(NRPB) has recently published a scientific review of thehealth effects of UVR (NRPB 2002). Reviews of relevantUVR biological action spectra were published in amonograph on the measurement of optical radiationhazards ( ICNIRP /CIE 1998). The important publicationsthat relate most directly to the GUIDELINES [some of whichhave appeared since the Environmental Health Criteria(EHC) document was drafted] are referenced in therationale (Appendix).

3 The purpose of these GUIDELINES is to provide basicprinciples of protection against non-coherent ultravioletradiation, so that they may serve as guidance to thevarious international and national bodies or individualexperts who are responsible for the development ofregulations, recommendations, or codes of practice toprotect workers and the general public from the poten-tially adverse effects of Committee recognized that when standards orexposure limits (ELs) are established, various valuejudgments are made. The validity of scientific reports hasto be considered, and extrapolations from animal exper-iments to effects on humans have to be made. Costs analyses are necessary, including economic im-pact of controls. The limits in these GUIDELINES werebased on the scientific data, and no consideration wasgiven to economic impact or other non-scientific priori-ties.

4 However, the limits represent conditions underwhich it is expected that nearly all individuals may berepeatedly exposed without acute adverse effects and,based upon best available evidence, without noticeablerisk of delayed effects (see paragraph on Special Con-siderations). Although a single set of limits can apply forexposure of the eye, it is not possible to provide a singleexposure limit that applies to all skin phototypes. Addi-tional guidance is required for applying GUIDELINES forskin Subcommittee IV (Optical Radiation) pre-pared the initial update of these GUIDELINES after anextensive review of the current scientific evidence. TheIRPA Associate Societies as well as a number of com-petent institutions and individual experts were consultedin the preparation of the GUIDELINES and their cooperationis gratefully its review of the whole database, ICNIRP noted thata substantial number of studies have been published since1989, when the last detailed rationale for the GUIDELINES waspublished, and since the UNEP/ ICNIRP /WHO EHC waspublished in 1994.

5 Many of the biological effects, whereonly tentative data were available in 1994, have now beenclarified. In particular, the understanding of UVA-induceddamage to DNA by indirect mechanisms, the involvement* ICNIRP , c/o BfS R. Matthes, Ingolstaedter Landstr. 1, 85764 Oberschleissheim, Germany. The initial GUIDELINES were published in Health Phys 49:331 340; 1985, amended in Health Phys 56:971 972; 1989, and recon-firmed by ICNIRP in Health Phys 71:978; correspondence or reprints contact: R. Matthes at the aboveaddress or email at received5 February2004;accepted30 April2004)0017-9078/04/0 Copyright 2004 Health Physics Society171of new mechanisms for cell protection against the harmfuleffects of photosensitized reactions, and the participation ofUVA in the chain of events believed to play a role inmelanocytic and non-melanocytic skin cancer provide abetter understanding of the risk of human exposure to is further evidence for the importance of early life(childhood and adolescence) irradiation for melanocyticskin cancer (IARC/WHO 2001) and probably for basal cellcarcinoma (Kricker et al.

6 1995; Gallagher et al. 1995a, b).There has been significant improvement in the understand-ing of the complex chain of events involved in photocarci-nogenesis, , the discovery of a UVR signature at themolecular level ( , the p53 gene mutation) (Mukhtar andElmets 1996; IARC 1992). Progress has also been made instandardizing several action spectra including those forphotocarcinogenesis and erythema by the InternationalCommission on Illumination (CIE 1999, 2000, 2002).It was noted, however, that a number of issues stillneed further research before a more complete health riskassessment can be made. These include the modulationof the immune system by both UVA and UVB and theirinteraction with several chromophores; the apparent roleof UVA in the development of melanocytic skin cancer;and the role of both UVA and UVB in the developmentof different types of cataract (UNEP 1994).

7 The Interna-tional Agency for Research on Cancer (IARC) of theWHO recently reviewed the impact of sunscreens(IARC/WHO 2001). ICNIRP concludes that, while significant clarificationhas occurred with respect to health risk assessment fromexposure to UVR, recent data do not provide any resultssuggesting that the exposure limit values contained in Table1 of the 1989 GUIDELINES need to be amended. This conclu-sion is supported by a review conducted by the NationalRadiological Protection Board (NRPB 2002). Thus, IC-NIRP reaffirms the 1989 GUIDELINES on exposure limits toUVR as valid for current use. ICNIRP will continue tomonitor the scientific literature and amend the GUIDELINES onexposure limits as radiation (UVR) occupies that portion ofthe electromagnetic spectrum from at least 100 to 400nanometers (nm).

8 In discussing UVR biological effects,the International Commission on Illumination (CIE) hasTable exposure limits and spectral weighting function. a(nm)ELd(J m 2)ELd(mJ cm 2)S( )b a(nm)ELd(J m 2)ELd(mJ cm 2)S( )b1802, , , , , , chosen are representative; other values should be interpolated (see Eqns. 2a c).bRelative spectral lines of a mercury discharge for a monochromatic source, but also limited by a dose-rate of 10 kW m 2(1 Wcm 2) for durations greater than1saswell inorder to preclude thermal PhysicsAugust 2004, Volume 87, Number 2divided the UV spectrum into three bands. The band 315to 380 400 nm is designated as UVA, 280 to 315 nm asUVB, and 100 to 280 nm as UVC (CIE 1987, 1999).Wavelengths below 180 nm (vacuum UV) are of littlepractical biologic significance since they are readilyabsorbed in air.

9 ultraviolet radiation is used in a widevariety of medical and industrial processes and forcosmetic purposes. These include photocuring of inksand plastics (UVA and UVB), photoresist processes (allUV), solar simulation (all UV), cosmetic tanning (UVAand UVB), fade testing (UVA and UVB), dermatology(all UV), and dentistry (UVA). Even though the principaloperating wavelengths for most of these processes are inthe UVA, almost always some shorter wavelength (UVBand UVC) radiation and violet light are emitted as industrial applications employ arc sources for heator light ( , welding), which also produce UVR as anunwanted admixture for which control measures may benecessary. While it is generally agreed that some low-level exposure to UVR benefits health (UNEP 1994;Preece et al. 1975; Clemens et al.)

10 1982; Holick 2000;Webb et al. 1988, 1989; MacLaughlin and Holick 1985),there are adverse effects (de Gruijl 1997; UNEP 1994; ICNIRP /CIE 1998) that necessitate the development anduse of ELs for UVR. However, the development of UVREL poses a real challenge to achieve a realistic balancebetween beneficial and adverse health 1980, it was generally thought that the mostsignificant adverse UVR health effects resulted fromexposures at wavelengths below 315 nm; but today theseeffects are recognized to be produced at longer wave-lengths (UVA) at substantially higher doses. At one time,wavelengths below 315 nm were collectively known as actinic radiation, when it was thought that these effectsoccurred only in the UVB and UVC. This guideline hasbeen limited to wavelengths greater than 180 nm whereUVR is transmitted through air.