INTERNATIONAL ISO STANDARD 14644-1 Fst edition 11999:05-04 Cleanrooms and associated controlled environments — Part 4: . Classification of air cleanliness Salles propres ot environnements mafvisés apparentés — Parti 1; Classification de la propreté de Fair Reference number 180 14844-1:1990(€)ISO 14644-1:1999(E) ©1so Contents Foreword . Introduction 1 Scope 2. Definitions 3. Classification . 7 44 Demonstration of compliance Annexes, Annex A (informative) Graphical illustration of the classes of Table 1. Annex B (normative) Determination of partictlate cleanness classification using a discrete-patcle-counfing, ight-satterng strum ‘Annex C (normative) Statistical treatment of particle. concentration data .. ‘Annex D (informative) Worked examples of classification calculations .... 10° Annex E (normative) Conaieraten rte coprdngans sing partes ‘Outside the size range applicable for classification. ‘Annex (informative) Sequential sampling procedure Bibliography Figures {or selected ISO classes... Figure F1 Boundaries for pass or fl by the sequential sampling j Procedure Tables. no de No io N Table 1 Selected aibome partzlate cleanliness classes clearvooms and clean zones tribution fr the 95% Upper conden it nan 9 Table C.1 Students tdi Table F1 Upper and lower limits for time at which C observed counts, should arrive 16 © 150 1999 [Nights served, Unies neni specied,no pat ofthis pubicaton msy be reproduced or ulized in en form or by any mens, lor machanial, Including photocopying nc micrefin without permission in witing Fm the publisher Intemational Organization fr Standardization (Cane Potala Se" CH=1211 Gonbve 20» Suteeiand Intemet.iso@iso.ch Printed in Switzerlande1so ISO 14644-1:1999(E) Foreword 180 {the International Organization for Standardization) is & worldwide federation of national standards bodies {ISO member bodies). The work of preparing Intemational ‘Standards is normally carried out through ISO technical committees. Each member body Interested in a subject for which a technical committes has been established has the right to be represented on that committe. Intemational organizations, governmental and nongovernmental, in lisison wit ISO, also take partin the work. 1SO collaborates closely with the International Electtotechnical Commission ([EC) on all maters of electrotechnicel standardization “Draft Inliational Standards adopted by the technical committees are clculated to the 7 member bodies for voting. Publication as an International Standard requires approval by atleast 75% of the member bocles casting a vote, International Standard ISO 14644-1 was propared by Technical Commit Cleanrooms and associated controled environments. 180 14644 consists of the folowing parts, under the general tite Cleanrooms and ‘associated controlled eovironments.= — Part: Chestteaton of ak ceaniness — Part 2:Specitcations| for tesa and monitoring to reve continded compliance with ISO 14044-1 = Part 3: Metrology and test methoes | i i "Part 4: Design, construction and start-up Part 5: Operations “poi! Terms anc Bench art 7:.Enhanced clean devices Urs should nol tl ites td for parts 2 7 ae working ies lth ie of ho release par nthe eve baton or ore fee pre ae deed rom the work program, the remaining pare may bo renumbered Aeros Bard Cfo an tga partlthis pat of $0 14844, Annexes ADE, and F tre ter rtrmaton ony. Iso/Te 200, oT(as 1SO 14644-1:1999(E) Introduction Cieanrooms and sssociated contvolled environmen provide forthe conta of aitorne arate contamination ovls appropriate for accomplishing contaminaton-senstve facts, Products and process that benefit fram the contol farbome contamination includ these in such ndustie es eeospace, irelecroncs pharmaceuticals, medal deve, food, and heaters ‘This part of ISO 14644 assigns ISO classiftion levels id he specication of sirdeninessin learrooms andastocstedconroleservfonment, alo jresirbosthe ‘landard method of testing as wala the proc eterining the concentration of airborne pares. \ For classifcaion purposes, this pat af 180 Tae iia 6°a designated Tangh of | considered parte sizes or determinalion of patil concentration ns, This pat ofISO 14644 elo provides standard protocols for the determination and designation of clasni- nesses hatarebase on arn once ace shale orlargrtan he size range designated for lasiialon, , This pat of ISO 14644 is one ofa seres of standerds gencemed with eleanvéoms and contamination cool Many factors desdes aoome partouate cleanliness must be considered inthe design, specfeaton, operation, ar contol of Sleanrooms and ater entalled environments These are coveredinsdmedetalit other arts ofthe nteratinal Standards prepared by ISOITC 209 Insome crcumstances, rlovant“aguatory agencles may impose supplementary plies, oF restos, ash salon dures may'bs equines." Serropeneon earmmetemasorn VC @IsoINTERNATIONAL STANDARD © ISO ISO 14644-1:1999(E) Cleanrooms and associated controlled environments — Part 1: Classification of air cleanliness 4 Scope f ‘This par of ISO 14844 covers the ciassiication of air clean ness in cleanrooms and associated vontrolled-environments=—> exclusively in terms of concontration of airborne, particles. | Only particle populations having cumiaiative distributions based | ontheeshold (lower limit sizesranging from 0,1yumtoSumare | considered for classification purposes. \ | ‘This part of ISO 14844 does not provide for classification of | porfcle populations that are outside of the specified particle | size range, 0,1 umtoSum. Concentrations of ultrafine particles: (particles smalier then 0,1 4mm) and macroparticies (particles larger than 5 um) may be used to quantiy these | terms of U descriptors and M descriptors, respectively ‘This part of ISO 14844 cannot be used, ta characterize the. physical, chemical, radiological, or Viable nature:of airborne’! T particles. % a NOTE _Theacualdistibutlon ofparicle conééntratons withinincre=== ‘mental size ranges normally inet predictable and typically \s.variable ‘overtime. 