EN 13795-2:2019

SLOVENSKI STANDARD
01-julij-2019
Nadomešča:
SIST EN 13795:2011+A1:2013
Operacijska oblačila in pokrivala - Zahteve in preskusne metode - 2. del: Čista
oblačila
Surgical clothing and drapes - Requirements and test methods - Part 2: Clean air suits
Operationskleidung und -abdecktücher - Anforderungen und Prüfverfahren - Teil 2: Rein-
Luft-Kleidung
Vêtements et champs chirurgicaux - Exigences et méthodes d’essai - Partie 2 : Tenues
de bloc
Ta slovenski standard je istoveten z: EN 13795-2:2019
ICS:
11.140 Oprema bolnišnic Hospital equipment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 13795-2
EUROPEAN STANDARD
NORME EUROPÉENNE
April 2019
EUROPÄISCHE NORM
ICS 11.140 Supersedes EN 13795:2011+A1:2013
English Version
Surgical clothing and drapes - Requirements and test
methods - Part 2: Clean air suits
Vêtements et champs chirurgicaux - Exigences et Operationsbekleidung und -abdecktücher -
méthodes d'essai - Partie 2 : Tenues de bloc Anforderungen und Prüfverfahren - Teil 2: Rein-Luft-
Kleidung
This European Standard was approved by CEN on 24 October 2018.

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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, 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
© 2019 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 13795-2:2019 E
worldwide for CEN national Members.

Contents Page
European foreword . 4
Introduction . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 7
4 Performance requirements . 10
5 Manufacturing and processing requirements and documentation . 11
6 Information to be supplied with the product . 11
6.1 Information to be supplied to the user . 11
6.2 Information to be supplied to the processor . 11
Annex A (normative) Testing . 12
A.1 General . 12
A.2 Test methods and conformance . 12
A.2.1 Test method for evaluation of cleanliness microbial/bioburden . 12
A.2.2 Test method for evaluation of particle release . 12
A.2.3 Test method for evaluation of bursting strength in dry state . 13
A.2.4 Test method for evaluation of tensile strength in dry state . 13
A.2.5 Test method for evaluation of dry microbial penetration . 13
A.2.6 Test method for evaluation of biocompatibility . 13
A.3 Treatment of results . 13
Annex B (informative) Rationales . 15
B.1 General . 15
B.2 Cleanliness – microbial . 15
B.3 Particle release . 15
B.4 Bursting strength – dry . 16
B.5 Tensile strength – dry . 16
B.6 Resistance to microbial penetration – dry . 16
B.7 Labelling . 17
B.8 Treatment of results . 17
B.9 Flammability . 18
B.10 Electrostatic discharge . 18
Annex C (informative) Environmental aspects . 19
Annex D (informative) Guidance to users for selecting products . 20
D.1 General . 20
D.2 Performance levels . 20
D.3 Functional design aspects . 20
D.3.1 Size . 20
D.3.2 Accessories . 20
D.4 Comfort . 21
D.4.1 General . 21
D.4.2 Clean air suits . 21
D.4.3 Practical trials . 21
Annex E (informative) Functional design . 22
E.1 General . 22
E.2 Test method for measuring source strength . 22
E.2.1 Dispersal chamber . 22
E.2.2 Operating room . 23
E.2.3 Measuring bacteria carrying airborne particles . 23
E.2.4 Source strength . 23
E.3 Use of source strength measurements . 24
Annex ZA (informative) Relationship between this European standard and the essential
requirements of Directive 93/42/EEC [1993 OJ L 169] aimed to be covered . 26
Bibliography . 27

European foreword
This document (EN 13795-2:2019) has been prepared by Technical Committee CEN/TC 205 “Non-
active medical devices”, the secretariat of which is held by DIN.
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 October 2019, and conflicting national standards shall
be withdrawn at the latest by October 2019.
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.
Together with EN 13795-1:2019, this document supersedes EN 13795:2011+A1:2013.
This document has been prepared under a mandate given to CEN by the European Commission and the
European Free Trade Association, and supports essential requirements of EU Directive(s).
