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CAN CGSB 4.2 No. 45-M88 (2013): Standard Test Method for Flame Resistance of Textiles – 45° Angle Test
A comprehensive guide to the Canadian standard for evaluating the flammability characteristics of textile materials using the 45-degree angle test
CAN CGSB 4.2 No. 45-M88 (2013) is a Canadian national standard developed by the Canadian General Standards Board (CGSB). Originally published in 1988 and reaffirmed in 2013, it specifies a small-scale laboratory test method for measuring the ignition resistance and flame spread of textile materials when exposed to a controlled small flame. This standard is widely referenced in Canadian regulations and industry specifications for apparel, curtains, draperies, upholstery, and other textile products where a certain level of flame resistance is required.
Scope and Application
The standard applies to woven, knitted, and nonwoven textile fabrics intended for use in clothing, household furnishing, and similar applications. It is specifically designed to evaluate the response of textiles to a small flame under controlled conditions and to classify their flammability behavior.
CAN CGSB 4.2 No. 45-M88 (2013) is not intended for use with pile fabrics or textile products that are inherently resistant to ignition, such as those made from glass or carbon fibers, nor is it applicable for assessing the flammability of floor coverings, which are governed by other standards. The test method is often used in conjunction with regulatory requirements under the Canada Consumer Product Safety Act (CCPSA) and referenced by manufacturers, testing laboratories, and certification bodies to help ensure consumer safety.
Tip: This standard is intended for small-flame ignition behavior. For larger ignition sources or different orientations, refer to other methods such as CAN/CGSB-4.2 No. 27.5 or NFPA 701.
Technical Requirements
Test Apparatus
The apparatus required by the standard includes a metal test chamber with a draft shield, a specimen holder that supports the fabric at a 45° angle, a Tirrill burner (or equivalent) with a precise flame-height control, and a timing device accurate to 0.1 seconds. The entire assembly must be located in a draft-free environment or within a fume hood with the sash partially closed to prevent air currents.
Specimen Preparation and Conditioning
Test specimens are cut to a standard size of 50 mm × 150 mm (2 in × 6 in). Five specimens are taken in the warp (lengthwise) direction and five in the weft (crosswise) direction. Prior to testing, specimens are conditioned for at least 24 hours at 21 ± 1°C and 65 ± 2% relative humidity. Conditioning ensures reproducible results by stabilizing moisture content in the fabric.
Test Procedure
The conditioned specimen is mounted in the holder at a 45° angle with its surface facing upward. A gas flame (approximately 38 mm high) is applied to the lower surface of the specimen for 1 second. After flame removal, the following observations are recorded for each specimen:
- Ignition (whether the fabric ignites during flame application)
- Afterflame time (seconds the flame continues after the burner is removed)
- Afterglow time (seconds the fabric continues to glow after flaming ceases)
- Nature of ignition (flaming, melting, or glowing)
- Whether the flame spreads to the top edge or beyond a specified char line
| Parameter | Requirement |
|---|---|
| Specimen size | 50 mm × 150 mm (2 in × 6 in) |
| Number of specimens | 5 warp + 5 weft (10 total) |
| Conditioning atmosphere | 21 ± 1°C, 65 ± 2% RH |
| Flame height | 38 mm (1.5 in) measured from burner tip |
| Flame application time | 1.0 ± 0.1 s |
| Burner type | Tirrill burner; fuel: commercial methane or propane |
| Evaluation criteria | Afterflame time, afterglow time, flaming to edge, char length |
Classification of Results
Based on the test results, textiles are typically classified into one of three categories similar to the U.S. Code of Federal Regulations (16 CFR Part 1610):
- Class 1 – Normal Flammability: Fabrics that have a low to moderate flame spread and do not ignite readily. These are considered acceptable for general use.
- Class 2 – Intermediate Flammability: Fabrics that exhibit more rapid ignition or flame spread. Some restrictions may apply depending on the end use.
- Class 3 – Rapid Flame Spread: Fabrics that ignite easily and flame spreads rapidly. Such fabrics are typically unsuitable for apparel and may be prohibited in certain applications.
WARNING: CAN CGSB 4.2 No. 45-M88 (2013) is a test method standard. It does not prescribe pass/fail criteria; those are defined by the invoking regulation or specification. Always verify the applicable requirements with the authority having jurisdiction.
