Cleanrooms and associated controlled environments - Part 8: Assessment of air cleanliness by chemical concentration (ACC) (ISO 14644-8:2022)

2020-11-18 (data): Minor revision.

Reinräume und zugehörige Reinraumbereiche - Teil 8: Klassifizierung der Luftreinheit anhand der Chemikalienkonzentration (ACC) (ISO 14644-8:2022)

Dieses Dokument beschreibt die typischen Beurteilungsprozesse zur Bestimmung der Bewertungsstufen für die chemische Luftreinheit (ACC) in Reinräumen und zugehörigen Reinraumbereichen hinsichtlich der luftgetragenen Konzentrationen spezifischer chemischer Substanzen (einzeln, gruppenweise oder als Kategorien) und stellt ein Protokoll zur Verfügung, um Prüfverfahren, Analyse und Zeitgewichtungsfaktoren in die Bestimmung einzuschließen. Dieses Dokument betrachtet ausschließlich Konzentrationen von luftgetragenen chemischen Kontaminanten im Bereich von 100 g/m3 und 10−12 g/m3 unter Reinraumbetriebsbedingungen.
Dieses Dokument ist nicht anwendbar bei solchen Industriezweigen und Prozessen oder Produktionen, bei denen oder bei der das Vorhandensein von luftgetragenen chemischen Substanzen nicht als Risiko für das Produkt oder den Prozess betrachtet wird.
Es ist nicht Ziel dieses Dokuments, die Beschaffenheit luftgetragener chemischer Kontaminanten zu beschreiben.
Dieses Dokument gibt keine Klassifizierung für chemische Oberflächenkontamination vor.

Salles propres et environnements maîtrisés apparentés - Partie 8: Évaluation de la propreté chimique de l'air (ISO 14644-8:2022)

Le présent document établit les processus types d’évaluation permettant de déterminer les niveaux de gradation de la propreté chimique de l’air (ACC) dans les salles propres et les environnements maîtrisés apparentés, en termes de concentrations aéroportées de substances chimiques spécifiques (individuelle, groupe ou catégorie), et fournit un protocole permettant d’intégrer les méthodes d’essai, l’analyse et les facteurs de pondération pour leur détermination. Le présent document ne prend actuellement en compte que les concentrations de contaminants chimiques dans l’air comprises entre 100 g/m3 et 10−12 g/m3 dans des conditions d’exploitation de salles propres.
Le présent document ne s’applique pas aux secteurs industriels, aux procédés ou aux types de production où la présence de substances chimiques en suspension dans l’air n’est pas considérée comme un risque pour le produit ou le procédé.
Le présent document ne vise pas à décrire la nature des contaminants chimiques dans l’air.
Le présent document ne fournit pas de classification de la contamination chimique des surfaces.

Čiste sobe in podobna nadzorovana okolja - 8. del: Ocenjevanje čistosti zraka na osnovi koncentracije onesnaževal v zraku (ACC) (ISO 14644-8:2022)

General Information

Status
Published
Public Enquiry End Date
01-May-2022
Publication Date
18-Jul-2022
Technical Committee
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
13-Jul-2022
Due Date
17-Sep-2022
Completion Date
19-Jul-2022

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Standards Content (sample)

SLOVENSKI STANDARD
SIST EN ISO 14644-8:2022
01-september-2022
Nadomešča:
SIST EN ISO 14644-8:2014
Čiste sobe in podobna nadzorovana okolja - 8. del: Ocenjevanje čistosti zraka na
osnovi koncentracije onesnaževal v zraku (ACC) (ISO 14644-8:2022)
Cleanrooms and associated controlled environments - Part 8: Assessment of air
cleanliness by chemical concentration (ACC) (ISO 14644-8:2022)

Reinräume und zugehörige Reinraumbereiche - Teil 8: Klassifizierung der Luftreinheit

anhand der Chemikalienkonzentration (ACC) (ISO 14644-8:2022)

Salles propres et environnements maîtrisés apparentés - Partie 8: Évaluation de la

propreté chimique de l'air (ISO 14644-8:2022)
Ta slovenski standard je istoveten z: EN ISO 14644-8:2022
ICS:
13.040.35 Brezprašni prostori in Cleanrooms and associated
povezana nadzorovana controlled environments
okolja
SIST EN ISO 14644-8:2022 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 14644-8:2022
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SIST EN ISO 14644-8:2022
EN ISO 14644-8
EUROPEAN STANDARD
NORME EUROPÉENNE
July 2022
EUROPÄISCHE NORM
ICS 13.040.35 Supersedes EN ISO 14644-8:2013
English Version
Cleanrooms and associated controlled environments - Part
8: Assessment of air cleanliness by chemical concentration
(ACC) (ISO 14644-8:2022)

Salles propres et environnements maîtrisés apparentés Reinräume und zugehörige Reinraumbereiche - Teil 8:

- Partie 8: Évaluation de la propreté chimique de l'air Klassifizierung der Luftreinheit anhand der

(ISO 14644-8:2022) Chemikalienkonzentration (ACC) (ISO 14644-8:2022)
This European Standard was approved by CEN on 4 June 2022.

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 standard without any alteration. Up-to-date lists and bibliographical references

concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN

member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by

translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management

Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,

Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,

Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and

United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels

© 2022 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 14644-8:2022 E

worldwide for CEN national Members.
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SIST EN ISO 14644-8:2022
EN ISO 14644-8:2022 (E)
Contents Page

European foreword ....................................................................................................................................................... 3

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SIST EN ISO 14644-8:2022
EN ISO 14644-8:2022 (E)
European foreword

This document (EN ISO 14644-8:2022) has been prepared by Technical Committee ISO/TC 209

"Cleanrooms and associated controlled environments" in collaboration with Technical Committee

CEN/TC 243 “Cleanroom technology” the secretariat of which is held by BSI.