For relationship with EU Directive(s), see informative Annex ZA, which is an integral part of this
document.
EN 13795 consists of the following parts, under the general title Surgical clothing and drapes —
Requirements and test methods:
— Part 1: Surgical drapes and gowns
— Part 2: Clean air suits
The following changes have been introduced:
a) Restriction to the product ‘clean-air suit’ in this Part of the EN 13795 standard series (for surgical
drapes and gowns see EN 13795-1);
b) Alignment of the Standard title and the Scope;
c) Revision of the Normative references and the Bibliography;
d) Alignment of the Clause ‘Terms and definitions’;
e) Revision of the performance requirements in Table 1;
f) Movement of former Clause 5 ‘Testing’ to A.1 and editorial alignment;
g) Revision of Clause ‘Manufacturing and processing requirements‘ by adding of documentary
requirements and a section for the introduction of a QM system;
h) Enhancement and improved structuring of Clause ‘Information to be supplied by the manufacturer
or processor’;
i) Deletion of the former Annex A ‘Details of significant changes between this document and the
previous edition’;
j) Complete revision and extension of Annex A ‘Testing’ (formerly Annex B ‘Test methods’);
k) Inclusion of a new Annex B ‘Rationales’ which provides precise reasons for the essential
requirements of this document and which is intended for users aware of the subject of this
document, but who did not join whose development;
l) Deletion of the former Annex C ‘Prevention of infection in the operating room‘;
m) Inclusion of a new Annex C ‘Environmental aspects’;
n) Inclusion of a new Annex D ‘Guidance to users for selecting products‘;
o) Inclusion of a new Annex E 'Functional design';
p) Revision of Annex ZA on the relationship to the Medical Device Directive (93/42/EEC);
q) Complete editorial revision.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Introduction
Clean air suits are used to minimize the spread of infective agents to patients’ surgical sites and
equipment, through prevention of dispersal of bacteria-carrying skin scales from the operating room
staff, thereby helping to prevent post-operative surgical site infections.
The performance required of working clothes for clinical staff varies with, for example, the type and
duration of the procedure, and the susceptibility of the patient to infection. In infection-prone invasive
operations, a clean air suit can contribute to reduction of infection risks, in conjunction with ventilation
and correct working methods.
This document is intended to assist the communication between manufacturers and third parties with
regard to material or product characteristics and performance requirements.
Therefore, Annex B provides comprehensive information on characteristics, measurement of
performance and performance requirements. Annex C clarifies that this document does not include
environmental provisions. Annex D explains the concept of performance levels and provides guidance
to users for selecting products. Annex E gives information on the impact of the design of clean air suits
and the source strength concept as an evaluation means for the impact of the entire clothing (including
clean air suits) on particle release.
This document focuses on Essential Requirements arising from the Medical Device Directive
93/42/EEC, which are applicable to clean air suits. The requirements and guidance in this document
are expected to be of help to manufacturers and users when designing, processing, assessing and
selecting products. It is the intention of this document to ensure the same level of safety from single-use
and reusable clean air suits throughout their useful life.
1 Scope
This document specifies information to be supplied to users and third party verifiers in addition to the
usual labelling of medical devices (see EN 1041 and EN ISO 15223-1), concerning manufacturing and
processing requirements.
This document gives information on the characteristics of single-use and reusable clean air suits used as
medical devices for clinical staff, intended to prevent the transmission of infective agents between
clinical staff and patients during surgical and other invasive procedures.
This document specifies test methods for evaluating the identified characteristics of clean air suits and
sets performance requirements for these products.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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.
EN 29073-3:1992, Textiles - Test methods for nonwovens - Part 3: Determination of tensile strength and
elongation
EN ISO 139:2005, Textiles — Standard atmospheres for conditioning and testing (ISO 139:2005 +
Amd. 1:2011)
EN ISO 9073-10:2004, Textiles - Test methods for nonwovens - Part 10: Lint and other particles
generation in the dry state (ISO 9073-10:2003)
EN ISO 10993-1:2009, Biological evaluation of medical devices - Part 1: Evaluation and testing within a
risk management process (ISO 10993-1:2009)
EN ISO 11737-1:2018, Sterilization of medical devices — Microbiological methods — Part 1:
Determination of a population of microorganisms on products (ISO 11737-1:2018)
EN ISO 13938-1:1999, Textiles - Bursting properties of fabrics - Part 1: Hydraulic method for
determination of bursting strength and bursting distension (ISO 13938-1:1999)
EN ISO 22612:2005, Clothing for protection against infectious agents - Test method for resistance to dry
microbial penetration (ISO 22612:2005)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp

Impacted by EN ISO 139:2005+A1:2011
3.1
colony forming unit
CFU
unit by which the culturable number of microorganisms is expressed
Note 1 to entry: The culturable number is the number of microorganisms, single cells or aggregates, able to
form colonies on a solid nutrient medium.
3.2
clean air suit
suit, used as working garment, intended and shown to minimize contamination of the operating room
air from skin scales originating on the skin of persons wearing it
Note 1 to entry: A scrub suit is a working garment for operating room staff that does not need to meet the
requirements for a clean air suit. The scrub suit is not primarily intended to prevent airborne dispersal from staff,
and can be designed and processed as the manufacturer thinks fit.
Note 2 to entry: A clean air suit consists of a coverall, or a blouse and trousers.
3.3
cleanliness
freedom from unwanted foreign matter
Note 1 to entry: Such matter can be microorganisms, organic residues or particulate matter.
3.3.1
cleanliness — microbial
freedom from population of viable micro-organisms on a product and/or a package
Note 1 to entry: In practical use, microbial cleanliness is often referred to as ‘bioburden’.
3.4
infective agent
microorganism that has been shown to cause wound infections or that might cause infection in a
member of the surgical team or the patient
3.5
manufacturer
natural or legal person with responsibility for the design, manufacture, packaging and labelling of a
device before it is placed on the market under his own name, regardless of whether these operations
are carried out by that person himself or on his behalf by a third party
Note 1 to entry: For more details refer to the Medical Device Directive 93/42/EEC.
3.6
particle release
release of fibre fragments and other particles during mechanical stress simulating handling and use
3.7
performance level
discrete standard defined to classify products according to the performance requirements of this
document
Note 1 to entry: With the introduction of two performance levels this document acknowledges the fact that
products are challenged to differing extents during surgical procedures, dependent upon the microbial cleanliness
of the operating room required for the procedure.
3.7.1
standard performance
classification addressing minimum performance requirements for various characteristics of products
used as medical devices in invasive surgical procedures
3.7.2
high performance
classification addressing elevated performance requirements for various characteristics of products
used as medical devices in invasive surgical procedures
Note 1 to entry: Examples of surgical procedures where high performance level might be considered are
infection prone clean surgical procedures where air counts in the operating room of ≤ 10 CFU/m are required.
3.8
processor
natural or legal person who processes products so that their performance complies with the
requirements of this document
Note 1 to entry: A processor who places a product on the market is a manufacturer in the sense of this
document.
Note 2 to entry: A processor of reusable products is often referred to as a ‘reprocessor’ and processing reusable
products is often referred to as ‘reprocessing’ (as e.g. in Medical Device Directive 93/42/EEC). References in
EN 13795-1 and this document to ‘processors’ include ‘reprocessors’ and to ‘processing’ include ‘reprocessing’.
3.9
product
clean air suit
3.10
resistance to microbial penetration
ability of material(s) to withstand penetration of micro-organisms from one side of the material
through to the other
3.10.1
dry penetration
effect of a combination of air movement and mechanical action by vibration on microbial penetration in
dry condition
3.11
reusable product
product intended by the manufacturer to be reprocessed and reused
3.12
single-use product
product intended to be used once only for a single patient
3.13
source strength
average number of bacteria-carrying particles (CFU) emitted per second from a person wearing a
specified garment during a certain activity in a specified environment
3.14
surgical procedure
surgical intervention performed by a surgical team
3.14.1
invasive surgical procedure
surgical procedure penetrating skin or mucosa
4 Performance requirements
To comply with this document, products shall meet all the requirements specified in this document
including Table 1, when tested according to Annex A of this document throughout their useful life.
