SIST ENV 12718:2002

SLOVENSKI STANDARD
SIST ENV 12718:2002
01-maj-2002
Medicinske kompresijske nogavice
Medical compression hosiery
Medizinische Kompressionsstrümpfe
Bas médicaux de compression
Ta slovenski standard je istoveten z: ENV 12718:2001
ICS:
11.120.20 Sanitetni materiali, obveze in Wound dressings and
komprese compresses
SIST ENV 12718:2002 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST ENV 12718:2002

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SIST ENV 12718:2002
EUROPEAN PRESTANDARD
ENV 12718
PRÉNORME EUROPÉENNE
EUROPÄISCHE VORNORM
August 2001
ICS 11.120.20
English version
Medical compression hosiery
Bas médicaux de compression Medizinische Kompressionsstrümpfe
This European Prestandard (ENV) was approved by CEN on 23 June 2001 as a prospective standard for provisional application.
The period of validity of this ENV is limited initially to three years. After two years the members of CEN will be requested to submit their
comments, particularly on the question whether the ENV can be converted into a European Standard.
CEN members are required to announce the existence of this ENV in the same way as for an EN and to make the ENV available promptly
at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in parallel to the ENV) until the final
decision about the possible conversion of the ENV into an EN is reached.
CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,
Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2001 CEN All rights of exploitation in any form and by any means reserved Ref. No. ENV 12718:2001 E
worldwide for CEN national Members.

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SIST ENV 12718:2002
ENV 12718:2001 (E)
Contents
page
Foreword .3
Introduction .4
1 Scope.5
2 Normative references.5
3 Terms and definitions.5
4 Compression classes .7
5 Nominal dimensions and standard sizes.7
6 Heel.14
7 Seams.14
8 Edges.15
9 Achievement of compression profile.15
10 Mechanical properties .15
11 Packaging .16
12 Marking and instructions for use .16
Annex A (informative) Hosiery manufacturing methods .18
Annex B Method for testing compressive properties of hosiery.23
(normative)
Annex C (normative) Method of determination of extensibility of hosiery.39
Annex D Examples of methods of compression testing .40
(informative)
Annex ZA (informative) Clauses of this European Prestandard addressing essential
requirements or other provisions of EU Directives.41
Bibliography .43
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SIST ENV 12718:2002
ENV 12718:2001 (E)
Foreword
This European Prestandard has been prepared by Technical Committee TC 205 'Non-active medical
devices' the secretariat of which is held by BSI.
This European Prestandard 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
prestandard.
Annexes B and C are normative and form part of this European Prestandard. Annexes A, D and ZA are
for information only.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to announce this European Prestandard: Austria, Belgium, Czech
Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg,
Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom.
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ENV 12718:2001 (E)
Introduction
An important property of hosiery is its durability, i.e. the retention of its designated compression during
its lifetime. Hitherto the durability of hosiery has been achieved by the choice of the materials of
construction and the methods by which hosiery has been manufactured. Experience has shown that
hosiery having appropriate medical characteristics can be produced by paying due regard to
information in annex A.
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ENV 12718:2001 (E)
1 Scope
This European Prestandard specifies requirements and gives test methods for medical compression
hosiery, including custom-made hosiery (class 030606, EN 29999), knitted from threads made of natural
fibres or synthetic fibres and elastic threads. It is applicable to medical compression hosiery which is
used as a medical device for the treatment of venous and/or lymphatic diseases of the leg. This
European Prestandard does not give requirements connected with the manufacture of hosiery.
NOTE Manufacturing methods that have been shown by experience to be satisfactory are given for information
in annex A.
2 Normative references
This European Prestandard incorporates by dated or undated reference, provisions from other
publications. These normative references are cited at the appropriate places in the text, and the
publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of
these publications apply to this European Prestandard only when incorporated in it by amendment or
revision. For undated references the latest edition of the publication referred to applies (including
amendments).
