SIST EN ISO 10801:2011
(Main)Nanotechnologies - Generation of metal nanoparticles for inhalation toxicity testing using the evaporation/condensation method (ISO 10801:2010)
Nanotechnologies - Generation of metal nanoparticles for inhalation toxicity testing using the evaporation/condensation method (ISO 10801:2010)
This work will cover to a standard method for generation of silver nanoparticles to be
tested for inhalation toxicity on experimental animals. More detailed defining of the scope
will be discussed in the following specific items.
1) Generator set-up: flat-plate ceramic heater was connected to an AC power
supply and housed within a quartz case
2) Heater dimension: 50 × 5 × 1.5 mm3.
3) Surface temperature: about 1500?
4) Voltage : 85 V
5) Highest temperature on the local heating area, Tmax,: 1140?
6) air changes per hour in an exposure chamber: 12-15 times
7) loading mass of the silver lump : 160 mg
8) Nanoparticle range: 4.5-157 nm
9) Geometric mean diameters of silver nanoparticles: less than 100 nm in nonaggregated/
nonagglomerated form
10) Silver Nanoparticle measurement: SMPS (scanning mobility particle sizer) and
CPC (Condensation particle counter), TEM (Transmission Electron microscopy)
Nanotechnologien - Erzeugung von Silbernanopartikeln zur Prüfung auf Toxizität nach Inhalation (ISO 10801:2010)
Diese Internationale Norm liefert Anforderungen und Empfehlungen zur Erzeugung von Metall-Nanopartikeln
als Aerosole, die für die Inhalationstoxizitätsprüfung geeignet sind, mit Hilfe des Verdampfungs-/
Kondensationsverfahrens. Seine Anwendung ist auf Metalle, wie Gold und Silber, beschränkt, für die
nachgewiesen wurde, dass für die Prüfung auf Toxizität nach Inhalation geeignete Nanopartikel nach dem
hier festgelegtem Verfahren (siehe Anhang A) erzeugt werden können.
Nanotechnologies - Génération de nanoparticules en métal pour essais de toxicité par inhalation en utilisant la méthode de condensation/évaporation (ISO 10801:2010)
L'ISO 10801:2010 donne des exigences et des recommandations pour générer des nanoparticules métalliques comme aérosols adéquats pour les essais de toxicité par inhalation par la méthode d'évaporation/condensation. Elle se limite aux métaux tels que l'or et l'argent, qui se sont révélés générer des nanoparticules appropriées aux essais de toxicité par inhalation lorsque ladite méthode est utilisée
Nanotehnologija - Pridobivanje kovinskih nanodelcev za preskušanje toksičnosti z uporabo metode izparevanja/kondenzacije (ISO 10801:2010)
Ta mednarodni standard podaja zahteve in priporočila za pridobivanje kovinskih nanodelcev kot aerosolov, primernih za preskušanje toksičnosti z uporabo metode izparevanja/kondenzacije. Njegova uporaba je omejena na kovine, kot so zlato in srebro, za katere je bilo dokazano, da tvorijo nanodelce, primerne za preskušanje toksičnosti z uporabo tehnike, ki jo določa (glej dodatek A).
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN ISO 10801:2011
01-oktober-2011
1DQRWHKQRORJLMD3ULGRELYDQMHNRYLQVNLKQDQRGHOFHY]DSUHVNXãDQMHWRNVLþQRVWL]
XSRUDERPHWRGHL]SDUHYDQMDNRQGHQ]DFLMH ,62
Nanotechnologies - Generation of metal nanoparticles for inhalation toxicity testing using
the evaporation/condensation method (ISO 10801:2010)
Nanotechnologien - Erzeugung von Silbernanopartikeln zur Prüfung auf Toxizität nach
Inhalation (ISO 10801:2010)
Nanotechnologies - Génération de nanoparticules en métal pour essais de toxicité par
inhalation en utilisant la méthode de condensation/évaporation (ISO 10801:2010)
Ta slovenski standard je istoveten z: EN ISO 10801:2010
ICS:
07.120 Nanotehnologije Nanotechnologies
SIST EN ISO 10801:2011 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
---------------------- Page: 1 ----------------------
SIST EN ISO 10801:2011
---------------------- Page: 2 ----------------------
SIST EN ISO 10801:2011
EUROPEAN STANDARD
EN ISO 10801
NORME EUROPÉENNE
EUROPÄISCHE NORM
December 2010
ICS 07.030
English Version
Nanotechnologies - Generation of metal nanoparticles for
inhalation toxicity testing using the evaporation/condensation
method (ISO 10801:2010)
Nanotechnologies - Génération de nanoparticules de métal Nanotechnologien - Erzeugung von Metall-Nanopartikeln
pour essais de toxicité par inhalation en utilisant la zur Prüfung auf Toxizität nach Inhalation unter Verwendung
méthode de condensation/évaporation (ISO 10801:2010) des Verdampfungs-/Kondensationsverfahrens (ISO
10801:2010)
This European Standard was approved by CEN on 14 December 2010.