The biocompatibility of the product has to be evaluated and approved for acceptable risk in accordance
with EN ISO 10993-1.
For general information on testing and details on the test methods given in this clause including Table 1
and their application for the purpose of this document, see Annex A.
NOTE Information on characteristics, which cannot be properly evaluated or which are not regarded
normative (as e.g. ‘comfort’) is given in Annexes B, D and E.
Table 1 — Characteristics to be evaluated and performance requirements for clean air suits
Requirement
Test method
(for normative
Characteristic Unit
Standard performance High performance
references see
Clause 2)
Microbial penetration
a a
EN ISO 22612 CFU
≤ 100 ≤ 50
— Dry
CFU/
Cleanliness microbial /
EN ISO 11737-1 ≤ 100 ≤ 100
Bioburden
100 cm
log
Particle release EN ISO 9073-10 ≤ 4,0 ≤ 4,0
(lint
count)
Bursting strength —
EN ISO 13938-1 kPa ≥ 40 ≥ 40
Dry
Tensile strength — Dry EN 29073-3 N ≥ 20 ≥ 20
a 8
Test conditions: challenge concentration 10 CFU/g talcum and 30 min vibration time.
The test methods given in Table 1 are materials tests. In order to manufacture a functioning clean air
suit, design shall also be considered. When the material of the clean air suit is tight, bacteria are
dispersed through the openings for head, arms and feet. Arm and feet openings shall therefore be
closed. A barrier hood should be worn, tucked into the gap at the neckline (see Annex E, E.1). If the
clean air suit consists of blouse and trousers, the blouse should be tucked into the trousers or designed
with a tightly fitting waist.
5 Manufacturing and processing requirements and documentation
5.1 The manufacturer and processor shall document that the requirements of this document are met
and that the fitness for the intended purpose has been established for each use, both for single-use and
reusable medical devices.
5.2 The manufacturer/processor shall establish, document, implement and maintain a formal quality
management system, which includes risk management and maintain its effectiveness. This quality
management system shall include requirements throughout product realization, including
development, design, manufacture, testing, packaging, labelling, distribution and, for reusable products,
processing and life-cycle control.
Inputs for product realization shall include the outputs from risk management.
A quality system such as EN ISO 13485 is recommended, in case of processing of reusable products
applied in accordance with EN 14065.
For testing processes, quantitative physical, chemical and/or biological tests are preferred.
5.3 A clinical evaluation for clean air suits shall be carried out and shall consider the performance of
the clothing system to establish fitness for purpose. The evaluation shall include the critical review of
the applicable clinical literature and the results of post market surveillance and vigilance.
6 Information to be supplied with the product
6.1 Information to be supplied to the user
6.1.1 The following information shall be supplied on request:
a) the identity or information on the test methods used;
b) the results of testing and test conditions for the characteristics given in Clause 4.
6.1.2 The manufacturer shall inform the user of residual risks due to any shortcomings of the
protection measures adopted.
6.1.3 The manufacturer shall provide sufficient information about intended use of the product or
product system when conducting a surgical procedure. This shall include information on the
performance level of the product.
6.2 Information to be supplied to the processor
For reusable products the manufacturer shall obtain information to be supplied to the processor on the
number of reuses based on standardized processes, together with information on measures for
maintaining the technical and functional safety of the medical device and packaging.
NOTE EN ISO 15797, though dealing with workwear and personal protective equipment (PPE), can be useful
in developing standardized methods for reusable surgical textiles since it contains information on the principles
and equipment for simulated industrial laundering.
Annex A
(normative)
Testing
A.1 General
A.1.1 Testing for evaluation of the performance of products shall be done according to the test
methods specified in A.2. All test results and test conditions shall be recorded and retained.
A.1.2 Testing shall be performed on the finished product. Testing shall include potential weak spots.
NOTE 1 Performance requirements can vary in relation to the risk of transfer of infective agents to or from the
wound and the sterile field, and in relation to the ventilation flow of the room.
NOTE 2 To ensure product performance, combinations of materials or products in systems can be used.
A.1.3 During manufacture and processing, testing shall be conducted according to the requirements of
the manufacturer's and processor's quality system.