7 2 Definitions For the purposes of this part of ISO 14644, the following ‘eintions appy. 2.1 General 2aa cleanroom room in which the concentration of arbome partcies is con trolled, and which is constructed and used in a manner to ‘minimize the introduction, generation, and retention of part- les inside thé room, and in which other relevant parameters, fg. temperature, humidty, and pressure, are contvolled 35 necessary 212 \ clean Zon | dedicated space in wnich the concentration of sirbome part cles is contoled, and which Is constructed and used in a ‘manner taminiize the introduction, generation, and retention of particles inside the Zone, and in which other relevant | parameters.-¢.9, temperalure, humidity, and pressure, are controlled asinecessary. "NOTE This Zane may Se operoe once and vay or iy nt be located within a leanom, aco installation =Seleanroom or one or more clean zones, together with all ‘associated structures, airtroatment systams, services, and tities 218 classification level (or the process of specifying or determining the level of airoome particulate cleanliness applicable to a cleanroom or ‘lean zone, expressed in terms of an ISO Class N, which represents maximum allowable concentrations (In particles er cubic metre oat for considered sizes of particles NOTE 1 Theconcentzations are detormined by using squaton (1) in 32, NOTE 2 _ Cletsicaton in accordance wth this Intemational Stan- dard ited othe ange extending fom ISO Cass 1 trough ISO tase 9. NOTES The considered paris stes (wor threshold values) ‘nplcabe for casifeaton In sccordanco with tis InternationalISO 14644-1:1999(E) Standard are Brite tothe range fom 0,1 yr though § ym. A ‘eaninass may be desaibed and spectied (but not clase) in ferme of U descriptors oF M dessipiors (600 281 oF 2.3.2) for ‘considered threshold porte sizes tha are ouside ofthe range ‘ovorad by laelfcation, NOTE 4 Inlermediste ISO classification numbers may be spect ‘ad, with 0.1 the smallest parmited increment; Le, the range of intermadate 1SO classes extends rom ISO Class 1,1 trough ISO Chess. NOTES Clasifeation maybe spaciied or accomplshedin eny of ‘tree eocupancy states (eee 24). 2.2 Airborne particles 224 2 particle Fodor liquid object wnich, fr purposes ofclassieation of Cleanliness, falls within a cumulative dietrbution that is based. ‘upon a threshold ((ower iit) size inthe range from 0,1 um to Sum 222 a particle size Giameter ofa sphere thet produces a respotse, By & gen pariclesaing instrument tat exalt oe reponse procuced by the parce being measired NOTE For cscrote-pate-counn, ligh-scatia nstunahi, the equivalent optical Samet is uses, mea 2.4 Occupancy states ©1so 2.3 Descriptors 234 U descriptor ‘measired or speced concantration, of particles per cubic ‘metre of er, Including the ulafine particles NOTE Tho U deserptormay be regarded as an upper tint for the ‘averages at samping locations (or a8 an upper confines tit, ‘depending un he nurber of sampling locations used to characte |2e the dsarroom or clean zoe). U descriptors cannot be used to afin aioome paricuate cleanness classes, but they may be ‘quoted Indepancenty or in conjuction wih siborne particulate ‘leenlingss lasses. 232 M descriptor measured or specified concentration of macroparicles pet ‘oubie'metra of alr, expressed in terms of the equivalent ‘diameter that is charactorstic of the measurement method used "| NOTE The Midescripr may be garded as an uppsr lint forthe ‘averages at sampling locations (oF as, an upper confine limit {depending uo he numberof mplinglocaone used chars lve the daanroom or clean zone). M deseptors cannot be used fo ‘define akborhe pertcuate cleanness ossaes, but they may bo fuoted independent or in conjunction with aibore particulate beanlness classes. \ 223 . —_ a rue ber ‘individual particles. ‘unit volume, in a ri fide pa rt motte Norris iernnench carbides sine, 24 ERE erinea was hossoosonpoe particle size distribution Ry ‘cumulative distribution of particle concentration dtafunctionof particle size 225 ultrafine particle particle with an equivalent diameter less than 0.1 yum 226 ‘macroparticle particle with an equivalent diameter greater than 5 wm 227 fre particle having an aspect (lengt-lo-wicth) ratio of 10 or more materials, or personnel present 242 “atrest condtion where the installation is complete with aqulpment installed and operating Ina manner agreed upon by the ‘customer and supplier, but wth no personnel present 243 ‘operational Condition where the installation is functioning in the specified ‘manner, withthe specified number of personnel present anc working in the manner agreed upon© Iso Iso 1464-1: Table 1 — Selected airborne particulate cleanliness classes for cleanrooms and clean zones ‘Maximum concentration limits (partclesin® of alr for particles equal to and larger 'S0.