This European Standard shall be given the status of a national standard, either by publication of an

identical text or by endorsement, at the latest by January 2023, and conflicting national standards shall

be withdrawn at the latest by January 2023.

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. CEN shall not be held responsible for identifying any or all such patent rights.

This document supersedes EN ISO 14644-8:2013.

Any feedback and questions on this document should be directed to the users’ national standards

body/national committee. A complete listing of these bodies can be found on the CEN website.

According to the CEN-CENELEC Internal Regulations, the national standards organizations of the

following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,

Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,

Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of

North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the

United Kingdom.
Endorsement notice

The text of ISO 14644-8:2022 has been approved by CEN as EN ISO 14644-8:2022 without any

modification.
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SIST EN ISO 14644-8:2022
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SIST EN ISO 14644-8:2022
INTERNATIONAL ISO
STANDARD 14644-8
Third edition
2022-06
Cleanrooms and associated controlled
environments —
Part 8:
Assessment of air cleanliness by
chemical concentration (ACC)
Salles propres et environnements maîtrisés apparentés —
Partie 8: Évaluation de la propreté chimique de l'air
Reference number
ISO 14644-8:2022(E)
© ISO 2022
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SIST EN ISO 14644-8:2022
ISO 14644-8:2022(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2022

All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may

be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on

the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below

or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
© ISO 2022 – All rights reserved
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SIST EN ISO 14644-8:2022
ISO 14644-8:2022(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction .................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ..................................................................................................................................................................................... 1

3 Terms and definitions .................................................................................................................................................................................... 1

3.1 General ........................................................................................................................................................................................................... 1

3.2 Contaminant categories ................................................................................................................................................................. 2

4 Testing and monitoring using grading levels ........................................................................................................................ 3

4.1 General ........................................................................................................................................................................................................... 3

4.2 ISO-ACC descriptor format ........................................................................................................................................................... 3

5 Demonstration of compliance with an ISO-ACC level .................................................................................................... 5

5.1 Principle ....................................................................................................................................................................................................... 5

5.2 Testing ............................................................................................................................................................................................................ 5

5.3 Test report .................................................................................................................................................................................................. 6

Annex A (informative) Parameters for consideration ...................................................................................................................... 7

Annex B (informative) Typical contaminants .........................................................................................................................................11

Annex C (informative) Typical methods of measurement .........................................................................................................15

Annex D (informative) Consideration of specific requirements for separative devices ...........................19

Bibliography .............................................................................................................................................................................................................................21

iii
© ISO 2022 – All rights reserved
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SIST EN ISO 14644-8:2022
ISO 14644-8:2022(E)
Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards

bodies (ISO member bodies). The work of preparing International Standards is normally carried out

through ISO technical committees. Each member body interested in a subject for which a technical

committee has been established has the right to be represented on that committee. International

organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.

ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of

electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www.iso.org/patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and

expressions related to conformity assessment, as well as information about ISO's adherence to

the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see

www.iso.org/iso/foreword.html.

This document was prepared by Technical Committee ISO/TC 209, Cleanrooms and associated controlled

environments, in collaboration with the European Committee for Standardization (CEN) Technical

Committee CEN/TC 243, Cleanroom technology, in accordance with the Agreement on technical

cooperation between ISO and CEN (Vienna Agreement).

This third edition cancels and replaces the second edition (ISO 14644-8:2013), of which it constitutes a

minor revision. The changes are as follows:

— the term class (classification, classified) changed to grade or assessment where appropriate;

— 3.1.2, definition revised;
— Bibliography updated;
— minor editorial changes.
A list of all parts in the ISO 14644 series can be found on the ISO website.

Any feedback or questions on this document should be directed to the user’s national standards body. A

complete listing of these bodies can be found at www.iso.org/members.html.
© ISO 2022 – All rights reserved
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SIST EN ISO 14644-8:2022
ISO 14644-8:2022(E)
Introduction

Cleanrooms and associated controlled environments provide for the control of airborne particulate

contamination to levels of cleanliness appropriate for accomplishing process activities sensitive to a

range of contaminants. Products and processes that benefit from the control of airborne contamination

include those in such industries as aerospace, microelectronics, pharmaceuticals, medical devices,

food, healthcare, optics, instrumentation, vacuum technology, coatings, photovoltaics, displays, LEDs,

coatings, automotive and surface analysis.

In some of these industries, the product or process can be sensitive to, or can be destroyed by, chemical

contamination resulting from chemicals that are present due to external, process or other generated

sources.

Within this document, the presence of chemicals is expressed as air chemical contamination. Chemical

contamination is a three-step event. The first step is generation due to external sources such as

process leakage, construction material, personnel or material outgassing. The second step is transport

as airborne chemical contamination. The third step is sorption on the sensitive surface, which can be

quantified as a surface chemical contamination.

The generating materials and the surfaces where sorption takes place will have a large influence on

the steps of generation and sorption in addition to the actual air contamination. Thus, for these two

steps, not only the contaminants but also the involved bulk and surfaces need to be defined. In order to

make a standard generally applicable to any type of cleanroom or associated controlled environment,

air chemical cleanliness (ACC) has been chosen for the level assessment.

This document assigns ISO grading levels to be used to specify the level of ACC within a cleanroom

and associated controlled environment, where the product or process is deemed to be at risk from air

chemical contamination.

