🌿 Exposure to ultraviolet radiation from artificial sources at the workplace — measurement of the effective radiant exposure in the band 180–400 nm

Environment PN-EN 14255-1

Overview

The standard specifies procedures for the measurement and assessment of the exposure of persons to ultraviolet radiation emitted by artificial sources wherever harmful effects cannot be excluded in advance. It concerns workplaces inside and outside buildings; it does not cover exposure during leisure time nor exposure to solar ultraviolet radiation (that is dealt with by Part 3). It applies to incoherent sources emitting both spectral lines and continuous spectra, in the band from 180 nm to 400 nm; it does not concern coherent sources, that is lasers, for which separate standards apply, nor the emission of radiation from products, nor exposures concerning the retina of the eye (those are described by Part 2). The standard does not lay down exposure limit values — it supports the application of the values laid down by national regulations or by international recommendations.

The quantities with which the measurement operates are strictly defined: the irradiance E in watts per square metre, the spectral irradiance Eλ(λ), the radiant exposure H in joules per square metre, the spectral radiant exposure Hλ(λ) and — the key ones for the assessment of the hazard — the effective radiant exposure Hs and the effective irradiance Es, calculated from the spectral quantities by weighting with the spectral effectiveness function of the ultraviolet hazard s(λ). The exposure time is denoted as Δtexp.

The procedure has seven steps: preliminary survey, analysis of the work task, measurement of the exposure, assessment of the exposure, decision on protective measures, decision on repeating the measurement and the assessment, and the drawing up of a report. The preliminary survey serves to decide whether a detailed assessment of the hazard based on measurements is needed at all — all the available information about the source of radiation and about the possible exposure of persons is collected. In some cases it is not necessary to carry out all the steps. An editorial note: the list of steps below has eight items, because we have set out the planning of the measurement separately — in the standard it is part of the step „measurement of the exposure".

The Polish context: the regulation on the maximum admissible concentrations and intensities of harmful agents lays down the maximum admissible exposures. The maximum admissible effective radiant exposure of the eyes and the skin to ultraviolet radiation during the daily working time, irrespective of its length, is 30 J/m², determined according to the effectiveness curve in the range 180–400 nm. In addition, in order to prevent cataract, the total radiant exposure of the eyes to radiation of the band 315–400 nm has been limited to 10 000 J/m² during the daily working time. The spectral distribution of the relative biological effectiveness of ultraviolet radiation causing erythema of the skin and inflammation of the cornea and of the conjunctiva is laid down both by the regulation and by the standard itself. Ultraviolet radiation is divided into bands: UV-A (near) 315–400 nm, UV-B (medium) 280–315 nm and UV-C 100–280 nm (the standard covers it only from 180 nm), the criterion of the assessment of the hazard being the prevention of erythema of the skin, of inflammation of the cornea and of the conjunctiva of the eye, of the development of neoplastic changes of the skin and of cataract of the lens.

THE SCALE OF CITATIONS AND THE PAIR OF PARTS 1 – 2 (read on 23.09.2026). Matching by the BEGINNING of the string: **73 entries at 20 laboratories**; by all forms (with the addition of "PN-EN-14255-1:2010" with a superfluous hyphen, 4 records) — 77 at 21. The second part of the same series, PN-EN 14255-2 (visible and infrared radiation), has 98 entries at 22 laboratories, so both parts are spread almost evenly across the scopes. The ratio of entries to laboratories is 3.6 — a laboratory that has this standard breaks it down on average into three to four lines, usually separating the spectral ranges or the measured quantities.

Two records add the method variant to the designation: "PN-EN 14255-1:2010 Metoda A Method A" and "…Metoda M Method M" — with the addition in two languages at once, because the accreditation scope is a bilingual document.

