Workwear for Protection Against Hydrocarbon Flash Fire and Optionally Steam and Hot Fluids

CAN/CGSB 155.20 is a Canadian national standard developed by the Canadian General Standards Board (CGSB). This standard establishes specific criteria for testing garments for flash fire protection. It also includes variations for testing multilayer systems, single-use garments, and rainwear and additionally provides optional test criteria for garments that protect against steam and hot water. CAN/CGSB 155.20 applies to newly manufactured workwear worn to protect against unplanned hydrocarbon flash fire exposure. This standard defines flash fire as a “fire that spreads rapidly through a diffuse fuel-air mixture without the production of damaging pressure.” Since the standard does not apply to planned or long-term exposure to fire, it does not govern specialized protective clothing, such as turnout gear worn by firefighters.

This standard establishes specific criteria for testing garments using manikin tests (ASTM F1930), flammability (ASTM D6413), thermal protective performance (CAN/CGSB-4.2 No. 78.1), and heat resistance & thermal shrinkage (CAN/CGSB 155.20 par 7.4). There are also requirements for hardware, trim, and labels, as well as additional requirements for disposable garments, rainwear, and steam and hot water protective garments.

The main requirements of CAN/CGSB 155.20 for typical workwear fabrics are:

  1. Manikin Testing
    • Using the ASTM F1930 manikin test, garments are exposed to a three-second flash fire at 84 kW/m² and the total predicted body burn is measured. CGSB 155.20 sets a maximum of 40% total predicted body burn (combined 2nd and 3rd degree predicted burns, including the exposed head) to pass. The test is three seconds – for two reasons:
      1. In theory, that is the upper limit of flash fire duration, and
      2. It is the area of greatest variability in results, affording the most accurate differentiation of fabric performance.
    • Garments must be cut to a standard pattern, size 42-RG coverall, and tested over 100% cotton t-shirt and briefs.
  2. Flammability Testing
    • The fabric is tested for flammability using the ASTM D6413 test method. It must not melt and drip, or have more than two seconds afterflame or more than 100 mm char length when tested before and after at least 50 cycles of laundering.
  3. Thermal Protective Performance
    • The fabric is tested for thermal protective performance using the CAN/CGSB-4.2 No. 78.1 test method. The fabric is placed over a sensor and is exposed to 84 kW/m² flame. The time it takes for the sensor to reach 2nd-degree burn criteria (using the Stoll Curve) is measured.
    • Average TPP value must be 6 cal/cm² or greater, with no individual specimen value less than 5.5 cal/cm².
  4. Heat Resistance & Thermal Shrinkage
    • The fabric is tested for heat resistance and thermal shrinkage by placing specimens in a 260°C (500°F) oven for five minutes.
    • Fabrics are measured before and after heat exposure to determine thermal shrinkage. Fabrics cannot shrink more than 10% in any direction as a result of thermal exposure.
    • Fabrics cannot melt and drip, separate, or ignite during or after the thermal exposure.

CAN/CGSB-155.20 was most recently updated in 2017.
CAN/CGSB standards are available free of charge. Use the link below to access CAN/CGSB-155.20-2017: