HOKLAS SC-22
Issue No. 5
Issue Date: 1 June 2017
Implementation Date: 1 September 2017
Page 1 of 14
HOKLAS Supplementary Criteria No. 22
‘Textiles and Garments’ Test Category
1 INTRODUCTION
1.1 This criteria document elaborates the generally stated requirements of HOKLAS 003
for the accreditation of testing under the test category of ‘Textiles and Garments’.
This criteria document shall be read in conjunction with current issue of
HOKLAS 003 and other relevant criteria documents. In areas not covered in this
document, the requirements stipulated in HOKLAS 003 and HKAS 002 and other
relevant criteria documents shall apply.
1.2 Laboratories should note that complying with this document might not necessarily
meet all the requirements of test standards. Individual test standards may have
specific requirements which shall be met when conducting the concerned tests.
2 SCOPE OF ACCREDITATION
2.1 HOKLAS offers accreditation in the following areas:
(a) Care performance test/dimensional stability
(b) Chemical analysis
(c) Colour fastness test
(d) Construction test
(e) Performance test
(f) Feather and down analysis
(g) Fibre analysis
(h) Flammability test
(i) Strength test
(j) Colour measurement
(k) Microbiological test (The specific requirements for the accreditation of this test area
are not detailed in this supplementary criteria. Laboratories seeking accreditation for
this test area shall read HOKLAS SC-08.)
3 TERMS AND DEFINITIONS
3.1 The term “shall” is used throughout this document to indicate those provisions which
are mandatory. The term “should” is used to indicate guidance which, although not
mandatory, is provided by HKAS as a recognised means of meeting the requirements.
3.2 Appendix B gives a list of selected documents which are useful for laboratory
operation.
HOKLAS SC-22
Issue No. 5
Issue Date: 1 June 2017
Implementation Date: 1 September 2017
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4. ORGANISATION
4.1 The technical management of the laboratory shall include at least a member with
in-depth knowledge and extensive experience in textiles and garments testing covered
in the scope of accreditation. The minimum qualification and experience
requirements for the technical management members are the same as those for the
approved signatory mentioned in section 6.6. He/she is responsible for the technical
operation of the laboratory with respect to textiles and garments testing.
5. PURCHASING SERVICES AND SUPPLIES
5.1 Critical consumables having an effect on the validity of tests shall be verified
according to the requirements stipulated in the test standards or the recommendation
given by the manufacturer, if no such requirements in the test standards. Procedures
for verification shall be documented and records shall be maintained. Typical
examples are:
(a) chlorine content of hypochlorite,
(b) size and mass to area ratio of dummy loading fabrics,
(c) dimensions and friction of liner for pilling tests,
(d) service time (in hours) of the illumination source (e.g. xenon lamp tubes and
filters) for colourfastness to light,
(e) light intensity and colour temperature of the illuminant simulator used in the
visual assessment, etc.
6. PERSONNEL
6.1 Supervisory personnel of the laboratory shall have a higher diploma in Textile
Technology, Textile Chemistry or Fashion and Clothing Technology, or higher
qualification or equivalent academic qualification, with not less than three years
relevant working experience. Staff members having equivalent academic
qualification and experience are acceptable.
6.2 Technical personnel shall have sufficient technical knowledge of the technology
stipulated in the test standards. They shall have satisfactorily completed the in-house
training of the tests to be carried out.
6.3 Laboratories shall provide adequate training to new technical personnel. The training
programme shall at least cover the following areas:
(a) techniques involved in the tests, including factors that may affect test results and
precautions to take for minimising such effects
(b) principles and operation of the equipment
(c) understanding of the need of equipment calibration and the measurement
traceability
HOKLAS SC-22
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Implementation Date: 1 September 2017
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(d) recording of test details and results
(e) drawing conclusion based on test results
(f) understanding of the laboratory’s management system
Laboratories shall also provide training to the technical personnel for new and
infrequent used techniques.
6.4 Technical personnel are only allowed to perform a test independently after their
performance has been assessed to be satisfactory. The continuing competence of
technical personnel shall be evaluated regularly. Records of training, competence
assessments (including any raw data), and authorization shall be maintained.
6.5 When the training provided is for specific techniques rather than specific test methods,
laboratories shall define and document which techniques are required for performing
what tests, and hence the trained technical personnel have been assessed to be
competent in performing what tests.