__| than the considered sizes shown below (concentration limits are calculated in lassfiation | accordance with equation (1) in 3.2) ‘number (N) tum | O24m | O3nm | O5um | thm Bum 180 Class 1 10 2 150 Ciass 2 00 24 0 4 180 Glass 3 7000) 257 102 35 8 isoGlass4 | 10000[ 2370| 1020 352 8 1s0Glass5 | 100000{ 23 700[ 10200] 3.820 32 28 180 Glass 6 | 10000000] 257000 35.200 8320 298 TSO Class 7 2 '362.000] 63.200, 2990 180 Glass 8 ==—=——F3620 000, 692000] 28300 180 Glass 9 36 200000] 8320000] 289 000 NOTE Unceraiities related to the measurement process require that concentration data with no more than three significant gues be used Fy determining the dassicatin level i 2.5 Roles I : '3.2 Classification number os |) || 'aibome-paiulate cleantiness shall be designated by Classication umber, 1. The maximum permited eoncentr=- customer 4 ‘ior of partic%s, C,, foF éach considered particle size, D, is ‘organization, or the agent theteot, responsible for speci¥ving determined from tre equation: supplier oa ‘organization engaged to satisty the specified requirements of ‘aclanrcom or clean zone is the maximum permitted concentration (In pat!- ces per cubic metre of air) of airborne particles that are equal to or larger than the considered particle 3 Classification size. C,, is rounded to the nearest whole number, Using no more than three significant figures. Nis the 180 classification number, which shall not 3.1 Occupancy state(s) exceedavaiue of9, Intermediate SO classification ‘Tho pareulate cleanliness of arin cleanroom or clean zone numbers may be spectied, with 0,1 the smallest halle defined in one or more of three occupancy states, viz permitted increment of N. as-built’, “atrost,or “operational (see 2.4). D__ isthe considered particle size, in micrometres. NOTE shouldbe recognized that the ‘es bul state plate 0.1 is @ constant, with a dimension of micrometres. {wo newy completed or newly mosied clenrooms or lean zones ‘Once tating in the “as-bui” state is completed, farther testing for compliance wile performed inthe"atost or the" operation sao, corboth Table 1 presents solacted airbome particulate cleanliness classes and the corresponding particle concentrations for Particles equal fo and larger than the considered sizes shown, Figure A.1 (see annex A) provides a represeniation of theIso 14644." 1999(E) selected classes in graphical form. In case of dispute, the concentration C, as derved from equation (1) shall serve 05 the standard value, 3.3 Designation “The designation of alrbome particulate cleanliness for clean- rooms and clean zones shall Include: 2) the classification number, expressed as “ISO Ciass N"; the occupancy state to which the classification apps: €) the considered parte sizes), and te related concen- ttaton(s), a8 determined by the classification equation (1) ware each considered threshold parce size isin he range {rom 0,1 ym through 5 um, Example designation: 23 180 Class 4: operational state; considered siz@6: wna ~ (0.2 um (2370 particles), 1m (83 patois) === ‘The considered particle size(s) for which the concentra- tion(s) wil be measured shall be agreed upon by the custom ‘er and the supple. | * Imeasurementsare tobe madeat more than one considered parte size, eac larger particle diameter (e.9.,0,) shall beat least 1,5 times the next smaller particle diameter (e.9, Dy). eg: 2 15 xD, Conilance with i eaantnase (SO: a) reduromen's specified by the customer is verifled by performing specified: testing procedures and by proving specified documentation ‘ofthe results and conditions of testing, as agreed upon by the. ‘customer and the supplier. 42 Testing “The reletence test methed for demonstrating compliance is Given in annex B. An sltematve method having compare catracy may be specie, although ro method is specied ‘oragroed upon, he reference mathed shal bo used ‘Tosts performed to demonstrate compliance shall be con- ducted using caibrtod instuments 4.3 Airborne particle concentration limits Upon completion of testing in accordance with 4.2, average particle concentrations and the 95% upper confidence limit olso (when applicable) shall be calculated using equations shown inannex C. ‘Average particle concentraton(s), calculated in accordance with equation (C.1), shall not exceed the concentration limit(s) determined by use of equation (1) in 32, as specified [3.3 0) forthe considered size(). In addition, for situations in which the number of sampling locations involved is at least two but not more than nine, the calculation of 85% upper confidence limits in accordance with C.3 shall not exceed the concentration limits established above. NOTE Worked examples ofclsscatoncalulstons are provided in annex, Particle concentrations used for determination ofconformance to classification limits shall be measured by the same method forall considered parte sizes. 44 Test report ‘The resuls trom testing each deanroom or clean zone shall be recorded and submitted asa comprehensive report along with @ statement of compliance or noncompliance withthe specified designation of airborne particulate cleanness clas- sifeation.