For level assessment purposes, this document provides guidance for a range of ACC levels and provides

standard protocols for specifying such levels with regard to chemical compounds, methods of test and

analysis, and time weighted factors.
Annexes A to D contain the following information:
— parameters for consideration: Annex A;
— typical contaminating chemicals and substances: Annex B;
— typical methods of measurement and analysis: Annex C;
— considerations of specific requirements for separative devices: Annex D.

This document is one of a series of standards concerned with cleanrooms and contamination control.

Many factors besides ACC need to be considered in the design, specification, operation and control of

cleanrooms and other controlled environments. These features are recognized in this document and

covered in some detail in other parts of the International Standards prepared by ISO/TC 209, including

the ISO 14698 series. In some circumstances, relevant regulatory agencies can impose supplementary

policies or restrictions. In such situations, appropriate adaptations of this document can be required.

NOTE When assessment of ACC at critical control point(s) is used as an additional cleanliness attribute to

classification of air cleanliness by airborne particle concentration in accordance with ISO 14644-1, then the

space can be described as a cleanroom or clean-zone. If ACC is used alone, then the space must be described as a

controlled zone.
© ISO 2022 – All rights reserved
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SIST EN ISO 14644-8:2022
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SIST EN ISO 14644-8:2022
INTERNATIONAL STANDARD ISO 14644-8:2022(E)
Cleanrooms and associated controlled environments —
Part 8:
Assessment of air cleanliness by chemical concentration
(ACC)
1 Scope

This document establishes typical assessment processes to determine grading levels of air chemical

cleanliness (ACC) in cleanrooms and associated controlled environments, in terms of airborne

concentrations of specific chemical substances (individual, group or category), and provides a protocol

to include test methods, analysis and time-weighted factors for their determination. This document

0 3 −12

currently considers only concentrations of air chemical contaminants between 10 g/m and 10 g/

m under cleanroom operational conditions.

This document is not relevant for application in those industries, processes or productions where the

presence of airborne chemical substances is not considered a risk to the product or process.

It is not the intention of this document to describe the nature of air chemical contaminants.

This document does not give a classification of surface chemical contamination.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.

ISO and IEC maintain terminology databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1 General
3.1.1
chemical contamination

non-particulate substances that can have a deleterious effect on the product, process or equipment

3.1.2
air cleanliness by chemical concentration
ACC

quantity of chemical detected in the air, expressed in terms of an ISO-ACC level N, which represents the

maximum allowable concentration of a given chemical species or a group of chemical species, expressed

in grams per cubic metre

Note 1 to entry: This definition does not include macromolecules of biological origin, which are judged to be

particles.
© ISO 2022 – All rights reserved
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SIST EN ISO 14644-8:2022
ISO 14644-8:2022(E)
3.1.3
air chemical contamination

any substance in the air that can, by its chemical nature, adversely affect the product, process or

equipment
3.1.4
surface cleanliness by chemical concentration
SCC
condition of the surface cleanliness with respect to its chemical concentration
3.1.5
surface chemical contamination

any substance on the surface that can, by its chemical nature, adversely affect the product, process or

equipment
3.1.6
contaminant category

common name for a group of compounds with a specific and similar deleterious effect when deposited

on the surface of interest
3.1.7
outgassing
release of chemical substances in the gaseous or vapour state from a material
3.1.8
air cleanliness by chemical concentration level

grading number stating the maximum allowable concentration of a given chemical species or a group of

chemical species in grams per cubic metre

Note 1 to entry: The range of concentrations are defined in Table 1 or determined by the formula for N in 4.2.

Note 2 to entry: Testing and monitoring in accordance with this document is limited to the range from 0 (the

grade with the lowest cleanliness) to –12 (the cleanest level).

Note 3 to entry: The ACC grading number is only valid in connection with the ACC descriptor that specifies to

which chemical species or group of chemical species it is related.

Note 4 to entry: The negative sign of the air chemical cleanliness levels (–1 to –12) is an integral part of the ACC

level number N and shall always be used.

Note 5 to entry: Intermediate ISO grade numbers may be specified, with 0,1 being the smallest practical

increment.
3.2 Contaminant categories
3.2.1
acid

substance whose chemical reaction characteristic is to establish new bonds by the acceptance of

electron pairs
3.2.2
base

substance whose chemical reaction characteristic is to establish new bonds by the donation of electron

pairs
3.2.3
biotoxic

contaminant substance that is obnoxious to the development and preservation of the life of organisms,

microorganisms, tissues or individual cells
© ISO 2022 – All rights reserved
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SIST EN ISO 14644-8:2022
ISO 14644-8:2022(E)
3.2.4
condensable

substance capable of depositing on a surface by condensation under cleanroom operating conditions

3.2.5
corrosive
substance that causes destructive chemical change of a surface
3.2.6
dopant

substance that, after sorption and/or diffusion, is incorporated in the bulk of a product and is capable of

changing the properties of materials, even in trace amounts
3.2.7
organic
species based on carbon-containing compounds
Note 1 to entry: Inorganic carbon-containing compounds are excluded.
3.2.8
oxidant

substance that, upon deposition onto a surface or product of interest, results in the formation of an

oxide or participates in a redox reaction
4 Testing and monitoring using grading levels
4.1 General

Testing or monitoring shall be specified by use of a descriptor as described in 4.2. This descriptor is

designated “ISO-ACC” and indicates the maximum total chemical concentration for a contaminant

category, an individual substance or a group of substances.
4.2 ISO-ACC descriptor format