6.6 Laboratories shall nominate at least one supervisory personnel for signatory approval.
The approved signatories shall have a higher diploma in Textile Technology, Textile
Chemistry or Fashion and Clothing Technology, or higher qualification and with not
less than three years relevant working experience. Staff members possessing
equivalent academic qualification and related work experience are acceptable. In
addition, he/she shall have at least six months of experience in the testing areas for
which signatory approval is sought. For individual staff member at supervisory level
who does not possess the required academic qualifications but has extensive
experience (at least ten years) in the testing area concerned, special consideration may
be given provided that records giving full details of employers, and the nature of
experience received are available. If a nominated signatory holds a qualification
conferred by an education institute outside Hong Kong, the laboratory shall provide
supporting evidence to substantiate that such qualification is equivalent to or above the
minimum level stated above. In all cases, candidates shall demonstrate to the
assessment team that his/her technical competence in the test areas under
consideration before signatory approval can be granted.
6.7 The technical personnel responsible for visual assessment of colour difference of
textiles, as well as approved signatories for the visual tests concerned, shall have
normal colour vision for the colour discrimination test methods. The technical
personnel and approved signatories shall undergo a colour defect check to ensure any
deficiency does not affect the quality of the examination results. A list of all
qualified technical personnel shall be maintained.
7. ACCOMMODATION AND ENVIRONMENTAL CONDITIONS
7.1 Where a conditioning room or chamber is used for conditioning and testing of textiles
and textile products, the standard atmospheric conditions defined in the test standards
shall be maintained throughout the room or chamber. Appropriate devices for
HOKLAS SC-22
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Implementation Date: 1 September 2017
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measuring and recording the temperature and relative humidity in the room or
chamber shall be used. Multiple measuring devices may be required to ensure
adequate monitoring of the atmospheric conditions throughout the room or chamber,
appropriate monitoring position(s) shall be properly selected and recorded. In order
to determine the standard atmospheric conditions within the room or chamber are
within the tolerances given in the test standards, the measurement uncertainty of the
temperature and relative humidity measuring devices being used shall be taken into
account. The resolution and the measurement uncertainty of the measuring device
should meet the requirements stipulated in the test standards, if any. Atmospheric
conditions records shall be kept. Any measuring device used shall be calibrated
regularly, and the results shall be recorded. Cases where atmospheric conditions fall
outside the acceptable ranges shall be recorded and the effects on test results shall be
evaluated. Appropriate actions shall be initiated if the cases are identified as
nonconforming work.In addition, laboratories shall maintain the records of start and
end time of conditioning when a sample is placed in a conditioning room or chamber.
Laboratories shall ensure that the sample is fully conditioned to the stated
environmental conditions before the test.
7.2 A dedicated space, if not a separate room, shall be used for visual assessment of colour
differences or determining appearance of textiles after tests (e.g. colour fastness,
pilling, smoothness and wrinkle, etc.). The space or room shall be so constructed
such that the rating results will not be affected by the lighting of neighbouring areas,
the reflection of the clothing of technical personnel on the test specimen and reflection
from surrounding surfaces. Laboratories shall be equipped with viewing boards and
viewing cabinets specified by corresponding test standards. The colours of the
boards and cabinets shall be checked regularly for conformity with test standards.
The checking records shall be maintained.
7.3 Laboratories shall take necessary precautions to prevent contamination from the
environment when performing chemical analysis.
8. TEST AND CALIBRATION METHODS AND METHOD VALIDATION
8.1 General
8.1.1 Laboratories may use a common test procedure to cover several similar tests specified
in national and international test standards (e.g. colour fastness to sea water (AATCC
Test Method 106 and ISO 105-E02)). However, differences between these test
standards, if any, shall be clearly identified in the common test procedure.
8.1.2 For visual assessment results, such as the grade of the test results of colourfastness,
pilling, smoothness, wrinkle, etc., laboratories shall define a verification system. The
verification system shall define the minimum number of raters or assessors and the
maximum allowable differences between their assessment results. Laboratories shall
take corrective actions when the difference is higher than the documented defined
limit.
HOKLAS SC-22
Issue No. 5
Issue Date: 1 June 2017
Implementation Date: 1 September 2017
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8.2 Chemical tests
8.2.1 For chemical tests such as pH and formaldehyde, it is essential to avoid contamination
of test samples and/or standard solutions by labware. Laboratories shall have
documented procedures for washing labware and selecting the types of labware to be
used (glass, PTFE, etc.) for specific tests. Attention shall also be given to the
possible presence of analytes in commercial detergents. In most cases, laboratories
are expected to have different washing, storage and segregation procedures for
labware used for different analyses.