- } “The test report sal include the following: 4) the name and address ofthe testing organization, and the date on whieh the test was performed: the qumber_and year of publication of this part of ISO * 1644, ie, ISO 14644-1: date of currant issue; ) & cles identicatiog of the physical location ofthe clean- room or clean zone. tested (including reference: to, adjacent, ‘areas f necessary), and speciic designations for coordinalés! of al sampling locations; ‘9) the specified designation citeria forthe cleanroom or clean zone, including the ISO classification, the relevant occupancy * state(s), and the considered particle size(s); €) details of hotest method used, with any special conditions ralating to the test or departures from the test method, and Identification ofthe test instrument and its current catibration certicate; 4). the test results, including particle concentration data forall sampling location coordinates. NOTE. Keoncentaions of wate parties or macroparicles are ‘quantites, as described in annex E he pertinent information should be included wth the test report.e180 ISO 14664-1:1999(E) Annex A (informative) Graphical illustration of the classes of Table 1 Figure A dopicts the air cleanness classes of Table 1 in graphical form, for ilustration purposes only. The ISO classes, of Table1 are shawn as lines representing the class concentration limits forthe considered threshold particle sizes. ‘They are based on calculations using equation (1) of 32 As the ines only approximate the cass limits, they are not fo.be used to defn the limits, Such determinations are made in ‘sccordance with equation (1). oF - The classification lines shown on the graph may not be extrapolated beyond the solid circle symbols, which Indicate the minimum and maximum particle size limits ‘acceptable for each of the ISO classes shown. “The classification lines do not represent actual particle size ‘istrlbutions found in cleanrooms and clean zones, ‘Airborne particle concentraton, C,, particlesim? { Cy =10"« (0,10) x) 02 03 05 10 5.0 Particle size, D, in um Figure A.1— Graphical representation of 1SO-class concentration limits for selected ISO classes. NOTE 1 Gy tepresants the maximum permitted concentration (in partles per cubic mere of aif) of altboene particles equal to and lager than the considered pace size, Nove2 Nopresent the specified ISO lass number.Iso 14644~ :1999(E) @1so Annex B (normative) Determination of particulate cleanliness classification using a discrete-particle-counting, light-scattering instrument B.1 Principle ‘Adisrete-parice-countngght-soatteringinstumentis used to determine the concentration of abome particles, equal and large tan the specified sizes, at designated sampling tecations B.2 Apparatus requirements _- B.2.1_ Particle-counting instrument Discrete-artcle counter (0°), light-scattering device hav- ing a means of displaying or recording the count and size of discrete particles in air with a size discrimination capably t- detect the total paricle conceritation inthe appropriate par- ticle slzo ranges for the class under consideration, and @ suitabie sampling system B.2.2 Instrument calibration ‘The instrument shall have a valid calibration éertifeaté the {requency and method of callraion should! be based! on current accepted practice B.3 Pretest conditions B.3.1 Preparation for testing Proto testing, voy thatalaspacsoftheclesnroomoc dean zone tat contrite to Is operational rtegty ere comple’ ‘nd funtonin in accordonce wth ts parformaine spectca- ton = Such pretesting may inuda, for example: 2) srfow volume o veloc toss; lor ») alt pressure difference test; ) containment leakage test 4) installed iter leakage test. B.3.2. Pretest equipment setup Perform equipment selup and pretest calibration ofthe inst ‘ment in accordance with the manufacture’ instructions. B.4 Sampling B.4.1_ Establishment of sampling locations B4t4 Derive the minum numberof sampling point cations fom equation (2.1): A 4) is the minimum number of sampling locations (ounded up to.@ whole number) ‘A _isthgareaofthecleanroomorciesn zone insquare mete. NOTE Intisoase ofunireconalhortzontl aio thosea Amey be considered as tha roes section ofthe moving al perpendicwiar the deci ofte ariow. B41.2 Ensure that the sampling locations aré evenly distributed ¥ groughout the’ area of the cleanroom. or clean-zone-and positioned atthe height ofthe work activity. tomer species ediional sampling locations, ther nd positions shal lso,be specified.» C16 31 NOTE... Such edltonal actions may be those considered eis, based on ark analy 5.4.2 Establishment of single sample volume per location B424 [At each sampling location, sample a sufficient volume of air ‘hata minimum of 20 particles would be detectediftne particle ‘concentration for the largest considered particle size were at ‘the class limit for the designated ISO class. ‘The single sample volume V, per location Is determined by using equation (8.2: 20 Ze x1 000 MO Com 2©1so where V, isthe minimum single sample volume per location, expressed in lites (except see B4.2.2) Gam 18 the class limit (number of particles per cubic metre) forthe largest considered particle size spec- lad forthe eoievant class. 20 is the defined number of particles that could be counted if the paricle concentration were at the class limi NOTE When Vi vorylarge, te tie requiedtor sampling canbe substantia. By using te soquental sampling procedure (see annox bath the required sample volume and the tie required to obtain samples may be ecvees, B4.2.2 The volume sampled at each location shall 86 atleast 2 tires, vith a minimum sampling ime at each location of min: B.4.3. Sampling procedure B431 Sat Up the patel counter (8.2.1 in accordae with the manufacturer's instructions and in compliance with the instru- ment calibration cetficete. B43.2 The sampling probe shall be postioned painting lio. the airflow. controlled or predictable (e.g, nonunidrectonal arfow), the inlet of the sampling probe shall be directed vertically upward B.4.3.3 Sample the volume of air determined