ISO 17166 pdf download

ISO 17166 pdf download.Erythema Reference Action Spectrum and Standard Erythema Dose 1. Introduction The problem of dosimetry in skin photobiology lies in the fact that the ability of ultraviolet (UV) radiation to elicit erythema in human skin depends strongly on wavelength, encompassing a range of four orders of magnitude between 250 nm and 400 nm. Thus a statement that a subject received an exposure dose of 1 J⋅cm -2 (10 4 J⋅m -2 ) of UV radiation conveys nothing about the consequences of that exposure in terms of erythema. If the radiation source was a UVA fluorescent lamp, no erythemal response would be seen apart from in people exhibiting severe, abnormal pathological photosensitivity. The same dose delivered from an unfiltered mercury arc lamp or fluorescent sun-lamp would result in marked violaceous erythema in most white skinned individuals. Consequently, photobiologists have long recognised the need to express the exposure as an erythemally-weighted quantity 1 . Recently the term minimal erythema dose (MED) has been used widely as a ‘measure’ of erythemal radiation. This is unreasonable because the MED is not a standard measure of anything but, on the contrary, encompasses the variable nature of individual sensitivity to ultraviolet radiation. Variables which affect the MED include optical and radiometric characteristics of the source; determinants of the exposure such as dose increment and field size; nature of the skin such as pigmentation, previous light exposure, and anatomical site; and observational factors such as definition of the end point, time of reading after exposure, and ambient illumination. To avoid further confusing misuse of the term MED , we propose that this term be reserved solely for observational studies in humans and other animals, and that a new term, the standard erythema dose (SED) be used as a standardized measure of erythemogenic UV radiation. 3. Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this Standard are encouraged to investigate the possibility of applying most recent editions of the standards indicated below. Members of CIE, the International Electrotechnical Commission (IEC) and the International Organization for Standardization (ISO) maintain registers of currently valid international standards. 1. Diffey BL. Whatever happened to the erythemal unit? Photodermatology 1984; 1: 103-105. 2. International Commission on Illumination. Berlin. Comptes...