8.2.2 The grade of reagents used (including water) shall be stated in the procedure together
with guidance on precautions to be observed in their preparation or use. Laboratories
shall ensure that reagents used are suitable for the applications. Reagents, where
critical, prepared in the laboratory shall be labelled to identify their substance, strength,
solvent (other than water), date of preparation and/or date of expiration and any
special precautions and restrictions of use. The person responsible for the
preparation of the reagent shall be identifiable from records.
8.2.3 Water is one of the most widely used reagents in chemical and colourfastness tests.
Hence, means to ensure that reagent water is of the required quality is necessary. The
performance of any water purification system shall be checked regularly to confirm
that the water produced continues to meet testing requirements. Records of such
checks shall be kept.
8.2.4 For compliance testing for a chemical parameter, it is essential to select a method
which gives a limit of detection well below the compliance limit and that it gives
reliable results at the limit.
8.3 Selection of test methods
8.3.1 If test methods are stipulated in legislation, the specified methods shall be used for
compliance testing against the legislation.
8.4 Validation of methods
8.4.1 Non-standard methods shall be validated and authorised before use. The validated
non-standard methods shall be documented and scope of application, performance
characteristics, quality control plans and calibration shall be defined.
8.4.2 The performance of a validated method may change due to many reasons. It is
therefore necessary to review the performance characteristics of test methods on a
regular basis and revise, if necessary. Such reviews may also be required when
performance of the method is affected by changes in equipment or environmental
conditions, etc.
HOKLAS SC-22
Issue No. 5
Issue Date: 1 June 2017
Implementation Date: 1 September 2017
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8.5 Estimation of Uncertainty of Measurement and Determination of Conformity with
Specification
Testing laboratories shall have and shall apply procedures for estimating uncertainty of
measurement for all tests having a numerical value as the final result or as an
intermediate result. In determining the overall measurement uncertainty for a test,
the uncertainty caused by the measurement equipment and those caused by the
measurement method and the operators must be taken into account.
It is recognised that there is more than one method for estimating measurement
uncertainty and there is no consensus on the method to be used for textiles and
garments testing. HOKLAS accepts methods for estimating uncertainty of
measurement given by reputable professional and standard writing bodies. However,
the uncertainty value obtained should be in line with the definition given in the
“International Vocabulary of Basic and General Terms in Metrology” (VIM) and
should include all major components of uncertainty in its estimation. Reference to
the ISO GUM Guide and EURACHEM/CITAC document “Quantifying Uncertainty in
Analytical Measurement” may be useful.
For assessing conformity with numerical specifications, international guidelines, such
as ILAC-G8:03 Guidelines on the Reporting of Compliance with Specification or
APLAC TC 004: Method of Stating Test and Calibration Results and Compliance with
Specification shall be followed.
9. EQUIPMENT
9.1 General recommendations on equipment calibration are given in the HOKLAS
Supplementary Criteria No. 2. - Specific recommendations on equipment
calibration/verification requirement. Recommendations on calibration for the test
equipment used in textiles and garments testing are given in Appendix A of this
document. These recommendations may be adopted in the absence of specific
recommendations from the equipment manufacturer, the test standards or reliable
calibration history.
10. MEASUREMENT TRACEABILITY
10.1 Evaluation tests
Evaluation tests here refer to assessments of change in properties of a sample, such as
colour, pilling, smoothness, etc., after it has undergone the testing steps. Usually, a
numerical grade, such as 1 to 5 for the change is given as the evaluation result.
Results shall be traceable to reference standards or materials specified in test standards.
Typical examples of acceptable traceability are listed below:
(a) Gray Scale or Chromatic Transference Scale for colour change and colour
HOKLAS SC-22
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Implementation Date: 1 September 2017
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staining of colourfastness tests;
(b) durable press replicas for appearance of durable press after repeated home
laundering;
(c) photographic comparative ratings for single and double needle seams for
appearance of seams after repeated home laundering;
(d) photographic comparative ratings for crease retention for appearance of crease
after repeated home laundering;
(e) photographic pilling standards for pilling tests;
(f) spray test rating chart for water repellency test; and
(g) wrinkle recovery replicas for wrinkle recovery of fabrics.
10.2 Chemical tests
10.2.1 Reference materials used for calibration shall provide the necessary measurement
traceability. The requirements given in HOKLAS Supplementary Criteria No. 1
‘Acceptability of chemical reference materials and commercial chemicals used for the
calibration of equipment’ shall be followed.