in B 42, as. minimum, at each sampling location, 1wGe N B434 oo ‘Where only one sampling location is required (8.4%), take & ‘minimum of tree single sample volumes (8.4.2) at that loca: tion, B.S Recording of results B.5.1. Average concentration of particles at each sampling location B.5.1.4 Recordthe resultof each sample measurement asthe concen tration ofeach of tne considered particle size(s) (2.3) appropri- ate to the relevent classification of air cleanliness. NOTE Consideration shoud be gven tothe requirements of.6.1 before proceeding with th calcubtlon of he 95% upper confidence fet Ifthe direction of the alriw being Sampled Ie not Iso 14844- }999(E) B5A2 \When only one sampling lcationis used, calculate and record the average value of the sample data (8.4.3.4) for each considered particle size, B5A3 When two or more single sample volumes are taken at a location, compute the average particle concentration for each ‘considered particle size fom the individual sample particle ‘concentrations (8.1.1), eccording to the procedure given in 6.2, and record the results, B.5.2 Requirement for computing the 95% upper confidence limit (UCL) B5.24 Whe the number of lcations sampled is more than one and less than ton, comput the overall mean of the averages, standard deviation, and 95% upper confidence limit from the ‘average paticle concentrations for allocations (8.5.1) fllow- Ing the procedure described in ©.3 B5.2.2 When only @ single location is sampled, or when more than rine are sampled, computing the 25% upper confidence limit 's not applicable B.6 Interpretation of results B.6.1 Classification requirements ‘The cléanroam or clean zone is deemed to have met the specified air cleanliness classification ifthe averages of the particle concentrations measured at each ofthe locations wihen applicable, the 95% upper confidence int calelate ‘according to 8.5.2, do not exceed the concentration limits determined in accordance with equation (1) of 3.2. ifthe resus of esting fall to meet the species sir cleanliness Classification, testing may be performed at addtional, evenly dlstrouted sampling locations. ‘The results of recalculation, including data from the added locations, shall be definitive B.6.2 Treatment of outliers ‘The result of the 95% UCL calculation may fall to meet the specified 180 class designation. If the noncompliance is ‘caused by asingle, nonrandom “outlier” valueresuling froman erroneous measurement (due to procedural error or equip- ‘ment matfunction) or from an unusually ow particle concentra tion (due to exceptionally clean ai), the outlier may be ex cluded from the calculation, provided that 2) the calculation is repeated, including all remaining sam- pling locations; ») atleast three measurement values remain in the calcula on;Fy ISO 14644-1:1999(E) ©) nomore than one measurement values excluded fom the calculation: 4) the suspected cause othe erroneous measurement orlow parte concentrationis documented and acceptedby both the customer and supplier. NOTE Widely divergent values for peice concentrations among the locations sampled may be Yeesonable and even Inetional, depending on the natu of the applaton ofthe cian instaition| under test esoISO 14644-1:1999(E) 180 Annex C (normative) Statistical treatment of particle concentration data C.1 Rationale ‘m isthe numberof individual location averages. ‘This statistical analysis considers only random errors (lack of precision), not errors ofa nonrandom nature (eg. biasassoch ated wih erroneous calibration). C.2 Algorithm for computation of average particle concentration at a location (x) 2 ‘When miitple samples are taken at alocai, equation (C1) shallbe used to determine the average particle concentaton athe locaton. Calelaton ofthe average particle concentra {tonshalbe performad foreach sampling lection atwnien wo or more samples have been taken (1) were % ls the average particle ogncentraton at location i representing any location, Xjs10%q_ are the particle canoentraiois ofthe jndl- vidual samples, i: 1» Is the numberof sarhples taken at location i 6.3 Algorithms for Computation of YS 95% upper confidence limit C.3.1 Principle “Ses This procedure Is applicable ely the numberof samplig locaton fs more than one ands than fo, n euch ceur- ance, this procedure shal be used in aio oe ago ‘itm of eqaton (C.1), €.3.2 Overall mean of the averages (x) Using equation (C.2), determine the overall (grand) mean of the averages. (c2) where Is the overall mean of the location averages. Fj; 10% jm_areindvidualocationaverages, determined by Using equation (C1). i 65 U0U =F + a ‘Allingividual location averages are equally weighted, regard- less ofthe number of samples taken at any given location, €.3.3. Standard deviation of the location averages (5) Using equation (.2), determine the standard deviation ofthe locaton averages, where '$_ is the/Standard deviation of the location averages. C.3.4 95% upper confidence limit (UCL) for the overall mean Using equatidn (C.4), determine the 95% upper confidence Jimit forthe overall mean. J (cay al Val of thé Students ¢istbuton (tog) forthe 95% UCL Bie gan in Table ©.1.Atematvely, Student's ¢dstibutions prided in statistical computer programmes are aso accept. able. ‘Table C.1 —Student’s ¢ distribution for the 95% ‘upper confidence limit, Nabe a ‘me |2fala|s|e |r<= ISO 14644-1:1999() eso Annex D (informative) Worked examples of classification calculations D.1 Example 1 Daa ‘The cleanroom under consideration has