1、BRITISH STANDARD BS EN 481: 1993 BS6069-3.5: 1993 Workplace atmospheres Sizefraction definitions for measurement of airborne particles The European Standard EN481:1993 has the status of a British Standard UDC 628.511:331.1:620.113BSEN 481:1993 This British Standard, havingbeen prepared under thedire
2、ction of the Environmentand Pollution Standards Policy Committee, waspublished underthe authorityof the Standards Boardand comes into effect on 15 September1993 BSI 06-1999 The following BSI references relate to the work on this standard: EPC/35 Draft for comment91/51961 DC ISBN 0 580 22140 7 Cooper
3、ating organizations The European Committee for Standardization (CEN), under whose supervision this European Standard was prepared, comprises the national standards organizations of the following countries: Austria Oesterreichisches Normungsinstitut Belgium Institut belge de normalisation Denmark Dan
4、sk Standardiseringsraad Finland Suomen Standardisoimisliito, r.y. France Association franaise de normalisation Germany Deutsches Institut fr Normung e.V. Greece Hellenic Organization for Standardization Iceland Technological Institute of Iceland Ireland National Standards Authority of Ireland Italy
5、Ente Nazionale Italiano di Unificazione Luxembourg Inspection du Travail et des Mines Netherlands Nederlands Normalisatie-instituut Norway Norges Standardiseringsforbund Portugal Instituto Portugus da Qualidade Spain Asociacin Espaola de Normalizacin y Certificacin Sweden Standardiseringskommissione
6、n i Sverige Switzerland Association suisse de normalisation United Kingdom British Standards Institution Amendments issued since publication Amd. No. Date CommentsBSEN 481:1993 BSI 06-1999 i Contents Page Cooperating organizations Inside front cover National foreword ii Foreword 2 0 Introduction 3 1
7、 Scope 3 2 Definitions 4 3 Principle of conventions 5 4 Assumptions and approximations 5 5 Specifications for conventions 5 Annex A (informative) Nomenclature of inhalable and respirable fractions in English 8 Annex B (informative) Numerical approximations to cumulative log-normal distributions 8 An
8、nex C (informative) Bibliography 8 National annex NA (informative) Committees responsible Inside back cover Figure 1 The inhalable, thoracic and respirable conventions as percentages of total airborne particles 6 Table 1 Numerical values of the conventions, as percentages of the inhalable convention
9、 or of total airborne particles 7BSEN 481:1993 ii BSI 06-1999 National foreword This British Standard has been prepared under the direction of the Environment and Pollution Standards Policy Committee and is the English language version of EN481:1993 Workplace atmospheres Size fraction definitions fo
10、r measurement of airborne particles, published by the European Committee for Standardization (CEN). A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard
11、does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, theEN title page, pages2 to10, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendment
12、s incorporated. This will be indicated in the amendment table on the inside front cover.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN481 July1993 UDC 628.511:331.1:620.113 Descriptors: Air, quality, air pollution, workroom, accident prevention, aerosols, sampling, suspended matter, measuremen
13、ts, particle density: concentration, specifications English version Workplace atmospheres Size fraction definitions for measurement of airborne particles Atmosphres des lieux de travail Dfinition des fractions de taille pour le mesurage des particules en suspension dans lair Arbeitsplatzatmosphre Fe
14、slegung der Teilchengrenverteilung zur Messung luftgetragener Partikel This European Standard was approved by CEN on 1993-07-27. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standar
15、d without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other lang
16、uage made by translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland
17、, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1993 Copyright reserved to CEN members
18、Ref. No. EN481:1993 EEN481:1993 BSI 06-1999 2 Foreword This European Standard was drawn up by Technical Committee137 “Assessment of workplace exposure” of which the secretariat is held by DIN. This standard was submitted for Formal Vote, and the result was positive. This European Standard shall be g
19、iven the status of a national standard, either by publication of an identical text or by endorsement, at the latest by January 1994, and conflicting national standards shall be withdrawn at the latest by January 1994. According to the CEN/CENELEC Internal Regulations, the following countries are bou
20、nd to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, United Kingdom.EN481:1993 BSI 06-1999 3 0 Introduction The proportion of total particulate matter which
21、 is inhaled into a human body depends on properties of the particles, on the speed and direction of air movement near the body, on breathing rate, and whether breathing is through nose or mouth. Inhaled particles can then deposit somewhere in the respiratory tract, or can be exhaled. The site of dep
22、osition, or probability of exhalation, depends on properties of the particle, respiratory tract, breathing pattern, and other factors. Liquid particles or soluble components of solid particles can be absorbed by the tissues wherever they deposit. Particles can cause damage close to the deposition si
23、te if they are corrosive, radioactive, or capable of initiating some other type of damage. Insoluble particles can be transported to another part of the respiratory tract or body, where they can be absorbed or cause a biological effect. There is a wide variation from one person to another in the pro
24、bability of particle inhalation, deposition, reaction to deposition, and clearance. Nevertheless, it is possible to define conventions for size selective sampling of airborne particles when the purpose of sampling is health-related. These conventions are relationships between aerodynamic diameter an
25、d the fractions to be collected or measured, which approximate to the fractions penetrating to regions of the respiratory tract under average conditions. Measurement conducted according to these conventions will probably yield a better relationship between measured concentration and risk of disease.