EN 980, Graphical symbols for use in the labelling of medical devices
EN 1041, Information supplied by the manufacturer with medical devices
EN 23758, Textiles — Care labelling code using symbols (ISO 3758:1991)
EN 26330:1993, Textiles — Domestic washing and drying procedures for textile testing
(ISO 6330:1984)
ISO 376, Metallic materials — Calibration of force-proving instruments used for the verification of
uniaxial testing machines
3 Terms and definitions
For the purposes of this Prestandard, the following terms and definitions apply:
3.1
compression
pressure exerted on the leg by the hosiery
3.2
compression classes
compression grades in which hosiery is produced, categorised by the compression at the ankle
3.3
unit of rubber thread thickness
conventional count of a rubber thread
gauge number round (not square)
number of threads which, when placed side by side, measure 25,4 mm
3.4
custom made hosiery
hosiery manufactured individually to suit the leg dimensions of an individual patient
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3.5
durability
ability of hosiery to retain its designated compression after a procedure that simulates repeated
washing and wearing
3.6
elastic material
material which increases its dimension under the action of an applied force and returns to almost its
original form when the force is removed
3.7
extensibility
maximum degree, expressed as a percentage of the unloaded size of the hosiery, in which the hosiery
can be stretched in the circumferential or in the longitudinal direction under the test procedure specified
in this European Prestandard
3.8
inlaid thread
elastic thread which does not form stitches or loops and which is inlaid in the direction of the course
3.9
medical compression hosiery
hosiery for treating leg diseases by means of graduated compression exerting a definite pressure on the
leg in a specific way
NOTE Abbreviated in this Prestandard to 'hosiery'.
3.10
practical elongation
elongation of hosiery in the circumferential direction with the hosiery on the leg, expressed as a
percentage of the unloaded circumference of the hosiery
3.11
pressure profile
representation of the compression exerted by the hosiery along the leg
3.12
residual pressure
compression at a certain point expressed as a percentage of the compression at the ankle
3.13
stiffness
increase in compression per centimetre increase in the circumference of the leg, expressed in
hectopascals per centimetre and/or millimetres of mercury per centimetre
3.14
standard size hosiery
hosiery manufactured in the types and sizes specified in this European Prestandard
3.15
tolerance of standard size hosiery
limits of the girth and length of the leg between which the standard size hosiery is intended to be used
3.16
unit of linear density
mass in grams of 10 000 m of yarn expressed in dtex
NOTE The basic unit is the tex (10 dtex = 1g/km)
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ENV 12718:2001 (E)
4 Compression classes
Hosiery shall be classified into five compression classes as shown in Table 1, and the compression shall
be measured in accordance with annex B.
NOTE 1 The package of hosiery compression Class 1 can be labelled in addition as follows:

15 mmHg (20hPa) to17 mmHg (23hPa): Class I.L (low)

18 mmHg (24hPa) to 21 mmHg (28hPa): Class I.H (high)
NOTE 2 Class A reflects the practice in some European countries but it is currently not supported by sufficient
scientific evidence.
Table 1 — Compression classes
1)
Compression class Compression at the ankle
2)
hPa mmHg
Ccl A light 13 to 19 10 to 14
Ccl I mild 20 to 28 15 to 21
Ccl II moderate 31 to 43 23 to 32
Ccl III strong 45 to 61 34 to 46
Ccl IV very strong 65 and higher 49 and higher
1)
The values indicate the compression exerted by the hosiery at a hypothetical cylindrical ankle.
2)
1 mmHg = 1,333 hPa.
5 Nominal dimensions and standard sizes
5.1 General
Hosiery size shall be designated by the lengths and girths on the human leg at the measuring points
given in Figure 1 and Table 2.
5.2 Measurement of length
If measured, lengths shall be measured and codes allocated in accordance with Table 3.
5.3 Measurement of girth
If measured, girths shall be measured and codes allocated in accordance with Table 4.