an area (A) of 80. Conformance with the specified airborne particulate cleani= res classification is tobe determined inthe operational state. “The specified air cleaniiness classification ofthe cleanroom is 180 Class 5. DA2 “wo conrad parce size arena 0.9 (0) a= 05 um (03) 2) Both parte sizes are within the size limitations for SO Ciass 5 [se0 3.3.6) and Table 1}, 0.1 pi 0,2 um, 0,5 ims Sum. ) Application ofthe particle size ratio requirement, Da 1.5 Dy e030}, shows complanes 05 umz {15 403 fim ) = 045 am) DAs i oR of “The maximum permite arbore parce concetralions ate celeatodin accordance wih ewaton (1) 66032) | For particles 2 0,3 um (D,): AER ula) ohare rounded to 10 200 partcles!n® For particles 2 0,5 ym (D,): : rounded to 3 520 particlesim? D.A4 ‘The numberof sampling point locations are derived in accor dance with equation (8.1) (see 8.4.1.1) = VA = 486 = 8,94 {rounded to 9) (3) 10 ‘Therefore the minimum numberof sampling locations is nine ‘and, as the number of sampling locations fs less than ten, the calculation ofthe 95% UCL according to annex Cis applicable. DAS ‘The single sample volume, Vis calculated in lives in accor dance with equation (8.2) (se B.4.2.1): (04) ‘The result is greater than 2 lites, and the ‘sample volume elected jvad 28 tres over a periad of 1 min (@fow rate Commonly avalabeindscrete-paricle-countinglight- seater ing instruments ‘This seletiwas based on: 2) V,>2ies (¢00 84.2.2) 1b) Cam?20 partclesin? (S00 8.4.2.1) 2) °Samplig Une 2 4 min (see 8.4.22). D.A.6 18 each semen (location ony anes {6 lites) i taken (6.4.2.1). Th courts oF ‘measurements ao recorded (65.1.1) belo. Number ct Number ot ‘samira “Sanies "parts 20,3 um) (20,5 wm) : sat 2 i 28 2 By Q 4 08 7 5 1 ° i 28 7 m8 : mF ° 18£3 @1so D.A7 From the raw data (0.1.6), the numberof paticles per cubic motte, x, 1s calculated: Sere sagem 05um oe ao on oo ee Each caleulated concentration value for0,8 um and'0\5 yom less than the limits established in D.13. This satisfies theirs part of classification (6.6.1) and therefore calculation of the 195% UCL according fo annex C can proceed... D.A.8 i ‘Computation of average concentration in accordance, with equation {C.1) (see 2) Is not applicable, as the seinple ‘volumes taken were single volumes which represent an aver- ‘age particle concantration at eachlocation. The overall igans ‘the averages ae calculated in accordance with uation (€.2) (5006.32). fi Forparicles >0,3um: Sp s8 57 t loobi ‘7a 800 8 750+6, e07 +2 107-43 738 Sloe 964 f = fx srr = 8.349,1 rounded to 6 349 particles? For particles > 0.5 pm: 1 (2s 857+ a) (0.8) a{ +903 +2161 9214679 1 1 x 6357 bx 6957 1708.3 rounded to 708 partciasin® ISO 14644-1:1999(E) D.1.9 “The standard deviations of the location averages are caleu- lated in accordance with equation (C.3) (see C.3.3) For particles 2 0,3 um (@ 750-6 349)° +(6 607-6 3497 +2 107-6 349 +(9 786-6 349% = t)46 957-3 349)° +7 000-8 3497 48 071-6 249)°+(@ 000-6 3497 | (5 H6 964-6 346)? on = fx sr 10073 = ° 4 641 259,1 rounded to 4 641 259 NTRS (08) 2.1544 rounded to 2 184 particlesim® For particles 2 0,5 ym: | ‘ (750-709? +(657-706)* ], (0-708)? + (250-706)? 2 -(796 706 + (898 - 7067 t@21-709?+(1 321-706)*|, ‘bay 1679~ 708)* On (0-10) 381,6 rounded to 382 partclesin® D.1.10 ‘The 85% upper confidence limits (UCL) are calculated in ‘accordance with equation (C.4) (seeC.3.4). Asthe rumber of individual averages is m = 9, the ¢ distribution taken from Table C.tis t= 1,9 21s 6% UCL 0,9} <6 940+ 49 ae oF) #77132 (ot) rounded to 7 713 partclesin® 1ISO 14644-1:1999(E) 95% UCL (20,5nmm) = 708 + wo 8) sr (0.12) rounded to 948 particlesim® Daa ‘The interpretation of results is carried out according to B.6.1 |nD.1.7, twas shown thatthe particle concentration of each single sample volume is ess than the specified class limits. In 1.1.10, twas shown thatthe calculated values ofthe 95% UCL are als less than the class limits established in D.1.3. ‘Therefore the airborne particulato cleanliness of the clean- room meets the required classification. oo D.2 Example 2 D.2.1 ‘This example is constructed to show the Influence ofthe 95% UCL calculations on the results ‘A cleanroom le spectied for a particulate cleanliness of ISO Cass 3 in operation. The number of sampling locations has been determined to be five. As the. umber of samplt locations is more than one and ess than ten, the caleuation of the 95% UCL according to annex C's applicable i Cnty one particle size (D2 0,1 ym) is Gonsidered, D.2.2 ‘The pale concentration iif ISO Ciass 8 at2 0,4 ums token fom Tablet D.2.3 taken (85.1.1), The number ofpartisles per cubic metre, x15" calculated foreach location and recorded below: ‘Sampling location x,2 04 um 1 926 2 958 3 937 4 983 5 214 Each value of the concentration for D = 0,1 um is less than ‘the limit established in 0.2.2. This result satisfies tho fist part of classification (8.61) and therefore calculation ofthe 95% UCL according o annex C can proceed. D.24 ‘The overall ean of the averages is caleulated in accordance vith equation (C.2) (sae C32) 12 Norrniceimne ©1so Za 3 025+ 058+ s07 +083 + 214 = 5 x 3998 (0.13) ‘= 799,8 rounded to 800 particles /m? D.2.5 ‘The slandard deviation ofthe location averages is calculated in acoordance with equation (C.3) (see C.3.3): (926 - soo}? + (988 - 800)? ot 3 | se07— 20 + (660-200? + (214-800)? 