An ACC grading number is only valid in connection with the ACC descriptor that specifies the chemical

substance or group of substances for which this level number is valid. The ISO-ACC descriptor is

expressed in the format:
ISO-ACC Level N (X)
where
© ISO 2022 – All rights reserved
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SIST EN ISO 14644-8:2022
ISO 14644-8:2022(E)

X is a chemical substance or a group of chemical substances which includes, but is not limited to:

— acid (ac);
— base (ba);
— biotoxic (bt);
— condensable (cd);
— corrosive (cr);
— dopant (dp);
— organic, total (or);
— oxidant (ox); or
— a group of substances or an individual substance;

N is the ISO-ACC level, which is the logarithmic index of concentration, c , expressed in grams per

cubic metre, and falls within a limiting range of 0 to −12. Intermediate concentrations may be

specified, with 0,1 being the smallest practical increment of N;
N = log [c ].
10 x

EXAMPLE 1 With an N-Methyl Pyrrolidone (NMP) sample, the measured value of air contamination was

3 3

8E-7 g/m ; N = −6,097. This is within the level limit of 1E-6 g/m for grade −6. The designation would be: “ISO-

ACC Level −6 (NMP)”.

EXAMPLE 2 With an organic compound sample, the measured value was 6E-5 g/m of total organic compounds

(TOC). This is within the level limit of 1E-4 g/m for grade −4. The designation would be: “ISO-ACC Level −4

(TOC).”

Table 1 and Figure 1 further illustrate the suggested ISO-ACC concentration levels as a function of

contaminant concentration for the specified species.
Table 1 — ISO-ACC grades
Concentration Concentration Concentration
ISO-ACC level
3 3 3
g/m µg/m ng/m
0 6 9
0 10 10 (1 000 000) 10 (1 000 000 000)
−1 5 8
−1 10 10 (100 000) 10 (100 000 000)
−2 4 7
−2 10 10 (10 000) 10 (10 000 000)
−3 3 6
−3 10 10 (1 000) 10 (1 000 000)
−4 2 5
−4 10 10 (100) 10 (100 000)
−5 1 4
−5 10 10 (10) 10 (10 000)
−6 0 3
−6 10 10 (1) 10 (1 000)
−7 −1 2
−7 10 10 (0,1) 10 (100)
−8 −2 1
−8 10 10 (0,01) 10 (10)
−9 −3 0
−9 10 10 (0,001) 10 (1)
−10 −4 −1
−10 10 10 (0,000 1) 10 (0,1)
−11 −5 −2
−11 10 10 (0,000 01) 10 (0,01)
−12 −6 −3
−12 10 10 (0,000 001) 10 (0,001)
© ISO 2022 – All rights reserved
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SIST EN ISO 14644-8:2022
ISO 14644-8:2022(E)
Key
X airborne concentration (g/m )
X airborne concentration (µg/m )
X airborne concentration (ng/m )
Y ISO-ACC level
Figure 1 — ISO-ACC levels as a function of concentration
5 Demonstration of compliance with an ISO-ACC level
5.1 Principle

Compliance with an ISO-ACC level requirement specified by the customer is verified by performing

specified testing procedures agreed between the customer and supplier and by providing specified

documentation of the results and conditions of testing.
5.2 Testing

Example test methods are given in Annex C. The list of typical methods described is not exhaustive.

Alternative methods of comparable accuracy may be specified by agreement.

NOTE 1 Analysis by different methods, even when correctly applied, can produce different results of equal

validity.

Tests performed to demonstrate compliance shall be conducted using suitable test methods and

calibrated instruments.
© ISO 2022 – All rights reserved
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SIST EN ISO 14644-8:2022
ISO 14644-8:2022(E)

Sampling locations shall be determined by agreement between the customer and the supplier.

It is recommended that replicate sampling is carried out at the locations agreed.

NOTE 2 In analytical measurement, the contribution of particulate contamination cannot always be excluded.

NOTE 3 For trace analysis using grab sampling, the incorporation of a shipping blank sample, prepared and

analysed in the same batch as the actual sample, is required to assess contamination from the overall process,

excluding the air sampling.

The elapsed time period shall be agreed between the customer and supplier. See A.4.3.

5.3 Test report

The results from testing each cleanroom or associated controlled environment shall be recorded and

submitted as a comprehensive report, along with a statement of compliance or non-compliance with

the specified ISO-ACC level or levels.
The test report shall include the following:

a) name of the test operator, the name and address of the testing organization, and the date, time and

duration of sampling;
b) number and year of publication of this document, i.e. ISO 14644-8:2022;

c) clear identification of the physical location of the cleanroom or controlled environment tested

(including reference to adjacent areas if necessary) and specific designations for coordinates of all

sampling locations;

d) specified designation criteria for the cleanroom or controlled environment, including the

occupancy state, the ISO-ACC level or levels, the specified test method(s) and, where applicable, the

substances, substance group or categories, the elapsed time period and the designated particulate

type;

e) details of the test procedure used, with any available data describing the test circumstances

or departures from the test method, and identification of the test instrument(s) and its current

calibration certificate(s);

f) test results, including air chemical concentration(s) data, for all sampling locations.