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, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2010 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 10801:2010: E
worldwide for CEN national Members.
---------------------- Page: 3 ----------------------
SIST EN ISO 10801:2011
EN ISO 10801:2010 (E)
Contents Page
Foreword .3
2
---------------------- Page: 4 ----------------------
SIST EN ISO 10801:2011
EN ISO 10801:2010 (E)
Foreword
This document (EN ISO 10801:2010) has been prepared by Technical Committee ISO/TC 229
“Nanotechnologies” in collaboration with Technical Committee CEN/TC 352 “Nanotechnologies” 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 June 2011, and conflicting national standards shall be withdrawn at
the latest by June 2011.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
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, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.
Endorsement notice
The text of ISO 10801:2010 has been approved by CEN as a EN ISO 10801:2010 without any modification.
3
---------------------- Page: 5 ----------------------
SIST EN ISO 10801:2011
---------------------- Page: 6 ----------------------
SIST EN ISO 10801:2011
INTERNATIONAL ISO
STANDARD 10801
First edition
2010-12-15
Nanotechnologies — Generation of metal
nanoparticles for inhalation toxicity
testing using the
evaporation/condensation method
Nanotechnologies — Génération de nanoparticules de métal pour
essais de toxicité par inhalation en utilisant la méthode de
condensation/évaporation
Reference number
ISO 10801:2010(E)
©
ISO 2010
---------------------- Page: 7 ----------------------
SIST EN ISO 10801:2011
ISO 10801:2010(E)
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.
COPYRIGHT PROTECTED DOCUMENT
© ISO 2010
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
ISO's member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2010 – All rights reserved
---------------------- Page: 8 ----------------------
SIST EN ISO 10801:2011
ISO 10801:2010(E)
Contents Page
Foreword .iv
Introduction.v
1 Scope.1
2 Normative references.1
3 Terms and definitions .1
4 Principle .3
4.1 Generation.3
4.2 Preparation of system.4
5 Requirements.4
5.1 Capacity and control.4
5.2 Nanoparticle properties .5
5.3 Exposure chamber atmosphere.5
5.4 System operational safety.5
6 Characterization of generator performance .6
6.1 Requirements for particle size distribution and mass concentration .6
6.2 Particle size distribution measurement .6
6.2.1 Sampling with DMAS.6
6.2.2 Sampling for microscopy .6
6.3 Mass concentration measured by filter sampling.6
6.3.1 Filter sampling for aerosol mass concentration .7
6.3.2 Frequency of sampling .7
7 Nanoparticle generation specifications .7
7.1 Test particle purity/impurities .7
7.2 Size range.7
7.3 Number concentration .7
7.4 Nanoparticle shape .7
7.5 Stability.7
7.6 Animal exposure.8
8 Assessment of results .8
9 Test report.8
Annex A (informative) Example method for evaporation/condensation generation of silver
nanoparticles .9
Bibliography.21
© ISO 2010 – All rights reserved iii
---------------------- Page: 9 ----------------------
SIST EN ISO 10801:2011
ISO 10801:2010(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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
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.
ISO 10801 was prepared by Technical Committee ISO/TC 229, Nanotechnologies.
iv © ISO 2010 – All rights reserved
---------------------- Page: 10 ----------------------
SIST EN ISO 10801:2011
ISO 10801:2010(E)
Introduction
The number of nanotechnology-based consumer products containing silver, gold, carbon, zinc oxide, titanium
dioxide and silica nanoparticles is growing very rapidly. The population at risk of exposure to nanoparticles
continues to increase as the applications expand. In particular, workers in nanotechnology-based industries
are at risk of being exposed to manufactured nanoparticles. If nanoparticles are liberated from products, the
public could be exposed as well.