4 seuze 574 ee ee = 107 99 ou to 107 294 | | 07308 = 220.7 t (0.15) | reundato 32 parent (p26 ‘The 95% UCL is calculated in accordance with equation (C.4) (000.34) |g the number ndvidual averages s m= 6 te dtd tiontakentromTable C.1s f= 2,4. ° a = 1108 particles? “D27 ‘The paticle concentrations of allofthe single sample volumes are less then the specified classification limit (0.2.2). Caleuiation ofthe 95% upper confidence limit shows, however, thatthe airborne particulate cleanliness ofthe cleanroom does ‘not meet the specified classification. This constructed example demonstrates the effect of a single ‘outiying low particle concentration (Le. location 6) onthe result of te 95% UCL test Because noncanformance ofthe air cleanness classification results trom application ofthe 85% UCL, and is caused by 3 ‘single, low particle concentration, the procedure described in 2.6.2 may be followed to determine whether the noncorfor- ‘mance can be waived.e1so ISO 14644-1:1999(E) Annex E (informative) Considerations for the counting and sizing of particles outside the size range applicable for classification E.1 Principle in some stuations, ypically thse related to specie process requirements, atematve levels of ar cleanness may be pected thebasi of partie populations thatarenotwithin the size range applicable to classiaton, The maximum permited concentration of suchparticiesansthe choice test mth to very compliance are mates for agreement be- tween the customer and the supplier. Considerations fr test methods and preserbed formas for specication sf given in €.2 (for U descriptors) and E.3 (for M descriptors) E.2 Consideration of particles smaller than 0,1 um (ultrafine particles) — U descriptor E.2.1. Application IF contamination ks caused by partictes smaller than Ot um are to be assessed, somping dovices and measurement procedures appropriate tothe specific characteris of such particles should be employed ‘ ‘The number of sampling locations should be established in acvordanee with B.4.1 and the minum sample Volime’V, shouldbe 2 tras 6.4.2.2). £.2.2. U descriptor format: f ‘The ultrafine particle concentration ofthe U dascripior may be used slone or as a supplement to the-alrborne particulate cleaniness class, The U descriptor is exprossod in tha fora “U(x yt, whore x _isthemaximum permitedconcentratin ofutrafine particles (expressed as ultrafine particles per cubic motte of a Y-_isthe size in micrometres at which the applicable 5 um based onthe use of@ fime-offigh rosa! particle counter to detrine the aerodynamic ameter ofthe paris, the designation would be: "4 (10000; 25 ym); ine-otight aerosol particle counter 413ISO 14644-1:1999(E) @lso EXAMPLE2 —Tooxpressansiibomeparicleconcentrationaf 000 arcesinsin he parce size renge of 10020 1m, based onthe use ‘ofacascadeimpacorfolowed by miroscoplesiéngandeounting, the ‘esigration wou be: “1M(1 000; 19mta20ym}:caseade mpacterfolowos by microscope _S2ing ond counting’: NOTE2 Suitable methods of test for concantations of abo parle largr than 5 um are given in IEST:G-CC1008 (2 NOTES ha dosrplr designations usedasasupplementto| snalbome partcuatadeantiness cls, themacroparici concent ton (2) should be not greater than the paicle concentration limi (partes percubicmete| appcabletothe consicrod sizeof Spm or the specied 50 class. Conselo Mexicano de | 14elso Iso 14664~ 1999(E) Annex F (informative) Sequential sampling procedure tations F.1. Background and li F.1.4. Background Ifthe air being sampled is signfiantly more or significantly less contaminated than the speciied class concentration imi for the considered partici size, use of the sequential sampling procedure can reduce sample volumes and sampling times, often dramaticaly. Some’ savings-may——- also. be realized when the concentration, is “near-the: ‘specified limit, Sequential sampling Is most appropriate ‘when air cleanliness is expected to quality as ISO Class 4 or cleaner, NOTE For further informaton’on sequential sampling, see IEST-6-001004(3}, F.1.2. Limitations ‘The principal imitations of sequential sampling are: fa) The procedure is only applicable to sampling elmed at 2 total of 20 particles par measurement, for parcles of the considered size at the specified class..or. concentratos lit ‘ b) Each sample measurement:requires supplementary ‘monitoring and” data) anaiysis)(wich through computerized automation. ©) Parle concentrations are not “deter 7as 25 anc ber fecitalad yy precisely as with conventional sampling procedures, due to the reduced sample volume F.2. Basis for the procedure The procedure is based on comparison of reabtime ‘cumilative particle counts to reference count values. Reference values are derived from equations for upper and ower limit boundaries: Upperlimi:, C=3,96 + 103 6 C=-9,96+1,03 6 4) Lower init: _ (2) where C isthe observed count; Eis the expected count To aciligia “comparisons, helpful references have been provided in the form of a graph, Figure F.1, and in tabular form as Table F.1. Either format may be used. [As airs being Sampled at each designated location-the run- ring total particle count is continuously compared to reference count limits which are'2 function of the proportion of the pre- sorbed total voliriethat has. Ben’ sermpled. If the running total court i fess than tho iovior reference count limit corre sponding tothe volume that has been sampled, the air being Stop counting, FAIL 204 64 198 + 1,036 104 Observed count, ¢ Continue counting C 3,96 + 1,03E Stop counting, PASS T T 10 8 20 Expected count, E Figure F.1 — Boundaries for pass or fail by the sequential sampling procedure 15ISO 14644-1:1999(E) Iso ‘Table