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CAN CGSB 4.2 No. 12.3-2005 (2013): Accelerated Laundering Test for Dimensional Change of Textiles
A detailed reference on the Canadian standard method for evaluating fabric shrinkage after accelerated laundering procedures
Scope and Purpose
CAN CGSB 4.2 No. 12.3-2005 (R2013) is a Canadian national standard developed by the Canadian General Standards Board (CGSB) that specifies a test method for determining the dimensional change of textile fabrics when subjected to accelerated laundering. This standard is part of the CGSB 4.2 series of textile test methods and was reaffirmed in 2013, confirming its continued technical validity. The method is designed to simulate the effects of repeated household or commercial laundering in a shortened time frame, allowing manufacturers, testing laboratories, and quality assurance personnel to predict how a fabric will behave after multiple wash and dry cycles. The test provides a controlled, reproducible procedure that is widely referenced in Canadian textile procurement specifications and product quality programs. It is closely aligned with international practices such as AATCC 135 and ISO 6330, though it retains specific provisions tailored to Canadian regulatory and industrial requirements.
Tip: Manufacturers exporting textiles to Canada should ensure that dimensional change testing follows CAN CGSB 4.2 No. 12.3, as many Canadian retailers and public sector contracts require conformity to this specific standard rather than a generic international method.
Technical Requirements and Test Procedure
Apparatus and Materials
The standard specifies the use of a front-loading washing machine (Type A as defined in the standard) with a net drum capacity of 18–22 L, a programmable dryer, and a conditioned laboratory environment (20 ± 2 °C, 65 ± 5 % RH). The washing machine must be capable of delivering the specified temperature profiles (−5 °C to +10 °C tolerance) and agitating at 40 ± 2 strokes per minute with a load volume of 0.30–0.35 m³. A calibration reference fabric and AATCC standard reference detergent (or equivalent as described in the standard) are mandatory. The following table summarizes the key laundering conditions:
| Parameter | Specification |
|---|---|
| Washing machine type | Front-loading, Type A per CGSB 4.2 No. 12.3 |
| Water temperature | 25 ± 2 °C for warm cycle; 40 ± 2 °C for hot cycle |
| Total water volume | 15 ± 1 L |
| Detergent dosage | 90 ± 1 g of AATCC reference detergent 1993 |
| Agitation speed | 40 ± 2 cpm |
| Load size (total fabric mass) | 1.8 ± 0.05 kg (including test specimens and ballast) |
| Drying method | Tumble dry at 60 ± 3 °C until dry, or line dry per standard options |
Specimen Preparation and Marking
Three test specimens of 380 × 380 mm are cut from a fabric sample, ensuring edges are parallel to warp and weft directions. Each specimen is conditioned in the standard atmosphere for at least 4 hours before initial measurements. Three pairs of reference marks are placed in both the lengthwise (warp) and widthwise (weft) directions, each pair spaced 250 mm apart. The marks must be permanent and non-toric, typically using indelible ink or stitched threads. The distance between marks is measured to the nearest 1 mm under standard conditioning before laundering.
Warning: Inaccurate marking or improper conditioning can lead to measurement errors exceeding 1 %. Ensure that marking tools do not distort the fabric structure and that all pre‑laundering measurements are completed within 5 minutes of removal from the conditioning environment.
Laundering and Drying
The three specimens are placed in the washing machine along with enough ballast fabric (same material or polyester/cotton sheeting) to achieve a total load mass of 1.8 ± 0.05 kg. The selected wash cycle— typically the “accelerated” cycle defined in the standard— is run for a specified duration. After washing, the load is transferred to the dryer. The standard offers two drying options: tumble dry at 60 °C until all moisture is removed, or line dry for 24 hours. Tumble drying is preferred for most textile types. The exact cycle parameters are detailed in Annex A of the standard and vary depending on fabric category (e.g., cotton, cotton/polyester blends, woven vs. knitted) and final product use.
Measurement and Calculation
After drying, specimens are conditioned again in the standard atmosphere for at least 4 hours (or for 24 hours if line dried) before re-measurement. The distance between each pair of reference marks is measured again to the nearest 1 mm. Dimensional change (D) for each direction is calculated using the formula:
D (%) = [(L₁ − L₀) / L₀] × 100
where L₀ is the original distance and L₁ is the distance after laundering. A negative value indicates shrinkage; a positive value indicates elongation. The % change for the fabric is reported as the average of the three specimens for both warp and weft directions. Results are rounded to the nearest 0.1%.
