EN 60068-2-10:2005

SLOVENSKI SIST EN 60068-2-10:2005

STANDARD
december 2005
Okoljski preskusi – 2-10. del: Preskusi – Preskus J in navodilo: razvoj modela
(IEC 60068-2-10:2005)
Environmental testing - Part 2-10: Tests – Test J and guidance: Mould growth (IEC
60068-2-10:2005)
ICS 19.040 Referenčna številka
©  Standard je založil in izdal Slovenski inštitut za standardizacijo. Razmnoževanje ali kopiranje celote ali delov tega dokumenta ni dovoljeno

EUROPEAN STANDARD EN 60068-2-10
NORME EUROPÉENNE
EUROPÄISCHE NORM July 2005
ICS 19.040 Supersedes HD 323.2.10 S3:1988

English version
Environmental testing
Part 2-10: Tests –
Test J and guidance: Mould growth
(IEC 60068-2-10:2005)
Essais d'environnement Umgebungseinflüsse
Partie 2-10: Essais – Teil 2-10: Prüfverfahren –
Essai J et guide: Moisissures Prüfung J und Leitfaden:
(CEI 60068-2-10:2005) Schimmelwachstum
(IEC 60068-2-10:2005)
This European Standard was approved by CENELEC on 2005-06-01. CENELEC 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 Central Secretariat or to any CENELEC 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 CENELEC member into its own language and
notified to the Central Secretariat has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden,
Switzerland and United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Central Secretariat: rue de Stassart 35, B - 1050 Brussels

© 2005 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.

Ref. No. EN 60068-2-10:2005 E
Foreword
The text of document 104/365/FDIS, future edition 6 of IEC 60068-2-10, prepared by IEC TC 104,
Environmental conditions, classification and methods of test, was submitted to the IEC-CENELEC
parallel vote and was approved by CENELEC as EN 60068-2-10 on 2005-06-01.
This European Standard supersedes HD 323.2.10 S3:1988.
The main changes with respect to HD 323.2.10 S3:1988 are:
– two test fungi replaced by two others;
– concentration of the spores defined for each test fungus;
– spores suspension in mineral salt solution additionally introduced;
– pre-conditioning of the specimens by damp heat storage prescribed;
– supersonic aerosolization of the spores suspension as the preferred inoculation method
introduced;
– duration of incubation reduced from 84 days to 56 days;
– extent of mould growth grade 2 split into grade 2a and grade 2b;
– detailed information on methods of inoculation given in Annex B;
– Annex E: flow-chart deleted.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2006-03-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2008-06-01
Annex ZA has been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 60068-2-10:2005 was approved by CENELEC as a
European Standard without any modification.
__________
- 3 - EN 60068-2-10:2005
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
NOTE Where an international publication has been modified by common modifications, indicated by (mod), the relevant
EN/HD applies.
Publication Year Title EN/HD Year
1)
ISO/IEC 17025 1999 General requirements for the competence EN ISO/IEC 17025 2000
of testing and calibration laboratories

ISO 846 1997 Plastics - Evaluation of the action of EN ISO 846 1997
microorganisms
MIL-STD-810F 2000 Method 508.5 Fungus - -

WHO, 1993 Laboratory Biosafety Manual - -
ISBN 92 4
1)
EN ISO/IEC 17025:2000 is superseded by EN ISO/IEC 17025:2005, which is based on ISO/IEC 17025:2005.