5.4 Sizes
NOTE In order to facilitate the use of hosiery and to give a unique basis for the test methods specified in this
European Prestandard, this system of sizes is specified based on the ankle girth (cB).
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5.4.1 Length
Except for custom-made hosiery, lengths and range of length shall be chosen from Table 5.
5.4.2 Girth
Except for custom-made hosiery, girths and range of girths shall be chosen from Table 6.
5.5 Designation of type and size of hosiery
Hosiery shall be designated by the type code according to Table 7 followed, except for custom-made
hosiery, by three pairs of numbers indicating the dimensions of the legs that the hosiery is intended to fit
as follows:

the range of girth at the ankle according to Table 6

the range of girth at the upper end of the hosiery according to Table 6


the range of length according to Table 5
Where values for intermediate measuring points fall in the same vertical column of Table 6 or on the
straight lines drawn from the smallest and widest ankle dimension to the smallest and widest girth
dimension at the upper end of the hosiery, no further information is required.
If values of intermediate measuring points don’t fall on the straight lines, then a diagrammatic
representation of the range of leg sizes that the hosiery is intended to fit shall be supplied either on the
package, or in a leaflet in the package. The same applies in the figurative sense to the dimensions of the
length given in Table 5.
NOTE 1 An example of type and size designation is AD 22-24 (34-36/41-45)
where
AD is the code for below-knee hosiery;
22-24 is the range of girth at the ankle (22 cm to 24 cm);
34-36 is the range of girth at the upper end of the hosiery (34 cm to 36 cm);
41-45 is the range of length (lD) (41 cm to 45 cm).
For the measuring points between the ankle and the upper end of the hosiery according to Figure 1 the
range of girths shall be marked according to clause 12.
NOTE 2 A further example of type and size designation is AF 22-24 (46-56/60-64)
where
AF is the code for mid-thigh hosiery;
22-24 is the range of girth at the ankle (22 cm to 24 cm);
46-56 is the range of girth at the upper end of the hosiery (46 cm to 56 cm);
60-64 is the range of length (ID) (60 cm to 64 cm)
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NOTE Measurements should preferably be taken at the patient's leg in a standing position.
Figure 1 — Measuring points, lengths and girths on the human leg (see Table 2)
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Table 2 — Nominal measuring points (see Figure 1)
Description of the measuring point
Measuring
point
a sole of the foot at the heel
A forefoot at the implantation of the toes
B ankle at the point of its minimum girth
B1 point at which the Achilles tendon changes into the calf muscles
C calf at its maximum girth
D just below the tibial tuberosity
E centre of the patella and over the back of the knee
F between K and E
G 5 cm below K with the patient in the upright position
H greatest lateral trochanteric projections of the buttock
K centre point of the crutch
K1 level at the pubic symphysis
K2 level at the infra-gluteal fold
T natural waistline
X middle of the foot
Yinstep
Ztip of toe
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Table 3 — Nominal measurement of length
Length Length of the leg
2)
code
lB distance measured from a to B
lB1 distance measured from a to B1
lC distance measured from a to C
lD distance measured from a to D
lE distance measured from a to E
lF distance measured from a to F
lG distance measured from a to G
lH distance measured from a to H
lK distance measured from a to K
lT distance measured from a to T
lX distance measured from the most prominent part of the heel to X
lA distance measured from the most prominent part of the heel to A (foot length without toe)
lZ horizontal distance between the perpendiculars in contact with the end of the most
prominent toe and the most prominent part of the heel (total foot length)
1)
lGT distance measured from G to T
1)
lK1T distance measured from K1 to T
1)
lK2T distance measured from K2 to T
1)
For panty hose only, measured along the body.
2)
l = length.