Success: Many quality programs accept dimensional change results within ± 2.0 % for woven fabrics and ± 3.0 % for knits as passing. Always confirm the requirement with your client or regulatory body.
Implementation and Key Considerations
Implementing CAN CGSB 4.2 No. 12.3 requires careful attention to laboratory infrastructure: the specified washing machine must be calibrated, water supplies must meet hardness < 50 mg/L CaCO₃, and temperature profiling must be validated. The standard includes detailed pass/fail criteria for machine calibration using the calibration reference fabric. Laboratory personnel should be trained to recognize fabric distortions— bowing, skewing, and curling— which may require separate reporting. The standard also offers alternative drying procedures (line dry or flat dry) for fabrics that are sensitive to tumbling. It is essential to select the appropriate drying option based on the intended end‑use care label of the product. Interlaboratory reproducibility is quoted as ± 0.5 % (95 % confidence) for most woven fabrics when the same machine type is used.
Compliance and Regulatory Notes
CAN CGSB 4.2 No. 12.3-2005 is a voluntary national standard unless referenced in procurement contracts or regulations. However, many Canadian federal and provincial contracts for textiles, including uniforms, linens, and protective clothing, require compliance with this method. Laboratories accredited under ISO/IEC 17025 by the Standards Council of Canada (SCC) often include CAN CGSB 4.2 No. 12.3 in their scope. The standard is reviewed periodically; a new edition may supersede the 2005 version. Users should verify the current version with CGSB. When reporting results, it is essential to include the exact laundering and drying conditions used, as small variations can affect comparability.
Important: The 2013 reaffirmation does not introduce technical changes; the original 2005 method remains in effect. However, always check with the issuing body for any amendments or corrigenda that may apply to your testing program.
Q: How does CAN CGSB 4.2 No. 12.3 differ from AATCC 135?
A: While both methods assess dimensional change through accelerated laundering, CAN CGSB 4.2 No. 12.3 specifies a different dynamic load (1.8 kg) and a unique cycle profile for the Type A washing machine. It also mandates the use of AATCC reference detergent but includes optional drying methods that are more explicitly defined than in AATCC 135. Canadian procurement often requires direct compliance with the CGSB standard rather than AATCC.
A: While both methods assess dimensional change through accelerated laundering, CAN CGSB 4.2 No. 12.3 specifies a different dynamic load (1.8 kg) and a unique cycle profile for the Type A washing machine. It also mandates the use of AATCC reference detergent but includes optional drying methods that are more explicitly defined than in AATCC 135. Canadian procurement often requires direct compliance with the CGSB standard rather than AATCC.
Q: Can I use a front-loading residential washing machine?
A: The standard explicitly requires a Type A front-loading machine that meets the capacity and agitation specifications listed. Many common residential machines do not meet the calibration tolerance or drum volume requirements. Only machines specifically approved by CGSB and calibrated per the method are acceptable for producing compliant results.
A: The standard explicitly requires a Type A front-loading machine that meets the capacity and agitation specifications listed. Many common residential machines do not meet the calibration tolerance or drum volume requirements. Only machines specifically approved by CGSB and calibrated per the method are acceptable for producing compliant results.
Q: What should I do if my fabric shows skew or bow?
A: CAN CGSB 4.2 No. 12.3 does not directly measure fabric skew, but it notes that if distortion occurs, the dimensional change measurements should be taken as the straight-line distance between marks along the direction of the fabric. For proper evaluation of skew, a separate method such as CGSB 4.2 No. 12.4 or an equivalent standard should be used. Always report any visible distortion alongside the dimensional change results.
A: CAN CGSB 4.2 No. 12.3 does not directly measure fabric skew, but it notes that if distortion occurs, the dimensional change measurements should be taken as the straight-line distance between marks along the direction of the fabric. For proper evaluation of skew, a separate method such as CGSB 4.2 No. 12.4 or an equivalent standard should be used. Always report any visible distortion alongside the dimensional change results.
© 2026 – Technical reference document for informational purposes. Always refer to the official standard published by the Canadian General Standards Board for complete requirements.