NORME CEI
INTERNATIONALE
IEC
60068-2-10
INTERNATIONAL
Sixième édition
STANDARD
Sixth edition
2005-06
BASIC SAFETY PUBLICATION
PUBLICATION FONDAMENTALE DE SÉCURITÉ
Essais d’environnement –
Partie 2-10:
Essais – Essai J et guide:
Moisissures
Environmental testing –
Part 2-10:
Tests – Test J and guidance:
Mould growth
CODE PRIX
V
Commission Electrotechnique Internationale
PRICE CODE
International Electrotechnical Commission
МеждународнаяЭлектротехническаяКомиссия
For price, see current catalogue
Pour prix, voir catalogue en vigueur

60068-2-10  IEC:2005 – 3 –
CONTENTS
FOREWORD.5

1 Scope.9
2 Normative references .9
3 General description .9
4 Health hazards to operators .11
5 Description of the test variants .11
5.1 Test variant 1 .11
5.2 Test variant 2 .11
6 Reagents and materials.13
6.1 Cultures or spores – Supply and conditions.13
6.2 Preparation of spore suspension .15
6.3 Control strips.17
7 Description of test apparatus .17
7.1 Inoculation by spraying.17
7.2 Incubation of small specimens.17
7.3 Incubation of large specimens .19
8 Severities .19
9 Initial examinations.19
10 Pre-conditioning .19
10.1 Cleaning.19
10.2 Damp heat storage .21
11 Conditioning .21
11.1 Application .21
11.2 Inoculation .21
11.3 Incubation .23
12 Final examinations .23
12.1 Visual examination .23
12.2 Effect of growth .25
12.3 Extent of growth .25
13 Information to be given in the relevant specification .27
14 Information to be given in the test report as a minimum .27

Annex A (informative) Danger to personnel.29
Annex B (normative) Inoculation methods (see also 11.2) .33
Annex C (informative) Recommended safety precautions.39
Annex D (informative) Decontamination procedures.43
Annex E (informative) Information on the test fungi.47
Annex F (informative) Guidance.51

60068-2-10  IEC:2005 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ENVIRONMENTAL TESTING –
Part 2-10: Tests – Test J and guidance:
Mould growth
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 60068-2-10 has been prepared by IEC technical committee 104:
Environmental conditions, classification and methods of test.
This sixth edition cancels and replaces the fifth edition published in 1988. This edition
constitutes a technical revision.
The main changes with respect to the previous edition are listed below:
– Two test fungi replaced by two others
– Concentration of the spores defined for each test fungus
– Spores suspension in mineral salt solution additionally introduced
– Pre-conditioning of the specimens by damp heat storage prescribed

60068-2-10 © IEC:2005 – 7 –
– Supersonic aerosolization of the spores suspension as the preferred inoculation method
introduced
– Duration of incubation reduced from 84 days to 56 days
– Extent of mould growth grade 2 split into grade 2a and grade 2b
– Detailed information on methods of inoculation given in Annex B
– Annex E: flow-chart deleted
The text of this standard is based on the following documents:
FDIS Report on voting
104/365/FDIS 104/373/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
It has the status of a basic safety publication in accordance with IEC Guide 104.
This standard forms Part 2-10 of IEC 60068 which consists of the following major parts, under
the general title Environmental testing:
Part 1: General and guidance
Part 2: Tests
Part 3: Supporting documentation and guidance
Part 4: Information for specification writers
Part 5: Guide to drafting of test methods
The committee has decided that the contents of this publication will remain unchanged until
the maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in
the data related to the specific publication. At this date, the publication will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.
60068-2-10  IEC:2005 – 9 –
ENVIRONMENTAL TESTING –
Part 2-10: Tests – Test J and guidance:
Mould growth
1 Scope
This part of IEC 60068 provides a test method for determining the extent to which
electrotechnical products support mould growth and how any mould growth may affect the
performance and other relevant properties of the product.
Since mould growth conditions include high relative humidity, the test is applicable to
electrotechnical products intended for transportation, storage and use under humid conditions
over a period of some days at least.
2 Normative references
The following referenced documents are indispensable for the application of this document.
For dated references, only the edition cited applies. For undated references, the latest edition
of the referenced document (including any amendments) applies.
ISO/IEC 17025:1999, General requirements for the competence of testing and calibration
laboratories
ISO 846:1997, Plastics – Evaluation of the action of microorganisms
MIL–STD–810 F:2000, Method 508.5 Fungus
nd
Laboratory Biosafety Manual 2 Ed., WHO 1993, ISBN 92 4 1544503
3 General description
This test covers the inoculation of electrotechnical products with a selection of mould spores
followed by a period of incubation under conditions which promote spore germination and the
growth of mould.
Two variations of the test are given. Variant 1 specifies inoculation of the specimen with the
mould spores without nutrients whereas variant 2 specifies the inoculation with the mould
spores suspended in a nutritive solution which supports mould growth.
It is advisable to use testing procedures such as specified for plastics in ISO 846 to assess
the vulnerability to damage by mould growth of the constructional materials used.
NOTE Laboratories for microbiological testing of technical products should be accredited in accordance with
ISO/IEC 17025. See further Annex F.