There is currently limited, but growing, knowledge about the toxicity of nano-sized particles. The processes of
nanoparticle production include gas-phase, vapour-phase, colloidal and attrition processes. Potential paths of
exposure include inhalation, dermal and ingestion. Inhalation may arise from direct leakage from gas-phase
and vapour-phase processes, airborne contamination of the workplace from deposition or product recovery
[7]
and handling of product, or post-recovery processing and packing . Exposure to manufactured nano-sized
particles might occur during production, use and disposal in the ambient air or workplace and is of concern for
public and occupational health.
There are currently neither generally accepted methods of inhalation toxicology testing for nano-sized
particles nor specific nanoparticle generation methods for such testing. The ability to disperse respirable nano-
sized particles from powders has been an obstacle to evaluating the effects of inhalation of nano-sized
particles on the respiratory system. Although it is possible to disperse nanoparticles in air from powders, the
size of the particles so generated may be larger than desired due to aggregation and agglomeration. In order
to gain vital information for evaluating the health effects of nanoparticles by inhalation, nano-sized particles
need to be generated and transported to a test environment containing experimental animals for testing
short- or long-term inhalation toxicity. The nanoparticle generation method based on evaporation of metal
(silver in this example) and subsequent condensation is capable of providing a consistent particle size
distribution and stable number concentrations, suitable for short- or long-term inhalation toxicity study.
This International Standard provides a method for stable silver nanoparticle generation with particle sizes up
to 100 nm. A detailed method is described in Annex A. The generation method provided here has sufficient
stability for continuous inhalation toxicity testing up to 90 days. The generated nanoparticles can be used in
various experimental systems, including high-throughput human cell-based labs-on-a-chip, a variety of
[8][9][10][11]
additional in-vitro methods , as well as the animal experiments that may still be performed at this
time, which include, but are not limited to, whole-body, head-only and nose-only. The method is not limited to
the silver nanoparticles used in this example and may be used to generate other metallic nanoparticles with a
similar melting temperature and evaporation rate, such as gold. However, this method is not applicable to the
generation of nanoparticles of all metals.
© ISO 2010 – All rights reserved v
---------------------- Page: 11 ----------------------
SIST EN ISO 10801:2011
---------------------- Page: 12 ----------------------
SIST EN ISO 10801:2011
INTERNATIONAL STANDARD ISO 10801:2010(E)
Nanotechnologies — Generation of metal nanoparticles for
inhalation toxicity testing using the evaporation/condensation
method
1 Scope
This International Standard gives requirements and recommendations for generating metal nanoparticles as
aerosols suitable for inhalation toxicity testing by the evaporation/condensation method. Its application is
limited to metals such as gold and silver which have been proven to generate nanoparticles suitable for
inhalation toxicity testing using the technique it specifies (see Annex A).
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/TS 27687, Nanotechnologies — Terminology and definitions for nano-objects — Nanoparticle, nanofibre
and nanoplate
ISO 15900, Determination of particle size distribution — Differential electrical mobility analysis for aerosol
particles
ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories
1)
OECD Test Guideline (TG) 403, Acute Inhalation Toxicity
1)
OECD Test Guideline 412 (TG) 412, Subacute Inhalation Toxicity: 28-Day Study
1)
OECD Test Guideline 413 (TG) 413, Subchronic Inhalation Toxicity: 90-day Study
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO/TS 27687 and ISO 15900 and the
following apply.
3.1
differential mobility analysing system
DMAS
system used to measure the size distribution of submicrometre aerosol particles consisting of a DEMC, a
particle charge conditioner, flow meters, a particle detector, interconnecting plumbing, a computer and
suitable software
NOTE Adapted from ISO 15900:2009, definition 2.8.
1) Organization for Economic Cooperation and Development (OECD) publication.
© ISO 2010 – All rights reserved 1
---------------------- Page: 13 ----------------------
SIST EN ISO 10801:2011
ISO 10801:2010(E)
3.2
differential electrical mobility classifier
DEMC
differential electrical mobility spectrometer
DEMS
classifier that is able to select aerosol particle sizes from a distribution that enters it and pass only selected
sizes to the exit
NOTE 1 A DEMC classifies aerosol particle sizes by balancing the electrical force on each particle in an electrical field
with its aerodynamic drag force. Classified particles have different sizes due to their number of electrical charges and a
narrow range of electrical mobility determined by the operating conditions and physical dimensions of the DEMC.
NOTE 2 Adapted from ISO 15900:2009, definition 2.7.
3.3
condensation particle counter
CPC
instrument that detects particles and that can be used to calculate particle number concentration given the
known flow rates into the detector
NOTE 1 The range of particles detected are usually smaller than several hundred nanometers and larger than a few
nanometers. A CPC is one possible detector for use with a DEMC.