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Table 4 — Nominal measurement of girth
1)
Girth code Girth of the leg
cA girth measured at A
cB girth measured at B
cB1 girth measured at B1
cC girth measured at C
cD girth measured at D
cE girth measured at E
cF girth measured at F
cG girth measured at G
cH girth measured at H
cT girth measured at T
cX girth measured at X
cY girth at Y, measured with the foot in maximum dorsal flexion
1)
c = girth.
Table 5 — Nominal leg lengths for standard size hosiery
Length
Length code
cm
short hosiery normal hosiery long hosiery
lG 65 68 71 74 77 80 83
lF 54 57 59 62 64 67 69
lE 41 43 45 47 49 51 53
lD 35 37 38 40 41 43 44
lC 27 29 30 32 33 35 36
lB1 1920 2122 23 24 25
lB 10 11 11 12 12 13 13
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Table 6 — Nominal leg girths
Size of hosiery
Girth Slender supplement 18 19 20 21 22 23 24 25 26 27 28 29 30 Sturdy supplement
code
Circumferences in cm
cG 43 45 46 48 49 51 52 54 55 57 58 60 61 63 64 66 67 69 70 72 73 74 76 77 79 80
cF 35 37 38 40 41 43 44 46 47 49 50 52 53 55 56 58 59 60 61 62 63 65 66 68 69 71
cE 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 ---
cD 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 49 --- ---
cC 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 --- --- ---
cB 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 --- --- --- ---
1
cB --- --- 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 --- --- --- ---
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Table 7 — Designation of types of hosiery
Type of hosiery Code
1)
Below-knee hosiery AD
2)
Mid-thigh hosiery AF
3)
Thigh hosiery AG
4) 5)
Single leg panty AGTL , AGTR
4)
Panty hosiery AT
1)
AD: Upper end of hosiery corresponds to measuring position D. An area of
maximum 10 mm below can be less or non-compressive.
2)
AF: Compressive up to measuring position F. There can be a less or non-
compressive welt or part above.
3)
AG: Upper end of hosiery corresponds to measuring position G. An area of
maximum 50 mm (stretched condition) below upper end can be less or non-
compressive.
4)
AGT/AT: Compressive at least up to measuring position G.
5)
L = left leg; R = right leg.
6 Heel
Hosiery shall have a closed and knitted heel with the appropriate anatomic form and stretch qualities. If
the hosiery is of the type described in A.8.1 b), it shall be knitted with a reciprocated heel.
Testing shall be carried out by visual inspection.
7 Seams
Seams shall be smooth on the inside of the hosiery.
NOTE Seams can be overlocked.
Testing shall be carried out by visual inspection.
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8 Edges
Edges shall be non-fray.
Testing shall be carried out by visual inspection.
9 Achievement of compression profile
The compression profile shall be achieved by knitting and not by shaping or forming.
NOTE There can be boarding for presentation.
10 Mechanical properties
10.1 Extensibility
Hosiery shall be capable of being stretched at least 120 % in the circumferential direction at the
measuring points B, B1, C, D, E, F and G, where appropriate. The stretch capability in the longitudinal
direction shall be at least 30 % at the measuring points B, B1, C, D, E, F and G, where appropriate.
Testing shall be carried out in accordance with annexes B and C.
10.2 Practical elongation
The practical elongation shall be not less than 15 % and not more than 140 % at the measuring points
B, B1, C, D, E, F and G, where appropriate.
Testing shall be carried out in accordance with annex B.
10.3 Residual pressure
In order to avoid irregularities of the pressure profile along the leg, pressure shall be measured at
measuring points B, B1, C, D, E, F and G, where applicable (see B.2.4).
The residual pressures shall be calculated for measuring points B1, C, D, E, F and G where
applicable (see B.5.2).
The residual pressures (pressure profile) of the hosiery shall lie within the area determined by the
values given in Table 8.
NOTE This should apply also, if at measuring points D and F or G, where applicable, residual pressure is
calculated from the pressures obtained for the highest girth at measuring point B and for the lowest girth given by
the producer for D, F, and G, as well as when calculated for the lowest given for B and the highest ones for D, F,
and G.