A.1.4 Alternative test methods for monitoring may be used provided that they are validated and
address the same characteristic and that the results have been shown to correlate with the test methods
given in this document.
A.1.5 Where the test methods of this document do not specify the atmosphere for pre-conditioning,
conditioning and testing, the specifications of EN ISO 139 shall be applied. Prior to testing, the samples
shall be conditioned in the relaxed state.
A.2 Test methods and conformance
A.2.1 Test method for evaluation of cleanliness microbial/bioburden
For evaluation of cleanliness — microbial, the product shall be tested according to EN ISO 11737-1.
NOTE EN ISO 11737-1 does not provide a fixed test method but specifies requirements for test methods and
test mechanisms. The requirements of EN ISO 11737-1 are such that different test methods developed in
accordance with it provide comparable results.
Five specimens shall be tested. The results shall be expressed as CFU/100 cm . Report the individual
results and determine Md and Uq (see A.3). Uq shall be equal to or less than the performance
requirements in Table 1.
A.2.2 Test method for evaluation of particle release
For evaluation of particle release, the product shall be tested according to EN ISO 9073-10.
NOTE 1 EN ISO 9073-10 allows for the test method to be conducted in a laminar flow hood. It is important to
validate that laminar flow is occurring if equipment required for the test is located in the hood.
As specified in EN ISO 9073-10, ten specimens, five for each side of the material, shall be tested. The
result of the test, i.e. the coefficient of linting, shall be calculated for particles in the size range 3 µm to
25 µm and reported as log of the count value. Report the individual results and determine Md and Uq
(see A.3). Uq shall be equal to or less than the performance requirements in Table 1.
NOTE 2 Particles of this size range are considered to be capable of carrying microorganisms.
A.2.3 Test method for evaluation of bursting strength in dry state
For evaluation of bursting strength, the product shall be tested according to EN ISO 13938-1. The size of
the test area shall be 10 cm (35,7 mm diameter).
The test conditions should be specified in the test report.
If there are differences in the test results of both sides of material, both sides should be tested and the
results should be recorded.
Five specimens shall be tested. The pressure needed to break or compromise the barrier of the sample
shall be reported. Report the individual results and determine Md and Lq (see A.3). Lq shall be equal to
or greater than the performance requirements in Table 1.
A.2.4 Test method for evaluation of tensile strength in dry state
For evaluation of tensile strength, the product shall be tested according to EN 29073-3 in the dry states
both in longitudinal and in lateral directions.
Five specimens shall be tested for each direction. The maximum force measured shall be reported.
Report the individual results and determine Md and Lq (see A.3). Lq shall be equal to or greater than
the performance requirements in Table 1.
A.2.5 Test method for evaluation of dry microbial penetration
For evaluation of dry microbial penetration, the product shall be tested according to EN ISO 22612.
If both sides of the material to be tested are different, the side intended to cover the contamination
source during use as stated by the manufacturer shall be exposed to the contamination source.
NOTE The side intended to cover the contamination source during medical use is, e.g. the inner side of a clean
air suit.
If the product has an antimicrobial treatment, it shall be mentioned in the test report since it can
influence the results.
Ten specimens shall be tested. Report the individual results and determine M and L (see A.3). L shall
d q q
be equal to or greater than the performance requirement in Table 1.
A.2.6 Test method for evaluation of biocompatibility
The manufacturer shall complete the evaluation of the clean air suit according to EN ISO 10993-1:2009
and report the results of the evaluation.
A.3 Treatment of results
In order to determine whether a sample conforms to the performance requirements of this document, it
is necessary to convert the replicate results from a test into an acceptance value (or test statistic). The
median (M ) was the chosen value (see Annex B), together with one of two test statistics a) the lower
d
quartile value (L )for minimum performance (PR ) and b) the upper quartile (U ) for maximum
q min q
performance (PR ).
max
For conformance of the product the following values can be determined:
— L ≥ PR (see Table 1);
q min
— U ≤ PR (see Table 1); and
q max
— Md, Lq and Uq (or any percentile value)
by using the following general method.