60068-2-10  IEC:2005 – 11 –
Surface contamination in the form of dusts, splashes, condensed volatile nutrients or grease
may be deposited upon assembled specimens. This can be brought about by storage and use
or transport with the product exposed to the atmosphere or handled without protective
covering. This surface contamination can cause an increased colonization by fungi and may
lead to greater growth and damage. An assessment of the effect of such contamination can
be given by the application of test variant 2.
Due to the difficulty of maintaining the necessary conditions in a very large chamber, a large
composite equipment will normally be tested as a number of sub-units. This will in any case
minimize the cost of the test since several sub-units may be so similar in construction that
only one of them need be tested.
4 Health hazards to operators
This test procedure requires the use of viable mould spores and the application of ambient
conditions which promote mould growth.
Therefore before any attempt is made to handle mould cultures, or to carry out steps of the
test subsequently described, it is important that the annexes of this standard be studied.
Annex A Danger to personnel
Annex B Inoculation methods
Annex C Recommended safety precautions
Annex D Decontamination procedures
nd
Laboratory Biosafety Manual, 2 Ed., World Health Organization 1993, ISBN 92 4 1544503
includes general background reading on safety in facilities dealing with fungi.
5 Description of the test variants
5.1 Test variant 1
After a 28 days incubation period determine
– the extent of mould growth by visual inspection;
– the physical damage caused by mould growth;
– in the case of mould growth the effect on functioning and/or electrical properties if
required in the relevant specification.
The incubation period shall be extended to a total of 56 days before checking the function
and/or measuring electrical properties if required in the relevant specification.
5.2 Test variant 2
After a simulated contamination with nutrients followed by a 28 days incubation period
determine
– the extent of mould growth by visual inspection;
– the physical damage caused by mould growth;
– the effect of the mould growth on functioning and/or electrical properties if required in the
relevant specification.
60068-2-10  IEC:2005 – 13 –
The surface resistance of the specimen will be reduced by application of nutrients for
simulation of contamination without any mould growth. This effect should be considered if
checking the function and/or measuring electrical properties.
Due to the application of nutrients, mould growth will exist; failing this, a fungicidal effect shall
be considered.
6 Reagents and materials
6.1 Cultures or spores – Supply and conditions
The following fungi shall be used for performing the test (see Table 1). The nature of the
attack to be expected from each fungus is indicated for guidance. The spores of all cultures,
however, shall be used together in a mixed suspension whatever the nature of the specimen.
The cultures or freeze-dried spores shall be obtained from a recognized mycological cultures
collection. They shall be supplied in containers with the date of inoculation of the culture
thereon.
A certificate shall confirm the accordance of the culture with the fungus and strain number as
specified in Table 1 and/or Annex E.
Cultures and freeze-dried spores shall be handled and stored in accordance with the
recommendations of the supplier and the relevant requirements of this standard. Preparing a
culture by the test laboratory from a stock culture or from freeze-dried spores the date of
inoculation shall be marked on the culture tube.
Table 1 – Test fungi
3)
No. Name Strain No. Attacks Note
1) 2)
1 Aspergillus niger ATCC 6275 many materials
1) 2)
2 Aspergillus terreus ATCC 10690 plastic materials
1) 2)
3 Chaetomium globosum ATCC 6205 cellulose
hydrocarbon based
4 Hormoconis resinae DSM 1203
–
lubricants
1) 2)
5 Paecilomyces variotii ATCC 18502 plastics and leather
many materials
1) 2)
6 Penicillium funiculosum ATCC 36839
especially textiles
1) 2)
7 Scopulariopsis brevicaulis ATCC 36840 rubber
cellulose, textiles
2)
8 Trichoderma virens ATCC 9645
and plastics
1)
Also specified in ISO 846.
2)
3) Also specified in MIL–STD–810 F, Table 508.5–Ι.
See also Annex E.
Cultures shall be used for preparing the test spore suspension when they are well sporulated.

60068-2-10  IEC:2005 – 15 –
This is reached in most cases after a 7 to 14 days incubation period at (29 ± 1) °C.
NOTE The supplier of cultures or freeze-dried spores may recommend other conditions to develop the culture.
If the cultures are not for immediate use, they shall be stored in a refrigerator at a
temperature between 5 °C and 10 °C, for a continuous period of not more than six weeks
commencing not earlier than 14 days and not later than 28 days from the date of inoculation
given on the container.
The lid of the container shall not be opened once the preparation of the spore suspension has
started. Only one suspension shall be made from the opened container.
6.2 Preparation of spore suspension
6.2.1 General
The suspension is first prepared in sterilized distilled water, to which has been added a
wetting agent with a concentration between 0,005 % and 0,01 %. An agent based on N-
methyl-taurine or on dioctyl-sodium sulphosuccinate has been found to be suitable. The
wetting agent shall not contain substances which support or inhibit mould growth.
10 ml of the water containing the wetting agent shall be added gently to each culture.
A platinum or nichrome wire shall be sterilized by heating to red heat in a flame and allowed
to cool. This wire shall be used to gently scrape the surface of the culture to liberate spores.
The liquid shall be slightly agitated to disperse the spores without detaching mycelial
fragments and the suspension shall be gently decanted and filtered through a thin layer of
sterile glass wool or through a micro filter funnel with a pore size from 40 µm to 100 µm into a
sterilized centrifuge tube.
The filtered spore suspension shall be centrifuged and the supernatant liquid shall be
discarded. The residue shall be re-suspended in not less than 10 ml of sterilized distilled
water and centrifuged again. The spores shall be washed in this manner three times.
6.2.2 Preparation for test variant 1
Dilute the final spore residue of each culture in a volume of
– mineral salt solution in accordance with 6.3 but without sucrose (saccharose) if the
relevant specification prescribes visual inspection only (see 5.1);
– sterilized distilled water if the relevant specification prescribes checking the function or
measuring electrical properties (see 5.1);
6 6
that adjusting the spore concentration to 1 × 10 to 2 × 10 /ml determined with a counting
chamber or by turbimetry.
Blend equal volumes of the single suspensions sufficient for the relevant inoculation
procedure to obtain the final mixed spore suspension ready for inoculation. Spore suspension
in mineral salt solution shall be used within 48 h after preparation. Spore suspension in
sterilized distilled water shall be used within 6 h after preparation.
NOTE Prepare total volumes of about 100 ml for inoculation by spraying or of about 500 ml for inoculation by
painting or dipping.
60068-2-10  IEC:2005 – 17 –
6.2.3 Preparation for test variant 2
Dilute the final spore residue of each culture in such a volume of nutritive solution in
6 6
accordance with 6.3 adjusting the spore concentration to 1 × 10 to 2 × 10 /ml determined
with a counting chamber or by turbimetry.
Blend equal volumes of the single suspensions sufficient for the relevant inoculation
procedure to obtain the final mixed spore suspension ready for inoculation. Use the spore
suspension within 6 h after preparation.
NOTE See 6.2.2.
6.3 Control strips
The control strips called for in the test shall consist of strips of pure white filter paper or
untreated cotton textile.
The nutritive solution called for in preparing the control strips shall consist of a solution of the
following reagents in distilled water.
Reagent g/l
Potassium dihydrogen phosphate (KH PO) 0,7
2 4
Dipotassium hydrogen phosphate (K HPO) 0,3
2 4
Magnesium sulphate (MgSO · 7 HO) 0,5
4 2
Sodium nitrate (NaNO) 2,0
Potassium chloride (KCl) 0,5
Ferrous sulphate (FeSO · 7 HO) 0,01
4 2
Sucrose (saccharose) 30,0
The pH shall be 6,0 to 6,5 at 20 °C. It shall be adjusted with 0,01 molar NaOH if needed.
The solution shall be sterilized in an autoclave at (120 ± 1) °C for 20 min.
Immediately before inoculated (see 11.2), the control strips shall be saturated by the nutritive
solution, removed from it and allowed to drain free of drips.
7 Description of test apparatus
7.1 Inoculation by spraying
Preferably a supersonic aerosol apparatus, as used for therapeutic treatment by inhalation,
should be used in connection with a safety inoculation chamber (see Annex B).
7.2 Incubation of small specimens
Containers of glass or plastic with lids provided with devices for putting on or suspending the
specimens and control strips shall be used.
The container shall be of such size and shape as to expose a sufficient surface area of free
water in the base at all times in order to maintain a value of relative humidity greater than
90 % within it.
60068-2-10  IEC:2005 – 19 –
The devices for putting on or suspending shall be such as to ensure that specimens and
control strips are not allowed to touch or to be splashed by the water.
The containers shall be placed in a chamber maintaining a uniform temperature throughout
the working space within the range of 28 °C to 30 °C for incubating the specimens and control
strips. Any periodic cycling of temperature due to action of the thermostat shall not exceed
1 °C/h.
7.3 Incubation of large specimens
A suitable humidity chamber shall be used for incubation specimens too large for the
containers specified in 7.2. The humidity chamber shall have a well sealed door to prevent
exchange of atmosphere between its interior and the laboratory.
The relative humidity within the working space shall be maintained at a value greater than
90 %. No condensed water from the walls or roof of the chamber shall be allowed to fall on
the specimens and control strips. The temperature throughout the working space shall be
maintained uniformly within the range of 28 °C to 30 °C. Any periodic cycling of the
temperature due to action of the thermostat shall not exceed 1 °C/h.
In order to achieve the specified humidity and temperature uniformly throughout the working
space it may be necessary to use forced air circulation within it. The flow rate shall not
exceed 1 m/s over the surface of the specimen(s).
8 Severities
The severity for each test variant is determined by the duration of the incubation.
Test variant 1 – severity 1 28 days
– severity 2 56 days
as required in the relevant specification.
Test variant 2 – severity 28 days
9 Initial examinations
The specimens shall be visually inspected and shall be electrically and mechanically checked
as required by the relevant specification.
10 Pre-conditioning
10.1 Cleaning
The specimens shall be used for the test in the “as received” condition. Normally, they shall
not be submitted to any special cleaning.
If prescribed by the relevant specification half of the lot of specimens shall be cleaned by
washing with ethanol or demineralized water containing a detergent followed by rinsing with
demineralized water free of detergent and the other half shall remain in the “as received”
condition. By this means any mould growth caused by the use of unsuitable materials in
construction of the product can be distinguished from that due to surface contamination.