NOTE 2 In some cases, a condensation particle counter may be called a condensation nucleus counter (CNC).
NOTE 3 This definition is different from the one given in ISO 15900.
3.4
inhalation exposure chamber
inhalation chamber
exposure chamber
system prepared to expose experimental animals to an inhaled test substance of predetermined duration and
dose by either the nose-only or whole-body method
NOTE 1 The term “nose-only” is synonymous with “head-only” or “snout-only”.
NOTE 2 Adapted from OECD TG 403, OECD TG 412, OECD TG 413.
3.5
evaporation/condensation nanoparticle generator system
device used to make a nanoparticle aerosol by the evaporation/condensation method, which can be
connected to an inhalation chamber or other toxicity testing device
3.6
geometric mean diameter
GMD
measure of the central tendency of particle size distribution using the logarithm of particle diameters,
computed for the DMAS by
n
ΔNdln
()
∑ ii
im=
ln(GMD)=
N
where
d is the midpoint diameter for size channel i;
i
N is the total concentration;
ΔN is the concentration within size channel i;
i
2 © ISO 2010 – All rights reserved
---------------------- Page: 14 ----------------------
SIST EN ISO 10801:2011
ISO 10801:2010(E)
m is the first channel;
n is the last channel.
NOTE The GMD is normally computed from particle counts and, when noted, may be based on surface area or
particle volume with appropriate weighting.
3.7
geometric standard deviation
GSD
measure of width or spread of particle sizes, computed for the DMAS by
n 2
Nd⎡⎤ln − ln GMD
()
∑ ii
⎣⎦
im=
ln(GSD)=
N−1
3.8
count median diameter
CMD
diameter equal to GMD for particle counts assuming a logarithmic normal distribution
NOTE The general form of the relationship as described in ISO 9276-5 is
2
rp− s
()
CMD==xx e
50,rp50,
where
e is the base of natural logarithms, e = 2,718 28;
p is the dimensionality (type of quantity) of a distribution, where
p = 0 is the number,
p = 1 is the length,
p = 2 is the area, and
p = 3 is the volume or mass;
r is the dimensionality (type of quantity) of a distribution, where
r = 0 is the number,
r = 1 is the length,
r = 2 is the area, and
r = 3 is the volume or mass;
s is the standard deviation of the density distribution;
x is the median particle size of a cumulative distribution of dimensionality r.
50,r
4 Principle
4.1 Generation
The test airborne nanoparticles are generated by heating solid silver to evaporate silver from the solid silver
precursor. The entrained silver vapour is then cooled to nucleate and the vapour condensed to form a silver
nanoparticle aerosol. One experimental method that describes the generation of silver nanoparticles with the
evaporation/condensation method is described in Annex A.
© ISO 2010 – All rights reserved 3
---------------------- Page: 15 ----------------------
SIST EN ISO 10801:2011
ISO 10801:2010(E)
4.2 Preparation of system
4.2.1 Prior to interfacing the nanoparticle generating system with the exposure chamber or chambers,
nanoparticle size analysis should be performed to establish the number concentrations and size distribution of
nanoparticles and to determine the stability of the generated aerosol. For this process, parameters selected to
generate the silver nanoparticle aerosol include flow rate, evaporation temperature, quench-zone length and
temperature gradients, among others. During exposure tests, analysis should be conducted continuously
and/or intermittently, depending on the method of analysis, so as to determine the consistency of particle size
distribution without disrupting the inhalation exposure.
4.2.2 Inhalation chambers and supporting equipment shall be prepared in accordance with OECD TG 403,
OECD TG 412 and OECD TG 413.
4.2.3 Inhalation chambers and supporting equipment shall be prepared for nanoparticle exposure studies.
NOTE 1 Aerosolized nanoparticles can be deposited to walls by Brownian diffusion and particle size change due to
aggregation/agglomeration. This deposition process depends on the particle size, electrostatic charge, particle number
concentration and residence time. See standard texts on aerosol science, viz. Reference [12].
NOTE 2 Charge neutralization might be required, depending on the purpose of the study.
If charge distribution is considered a characterization requirement, this shall be specified and measured in the
study.
NOTE 3 To reduce deposition losses, conductive tubing of minimum length and diameter consistent with instrument
tube diameters is selected to interface with instrumentation and thereby avoid expansions and restrictions.
4.2.4 An inhalation chamber or chambers and supporting equipment, such as sampling probes and
manifolds, shall be characterized to ensure compliance with OECD TG 403, OECD TG 412 and
[31]
OECD TG 413 or US EPA Guidelines , for determining any sampling bias.
