Lined antistatic rubber footwear

Articles chaussants doublés, en caoutchouc anti-électrostatique

General Information

Publication Date
Withdrawal Date
Current Stage
6060 - International Standard published
Completion Date
Ref Project


Buy Standard

ISO 2251:1975 - Lined antistatic rubber footwear
English language
6 pages
sale 15% off
sale 15% off

Standards Content (sample)

@ 7751


Lined antistatic rubber footwear
Articles chaussants doublés, en caoutchouc anti-électrostatique
First edition - 1975-07-15
UDC 685.315.4 : 678.4/.8 Ref. No. IS0 2251 -1975 (E)

Descriptors : rubber products, footwear, antistatic agents, specifications, tests, air-tightness tests, ageing tests (materials), bend tests.

Price based on 6 pages
---------------------- Page: 1 ----------------------

IS0 (the International Organization for Standardization) is a worldwide federation

of national standards institutes (IS0 Member Bodies). The work of developing
International Standards is carried out through IS0 Technical Committees. Every
Member Body interested in a subject for which a Technical Committee has been set

up 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.

Draft International Standards adopted by the Technical Committees are circulated
to the Member Bodies for approval before their acceptance as International
Standards by the IS0 Council.
International Standard IS0 2251 was drawn up by Technical Committee
lSO/TC 45, Rubber and rubber products, and circulated to the Member Bodies in
February 1974.
It has been approved by the Member Bodies of the following countries
Belgium Netherlands Thailand
Czechoslovakia New Zealand Turkey
Egypt, Arab Rep. of Poland United Kingdom
France Romania U.S.A.
Germany South Africa, Rep. of U.S.S.R.
Hungary Spain Yugoslavia
India Sweden
Mexico Switzerland
The Member Body of the following country expresseddisapproval of the document*
on technical grounds :
clause 8 only.
O International Organization for Standardization, 1975
Printed in Switzerland
---------------------- Page: 2 ----------------------
IS0 2251 -1975 (E)
Lined antistatic rubber footwear
lining and the other, or others, acting as reinforcement. The
strength of the one fabric, or the composite strength if
This International Standard applies to lined rubber
there are more than one, shall be determined in accordance
footwear with antistatic properties for special purpose
with the method described in annex A, the minimum
applications where portable electrical equipment rnay be
requirements, for 25 mm wide test pieces, being as shown
used, or where potential electrical defects from other causes
below :
may develop, and where it is consequently necessary to
have a lower limit on resistivity (upper limit on
L Warp Weft
Upper and vamp 250 N 200 N
Experience has shown that for antistatic purposes the
discharge path should have an electrical resistance not
greater than lo8 R at any time throughout its useful life. A
3.2 Knitted fabrics
value of 5,O X lo4 L? for antistatic products is suggested as
Knitted fabrics rnay be used by agreement between
the lowest limit of resistance to give adequate protection
purchaser and supplier.
against fire and dangerous electric shock in the event of any
apparatus becoming defective when operating up to 250 V.
During service the resistance of footwear made from

antistatic material rnay change significantly. The user is 4 BOOT UPPER - MINIMUM THICKNESS

recommended to carry out the test for electrical resistance
The combined thickness of the rubber and fabric shall be
at frequent intervals and after not more than 200 h wear.
not less than the minimum values shown in figure 1 at the
No insulating element should be introduced between the
points indicated.
foot of the wearer and the insole of the footwear.
The floor surfaces of rooms where the footwear will be
used shall also be antistatic. 5 SPECIAL REINFORCEMENTS
If necessary the top of the boot rnay be finished off by a
top binding or other suitable means.
L This International Standard specifies the requirements for
Eyelets, if fitted, shall be corrosion-resistant and of
rubber footwear with antistatic properties.
non-ferrous materials.
I SO/ R 37, Determination of tensile stress-strain properties
of vulcanized rubbers.
6.1 Tensile requirements before ageing
ISO/R 188, Vulcanized rubbers - Accelerated ageing or
heat resistance tests.
Three test pieces shall be cut from both outsoles and heels,
then reduced by careful buffing to the thickness required
ISO/R 471, Standard atmospheres for the conditioning and
by ISO/R 37, or any other suitable method, taking care to
testing of rubber test pieces.
avoid an increase in temperature. The tensile strength and
ISO/R 1421, Determination of breaking strength and
elongation at break of outsoles and heels shall then be
elongation at break of fabrics coated with rubber or
determined according to the method described in
ISO/R 37, using dumb-bell test pieces. A smaller dumb-bell
test piece may be used for the heels, if size makes this
necessary. The size of the dumb-bell shall be stated when
expressing resu Its.
3.1 Woven fabrics
All three test pieces shall be free from visible defects. If the

The lining of a boot rnay consist of one fabric forming the median of any of the sets of three values determined is

leg lining or of two or more fabrics, one forming the leg below, and the highest value in the set is above, the

---------------------- Page: 3 ----------------------
IS0 2251 -1975 (E)
The resistance of the footwear, when tested by the method
described in annex C, shall be between 5,O X lo4 and
5.0 x 107 a.
Minimum tensile Minimum elongation
9.1 Leakage test
strength at break
MPa %
When finished boots are tested by the manufacturer, there
shall be no leakage of air.
Outsoles 300
After sealing the top of the boots, air shall be forced in, to
a pressure of 15 kPa.
I Heels I 200
The boots shall then be immersed in water to within 75 mm
of the top and examined for escape of air.
6.2 Tensile requirements after ageing
Ankle boots which show any sign of leakage in the vicinity
After submission to the ageing treatment given in table 2
of either the eyelets or the gusset shall be submitted to an
the tensile strength and elongation at break of outsoles and
immersion test. The boots shall be weighted and immersed
heels determined as above shall be in accordance with the
in water to within 75 mm of the top for a period of 16 h
values given in table 2.
and then examined to see if water has penetrated to the
inside of the boot.
9.2 Dry heat ageing test
Ageing Tensile strength Elongation at break
All rubber components shall be capable of withstanding
% of unaged value
treatment % of unaged value
exposure to air at a temperature of loo+ 1 OC and at
atmospheric pressure for a period of 24 h in suitable
outsoles heels
apparatus, without developing any signs of brittleness or
tackiness. For the purpose of this test, the test pieces may
168 h at 70 I 1 "C
be entire articles or pieces cut from them. The test shall be
in accordance with
+ 10
carried out in accordance with the general provisions given
f 20 f 20
the oven method
- 30
in clause 3 of ISO/R 188.
described in
r ISOlR 188
9.3 Flexing test
When tested in accordance with annex B after having been
submitted to the dry heat ageing test described in 9.2, the
uppers shall withstand not less than the number of
continuous flexes given in table 4 without the rubber face
The minimum thickness of soling shall be in accordance
showing pinholes or any sign of cracking, and without b
with the requirements of table 3.
separation of the plies when viewed with the unaided eye.
For this purpose only those parts of the test piece shall be
TABLE 3 - Minimum thicknesses
observed which are under tension during the test, i.e. the
folds which form a diamond shape. Pinholes or cracking
associated with machine damage shall be ignored.
Minimum outer sole Minimum total thickness
The test pieces shall receive a minimum of 2 days' rest after
thickness including insole
having been subjected to the dry heat ageing test described
and filling
in 9.2.
non- cleated non- cleated
The testing equipment should be kept away from any
cleated (at cleats) cleated (at cleats)
source of ozone.
TABLE 4 - Flexing test lim

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.