th
To calculate the k percentile (where k is 25 for identifying the lower quartile number and 75 for
identifying the upper quartile value):
1. Order all the values in the data set from the smallest to largest;
2. Multiply k percent by the total number of values, n. This product is called the index;
3. If the index obtained in step 2 is not a whole number, round it up to the nearest whole number and
go to step 4a. If the index obtained in step 2 is a whole number, go to step 4b;
4a. Count the values in your data set from left to right (from the smallest to the largest value) until you
th
reach the number indicated by step 3. The corresponding value in the data set is the k percentile;
4b. Count the values in your data set from left to right until you reach the number indicated by step 2.
th
The k percentile is the average of that corresponding value in the data set and the value that
directly follows it.
Annex B
(informative)
Rationales
B.1 General
This annex provides a concise rationale for the important requirements of this document and is
intended for use by those who are familiar with the subject of this document but who have not
participated in its development. An understanding of the reasons for the main requirements is
considered essential for its proper application. Furthermore, as clinical practices and technologies
change, it is believed that rationales for the present requirements will facilitate any revisions of this
document necessitated by those developments.
The first task undertaken by CEN/TC 205/WG 14 in its early days was deciding on the key product
characteristics which needed to be assessed. After much consideration four categories emerged, namely
barrier properties, strength properties relevant to maintaining barrier properties, particle release and
bioburden level. Most of the performance limits in this document are based on expert consensus.
In the operating room, several measures are taken to prevent deep post-operative wound infection. In
clean operations, the skins of the patient or of other persons present in the operating room are the main
sources of infection. Antimicrobial prophylaxis is often administered to kill or inhibit bacteria from
infecting the wound, but with increasing risks of antimicrobial resistance can fail. Airborne
contamination of the sterile field shall therefore be reduced to a minimum [14].
A level of ≤ 10 CFU/m is generally accepted as a definition for ultra-clean air in operating rooms
intended for infection-prone clean surgery [15]. This can be achieved through a combination of
ventilations, clothing and restriction of movement in the operating room (see also Figure E.2).
B.2 Cleanliness – microbial
The test for microbial cleanliness is intended to estimate the numbers of viable organisms on the
products. This is frequently referred to as the 'bioburden', which manufacturers routinely measure.
In a bioburden (cleanliness) test, the presence of microorganisms is expected, and the test is designed
to quantify the amount of microorganisms present (for example, through rinsing, filtering and
counting).
The cleanliness limit of 100 CFU (Table 1) is based on what is routinely achievable at present, both for
single-use and reusable clean air suits as finished products. For re-usable clean air suits, it requires a
controlled laundry process. A controlled handling procedure is mandatory (e.g. one-product packaging)
to reduce contamination during transport and storage.
B.3 Particle release
This method is designed to measure the release of particles from the device.
Particle release is a concern during surgery as foreign body contamination can cause an increased
frequency of postoperative complications such as keloids, wound dehiscence, incisional hernias, chronic
abscesses, intestinal obstruction and, in some circumstances, even death [16], [17]. Fibres from gowns
and drapes which have been deposited in wounds have been shown to cause post-operative
granulomas [18], [19]. Blood clots around fibres can cause emboli, obstructing vital blood vessels [20].
Fibres can also reduce the ability of tissue to resist infection, due to impaired function of the blood and
tissue macrophage systems [21], [22].
As well as having a direct effect clinically, an indirect effect is observed, whereby fibres and particles
released from operating room materials can deposit on surfaces in the operating room, providing a
potential vector for microorganisms to be transported into wounds and cavities [23]. See section on
“Resistance to microbial penetration” for a discussion on contamination versus infection.
The particulate size range of 3 µm to 25 µm has been chosen based on the opinion that particles smaller
than 3 µm are too small to carry microorganisms, and particles larger than 25 µm are too large to
remain airborne because of gravity. This is supported in work published by Noble in 1963 who found
that “Organisms associated with human disease or carriage were usually found on particles in the range 4
µm to 20 µm equivalent diameter” [24].
B.4 Bursting strength – dry
This test is designed to assess the device’s ability to withstand pressure over, for example, a clinician’s
elbow or hip and to ensure its barrier properties are not prejudiced by mechanical failure.