F-1 — Upper and lower limits for time at which C observed courits should arrive FAILS IF COUNT, C, COMES EARLIER THAN EXPECTED PASSES IF COUNT, C, COMES LATER THAN EXPECTED NOTE Fractional imes are give as the ration of total times (t=/1:000-0 atthe clas ln, serie lund oot in ie cam fcancsiin ode N if to running court exceeds ihe upper eerie count nk coresponding lo the volume sampled, the alr belng sampled falls to meet the specified class or concentration lini, ard sampling Is halted, As long as the running count remains. between the upper and lower limits, sampling continues unt the full sample has been accumulated. Inthe graph, Figure F1, the number of observed counts, Cis platted versus &, the expected number of counts for air being sampled atarate (volume versus tie) that would produce 20, ‘counts inthe ime it would take to measure efulsinglo sample of air i the concentration were at the specified mit for the considered particle size. ‘Table F.1 provides en equivalent method, in which the time of the observed count, Cs compared with incremental fractions fof the te that would be required to measure a ful single ‘sample, as shown in the table. Ifthe count occurs ear than ‘woud be expected from the table, the ar being sampled falls to meet the specified limit. Ifthe count occurs later than 16 ‘expected, the airbelng Sampled meets the prescribed limit. At ost. 21 compart of price aval tina with ing, fines dn the tbe weld be required.) 123125 1 -3 Procedure for sampling F.3.1 Sequential sampling references “Two optional comparison techniques are provided for judging the result as data collection proceeds. Progressive computer ized analysis ofthe data is beneficial and recommended. F.3.2_ Graphical sampling comparison Figure F.1 ilustrates the boundaries established in equations (1) and (F.2), as tuncated by the limitations of E= 20, representing the time required to collect a full sample, end (C=20, the maximum observed count alowed. ‘The observed countis potted versus the expected countfor air having @ particle concentration precisely atthe specified class level. The passage oftime coresponds to increasing numbers of expected counts, with E=20 representing the time required©180 ISO 14644-1:1999(E) toacoumulate afulsample volume ifthe particle concentration ‘ware at the class lim ‘The procedure for sequential sampling using Figure Fs 2s folows: ‘As sampling proceeds, record the numberof particles counted ‘aga function oftme, and compere the count withthe upper and lower mit nes of Figure F:1 the cumulative observed count _ crosses the upper ne, sampling at the locafon is stopped and the airs reported to have faled compliance with the spectied clase mi. If the cumulative observed count crosses the lower line, sampling is topped and the air passes the specied class limit Ifthe cumulative observed count remains between the - Upper and lower lines, sampling wil continue If the total count is 20 or less at the ond of the prescribed sampling petlod and has not crossed the upper ne, the aris judged to have complied with the class mit F.3.3 Tabular sampling comparison 5 ‘Table F.1 provides an equivalent method for use with sequen tial eammping, also based on equations (F.1) and (F.2). The time, onthe table's assigned avalue of"1,000 0'torepresent | the duration ofa complete single sample. ‘The volume of this ‘sample isthe volume necessary to provide 20 patie, if the alrcontain precisely the classlimit equivalentconcentrationof| parlclas ofthe considered size. The ime values listed in the {able are the fractional portons of the total time required for ‘accumulation ofthe entre single sample. | ‘The procedure for sequential samplig using Table Ft Is as follows: - I ‘As sampling proceeds, record the number of particles counted ‘asa function oftime, and compare the time atwhich each count Is observed with the times showin the to goiumns of tie table, fa given cumulative dbsétved count occurs earierthart~ ‘expected, as indicated by comparison with the l-hand col umn, semplingis stopped and te aris reported to have fa compliance with the specified class Imi. Ifthe cumulative ‘observed count occurs later than expected, as indicated ‘by ‘comperison with the right-hand column, sampling is stopped and the airs reported to be in compliance withthe specified L limit. ifthe cumulative observed count continuously arives ‘between the times shown in the two columns, samping wil continue. M eaunting continues through 24 comparisons with the lefthand column and no count arrives earlier than ts ‘expected tine, the air passes the spectied limit for ful singlo sample | malizacion M7ISO 14644-1:1999(E) @1so Bibliography [1] IEST-6-cC1002, Determination of the Concentra- tion of Airbome Utrafine Particles. Mount Prospect, inci institute of Enviconmental Sciences and Technology (1889), 1) IEST-G-CC1003, Measurement of Airborne Macropartcies. Mount Prospect, linois:Intitate of Environ- mental Sciences and Technology (1988) 18 [S| IEST-G-C01004, Saquential Sampling Plan for Use in Classification ofthe Particulate Cleanliness of Ar in Clean- roams and Clean Zones. Mount Prospect, linos: Institute of Environmental Sciences and Technology (1888)ISO 14644-1:1999(E) 81s0. ano ae | ee Ics 13.040.30 ‘ce based on 18 pages eSselo Mexicano cde con yGENOR Blvd, Manuel Avila Camacho no. 6-A Despacho 610, 6° piso Col. El Parque, C.P. 53390 Naucalpan , Edo. México Tel. (55) 5395 4601 Fax, (55) 5580 0843 E-mail: direccioncomenor@comenor.org.tm ]