© ISO 2022 – All rights reserved
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SIST EN ISO 14644-8:2022
ISO 14644-8:2022(E)
Annex A
(informative)
Parameters for consideration
A.1 Principles

This annex is intended to give guidance to consideration of parameters affecting or contributing to ACC

within a cleanroom or associated controlled environment. It is important to consider the development

of such parameters at the initial stages of design and control requirements, along with any special

considerations for operation of the facility.
A.2 Concepts for establishing parameters

The following principles permit the establishment of the parameters which influence the ACC or which

contribute to it and which should be taken into account.

a) First, establish if the product or process is affected by chemical contamination, as in many

industries consideration of chemical contamination is not a governing factor.

b) Establish the contaminant categories that affect the product or process and if any particular

substances or substance groups require special consideration.

c) Establish the maximum concentrations of contaminant categories and/or substances or substance

groups permitted for the product or process and designate the associated ISO-ACC descriptor in

accordance with 4.2.

d) Establish sources of chemical contamination and concentration levels that can occur from:

1) outdoor air (providing fresh air to the facility);

2) construction materials in the facility, especially those in contact with recirculating and make-

up air streams;
3) cross-contamination that can occur within the facility;
4) operation and maintenance of the facility;
5) personnel, cleanroom apparel and auxiliary materials;
6) process media and tooling.
Further guidance on these occurrences is given in A.3 to A.8.

e) Establish the design requirements to avoid or reduce chemical contamination generated as per

A.2 d) to achieve the ISO-ACC level for the product or process.
A.3 Outdoor air

A.3.1 Where outdoor air is provided as fresh air to the facility to which the product or process is

exposed, the
...

SLOVENSKI STANDARD
oSIST prEN ISO 14644-8:2022
01-april-2022

Čiste sobe in podobna nadzorovana okolja - 8. del: Klasifikacija čistosti zraka na

osnovi koncentracije onesnaževal v zraku (ACC) (ISO/FDIS 14644-8:2022)

Cleanrooms and associated controlled environments - Part 8: Classification of air

cleanliness by chemical concentration (ACC) (ISO/FDIS 14644-8:2022)

Reinräume und zugehörige Reinraumbereiche - Teil 8: Klassifizierung der Luftreinheit

anhand der Chemikalienkonzentration (ACC) (ISO/FDIS 14644-8:2022)

Salles propres et environnements maîtrisés apparentés - Partie 8: Classification de la

propreté chimique de l'air (ISO/FDIS 14644-8:2022)
Ta slovenski standard je istoveten z: prEN ISO 14644-8
ICS:
13.040.35 Brezprašni prostori in Cleanrooms and associated
povezana nadzorovana controlled environments
okolja
oSIST prEN ISO 14644-8:2022 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN ISO 14644-8:2022
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oSIST prEN ISO 14644-8:2022
FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 14644-8
ISO/TC 209
Cleanrooms and associated controlled
Secretariat: ANSI
environments —
Voting begins on:
2022-02-08
Part 8:
Voting terminates on:
Classification of air cleanliness by
2022-05-03
chemical concentration (ACC)
Salles propres et environnements maîtrisés apparentés —
Partie 8: Classification de la propreté chimique de l'air
ISO/CEN PARALLEL PROCESSING
RECIPIENTS OF THIS DRAFT ARE INVITED TO
SUBMIT, WITH THEIR COMMENTS, NOTIFICATION
OF ANY RELEVANT PATENT RIGHTS OF WHICH
THEY ARE AWARE AND TO PROVIDE SUPPOR TING
DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
Reference number
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
ISO/FDIS 14644-8:2022(E)
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN-
DARDS TO WHICH REFERENCE MAY BE MADE IN
NATIONAL REGULATIONS. © ISO 2022
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oSIST prEN ISO 14644-8:2022
ISO/FDIS 14644-8:2022(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2022

All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may

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© ISO 2022 – All rights reserved
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oSIST prEN ISO 14644-8:2022
ISO/FDIS 14644-8:2022(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction .................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ..................................................................................................................................................................................... 1

3 Terms and definitions .................................................................................................................................................................................... 1

3.1 General ........................................................................................................................................................................................................... 1

3.2 Contaminant categories ................................................................................................................................................................. 2

4 Testing and monitoring using grading levels ........................................................................................................................ 3

4.1 General ........................................................................................................................................................................................................... 3

4.2 ISO-ACC descriptor format ........................................................................................................................................................... 3

5 Demonstration of compliance with an ISO-ACC level .................................................................................................... 5

5.1 Principle ....................................................................................................................................................................................................... 5

5.2 Testing ............................................................................................................................................................................................................ 5

5.3 Test report .................................................................................................................................................................................................. 6

Annex A (informative) Parameters for consideration ...................................................................................................................... 7

Annex B (informative) Typical contaminants .........................................................................................................................................11

Annex C (informative) Typical methods of measurement .........................................................................................................15

Annex D (informative) Consideration of specific requirements for separative devices ...........................19

Bibliography .............................................................................................................................................................................................................................21

iii
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oSIST prEN ISO 14644-8:2022
ISO/FDIS 14644-8:2022(E)
Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards

bodies (ISO member bodies). The work of preparing International Standards is normally carried out

through ISO technical committees. Each member body interested in a subject for which a technical

committee has been established has the right to be represented on that committee. International

organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.

ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of

electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www.iso.org/patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and

expressions related to conformity assessment, as well as information about ISO's adherence to

the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see

www.iso.org/iso/foreword.html.

This document was prepared by Technical Committee ISO/TC 209, Cleanrooms and associated controlled

environments, in collaboration with the European Committee for Standardization (CEN) Technical

Committee CEN/TC 243,   Cleanroom technology, in accordance with the Agreement on technical

cooperation between ISO and CEN (Vienna Agreement).

This third edition cancels and replaces the second edition (ISO 14644-8:2013), of which it constitutes a

minor revision. The changes are as follows:

— the term class (classification, classified) changed to grade or assessment where appropriate;

— 3.1.2, definition revised;
— Bibliography updated;
— minor editorial changes.
A list of all parts in the ISO 14644 series can be found on the ISO website.