Method principle

The assessment is carried out in seven steps: preliminary survey, analysis of the work task, measurement of the exposure to ultraviolet radiation, assessment of the exposure, decision on protective measures, decision on repeating the measurement and the assessment, and preparation of a report. The preliminary survey decides whether a detailed assessment based on measurements is necessary — all the available information about the source and about the possible exposure of persons is used in it; in some cases not all the steps are needed. The measurement consists in determining the radiometric quantities at the workplace: the irradiance E [W/m²] and the spectral irradiance Eλ(λ) [W/(m²·nm)], and from them — by integration over the exposure time Δtexp — the radiant exposure H [J/m²] and the spectral radiant exposure Hλ(λ). For the assessment of the hazard the effective quantities are calculated: the effective radiant exposure Hs as the integral of the spectral radiant exposure weighted with the spectral effectiveness function of the ultraviolet hazard s(λ) over the range of wavelengths, or as the integral of the effective irradiance Es over the exposure time. The values obtained are compared with the limits from the national regulations — in Poland 30 J/m² of effective radiant exposure of the eyes and the skin in the range 180–400 nm per daily working time and 10 000 J/m² of radiant exposure of the eyes in the band 315–400 nm.

Applications

• Welding shops and arc cutting workplaces — the strongest artificial sources of ultraviolet radiation in industry
• Germicidal lamps and UV-C disinfection systems in food plants, waterworks and hospitals
• Curing of varnishes and adhesives with UV radiation — printing, furniture making, electronics
• Laboratories with UV lamps (transilluminators, laminar flow cabinets with a germicidal lamp)
• Assessment of the effectiveness of protective measures and the decision on their choice at the workplace

Key parameters

Standard

Standard number

PN-EN 14255-1:2010 (wersja polska; wprowadza EN 14255-1:2005 [IDT])

Title (PL)

Pomiar i ocena ekspozycji osób na niespójne promieniowanie optyczne — Część 1: Promieniowanie nadfioletowe emitowane przez źródła sztuczne na stanowisku pracy

Title (EN)

Measurement and assessment of personal exposures to incoherent optical radiation — Part 1: Ultraviolet radiation emitted by artificial sources in the workplace

Step-by-step procedure

1. Preliminary survey

   Collect all the available information about the source of radiation and about the possible exposure of persons and decide whether a detailed assessment of the hazard based on measurements is necessary. In some cases the further steps are not needed.

2. Analysis of the work task

   Set out the activities of the worker: where they stand, how long they remain in the field of radiation, which parts of the body are uncovered, when the source is operating. From this analysis follow the places of measurement and the exposure time.

3. Planning of the measurement

   Establish which quantities have to be determined (irradiance, spectral irradiance, the effective quantities) and with what instrument — a radiometer with a detector weighted with the function s(λ) or a spectroradiometer.

4. Measurement of the exposure

   Carry out the measurements at the place corresponding to the position of the eyes and of the uncovered skin of the worker, under conditions of operation of the source consistent with the analysis of the work task. Note the exposure time Δtexp.

5. Calculation of the effective quantities

   Calculate the radiant exposure H (the integral of the irradiance over the exposure time) and the effective quantities Es and Hs by weighting the spectral quantities with the spectral effectiveness function of the ultraviolet hazard s(λ) in the range 180–400 nm.

6. Assessment

   Compare the values calculated with the limits from the national regulations: an effective radiant exposure of 30 J/m² for the eyes and the skin in the range 180–400 nm per daily working time and 10 000 J/m² for the eyes in the band 315–400 nm.

7. Protective measures and repetition

   Take a decision on protective measures and then on whether and when the measurement and the assessment should be repeated (a change of the source, of the organisation of the work or of the protective measures).

8. Report

   Draw up a report covering the description of the source and of the workplace, the analysis of the work task, the conditions and the results of the measurements, the effective quantities calculated, the comparison with the admissible values and the conclusions as to protective measures.

Required equipment and apparatus

Health and safety (OHS)

• The person carrying out the measurement is in the field of ultraviolet radiation — protective goggles with a UV filter, a face shield and clothing covering the skin are obligatory.
• The effects of ultraviolet radiation are delayed: erythema of the skin and inflammation of the cornea (welders’ flash / arc eye) appear after hours, so the absence of sensations during the measurement does not mean the absence of exposure.
• UV-C germicidal lamps are sometimes switched on remotely or automatically — before the measurement arrange with the user for the switching-on to be blocked.
• Do not look directly into the source, including through viewing windows and optical instruments without a filter.
• A measurement in a welding shop means in addition welding fumes and hot elements — apply the protective measures proper to that workplace.

Frequently asked questions