IS 14944: Surgical Dressings - Methods of Test

19 Pages·2001·2 MB·English

by  Bureau of Indian Standards

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IS 14944 (2001): Surgical Dressings - Methods of Test [MHD
14: Hospital Planning]
“!ान $ एक न’ भारत का +नम-ण”
Satyanarayan Gangaram Pitroda
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Is 14944:2001

Indian Standard
SURGICAL DRESSINGS — METHODS OF TEST
ICS 11.160

0 BIS 2001
BUREAU OF INDIAN STANDARDS
MANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARG
NEW DELHI 110002

May2001 Price Group 7
Surgical Dressings Sectional Committee, MHD 15
FOREWORD
This Indian Standard was adopted by the Bureau of Indian Standards, after the draft finalized by the Surgical
Dressings Sectional Committee had been approved by the Medical Equipment and Hospital Planning Division
Council.
Protective coverings for wounds are called dressings. These areplaced directly onto wounds and may be used
to control bleeding, to absorb secretions ortoprevent contamination bybacteria orforeign material such asdirt.
Dressings should be large enough to cover a wound completely. They should be sterile so that they do not
introduce bacteria that could causeinfection. Adressing shouldalsobeabsorbent inordertoprevent accumulation
ofsweat, otherwise the skin around the wound becomes moist and soft,thus encouraging infection. These are of
various types, forexample, adhesive bandages, which consistofabsorbent padsheld inplace. They arecommonly
used to protect small wounds. Non stick dressings consist of anon-adherent layer ofperforated polyethylene or
viscose with an impregnated gauge pad backing. Improvised dressings which areused in an emergency almost
any clean dry, and absorbent materials may beused to cover wound.
In view of the fact that a large number of surgical dressings are used inthe country by the doctors as well as
consumers, the committee decided toformulate astandard covering methods oftest for various types of surgical
dressings. The standard covers testmethods forboth adhesive andnon-adhesive types ofdressings. The standard
gives provision for conducting various tests for minimum breaking load, elasticity, extensibility, adhesiveness,
water-vapour pefieability, waterproofness, absorbency, content of antiseptics, etc.
There isno LSO/IECstandard onthesubject. This standard hasbeenprepared based onthe information provided/
data provided in the-British Pharmacopoeia.
For the purpose of deciding whether aparticular requirement of this standard is complied with the final value,
observed or calculated, expressing theresults ofatest, shallberounded off inacordance with IS 2:1960 ‘Rules
for rounding of numerical values (revised)’. The number of significant places retained inthe rounded off value
shall be the same as that of the specified value inthis standard.
IS 14944:2001
Indian Standard
SURGICAL DRESSINGS — METHODS OF TEST
1SCOPE solution. They shall be insoluble in 1.25 M
sodium hydroxide.
1.1 This standard specifies the methods of test for
d) To0.1g, add 10mlofzinc chloride solution,
various types of surgical dressings.
heat to 40”C and allow to stand for 2.5 h,
2 REFERENCES shaking occasionally. The tibres shall not
dissolve.
2.1 The following Indian Standards are necessary
adjuncts to this standard: 6.1.2 Polyac@onitrile
IS No. Title a) When examined under a microscope, the
307’3:1967 Assessment of surface roughness fibres shall be seen to be twisted ribbons of
3689:1966 Conversion factors and conversion uniform width and thickness or cylinders of
tables for yam counts uniform width. In cross-section, the former
are reniform or dumb-bell shaped and the
3 STANDARD TEST ATMOSPHERE latter are approximately circular.
3.1 Unless specified otherwise, the standard test b) When examined under a microscope, the
atmosphere shall be atemperature of 27* 2°C and a fibresshallbeclearlyvisibleinwater orliquid
relative humidity of 65 + 5percent. paraffin but not easily visible in cedarwood
oil or aliquid of similar refi-active index.
4 CONDITIONING FOR TESTING
c) The fibres shall dissolve in dimethyl-
4.1 The materials to be tested for weights, areas, formamide at90to 95°C within 5min. They
threads per stated length, minimum breaking load and shall be insoluble in ammoniacal copper
absorbency are unwrapped, opened out or unwound oxide solution, incold acetone andinboiling
xylene.
and subjected to standard test atmosphere (see 3.1)
for not less than 24 hours immediately before testing 6.1.3 Polyamide 6
unless specified otherwise, and shall be tested in the
same atmosphere. a) Heat 50mg with 0,5ml of 7Mhydrochloric
acid in a sealed glass tube at 11O“Cfor 18h
5 QUALITY OF REAGENTS and allow to stand for several hours. No