Any feedback or questions on this document should be directed to the user’s national standards body. A

complete listing of these bodies can be found at www.iso.org/members.html.
© ISO 2022 – All rights reserved
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oSIST prEN ISO 14644-8:2022
ISO/FDIS 14644-8:2022(E)
Introduction

Cleanrooms and associated controlled environments provide for the control of airborne particulate

contamination to levels of cleanliness appropriate for accomplishing process activities sensitive to a

range of contaminants. Products and processes that benefit from the control of airborne contamination

include those in such industries as aerospace, microelectronics, pharmaceuticals, medical devices,

food, healthcare, optics, instrumentation, vacuum technology, coatings, photovoltaics, displays, LEDs,

coatings, automotive and surface analysis.

In some of these industries, the product or process can be sensitive to, or can be destroyed by, chemical

contamination resulting from chemicals that are present due to external, process or other generated

sources.

Within this document, the presence of chemicals is expressed as air chemical contamination. Chemical

contamination is a three-step event. The first step is generation due to external sources such as

process leakage, construction material, personnel or material outgassing. The second step is transport

as airborne chemical contamination. The third step is sorption on the sensitive surface, which can be

quantified as a surface chemical contamination.

The generating materials and the surfaces where sorption takes place will have a large influence on

the steps of generation and sorption in addition to the actual air contamination. Thus, for these two

steps, not only the contaminants but also the involved bulk and surfaces need to be defined. In order to

make a standard generally applicable to any type of cleanroom or associated controlled environment,

air chemical cleanliness (ACC) has been chosen for the level assessment.

This document assigns ISO grading levels to be used to specify the level of ACC within a cleanroom

and associated controlled environment, where the product or process is deemed to be at risk from air

chemical contamination.

For level assessment purposes, this document provides guidance for a range of ACC levels and provides

standard protocols for specifying such levels with regard to chemical compounds, methods of test and

analysis, and time weighted factors.
Annexes A to D contain the following information:
— parameters for consideration: Annex A;
— typical contaminating chemicals and substances: Annex B;
— typical methods of measurement and analysis: Annex C;
— considerations of specific requirements for separative devices: Annex D.

This document is one of a series of standards concerned with cleanrooms and contamination control.

Many factors besides ACC need to be considered in the design, specification, operation and control of

cleanrooms and other controlled environments. These features are recognized in this document and

covered in some detail in other parts of the International Standards prepared by ISO/TC 209, including

the ISO 14698 series. In some circumstances, relevant regulatory agencies can impose supplementary

policies or restrictions. In such situations, appropriate adaptations of this document can be required.

NOTE When assessment of ACC at critical control point(s) is used as an additional cleanliness attribute to

classification of air cleanliness by airborne particle concentration in accordance with ISO 14644-1, then the

space can be described as a cleanroom or clean-zone. If ACC is used alone, then the space must be described as a

controlled zone.
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oSIST prEN ISO 14644-8:2022
FINAL DRAFT INTERNATIONAL STANDARD ISO/FDIS 14644-8:2022(E)
Cleanrooms and associated controlled environments —
Part 8:
Classification of air cleanliness by chemical concentration
(ACC)
1 Scope

This document establishes typical assessment processes to determine grading levels of air chemical

cleanliness (ACC) in cleanrooms and associated controlled environments, in terms of airborne

concentrations of specific chemical substances (individual, group or category), and provides a protocol

to include test methods, analysis and time-weighted factors for their determination. This document

0 3 −12

currently considers only concentrations of air chemical contaminants between 10 g/m and 10 g/

m under cleanroom operational conditions.

This document is not relevant for application in those industries, processes or productions where the

presence of airborne chemical substances is not considered a risk to the product or process.

It is not the intention of this document to describe the nature of air chemical contaminants.

This document does not give a classification of surface chemical contamination.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.

ISO and IEC maintain terminology databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1 General
3.1.1
chemical contamination

non-particulate substances that can have a deleterious effect on the product, process or equipment

3.1.2
air cleanliness by chemical concentration
ACC

quantity of chemical detected in the air, expressed in terms of an ISO-ACC level N, which represents the

maximum allowable concentration of a given chemical species or a group of chemical species, expressed

in grams per cubic metre

Note 1 to entry: This definition does not include macromolecules of biological origin, which are judged to be

particles.
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oSIST prEN ISO 14644-8:2022
ISO/FDIS 14644-8:2022(E)
3.1.3
air chemical contamination

any substance in the air that can, by its chemical nature, adversely affect the product, process or

equipment
3.1.4
surface cleanliness by chemical concentration
SCC
condition of the surface cleanliness with respect to its chemical concentration
3.1.5
surface chemical contamination

any substance on the surface that can, by its chemical nature, adversely affect the product, process or

equipment
3.1.6
contaminant category

common name for a group of compounds with a specific and similar deleterious effect when deposited

on the surface of interest
3.1.7
outgassing
release of chemical substances in the gaseous or vapour state from a material
3.1.8
air cleanliness by chemical concentration (ACC) level

grading number stating the maximum allowable concentration of a given chemical species or a group of

chemical species in grams per cubic metre

Note 1 to entry: The range of concentrations are defined in Table 1 or determined by the formula for N in 4.2.

Note 2 to entry: Testing and monitoring in accordance with this document is limited to the range from 0 (the

grade with the lowest cleanliness) to –12 (the cleanest level).

Note 3 to entry: The ACC grading number is only valid in connection with the ACC descriptor that specifies to

which chemical species or group of chemical species it is related.

Note 4 to entry: The negative sign of the air chemical cleanliness levels (–1 to –12) is an integral part of the ACC

level number N and shall always be used.

Note 5 to entry: Intermediate ISO grade numbers may be specified, with 0,1 being the smallest practical

increment.
3.2 Contaminant categories
3.2.1
acid

substance whose chemical reaction characteristic is to establish new bonds by the acceptance of

electron pairs
3.2.2
base

substance whose chemical reaction characteristic is to establish new bonds by the donation of electron

pairs
3.2.3
biotoxic

contaminant substance that is obnoxious to the development and preservation of the life of organisms,

microorganisms, tissues or individual cells
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oSIST prEN ISO 14644-8:2022
ISO/FDIS 14644-8:2022(E)
3.2.4
condensable

substance capable of depositing on a surface by condensation under cleanroom operating conditions

3.2.5
corrosive
substance that causes destructive chemical change of a surface
3.2.6
dopant

substance that, after sorption and/or diffusion, is incorporated in the bulk of a product and is capable of

changing the properties of materials, even in trace amounts
3.2.7
organic
species based on carbon-containing compounds
Note 1 to entry: Inorganic carbon-containing compounds are excluded.
3.2.8
oxidant

substance that, upon deposition onto a surface or product of interest, results in the formation of an

oxide or participates in a redox reaction
4 Testing and monitoring using grading levels
4.1 General

Testing or monitoring shall be specified by use of a descriptor as described in 4.2. This descriptor is

designated “ISO-ACC” and indicates the maximum total chemical concentration for a contaminant

category, an individual substance or a group of substances.
4.2 ISO-ACC descriptor format

An ACC grading number is only valid in connection with the ACC descriptor that specifies the chemical

substance or group of substances for which this level number is valid. The ISO-ACC descriptor is

expressed in the format:
ISO-ACC Level N (X)
where
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oSIST prEN ISO 14644-8:2022
ISO/FDIS 14644-8:2022(E)

X is a chemical substance or a group of chemical substances which includes, but is not limited to:

— acid (ac);
— base (ba);
— biotoxic (bt);
— condensable (cd);
— corrosive (cr);
— dopant (dp);
— organic, total (or);
— oxidant (ox); or
— a group of substances or an individual substance;

N is the ISO-ACC level, which is the logarithmic index of concentration, c , expressed in grams per

cubic metre, and falls within a limiting range of 0 to −12. Intermediate concentrations may be

specified, with 0,1 being the smallest practical increment of N;
N = log [c ].
10 x

EXAMPLE 1 With an N-Methyl Pyrrolidone (NMP) sample, the measured value of air contamination was

3 3

8E-7 g/m ; N = −6,097. This is within the level limit of 1E-6 g/m for grade −6. The designation would be: “ISO-

ACC Level −6 (NMP)”.

EXAMPLE 2 With an organic compound sample, the measured value was 6E-5 g/m of total organic compounds

(TOC). This is within the level limit of 1E-4 g/m for grade −4. The designation would be: “ISO-ACC Level −4

(TOC).”

Table 1 and Figure 1 further illustrate the suggested ISO-ACC concentration levels as a function of

contaminant concentration for the specified species.
Table 1 — ISO-ACC grades
Concentration Concentration Concentration
ISO-ACC level
3 3 3
g/m µg/m ng/m
0 6 9
0 10 10 (1 000 000) 10 (1 000 000 000)
−1 5 8
−1 10 10 (100 000) 10 (100 000 000)
−2 4 7
−2 10 10 (10 000) 10 (10 000 000)
−3 3 6
−3 10 10 (1 000) 10 (1 000 000)
−4 2 5
−4 10 10 (100) 10 (100 000)
−5 1 4
−5 10 10 (10) 10 (10 000)
−6 0 3
−6 10 10 (1) 10 (1 000)
−7 −1 2
−7 10 10 (0,1) 10 (100)
−8 −2 1
−8 10 10 (0,01) 10 (10)
−9 −3 0
−9 10 10 (0,001) 10 (1)
−10 −4 −1
−10 10 10 (0,000 1) 10 (0,1)
−11 −5 −2
−11 10 10 (0,000 01) 10 (0,01)
−12 −6 −3
−12 10 10 (0,000 001) 10 (0,001)
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oSIST prEN ISO 14644-8:2022
ISO/FDIS 14644-8:2022(E)
Key
X airborne concentration (g/m )
X airborne concentration (µg/m )
X airborne concentration (ng/m )
Y ISO-ACC level
Figure 1 — ISO-ACC levels as a function of concentration
5 Demonstration of compliance with an ISO-ACC level
5.1 Principle

Compliance with an ISO-ACC level requirement specified by the customer is verified by performing

specified testing procedures agreed between the customer and supplier and by providing specified

documentation of the results and conditions of testing.
5.2 Testing

Example test methods are given in Annex C. The list of typical methods described is not exhaustive.

Alternative methods of comparable accuracy may be specified by agreement.

NOTE 1 Analysis by different methods, even when correctly applied, can produce different results of equal

validity.

Tests performed to demonstrate compliance shall be conducted using suitable test methods and

calibrated instruments.
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oSIST prEN ISO 14644-8:2022
ISO/FDIS 14644-8:2022(E)

Sampling locations shall be determined by agreement between the customer and the supplier.

It is recommended that replicate sampling is carried out at the locations agreed.

NOTE 2 In analytical measurement, the contribution of particulate contamination cannot always be excluded.