10.2.2 Calibration curves shall be constructed as specified in the test standards. As a
general guideline, at least three standards (excluding blank) shall be used to establish a
linear calibration graph. The standards used should cover the range of concentration
found in test samples. The lowest standard should be at a level at or below the
reporting limit of the test method. Criteria for the correlation coefficient of linear
calibration graph should be set and implemented. Guidelines given in
‘ISO 11095: 1996 - Linear calibration using reference materials’ should be consulted
for further details.
10.2.3 Calibration graphs shall be checked using mid-point calibration standard. The
frequency of such check depends on the stability of the equipment. A frequency of
around 5 per cent is normally considered as adequate, except otherwise specified in the
test standards or the stability of the equipment merits more frequent checking.
Acceptance criteria shall be established and the criteria shall commensurate with the
testing uncertainty.
11. SAMPLING
11.1 Sampling from sample lot or site is not covered in this document. Customers taking
their own samples should be made aware of proper storage, sampling and
transportation procedures.
11.2 Preparation of laboratory samples and test portions shall be based on national or
international standards unless otherwise specified in the relevant test standards.
General guidance is given in ISO 1130: 1975 Textile fibres – Some methods of
sampling for testing and ASTM D2258/D2258M - 16 – Standard Practice for
Sampling Yarn for Testing. Procedures for taking test portions from laboratory
samples shall be documented.
HOKLAS SC-22
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Issue Date: 1 June 2017
Implementation Date: 1 September 2017
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12. HANDLING OF TEST AND CALIBRATION ITEMS
12.1 Laboratories shall examine and record the condition and appearance of the samples
upon receipt. The information to be checked includes, where appropriate, number,
colour, pattern, garment type, etc. The laboratory should retain a swatch for sample
identification.
12.2 Test samples shall be suitably stored as soon as practicable. Laboratories shall define
the storage conditions for different types of samples. The storage conditions shall be
monitored and recorded to demonstrate that the requirements are fulfilled.
12.3 Frequently, it is necessary to split the sample for testing of different properties. It is
essential that such sub-samples represent the original samples and their identities are
maintained at all times. A system for identifying the test portions for colourfastness
tests, dimensional stability to washing tests, etc. shall be documented.
13. ASSURING THE QUALITY OF TEST AND CALIBRATION RESULTS
13.1 The quality control plans for monitoring the validity of tests undertaken shall define
the frequency of performing different programmes (e.g. proficiency testing
programmes, inter-laboratory comparison, etc.). The plans shall also define the
acceptance criteria of the programmes and actions to be taken in cases of acceptance
criteria not being met. A written corrective action plan and documentation of
corrective actions are required.
13.2 Laboratories shall establish regular schedules for participation in proficiency testing
programmes or inter-laboratory comparison. The number of laboratories participated
in inter-laboratory comparisons prefers to be more than two. Where practicable, at
least one of the participating laboratories shall have been accredited for the tests under
comparison. The frequency of participation shall commensurate with the volume of
work for each test parameter. The minimum frequency of participation shall be once
every four years for each test area according to the categorisation in section 2 of this
document.
13.3 Laboratories shall have documented procedures for rectifying unsatisfactory
performance in proficiency testing programmes or inter-laboratory comparisons. All
findings in connection with unsatisfactory performance shall be recorded.
14. REPORTING THE RESULTS
14.1 A description of the samples as received shall normally be given in test reports. The
description shall include, where relevant to the interpretation of test results, a
description of the number, appearance and colour, type of fabrics or garments and care
label when received. Any deviation from the test standard requirements shall be
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Implementation Date: 1 September 2017
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given.
14.2 Some test standards require the reporting of additional information. In these cases,
the test reports shall include all the information required by the test standards.
14.3 It is an acceptable practice for a customer to provide its specification to the laboratory
and request the laboratory to include a statement of compliance with the specification
in the report. However, if a specification is not provided and the laboratory compares
the test results with its commercial specification, any statement of compliance shall be
considered as opinions and interpretations. The technical criteria governing reporting
of opinions and interpretations as stated in HOKLAS 003 shall be followed.
HOKLAS SC-22
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Implementation Date: 1 September 2017
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Appendix A
(informative)
SPECIFIC CALIBRATION RECOMMENDATIONS
If the test standards do not specify the requirements for the equipment calibration /
verification, the following table sets out recommended parameters and maximum periods
between successive calibrations for equipment used in textiles and garments testing.