NOTE The sampling manifold consisting of conductive tubing, solenoid valves and/or other elements required for
routing samples from each inhalation chamber to on-line monitoring equipment may increase particle losses and alter
downstream particle size distributions if losses are dependent upon particle size.
4.2.5 Measurement instruments used in inhalation testing shall be calibrated and/or tested in accordance
with ISO/IEC 17025.
The differential mobility analysing system (DMAS) is usually calibrated at the factory and this should be
documented in the report.
5 Requirements
5.1 Capacity and control
Output, reliability and control of the generator shall be adequate for the planned study, as follows:
a) metal evaporation rate (µg/h);
3
b) air flow rate (m /h);
c) continuous operation of generator at target evaporation and air flow rates for study duration to be
considered.
4 © ISO 2010 – All rights reserved
---------------------- Page: 16 ----------------------
SIST EN ISO 10801:2011
ISO 10801:2010(E)
5.2 Nanoparticle properties
5.2.1 The geometric mean diameter (GMD) of nanoparticles shall be less than 100 nm. This is
accomplished primarily by controlling the metal evaporation and condensation rates and the residence time in
each of the reactor zones. If, despite all reasonable effort, this requirement is unable to be met, expert
judgement will need to be provided.
5.2.2 The geometric standard deviation (GSD) shall be less than 2 (as proposed in OECD TG 403,
OECD TG 412 and OECD TG 413).
5.2.3 Test article purity, including particle purity and particle surface purity, shall be established to meet the
objective of the study. Preferably prior to the start of the study, there should be a characterization of the test
article that includes its purity and, if technically feasible, the name and quantities of unknown contaminants
and impurities (OECD GD 39).
NOTE Determination of the chemical purity may require characterization of the surface chemistry of the generated
particles in addition to bulk chemical purity.
5.3 Exposure chamber atmosphere
5.3.1 Air delivered to test animals shall be breathable, with an adequate oxygen content of at least 19 %
[31]
(OECD TG 403, OECD TG 412 and OECD TG 413; US EPA Guidelines ).
This may be accomplished by supplying appropriate dilution air to the generator.
5.3.2 Care shall be taken that contaminants are not generated by evaporation of volatile compounds in
binders, lubricants, finishes and sealants used in the aerosol generator. This can be accomplished by
selection of appropriate materials and adequate bake-out of the system.
5.3.3 The temperature of the air delivered to the test inhalation chamber shall be within the limits for
[31]
inhalation studies (OECD TG 403, OECD TG 412 and OECD TG 413; US EPA Guidelines ).
5.3.4 Supply air to both the generator and inhalation chambers shall be free of oil, volatile compounds and
other contaminants, and shall be HEPA-filtered to remove aerosols, including nanoparticles, dust and
microorganisms.
5.4 System operational safety
5.4.1 All local safety requirements shall be respected.
5.4.2 Contact with hot surfaces and electrical conductors associated with the electrical heater or other
components shall be prevented.
5.4.3 Gas discharged to the atmosphere from the system shall be HEPA-filtered.
5.4.4 There shall be no measurable leaks to the atmosphere from the aerosol generator.
5.4.5 Exposure chambers should be maintained at negative pressure (u 5 mm water) with respect to
ambient conditions in order to avoid worker exposure in case of leakage. This pressure differential should be
monitored on a continuous basis and arranged to be kept within alarm limits. An alternative approach is to
maintain the apparatus at positive pressure with respect to ambient conditions to ensure that aerosols or
airborne contaminants cannot enter the exposure chamber. The apparatus at positive pressure should be
enclosed within ventilated secondary containment in order to minimize worker exposure.
For nose-only exposure, pressure should be slightly positive so as to ensure that animals will be properly
exposed. Due to potential leakage from this positive pressure, nose-only experiments should be conducted
inside the boundaries of an adequately designed fume hood (OECD GD 39).
© ISO 2010 – All rights reserved 5
---------------------- Page: 17 ----------------------
SIST EN ISO 10801:2011
ISO 10801:2010(E)
NOTE Frequent leak checks, e.g. by the soap bubble method, or the installation of permanent leak detectors may be
necessary when there is a risk of nanomaterial leakage. In nose-only exposure systems, the test atmosphere could leak
around the animal where it meets the exposure apparatus. Leaks can be prevented by using a restraint system that seals
[29]
the tube, although heat and moisture buildup in the tube is
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.