NOTE 3 For trace analysis using grab sampling, the incorporation of a shipping blank sample, prepared and

analysed in the same batch as the actual sample, is required to assess contamination from the overall process,

excluding the air sampling.

The elapsed time period shall be agreed between the customer and supplier. See A.4.3.

5.3 Test report

The results from testing each cleanroom or associated controlled environment shall be recorded and

submitted as a comprehensive report, along with a statement of compliance or non-compliance with

the specified ISO-ACC level or levels.
The test report shall include the following:

a) name of the test operator, the name and address of the testing organization, and the date, time and

duration of sampling;
b) number and year of publication of this document, i.e. ISO 14644-8:—;

c) clear identification of the physical location of the cleanroom or controlled environment tested

(including reference to adjacent areas if necessary) and specific designations for coordinates of all

sampling locations;

d) specified designation criteria for the cleanroom or controlled environment, including the

occupancy state, the ISO-ACC level or levels, the specified test method(s) and, where applicable, the

substances, substance group or categories, the elapsed time period and the designated particulate

type;

e) details of the test procedure used, with any available data describing the test circumstances

or departures from the test method, and identification of the test instrument(s) and its current

calibration certificate(s);

f) test results, including air chemical concentration(s) data, for all sampling locations.

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oSIST prEN ISO 14644-8:2022
ISO/FDIS 14644-8:2022(E)
Annex A
(informative)
Parameters for consideration
A.1 Principles

This annex is intended to give guidance to consideration of parameters affecting or contributing to ACC

within a cleanroom or associated controlled environment. It is important to consider the development

of such parameters at the initial stages of design and control requirements, along with any special

considerations for operation of the facility.
A.2 Concepts for establishing parameters

The following principles permit the establishment of the parameters which influence the ACC or which

contribute to it and which should be taken into account.

a) First, establish if the product or process is affected by chemical contamination, as in many

industries consideration of chemical contamination is not a governing factor.

b) Establish the contaminant categories that affect the product or process and if any particular

substances or substance groups require special consideration.

c) Establish the maximum concentrations of contaminant categories and/or substances or substance

groups permitted for the product or process and designate the associated ISO-ACC descriptor in

accordance with 4.2.

d) Establish sources of chemical contamination and concentration levels that can occur from:

1) outdoor air (providing fresh air to the facility);

2) construction materials in the facility, especially those in contact with recirculating and make-

up air streams;
3) cross-contamination that can occur within the facility;
4) operation and maintenance of the facility;
5) personnel, cleanroom apparel and auxiliary materials;
6) process media and tooling.
Further guidance on these occurrences is given in A.3 to A.8.

e) Establish the design requirements to avoid or reduce chemical contamination generated as per

A.2 d) to achieve the ISO-ACC level for the product or process.
A.3 Outdoor air

A.3.1 Where outdoor air is provided as fresh air to the facility to which the product or process is

exposed, the outdoor air quality and any seasonal variation should be established with regard to

the concentration of compounds or substances affecting the product or process. In addition, the

construction materials of heating, ventilation or air conditioning equipment, including cabling, should

be taken into account.
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oSIST prEN ISO 14644-8:2022
ISO/FDIS 14644-8:2022(E)

A.3.2 The analysis of the concentration should be conducted over a period of time sufficient to

evaluate its variability, along with consideration of any future developments that can affect the outdoor

air quality.

A.3.3 In some cases, due to, for example, prevailing winds or proximity of contaminating sources,

chemical contamination concentrations can be minimized by selective positioning of the fresh-air

intake(s) to the facility.

A.3.4 Outdoor air contamination levels entering the incoming air to a building can include variable

contamination levels from the same building exhaust, exhaust from neighbouring buildings, or other

contamination sources including farms, sewer plants, dumps, highways, airports, train yards, local

industry and other sources. These levels can vary dramatically with wind direction, wind velocity, time

of day, precipitation, temperature, sunlight or other factors. Thus, it is important to use continuous

monitoring where possible for the most important parameters, or to do periodic sampling on different

dates and with sampling for many hours or days, so that a typical average or highest level can be

assessed, rather than just a single data point.

Long-term average data are useful for predicting chemical filter lifetimes, and real-time data are

valuable to assess the highest levels encountered in terms of whether they will affect the most sensitive

products.
A.4 Construction materials

A.4.1 Construction materials serving the facility can be sources of chemical contamination because

of outgassing.

Examples of suitable cleanroom construction materials are given in ISO 14644-4:2001, Annex E.

A.4.2 The degree of material outgassing can be dependent upon the temperature, relative humidity

and pressure of the cleanroom or controlled environment, and these effects should be established

specific to the design of the facility.

A.4.3 Outgassing from materials of construction can, in many cases, decay exponentially and

asymptotically over a period of time. Thinner materials (e.g. coatings) and more volatile compounds

(e.g. solvents) tend to decay more rapidly, but thicker materials (floor tiles, insulation, ULPA filter

potting compounds) and higher boiling compounds (plasticisers, antioxidants, organophosphorus fire

retardants, larger silicones) can decay much more slowly, and possibly outgas at significant levels for

many years.

A.4.4 All materials forming the construction of a facility where air chemical contamination is of

concern should be assessed with regard to their combined chemical characteristics and selected

accordingly for their use. This analysis can be constructed as a table.
A.5 Cross-contamination

A.5.1 Chemical contamination can occur by migration between services, partial pressure change

transfer systems and processes within the facility.

A.5.2 The degree of such contamination should be assessed and evaluated as part of the initial design

concept.

A.5.3 In some cases, cross-contamination can be minimized or avoided by isolation, enclosure or

barrier technology to co
...

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