Type of equipment
Abrasion Tester
(Inflated
Diaphragm)
Calibration/verification parameter
Dimension of clamping ring and collar
Dead weight
Recommended maximum
period between successive
calibrations/verification
Initial
Initial
Thickness of diaphragm
Pressure gauge
Prior to installation and
thereafter once a year
1 year
Reciprocating motion, stroke length 1 year
Abrasion Tester
(Martindale)
Dimensions of specimen holder
Weight of holder and spindle
Initial
Initial
Rotational speed 1 year
Stroke of peg 1 year
Counter 1 year
Lissajous figure 6 months
Inflated Diaphragm
Bursting Tester
Dimensions of base plate and clamping rin
Thickness of diaphragm
g Initial
1 year
Pressure gauge 1 year
Performance check by busting 5 pieces of
standard aluminium sheet
6 months
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Type of equipment
Crimp Tester
Calibration/verification parameter
Scale
Recommended maximum
period between successive
calibrations/verification
Initial
Reel perimeter, if applicable Initial
Tensioning gauge 1 year
Crockmeter Dimensions (diameter of finger peg,
reciprocating rubbing distance)
Initial
Rubbing downward force 1 year
Cutting die Dimensions Initial
Performance check 1 year
Drycleaning
Cylinder
Dimension of cylinder
Angle of cylinder
Initial
1 year
Rotational speed 1 year
Elmendorf Tearing
Tester
Augmenting weights
Dimension of clamp
Initial
Initial
Slit length 1 year
Calibration of scale 1 year
Fade-o-meter Black panel temperature 1 year
Flammability Tester
(16CFR 1610)
Angle of specimen rack
Igniter tip alignment
1 year
1 year
Impingement time 3 months
Timer 3 months
Flammability Tester
(16CFR 1615)
Dead weight
Angle of burner
Initial
1 year
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Type of equipment Calibration/verification parameter
Angle of metal hook
Recommended maximum
period between successive
calibrations/verification
1 year
Flex Stiffness Tester Angle deflection 1 year
ICI Pilling Box Dimension of PU
dimensions of box
tube, template, inner Initial
Rotational speed 1 year
Counter 1 year
Performance check by reference fabrics 6 months
Perspiration Tester Dead weight Initial
Dimension of plate Initial
Rain tester and
Spray tester
Dimensions of the tester
Number, size and position of nozzles
Initial
Initial
Random Tumbler Timer 3 months
Rotational speed and gas flow 1 year
Rotary Platform
Double Head
Abrader
Dimensions of abrasive wheels
Weight set
Initial
Initial
Platform speed 1 year
Tensile Tester Force accuracy 1 year
Crosshead speed 1 year
Zero check 6 months
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Type of equipment
Tumble Dryer
Calibration/verification parameter Recommended maximum
period between successive
calibrations/verification
Temperature of delicate and permanent
press cycle
1 year
Note:
1. If the standard specifies the cooling time,
this parameter should also be verified
regularly, say yearly.
2. Some test standards may specify certain
dimensions for the tumble dryer and that
the drum action should be reversible and
these should be checked initially.
Wascator Verification of all program cards Initial
Temperature, liquor level, time
washing, rinse and spin speed of selected
program
1 year
Washer Agitation and spinning speed 1 year
Washing time 1 year
Washing temperature 1 year
Liquor level 1 year
Wira Steam
Cylinder
Steam generation rate
Dimension of cylinder
1 year
Initial
Dimension of supporting frame 1 year or more frequently,
depending on usage
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Implementation Date: 1 September 2017
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Appendix B
(informative)
BIBLOGRAPHY
VIM, ‘International Vocabulary of Basic and General Terms in Metrology’
GUM, ISO/IEC Guide 98-3:2008 ‘Uncertainty of Measurement – Part 3: Guide to the
Expression of Uncertainty in Measurement’
EURACHEM/CITAC, ‘Quantifying Uncertainty in Analytical Measurement’
ILAC-G8:03, ‘Guidelines on the Reporting of Compliance with Specification’
APLAC TC 004, ‘Method of Stating Test and Calibration Results and Compliance with
Specification’
APLAC TC 005, ‘Interpretation and Guidance on the Estimation of Uncertainty of
Measurement in Testing’
ISO 11095: 1996, ‘Linear Calibration Using Reference Materials’
ISO 1130: 1975 Textile fibres, ‘Some Methods of Sampling for Testing’
ASTM D2258/D2258M – 16, ‘Standard Practice for Sampling Yarn for Testing’
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