Materials with more than one layer can show several break points when tested for bursting strength,
e.g. one corresponding to each layer. In order to address the scope of the requirement it was agreed to
evaluate the performance of the material based on the pressure needed to break or compromise the
barrier of the sample.
The limit (see Table 1) is based on manufacturer’s experience of products deemed to be clinically
suitable in the market place.
B.5 Tensile strength – dry
The 'tensile strength' of a material is the maximum stress, generated by pulling or stretching the
material that a material can withstand before failing.
The test is designed to assess whether the basic strength of the device material is sufficient to ensure its
barrier properties are not prejudiced. It is a standard textile material test.
Materials with more than one layer can show several break points when tested for tensile strength, e.g.
one corresponding to each layer. In order to address the scope of the requirement it was agreed to
evaluate the performance of the material based on the force needed to break or compromise the barrier
of the sample.
The limit (see Table 1) is based on manufacturer’s experience of products deemed to be clinically
suitable in the market place.
Table 1 has limits for the material only in the dry state, as the clean air suit is expected to be protected
by a gown or apron if exposed to wet conditions during use.
B.6 Resistance to microbial penetration – dry
Dry bacterial penetration EN ISO 22612 is a test method that was designed to simulate the penetration
of bacteria-carrying skin scales through fabrics.
This test provides a means for assessing the resistance to penetration through barrier materials of
bacteria-carrying particles.
Whilst the relationship between contamination and infection is complex - contamination of the surgical
field does not necessarily lead to infection - it is generally agreed that healthcare facilities should
consider methods to reduce levels of airborne particles carrying bacteria in operating rooms [25].
The skin is the most important source of airborne contamination in the operating room. A person
releases approximately 10 skin particles per minute when walking and approximately 10 % of these
carry bacteria. Activity and friction against the skin, e.g. from clothing, increase the dispersal. Bacteria-
carrying skin scales are dispersed from the human body surface mainly from the lower part of the torso.
Normal shedding of human skin cells (keratinocytes) produces individual cells which are approximately
25-30 µm in diameter (when hydrated) [26]. Whyte and Bailey [27] noted that bacterial-carrying skin
scales are on average about 20 µm in size, whilst Mackintosh and colleagues [28] showed that dispersed
skin fragments had a wide size range extending below 5 µm for the minimum projected diameter
(MPD), with a median MPD about 20 µm, and with 7 % to 10 % less than 10 µm. When skin scales pass
through relatively impermeable clothing, they can also become fragmented, with the result that more
than 50 % of the bacteria-carrying particles can be less than 5 µm.
The skin scales behave aerodynamically as particles of unit density and size approximately 10 µm.
These particles are distributed in the operating room with air currents and settle on exposed surfaces,
thereby contaminating the sterile field and causing infection of the surgical site.
For microorganisms to penetrate the material in the dry state, they need to be carried on a physical
particle, for example, skin scales. In this test, the physical particles are composed of talc, where 95 % of
the particles shall be ≤ 15 µm. The referenced talc (Finntalc M15) has a median particle size of 4,5 µm, a
maximum size of approximately 17 µm, and approximately 18 % of the particles are ≤ 2 µm.
During the dry penetration test, the talcum particles are sifted through the material to be tested, and
spore-forming bacteria are used as marker organisms. The test is intended to measure penetration of
dust, e.g. skin scales through clothes, and has been shown to correlate well to airborne dispersal of
bacteria.
The size range in the test talc covers the range of skin fragments found in practice down to particle sizes
smaller than we would expect from skin fragmentation.
Penetration in this test method is influenced by the physical properties of the materials e.g. pore size
and tortuosity factor.
The limit of ≤ 100 CFU (Table 1) is based on results of materials used for the manufacturing of clean air
suits in clinical use today, both reusable and single-use.
Dry penetration is intended to examine the ability of a material to prevent airborne transmission. The
test is particularly relevant for the clean air suit, which is intended to prevent airborne transmission
when made from a tight material and adequately designed.
B.7 Labelling
Labelling requirements are adequately covered in Section 1
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