crystals shall be produced.
5.1 Unless specified otherwise, pur e chemicals and
b) To 50 mg, add 10 ml of 7 M hydrochloric
distilled ordeionized water~hall beemployed intests.
acid. The material shall disintegrate in the
NOTE—‘Purechemicals’shallmeanchemicalsthatdonotcon- cold and dissolve completely within a few
tainimpuritieswhichaffecttheresultsofanalysis.
minutes.
6 TESTS METHODS c) The material shall dissolve in a 70 percent
(m/m) solution of anhydrous formic acid,
6.1 Fibre Identification
6.1.4 Polyamide 6/6
6.1.1 Cotton
a) In contact with a flame, the material shall
a) Whenexamined undermicroscope, eachtibre
melt and burn, forming a hard globule of
shall be seen to consist of asingle cell, up to
residue and shall give off a characteristic
about 4 cm long and up to 40 pm wide, in
odour resembling that of celery.
the form of a flattened tube with thick and
b) Place 50 mg in an ignition tube held in the
rounded walls and often twisted.
vertical position and heat gently until thick
b) Treat with iodinated zinc chloride solution.
times areevolved;whenthetimes fillthetube,
The fibres shall become violet.
withdraw itfromtheflameandinsertastripof
c) The fibres shall be soluble in sulphuric acid
nitrobenzaldehydepaper.Aviolet-browncolour
(66 percent). They shall swelluniformly and
shallbeproduced slowlyonthepaperandfade
except for the contents of the lumen, finally
slowlyinair;itshalldisappearimmediately on
dissolve in ammoniacal copper oxide
washingwith 1M sulphuric acid.

1
IS 14944:2001
c) To 50 mg, add 10 ml of 7 M hydrochloric (66 percent). The fibres shallbe stained blue.
acid. T-hematerial shall disintegrate in the f) Treat with a 1.0 percent (m/v) solution of
cold and dissolve within a few minutes. phlcwoglucinol in ethanol (90 percent)
d) The material shall not dissolve in an 80per- followed by hydrochloric acid. The fibres
cent(m/m) solution ofanhydrous formic acid. shall not be coloured red.
!3 The fibres shall be soluble in sulphuric acid
6.1.5 Polyester
(66 percent). They shall swell and finally
a) When heated in dimethylformamide and in dissolve in ammoniacal copper oxide
1,2 -dichlorobenzene, thefibre shalldissolve solution. They shall be insoluble in formic
with difficulty. acid and almost insoluble in 1.25 M sodium
b) To 50 mg, add 10 ml of 7 M hydrochloric hydroxide.
-acid.The fibre shall remain intact even after h) To0,1g,add 10mlofzinc chloride solution,
prolonged “immersion. heatto40”Candallow tostand for2.5hours,
shaking occasionally. The fibres shall
6.1.6 Rubber
dissolve completely.
Treat carefully afew small pieces with alittle carbon
6.1.7.2 Matt viscose
tetrachloride in an evaporating dish, allow to swell,
add 0.2ml ofbromine, allow tostand for2rein, add 1 Comply with the tests for identification described
g of-phenol and remove the carbon tetrachloride by in6.1.7.1 with the following modifications.
heating on a water-bath. The pieces shall be stained
a) and b) When examined under amicroscope,
blue to violet-red.
the fibres shall be seen to contain numerous
6.1.7 Viscose granular particles with average diameters of
0.25 to 1pm.
When the term viscose is used in tests for fibre
identification, itmeans bright viscose ormatt viscose d) The solution shall become orange-yellow
as appropriate. after the addition of the hydrogen peroxide
solution.
6.1.7.1 Bright viscose
h) The granular particles shall remain
a) When examined in dry state under a undissolved.
microscope, the fibres shallbeseentobeofa
6.1.8 Wood?k@
uniform width with many longitudinal
parallel lines distributed unequally over the a) When examined under a microscope, the
width. In waddings, the end-cuts are more fibres shall show the characteristics of the
or less straight. In cross-section, they are timber, usually coniferous, from which the

approximately circular or elliptical, with a wood pulp has been prepared, as follows:

diameter ofabout 10to20 pm; thesurface of Con~erous woo&
the fibre shall be seen to be uneven or
Detached tacheids, transparent and laterally
crenated.
distended; bordered pits indistinct and may
b) When examined under a microscope, the appear as rounded, somewhat jagged holes;
fibres shall be clearly visible in chloral distinct lattice-like striations may be.present;
hydrate solution and in lactophenol, almost fibre ends are broadly rounded and swollen.
invisible incresol and invisible when viewed
Broad-leaved woods
between crossed polars in the orthogonal
Generally similar to coniferous woods but
position.
vessels show numerous well-preserved pits;
c) Treat with iodinated zincchloride solution. wall thickness tends to be uneven and may
The fibres shall become violet.
be pierced by slit-like pores.
d) Dissolve the residue obtained in the test for b) The fibres shall swell and finally dissolve in
sulphated ash(see6.1.?3)in5.mlof sulphuric
ammoniacal copper oxide solution, some
acid with slight warming, allow to cool and
developing spherical swellings.
add carefidly 0.2 ml of hydrogen peroxide
c) Soak in iodine solution for a few minutes,
solution (1Ovol). The solution shall not
remove the excess of reagent with filter
become orange-yellow.
paper and add 0.05 mlto0.1 ml of sulphuric
e) Soak in iodine solution for a few minutes, acid (66percent). The fibres shall be stained
remove the excessofreagent with filterpaper
blue.
and add 0.05 ml to 0.1 ml of sulphuric acid

2
Is 14944:2001
6.1.9 Method III
WOO[
a) When examined under a microscope, each Determine the total number of warp threads in the
hair shall beseentobecomposed ofacuticle unstitched material and measure the width from the
of imbricated, flattened, epithelial scalesand outside of the last warp thread on one side to the
a wide cortex of nucleated spindle shaped outside ofthe lastwarp thread on the opposite side. If
fibres and may have a narrow medulla of the num-berof units permits, repeat the determination
polyhedral or rounded cells. The free on not less than four other units selected as being
projecting edges of the epithelial scales are representative of the material being examined and
directed towards theapex ofthehairandgive calculate the average number of threads per 10 cm,
rise to numerous irregular transverse unless otherwise specified in the standard.
markings on the surface of the hair.
Method IV
b) The hairs shall be insoluble insulphuric acid
(66 percent) at 20”C; soluble in 1.25 M Determine the numbers of warp threads and weft
sodium hydroxide at 100”C;insoluble inbut threads in an area of 10cm x 10cm in each of three
coloured blue by ammoniacal copper oxide places. Calculate the average number of threads per
solution. 10cm inthe warp and inthe wetl directions.
c) Treat with trinitrophenol solution. The hairs
If the width of the ribbon gauze is less than 10 cm,
shall be stained yellow.
coiint the number of threads over the whole of the
width and calculate the uurnber ofthreads per 10 cm
6.2 Yarn Numbers
onthe basis of the declared width. Ifthe width of the
Yam are normal]y numbered in the Tex system. The
ribbon gauze isgreater than 10cm, omit the selvedge
tex number is the weight, in g, of 1000 m of yam.
in the count.
Agreed rounded values and their equivalents in
traditional counts and numbering systems are given 6.3.2 Fully Stretched
in IS 3689.
Determine the number of warp threads while the
The sectional count of rubber threads is given by the material isfully stretched bythe application ofaforce
value of its cross-sectional area, expressed in square of 10N per cm width (about 1.07 kgf per cm width)
millimetres, multiplied by 1000. in the weft direction. Determine the number of weft
threads while the material is fully stretched by
NOTE—Thesectionalcountcorrespondstothetexcountfora
application of a force 10 N per cm width (about
nominaldensityof1Mg/m3(=Ig/cm3).Theuseofthesectional
countisrecommended. 1.07kgf per cm width) in the warp direction. Count
the number of threads in a length of 10 cm, except
6.3 Threads per Stated Length that ifthere are 10ormore threads per cm, make the
6.3.1 Unstretched count inalength of2.5cmusing asuitable instrument.
Ifitisimpracticable tomeasure over alengthof 10cm,
Method I usethegreatest distance allowed bythematerial being
examined. If the size or number of units available
Determine the number of threads over a distance of
10 cm, or if this is impracticable, over the greatest permits, repeat the determination atnot lessthan four
other independent positions selectedasbeingrepresen-
distance allowed by the material being examined, If
tative of the material being examined and calculate
the size or number of units available permits, repeat
the average number of threads per 10 cm, unless
the determination atnot lessthan four other indepen-
otherwise specified in the standard.
dent positions selected as being representative of the
material being examined and calculate the average
6.4 Weight per Unit Area
number of threads per 10 cm, unless otherwise
specified in the standard. 6.4.1 Non-Adhesive Dressings
Method 11 Method I
Determine the number of threads over a distance of Determine the weight of the material being examined
2.5 cm by means of a suitable instrument. If the size (Wg). Measure its unstretched width (a cm)and its
or number of units available permits, repeat the fully stretched length (b cm) (see 6.6). CalcuIate the
determination atnot lessthan four other independent weight per unit area, in g m-2 from the expression
positions selected as being representative of the 10000 Wlab.
material being examined and calculate the average
Method II
number of threads per 10 cm, unless otherwise
specified in the standard. Determine the weight of the material being examined