60068-2-10  IEC:2005 – 21 –
When the grade 0 is required in the relevant specification (Test variant 1), consideration
should be given to the need to clean specimens because presence of contamination may
promote mould growth.
NOTE Grade 0, see 12.3.
10.2 Damp heat storage
The specimen(s) shall be stored under the conditions of incubation at (29 ± 1) °C and a
relative humidity > 90 % and < 100 % not less than 4 h immediately before inoculation.
11 Conditioning
11.1 Application
For the test variant stated in the relevant specification the application shall be carried out
according to the method described below.
11.1.1 Test variant 1
If the relevant specification requires checks of functioning and/or measurement of electrical
properties two groups of specimens shall be involved:
Group 1 test specimen(s) inoculated with the spore suspension and incubated;
Group 2 negative control specimen(s) sprayed or painted with or dipped in sterilized
distilled water in accordance with the inoculation method used for group 1 and
stored at the same temperature and relative humidity as prescribed for incubation
but in a sterile environment.
If the relevant specification requires no checks of functioning and/or measurement of
electrical properties the group 1 shall be used only.
11.1.2 Test variant 2
Two groups of specimens shall be involved:
Group 1 test specimens inoculated with spores suspended in the nutritive solution and
incubated;
Group 2 in accordance with test variant 1, group 2.
NOTE Negative control specimen(s) should be exposed to the specified conditions in a separate chamber to that
in which the inoculated specimens are held. To ensure that no mould grows on the negative control specimens, the
chamber should be sterilized by one of the methods given in D.1.1. The test is valid unless both the test
specimen(s) and a negative control specimen support growth.
11.2 Inoculation
The inoculation of the test specimen(s) and control strips (see 6.3) with the spore suspension
(see 6.2) shall be carried out by spraying if not otherwise prescribed in the relevant
specification.
If spraying is not suitable due to the size, design or other properties of the specimen
inoculation with spore suspension by dipping or painting may be carried out as stated in the
relevant specification.
NOTE Spraying by aerosolization of the spore suspension with a supersonic aerosol apparatus as used for
therapeutic treatment by inhalation in connection with a safety inoculation chamber (see Annex B) allows a very
homogeneous distribution of the spores on the surface to be tested giving a high reproducibility of the test results.
That should be the preferred inoculation method.