26、 NOTEFor further information on the factors affecting inhalation and deposition, and their application in standards, see 8, 9, 10, 11, 12 and 13. 1 Scope This standard defines sampling conventions for particle size fractions which are to be used in assessing the possible health effects resulting fro
27、m inhalation of airborne particles in the workplace. They are derived from experimental data for healthy adults. Conventions are defined for the inhalable, thoracic and respirable fractions; extrathoracic and tracheobronchial conventions may be calculated from the defined conventions. (The inhalable
28、 fraction is sometimes called inspirable the terms are equivalent. The nomenclature of the fractions is discussed in Annex A.) Assumptions are given in clause 4. The convention chosen will depend on the region of effect of the component of interest in the airborne particles (see clause 3). Conventio
29、ns are stated in terms of mass fractions, but they may also be used when the intention is to evaluate the total surface area or the number of particles in the collected material. In practice, the conventions will often be used to specify instruments to sample airborne particles for the purpose of me
30、asuring concentrations corresponding to the defined fractions. It should be noted that experimental error in the testing of instruments, and possible dependence on factors other than aerodynamic diameter, mean that it is only possible to make a statement of probability that an instruments performanc
31、e falls within a certain range, and that different instruments will fall within an acceptable range. NOTEThe problem of comparing instruments with the conventions is to be dealt with in another standard. One application is the comparison of mass concentration of airborne size fractions with limit va
32、lues. It should be noted with respect to relevant European Directives that the use of other methods is allowed provided that they yield the same or stricter conclusion. One important example is the respirable convention in relation to compliance with the limit value. Equipment matching the Johannesb
33、urg convention 2 will in practical circumstances give the same or a higher mass concentration (by up to about20 %) than equipment matching the respirable convention given in 5.3, so the use of equipment matching the Johannesburg convention will be consistent with the European Directive. The conventi
34、ons should not be used in association with limit values defined in completely different terms, for example for fibre limit values defined in terms of the length and diameter of fibres.EN481:1993 4 BSI 06-1999 2 Definitions For the purposes of this standard, the following definitions apply 2.1 sampli
35、ng convention A target specification for sampling instruments which approximates to, for each particle aerodynamic diameter: in the case of inhalable convention, the ratio of the mass concentration of particles entering the respiratory tract to the corresponding mass concentration in the air before
36、the particles are affected by the presence of the exposed individual and inhalation; in the case of the other conventions, the ratio of the mass concentration of particles entering the specified region of the respiratory tract to the mass concentration of particles entering the respiratory tract. (T
37、hese other conventions can also be expressed as ratios to the mass concentration of total airborne particles.) 2.2 particle aerodynamic diameter the diameter of a sphere of density1gcm 3with the same terminal velocity due to gravitational force in calm air, as the particle, under the prevailing cond
38、itions of temperature, pressure and relative humidity (see clause4) NOTEFor particles of aerodynamic diameter less than0,5 4m, the particle diffusion diameter should be used instead of the particle aerodynamic diameter. The particle diffusion diameter means the diameter of a sphere with the same dif
39、fusion coefficient as the particle under the prevailing conditions of temperature, pressure and relative humidity. 2.3 inhalable fraction the mass fraction of total airborne particles which is inhaled through the nose and mouth NOTEThe inhalable fraction depends on the speed and direction of the air
40、 movement, on breathing rate and other factors. 2.4 inhalable convention a target specification for sampling instruments when the inhalable fraction is the fraction of interest 2.5 extrathoracic fraction the mass fraction of inhaled particles failing to penetrate beyond the larynx 2.6 extrathoracic
41、convention a target specification for sampling instruments when the extrathoracic fraction is of interest 2.7 thoracic fraction the mass fraction of inhaled particles penetrating beyond the larynx 2.8 thoracic convention a target specification for sampling instruments when the thoracic fraction is o
42、f interest 2.9 tracheobronchial fraction the mass fraction of inhaled particles penetrating beyond the larynx, but failing to penetrate to the unciliated airways 2.10 tracheobronchial convention a target specification for sampling instruments when the tracheobronchial fraction is of interest 2.11 re
43、spirable fraction the mass fraction of inhaled particles penetrating to the unciliated airways 2.12 respirable convention a target specification for sampling instruments when the respirable fraction is of interest 2.13 total airborne particles all particles surrounded by air in a given volume of air
44、 NOTEBecause all measuring instruments are size-selective to some extent, it is often impossible to measure the total airborne particle concentration.EN481:1993 BSI 06-1999 5 3 Principle of conventions The sampling conventions recognize that only a fraction of the airborne particles which are near t
45、o the nose and mouth is inhaled. This fraction is called the inhalable fraction (see2.3). For some substances, the subfractions of this which penetrate beyond the larynx, or to the unciliated airways are of special significance for health. This standard presents conventionalized curves approximating
46、 to the fraction inhaled and the subfractions reaching beyond the larynx or to the unciliated airways. These curves are called the inhalable convention (see2.4), the thoracic convention (see2.8) and the respirable convention (see2.12). Extrathoracic (see2.6) and tracheobronchial (see2.10) convention
47、s may be calculated from these. Instruments used for sampling need to conform with the sampling convention appropriate to the region of the respiratory tract where deposition of the substance being measured might lead to biological effect. For example, the inhalable convention would be chosen if the
48、 substance might lead to a biological effect wherever it deposited, the thoracic convention would be chosen if the region was the bronchi, and the respirable convention if the region was the alveoli. Instruments can be used to collect individual fractions according to the conventions, or to collect
49、several fractions simultaneously. For example, an instrument could collect particles from the air according to the inhalable convention, and then separate this material into portions according to thoracic, tracheobronchial and respirable conventions. Alternatively, an instrument might just collect the respirable fraction from the air. In this case, the design would have to ensure that selection at the entry due to aerodynamic effects, and subsequently within the instrument, was such that the overall selection was in accord