3
Is 14944:2001
(Wg). Measure its unstretched width (a cm) and its Measure its unstretched width and its fully-stretched
unstretched length (b cm). Calculate the weight per length (see 6.6) and calculate its total area (A m2).
unit area, in g m-2from the expression 10000 W/ah. Complete thetestdescribed under Method I,beginning
at the words ‘Cut out rectangular.....’.
Method III
Method III
Cut a convenient sample from the material being
examined, preferably not less than 100 cm2in area, Measure the area of a sample weighing 9.0 to 11.0g.
and determine its weight (Wg) and its area (Acm2). Macerate the sample in successive portions of
If the test has been carried out on a dried sample, petroleum spirit (boiling range, 40 to 60°C) or other
correct the weight for percentage moisture regain. suitablesolventuntil.theadhesive appears tohave been
Calculate the weight per unit area, ing m-2,from the completely removed and dry the residual material to
expression 10000 W/A. constant weight in a current of warm air. From the
area of the unextracted sample, calculate the weight
If the size or number of units of the material being
per unit area of backing material, in g m-2.
examined permits, repeat the determination onfurther
samples and calculate the average value. 6.4.3 Weight ofAdhesive Mass
Method IV Carry outtheprocedure described under 6.4.2 Method
I, Method II or Method HI, as prescribed in the
Determine the weight of the whole ribbon gauze and
specification. Calculate the weight of adhesive mass,
calculate its area by multiplying the nominal width
ingm-2,fromtheexpression (w–j W/AwforMethods
by the length, measured on the unrolled gauze under
I and 11or (W–j)/A for Method 111where W is the
slight tension along the centre. Calculate the weight
original weight (ing) of unextracted sample,f is the
per unit area, in g m-2.
weight (in g) of dry residual backing material and A
6.4.2 Adhesive Dressings isthe original area (in m2)of unextracted sample.
Method 1 If the spread area of theadhesive (B m2) is different
from the original area of the sample, substitute B for
Determine the weight ofthe material being examined
A inthe above expression.
(Wg). Measure its width and length and calculate its
total area (A m2). Cut out rectangular full-width 6.5 Minimum Breaking Load
samples, each weighing 3to 4g,from three positions
Method I
approximately equidistant along the length of the
material being examined, combine the samples and Prepare five strips of the material being examined as
weigh accurately (w g). Macerate the combined representative ofthematerial aspossible, each200 mm
samples with successive 250-ml quantities of inlength andofknown widths notgreater than 25 mm

chloroform orother suitable solvent until theadhesive (or cut longitudinally to give strips of that width) so