Implementation Highlights
Successfully implementing CAN CGSB 4.2 No. 45-M88 (2013) requires attention to several critical details:
Apparatus Calibration
Regular verification of flame height, burner alignment, and timing device is essential. The standard recommends an initial set-up verification using a reference fabric (e.g., a Class 3 fabric). The gas flow rate must be adjusted to ensure a consistent flame that precisely contacts the specimen’s surface.
Specimen Integrity
Fabrics must be free from wrinkles, folds, or creases that could alter the orientation. When testing materials that melt, shrink, or drip (e.g., thermoplastics), the specimen holder should incorporate a backing paper or a catch tray to prevent dripping molten material from biasing results. The standard provides an annex for testing such fabrics.
Interpretation of Results
If any specimen ignites and the flame reaches the top or side edge of the specimen within a specified time, the fabric may be classified as having rapid flame spread. The afterflame time and afterglow are also recorded; a fabric that continues to flame for more than several seconds after the burner is removed may be considered to have significant flammability.
Best Practice: Always run a preliminary set of tests using a known standard fabric to confirm that your apparatus is operating within the required tolerances before testing unknown materials.
Compliance and Regulatory Notes
CAN CGSB 4.2 No. 45-M88 (2013) is often cited by national and provincial regulations in Canada. For example:
- Canada Consumer Product Safety Act (CCPSA) – for general apparel and children’s sleepwear flammability requirements.
- Hazardous Products Act – for textile products that present a fire hazard.
- Building codes – for curtain and drapery materials used in public buildings.
Since the standard was reaffirmed in 2013, it is considered current and remains in effect. Laboratories seeking accreditation for this test method must comply with ISO/IEC 17025 and participate in interlaboratory proficiency testing programs maintained by the Standards Council of Canada.
Important: Do not use the results from CAN CGSB 4.2 No. 45-M88 (2013) as a substitute for large-scale fire tests or for evaluating the performance of textiles under real fire conditions. This small-scale method is intended for quality control and classification purposes only.
Frequently Asked Questions
Q: Is CAN CGSB 4.2 No. 45-M88 (2013) equivalent to ASTM D1230-22?
A: The two standards share a similar 45° angle test principle and specimen size, but they differ in conditioning requirements, number of specimens, and classification criteria. CAN CGSB 4.2 No. 45-M88 (2013) is specifically adapted for Canadian regulatory contexts. Users must confirm which standard is required by their jurisdiction or specification.
A: The two standards share a similar 45° angle test principle and specimen size, but they differ in conditioning requirements, number of specimens, and classification criteria. CAN CGSB 4.2 No. 45-M88 (2013) is specifically adapted for Canadian regulatory contexts. Users must confirm which standard is required by their jurisdiction or specification.
Q: Can this test be used for all types of textile products?
A: No. The standard is suitable for most woven, knitted, and nonwoven fabrics, but it is not intended for pile or raised-fiber fabrics (e.g., fleece, terry cloth) unless specified otherwise. For such materials, alternative methods such as CAN/CGSB-4.2 No. 27.5 (for pile fabrics) may be more appropriate.
A: No. The standard is suitable for most woven, knitted, and nonwoven fabrics, but it is not intended for pile or raised-fiber fabrics (e.g., fleece, terry cloth) unless specified otherwise. For such materials, alternative methods such as CAN/CGSB-4.2 No. 27.5 (for pile fabrics) may be more appropriate.
Q: How often should the test apparatus be calibrated?
A: The standard does not specify a fixed calibration frequency, but best practice is to perform a daily check of flame height and gas flow before each test set, and to conduct a full calibration using a reference fabric every three months or after any relocation or repair of the equipment.
A: The standard does not specify a fixed calibration frequency, but best practice is to perform a daily check of flame height and gas flow before each test set, and to conduct a full calibration using a reference fabric every three months or after any relocation or repair of the equipment.
Q: Is the flammable classification defined in the standard or in the referencing regulation?
A: CAN CGSB 4.2 No. 45-M88 (2013) itself only describes the test method and reporting of results (e.g., afterflame time, char length). The classification (Class 1, 2, 3) and acceptance criteria are typically defined in the end-product regulation or specification that invokes this test method.
A: CAN CGSB 4.2 No. 45-M88 (2013) itself only describes the test method and reporting of results (e.g., afterflame time, char length). The classification (Class 1, 2, 3) and acceptance criteria are typically defined in the end-product regulation or specification that invokes this test method.
Note: All references to CAN CGSB 4.2 No. 45-M88 (2013) are based on the reaffirmed version available as of 2026. Readers should verify any amendments or updates with the Standards Council of Canada or the Canadian General Standards Board.