The residual pressure shall at no measuring point along the leg, except E, be of a higher value than
the residual pressure at the measuring point situated distally. At the E-level the residual pressure can
be lower than which follows from the interpolation of the values for D and F.
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With hosiery bearing an adhesive welt, at an upmost area not smaller than 50 mm, compression can be
15 percentage points higher than measured for the elastic knit directly below, but the residual pressure
of the adhesive welt shall not exceed the limits given in Table 8.
Testing shall be carried out in accordance with annex B.
Table 8 — Ranges of pressure profiles
% of compression exerted at ankle
Compression Class at B1 at C and D at F or G
Ccl A 70 to 100 50 to 80 20 to 60
Ccl I 70 to 100 50 to 80 20 to 60
Ccl II 70 to 100 50 to 80 20 to 50
Ccl III 70 to 100 50 to 80 20 to 40
Ccl IV 70 to 100 50 to 80 20 to 40
10.4 Durability of compression
NOTE In normal use hosiery should keep the compression according to its compression class for
approximately 6 months. Suitable hosiery manufacturing methods are given in annex A (informative).
11 Packaging
Except for custom-made hosiery, hosiery shall be packaged so that exposure of the hosiery to light is
minimized.
12 Marking and instructions for use
The information supplied by the manufacturer shall comply with EN 980 and EN 1041.
Specification for ranges of length and girth which differ from Table 5 and Table 6 according to 5.5, shall
be made available for the supplier/distributor in a suitable form.
12.1 Marking of hosiery
Hosiery shall be durably marked at least with the following information:
a) name or trade name of the manufacturer or authorized representative or importer within EEA;
b) name of the product;
c) fibre content (unless marked on the package);
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d) compression class;
e) either the type and size designation as specified in 5.5 or an indication that the hosiery is
custom made;
f) washing and treatment symbols in accordance with EN 23758.
12.2 Marking of the package
The package shall be marked at least with the following information:
a) name and address of the manufacturer or authorized representative or importer within EEA;
b) name of the product;
c) country of origin if manufactured outside the European Economic Community;
d) fibre content (unless marked on the hosiery);
e) compression class;
f) type and size designation as specified in 5.5 or an indication that the hosiery is custom made;
NOTE The following information can also be given.
g) Stiffness (test method annex B);
h) Graphical or tabulated representation of the range of leg measurements that the hosiery is
intended to fit.
12.3 Handling and usage
The package or a leaflet with the hosiery shall contain at least the following information:
a) instructions for washing and drying;
b) instructions for handling and usage;
c) contra-indications and warnings for misuse.
NOTE A diagrammatic representation of the range of leg sizes that the hosiery is intended to fit can also be
given.
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Annex A
(informative)
Hosiery manufacturing methods
A.1 Introduction
An important property of hosiery is the retention of its designed compression during its lifetime.
Hitherto the durability of hosiery has been achieved by the choice of the materials of construction and
the methods by which hosiery has been manufactured. Experience has shown that hosiery having
appropriate medical characteristics can be produced by paying due regard to the following.
A.2 Threads
Textile threads made of natural or synthetic fibres and elastic threads made of elastodiene or elastane
should be used. A method of test for the analysis of elastic threads is given in A.3.
A.3 Method of analysis of elastic threads in hosiery
Identification of elastic materials (e.g. elastane, elastodiene)
A.3.1 Chemical identification of elastane and elastodiene in hosiery
Chemical identification of elastic materials in hosiery.
A.3.2 Apparatus and reagents
A.3.2.1 Microscope
A.3.2.2 Microscope slides
A.3.2.3 Acetic acid solution, 98 % V/V in water.
A.3.2.4 Formic acid solution, 85 % V/V in water.
A.3.3 Test procedure
Mix three parts of acetic acid solution (A.3.2.3) and one part of formic acid solution (A.3.2.4).