60068-2-10  IEC:2005 – 23 –
11.3 Incubation
The conditions of incubation are (29 ± 1) °C and a relative humidity of >90 % and <100 %.
The conditions shall be maintained in the containers (see 7.2) for small specimens or in the
humidity incubation chamber (see 7.3) for large specimens.
Immediately after inoculation, the small specimens and at least 3 control strips shall be
arranged in the container in a well spaced layout and without restriction of setting the required
relative humidity. After that the container shall be placed in the incubation chamber.
Where applicable, negative control specimens shall be arranged in similar but sterilized
containers as for the inoculated specimens without control strips. The containers shall then be
placed in the incubation chamber.
In the case of large specimens a suitable number of control strips shall be placed in the
chamber with the specimens. Any negative control specimens shall be exposed in a separate
freshly disinfected chamber (see Annex D) used preferably for negative control specimens
only.
The containers or the humidity chamber shall be opened only to
– inspect the control strips ascertaining the viability of the spores and the maintenance of
the conditions of incubation after 7 days;
– supply the containers with oxygen from the air once every 7 days until the completion of
the prescribed duration of incubation;
– perform visual intermediate inspection(s) in accordance with 11.3.7.
The opening shall be for a few minutes only.
After the 7 days incubation, mould growth of more than one strain shall be visible to the naked
eye on each of the control strips. Otherwise the test shall be considered void and shall be
recommenced. In this case, the same specimens may be used.
Any interruption of the incubation is permitted for a visual inspection only and for not more
than 10 min in each case and if required in the relevant specification. Not more than two
visual inspections shall be prescribed to perform within the duration of the incubation. The
time(s) of the visual inspection shall be specified in the relevant specification.
12 Final examinations
12.1 Visual examination
The specimens shall be examined (see 12.3), checked and/or photographed (as required by
the relevant specification), immediately after they are removed from the container or humidity
chamber, because the growth can change its appearance by desiccation. See Annex C, for
recommended safety methods of handling.
Following a visual examination and assessment of the actual growth, the mycelium shall be
carefully removed with ethanol 70 % vol from the surface which shall then be examined
through a microscope to assess the nature and extent of any attack (e. g. etching) on the
specimen. See Annex C for recommended safety methods when removing the mould growth.