mass appears to have been removed, decant each that both surfaces arefreely accessible tothe standard
extract through asieve with anominal mesh aperture testatmosphere for24hpreceding thetest. Determine
of 106,~m and return any fibres retained by the sieve the“breakingload of each strip in turn on a machine
to the bulk of the fabric. having amovable gripwith aconstant rate of traverse
of270to 330 mmper minute and acapacity such that
Cover the extracted fabric with a 50 percent (v/v)
when the sample breaks, the reading obtained is 15to
solution of acetic acid and allow to stand until all of
85percent of the full-scale deflection. Place one end
the zinc oxide retained in the fabric has dissolved.
of the strip in the fixed grip and the other in the
Decant the liquid and wash the fabric with successive
movable grip insuch away that the distance between
quantities of w“ateruntil the washings are free from
the grips is 100 mm. Any strip that slips during the
acidity, passing the washings through the sieve, and
test or breaks within 10 mm of the grips should be
return any fibres retained by the sieve to the bulk of
excluded and replaced by another strip. Repeat the
the fabric.
procedure on the other four strips and calculate the
Dry the extracted fabric at 105”C, recondition it by average value.
subjecting it to the standard test atmosphere for 24 h
Me~hodII
and determine its weight (fg).
Carry out Method I, using six representative strips,
Calculate the weight per unit area, ing m-2,from the
each 200 mm long, and amachine having amovable
expression~/A w.
grip with aconstant rate of traverse of 90 to 110mm
Method [1 per minute. Place one end of a strip in the fixed grip
and the other in the movable grip in such a manner
Determine the weight of the whole sample (W g).
that the distance between the grips is 175mm except
4
Is 14944:2001
that in the case of plastic films, the distance may be in azig-zag with folds of 15to 20 cm and allow the
reduced to 100mm. Repeat theprocedure ontheother material to relax for 4.75 to 5.25 min from the time
tive strips and calculate the average value. of release of the tension. In the case of adhesive
material, fold it edge-to-edge along its length with
Method i[l
the adhesive surface innermost before removing the
For ribbon gauzes more than 50 mm wide, make two material from the grips. Unfold the zig-zag and
cutsparallel tothe selvedge edges soastoobtain from measure the length of material between the marks to
the centr.eof the ribbon pieces at least 60 mm wide. the nearest cm (r cm).
Remove wa~ threads from thetwo sidessoastoleave
Calculate the fully stretched length (Ls//) and the
fringes about 5 mm long and obtain a width of the
regain length (Lr/~.
remaining warp threads of exactly 50 mm.
Repeat theprocedure onanother sample and calculate
For ribbon gauzes of 50 mm or less wide, test the
the average values.
sample using the full width and calculate the result
with respect to a50 mm width. Prepare five pieces of Method 11
ribbon gauze of sufficient length toallow thedistance
For tubular products that are elastic in the width
betwen the clamps of the machine to be 200 mm.
direction, cut a sample 10 cm long and mark two
Clamp each piece in turn between the jaws of a
measuring points across the width, the distance
machine with a constant rate of traverse of 90 to
between which is not less than 50 percent of the
110mm per minute and determine the breaking load.
nominal lay-flat width. Apply a load of 20 N (about
Calculate the average value.
2kgf) by means of fingers or stirrups inserted in the
Met]lod IV
tube.
Prepare 10pieces, each 50mm wide and ofsufficient
6.7 Extensibility
length to allow the distance between the clamps of
the machine to be200 mm. Cut fivepieces inthewefl Method I
direction and five inthe warp direction, not lessthan
Carry out the tests on amachine with a constant rate
15 mm from the edges avoiding folded or fraying
of traverse using six samples of the material being
edges. Clamp each piece inturn between thejaws ofa
examined, eachatleast 100mm long andasrepresen-
machine with a constant rate of traverse of 90 to
tative as possible of the material, and calculate the
110mm per minute and measure the breaking loadof
average result.
each piece. Calculate the average value.
Determine the load required to produce a 20 percent
6.6 Elasticity
extension atarate of extension of270 to 330 mm per
Method I minute. The load shall not be more than .14N per cm

width (about 1.4kgf per cm width).
Measure the length of the material in the unstretched

condition (L cm). Place one end of the material in a Maintain the 20 percent extension of the material for
fixed grip and the other inamovable grip of aspring 55 to 65 s, allowto recover for 4.75 to 5.25 min and
dynamometer or other suitable device in such a way redetermine the length. The permanent set of the
that the material stretches in the elastic direction. elongated material shall not be more than 5 percent
Ensure that the ends ofthe material are securely held, of the original unstretched length.
forexample, bymeans ofpinsinthegrips,tominimize
Method II
any slip while the material isunder tension. Mark the
material between the grips at points approximately Measure the width of a 10-cm length of stockinette in
50 cm apart (1cm). Apply gradually to the movable
the unstretched condition. Insert two circular fingers,
grip, aforce of 10N per cm width (about 1.0kgf per
one fixed and one movable, within the stockinette in
cmwidth) ensuring that the full load isapplied within
such away that they are parallel to each other and to
-5sfrom starting to stretch. Measure the length ofthe
the length of the sample. By means of a spring
material between the marks, tothenearest cm,assoon
dynamometer orother suitable device, apply aload of
asthe full load isapplied (s cm).
2.5 kg within 5 sto the movable finger. Measure the
Maintain the load for atotal stretching time of 55 to extended width of the stockinette.
65 s, ensuring that at no time the load is exceeded,
6.8 Adhesiveness
and then release the tension as rapidly as possible
without allowing the material to tangle. Remove the Thetapeshatlcomplywith Tests 1and2given in6.8.2
material from the grips, loosely fold thewhole length
and 6.8.3.
5