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Place the test sample on a microscope slide (A.3.2.2). Moisten it with the mixture of acids and observe it
under the microscope (A.3.2.1).
If the test sample starts to swell, the thread is elastane. If there is no change in the test piece, the thread
is elastodiene.
A.4 Thread covering
Knitted elastane and elastodiene and inlaid elastane and elastodiene yarns should be covered using
one of the following methods.
a) Double covering: wrapping two spirals of non-elastic threads in opposite directions around an
elastic core.
b) Single covering: wrapping one spiral of non-elastic threads around an elastic core.
c) Stitch covering: knitting a chain stitch of a non-elastic yarn around an elastic core.
d) Core spinning: spinning a non-elastic staple yarn around an elastic core.
e) Core twisting: twisting together a non-elastic yarn with an elastic yarn.
f) Air jet covering: intermingling an elastic yarn with non-elastic yarn.
A.5 Draft during covering
Elastane and elastodiene manufacturers' recommendations for maximum extension should be followed
because the elastic core extension during covering, i.e. in the fully stretched state, influences strongly
the wear life of hosiery.
A.6 Thread linear density and thread thickness
The minimum linear density of elastane and non-elastic threads and the minimum thickness for
elastodiene threads should be as given in Tables A.1 and A.2.
Exact details of type and thickness should be obtained from the yarn manufacturer for elastane. The
thread should not lose more than 25 % of its original mass (see Note: A.7.1)
A method of measuring thickness is given in A.7.
Table A.1 — Minimum linear density or thread thickness of inlaid threads
Core
Material of elastic thread Sum total of linear density of
all coverings
Elastodiene 100 gauge 22 dtex
Elastane 310 dtex -
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Table A.2 — Minimum linear density or thread thickness of knitted threads
Material of elastic thread Core Sum total of linear density of
all coverings
elastane 33 dtex 33 dtex
elastodiene 140 gauge (round) 44 dtex
non-elastic thread 55 dtex -
A.7 Method of measuring thread thickness
A.7.1 Introduction
The method applies to natural, synthetic and textured yarns, elastane and elastodiene and to
establishing the type of covering used, i.e. single or double.
NOTE It is not possible to ascertain the exact thickness of elastane after it has been subjected to treatment
during covering because variations from the original thickness can be significant.
A.7.2 Preparation of test samples
A.7.2.1 Atmospheric conditioning
Condition the test sample in accordance with EN 20139:1992.
A.7.2.2 Removal of yarn from knitted hosiery
Cut open a sample piece to enable the yarn to be pulled out to obtain a total length of at least 1000 mm,
with the minimum length of single pieces of thread being 100 mm. Take care to ensure that the yarn is
not overstretched when being pulled out and that none of the filaments are damaged. Remove the
covering of covered yarn carefully and record the method of covering.
A.7.3 Apparatus
A.7.3.1 Instrument for measuring length, comprising a measure with the scale in millimetres,
having clamps for securing the test sample, and having the possibility to apply a pre-tension on the
yarn.
A.7.3.2 Cutting instrument, e.g. razor blade.
A.7.3.3 Weights, to establish pre-tension when required.
A.7.3.4 Balance, with an accuracy of not less than 0,1 % of the mass of test sample.
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A.7.4 Procedure
A.7.4.1 Elastodiene
Determine the yarn thickness in accordance with ISO 2321.
A.7.4.2 Elastane
Remove the covering of elastane carefully. Boil the bare sections of yarn in distilled water for
approximately 2 min and test as described in A.7.4.3.
For pre-tensioning, use the values given in Table A.3. If the yarn still curls slightly when applying the
pre-tension weight, then increase the pre-tension weight (to a maximum of 0,02 cN/tex) until the yarn
has straightened.
A.7.4.3 Non-elastic yarns
Lay out test yarns for 5 h, e
...