60068-2-10  IEC:2005 – 25 –
12.2 Effect of growth
When the relevant specification calls for electrical and/or mechanical checks while damp
(following incubation), it is essential that the relative humidity of the surroundings of the
specimen(s) shall not be allowed to fall unduly until after such checks have been made. The
checks shall therefore be carried out on small specimens while still exposed in the container
with the lid fitted and free water. For large specimens checks shall be made while they are
still in the humidity chamber.
NOTE When electrical connections have to be made or work has to be done on specimens in containers or
humidity chambers with the lids or doors necessarily opened, this operation should be carried out with regard to
the safety of operators. See Annex C for recommended safety methods of handling. Requirements of the
manufacturer for operation under damp heat conditions given in the operation manual will be observed.
Similar checks shall be made on the specimens inoculated with spore suspensions and those
inoculated with water only. Any significant difference between the two groups is considered to
be additional due to the presence of mould growth as well as the high humidity.
Following the checks, the specimens shall be removed and visually examined as prescribed in
12.1.1 and finally any attack on the specimen shall be determined as in 12.1.2.
If the relevant specification prescribes checks after recovery, the specimens shall be removed
from the container or chamber then visually examined as specified in 12.1.1 and then
exposed to the specified conditions for recovery for a period of 24 h at the conclusion of
which the checks shall be made.
12.3 Extent of growth
The specimens shall be inspected first by the naked eye and then if necessary with a
stereoscopic microscope with a nominal magnification of approximately 50 x.
The extent of growth shall be assessed and expressed according to the following grade:
Grade
0 No growth apparent under a nominal magnification of 50 x
Traces of growth plainly visible under the microscope
2a Sparse growth visible to the naked eye and/or under the microscope scattered only or
localized to a few places covering all together not more than 5 % of the test surface
2b Growth plainly visible to the naked eye and/or under the microscope distributed more
or less homogeneously on many places covering all together not more than 25 % of
the test surface
Growth plainly visible to the naked eye and covering more than 25 % of the test
surface
NOTE Where specimens comprising an assembly show varying grades of growth they should be assessed
separately. For test variant 2 grade 0 should be required only if it is specified to examine for a fungistatic effect.

60068-2-10  IEC:2005 – 27 –
13 Information to be given in the relevant specification
When this test is included in the relevant specification, the following details shall be given
Clause or subclause
a) Test variant 1 or 2    5, 11.1
b) Test variant 1 duration of incubation (severity)  5, 8
c) Initial electrical and mechanical measurements and  5, 9, 11.1
functional checks (only if performance deterioration
is to be determined)
d) Preconditioning by cleaning   10.1
e) Inoculation method (if not by spraying)   11.2
f) Interruption of incubation for visual intermediate inspection 11.3.7
g) Final examinations    12
h) Extent of growth (grade) to be approved (if needed)  12.3
14 Information to be given in the test report as a minimum
a) Test laboratory (name, address and accreditation)
b) Customer (name and address)
c) Description of the specimen(s)
d) Test standard, edition and test variant
e) Severity for test variant 1
f) Test fungi (if deviating from the test standard)
g) Initial, intermediate and final examinations (detailed)
h) Cleaning of the specimen(s) (if applied)
i) Method of inoculation
j) Conditions of incubation (if deviating from the test standard)
k) Mould growth on the control strips (after 7 days incubation)
l) Test results (specific observations inclusive)
m) Test criterion (permissible grade of mould growth if prescribed)
n) Evaluation of the performance (basing on the test criterion)

