CAN CGSB 4.175-2004 Part 8 (2013): Colourfastness of Textiles to Light – Xenon Arc Lamp Method

Scope and Field of Application

CAN CGSB 4.175-2004 Part 8 (2013) is a component of the multi-part Canadian General Standards Board (CGSB) standard covering textile test methods. This part specifically addresses the determination of colourfastness of textiles to light using a xenon arc lamp apparatus. It is intended to simulate the damaging effects of natural sunlight (including ultraviolet, visible, and infrared radiation) on coloured textile materials, under controlled laboratory conditions.

The standard applies to all textile products—natural, synthetic, and blended fibres—as well as to dyes, pigments, and finishes applied to textiles. It is widely referenced by manufacturers, testing laboratories, and regulatory bodies in Canada for verifying that textile goods meet minimum lightfastness performance criteria for domestic and commercial use.

Part 8 aligns with international methods such as ISO 105-B02 and AATCC TM 16, but includes specific conditioning and apparatus requirements tailored to the Canadian climate and regulatory landscape. The method is suitable for both initial type testing and routine quality control.

Technical Requirements

Test Apparatus and Calibration

The test requires a xenon arc lamp system capable of producing a spectral power distribution (SPD) that closely matches natural daylight. The apparatus must include:

• An air-cooled or water-cooled xenon arc lamp with appropriate filters (e.g., borosilicate glass or quartz) to simulate the solar spectrum.
• A specimen holder that ensures uniform exposure and allows periodic repositioning.
• A black standard thermometer (BST) to monitor black standard temperature, maintained at 65 °C ± 3 °C.
• Relative humidity control within the test chamber, typically 40 % ± 5 % for moderate conditions or 65 % ± 5 % for tropical simulations.
• An irradiance control system calibrated to maintain 1.10 W/(m²·nm) at 420 nm (or equivalent spectral region).

Test Specimen Preparation

At least three specimens per sample (50 mm × 100 mm) are cut and mounted on an inert backing card along with blue wool reference standards. Specimens are conditioned at 21 °C ± 1 °C and 65 % ± 2 % relative humidity for at least 4 hours prior to exposure. The standard defines seven blue wool references (grades 1 to 7) for visual grading.

Exposure and Rating Procedure

Exposure continues until the blue wool reference of grade 4 shows a visual change equal to contrast grade 4 on the grey scale (a change rating of 3.0–3.5). At this point, the test is terminated, and specimens are evaluated within 30 minutes under standard lighting (D65 illuminant, 1000–1200 lux). Colour change is rated using the grey scale for colour change (1–5).

Implementation Highlights

Implementing CAN CGSB 4.175-2004 Part 8 (2013) in a textile laboratory requires careful attention to the following aspects:

• Apparatus qualification: The xenon arc system must pass a spectral distribution test (e.g., using a spectroradiometer) to confirm it meets CGSB requirements. Instruments originally designed for ASTM G155 or ISO 105-B02 can usually be adapted, but filter combinations and temperature settings must be verified.
• Blue wool standard management: Calibrated blue wool references must be purchased from an approved supplier and stored in a light-tight, cool, dry environment. Their shelf life is typically two years from the date of manufacture.
• Sample mounting: All specimens must be mounted with the face side towards the light source, and no two specimens should shade each other. Repositioning of specimens (top to bottom, left to right) is recommended every 100 hours to compensate for any non-uniformity in the exposure area.
• Operator training: Visual grading requires trained operators who are free from colour vision deficiency. Regular inter-laboratory comparisons and proficiency testing are encouraged to maintain rating consistency.

Compliance Notes

Compliance with CAN CGSB 4.175-2004 Part 8 (2013) is typically required for textile products sold on the Canadian market that claim a specific lightfastness rating. The standard is referenced by other CGSB product standards (e.g., CAN/CGSB-4.2 for general test methods) and by procurement specifications from government agencies, such as Public Services and Procurement Canada (PSPC).

Conformity Assessment

Testing must be performed in a laboratory accredited by the Standards Council of Canada (SCC) or an equivalent body using ISO/IEC 17025. The test report must include:

• The standard designation (CAN CGSB 4.175-2004 Part 8 (2013)).
• Description of the sample, including fibre composition, colour, and finishing.
• Test conditions (temperature, humidity, irradiance).
• Grey scale rating for each specimen and the final reported rating (median of three specimens).
• Identification of the blue wool reference used and its result.

Periodic review of the standard is performed by the CGSB Committee on Textile Test Methods. Stakeholders may submit revision proposals through the CGSB public review process. The 2013 reaffirmation confirms that no technical changes were deemed necessary at that time, but future updates may incorporate LED-based light sources or revised spectral distribution requirements as lighting technology evolves.

Record Retention

Test reports and raw data (including irradiance logs, temperature records, and specimen photos) should be retained for a minimum of five years after the product discontinuation date, or as required by contract.

Published in 2004. Reaffirmed in 2013. All rights reserved by the Canadian General Standards Board. This article is for informational purposes and does not replace the official standard text.

Document year: 2026