60068-2-10  IEC:2005 – 29 –
Annex A
(informative)
Danger to personnel
A.1 General
It is the opinion of mycologists and pathologists that conducting the mould growth test can
constitute a health hazard, unless special precautions are taken.
The precautions detailed in Annexes A, B, C and D are based upon established
microbiological techniques and specialized equipment. Persons carrying out the test shall be
trained in microbiological laboratory work.
A microbiological laboratory shall be provided for mould growth testing.
The use of a microbiological safety cabinet (MSC) is recommended for carrying out certain
parts of the procedure.
Airborne mould spores continually enter the human body through the nose and mouth but they
do not normally present a hazard to health. Certain susceptible individuals may, however, be
affected by the repeated inhalation of some spores, including those of the moulds used in this
test and attention is drawn to the precautions to be adopted when carrying out the test. These
are outlined in Annex C. Growth of foreign fungi and other micro-organisms can develop as an
unintentional intruder during the incubation period at incubation locations and/or specimens.
Some of these fungi or other micro-organisms may be injurious to the human system.
Persons intended to be involved in this test should be advised to notify the medical officer, or
their own doctor, that they are required to undertake the work. Medical opinion for or against
participation should be followed.
Persons carrying out the test should be informed of the potential hazards to which they will be
exposed in relation to their current state of health.
National safety regulations shall be followed.
A.2 Notes for the guidance of medical officers
The test involves a hazard from the inhalation or traumatic implantation of spores.
The safety precautions to be adapted are given in Annex C and are designed to minimize this
hazard.
60068-2-10  IEC:2005 – 31 –
Specific hazards exist for susceptible persons, e. g. those who are
– atopic patients who are normally allergic to pollen, house dust, animal dander, etc. and
suffer from rhinitis, asthma or other allergic symptoms. The hazard here is in the
development of Type I allergy to mould spores, but in certain circumstances Type III
reactions may develop (Farmer's Lung type);
– patients who have chronic lung damage e.g. bronchiectasis, chronic bronchitis,
sarcoidosis, emphysema, etc. The deposition and germination of spores in lung cavities
may lead to the growth of the fungus as a fungus ball or aspergilloma, mainly associated
with Aspergillus spec. Healed tubercular lesions constitute a possible site for fungal
growth;
– patients who are currently undergoing broad–spectrum antibiotic treatment, being given
immuno-suppressive drugs including corticosteroids or taking other prescribed chemo
therapeutic preparations. Elimination of the normal bacterial flora of the respiratory and
alimentary tracts sometimes enables fungi to develop extensively, whilst immuno-
suppression may render the individual more susceptible to fungal infection.
Although the hazards involved in carrying out the test in accordance with the specified
procedures are regarded as low, it is recommended that persons in these categories should
not be involved in the test.
60068-2-10  IEC:2005 – 33 –
Annex B
(normative)
Inoculation methods
(see also 11.2)
B.1 General
Annex C "recommended safety precautions" shall be studied prior to commencing inoculation.
Spraying on the spore suspension to the specimens and control strips is a generally suitable
method.
B.2 Spraying by the aerosol inoculation method (AIM)
B.2.1 General
Using a spray gun for inoculation, the distribution of the spores on the surface of the
specimen is much more inhomogeneous than using the AIM.
The reproducibility and explainability of the test results are evidently better using the AIM, due
to a very homogeneous distribution of the spores on the specimen surface(s).
The AIM is favourably applicable to specimens with a barely surface wetted by the spore
suspension also.
Suitable dimensions of the safety inoculation box may be 500 mm x 500 mm x 500 mm. The
material of the box should be polymethylmetacrylate.
B.2.2 Description of the method
Aerosol inoculation method (AIM), see Figure B.1.
The spore suspension will be aerosolized by a supersonic aerosol apparatus as used for
therapeutic treatments by inhalation
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