CAN/ULC-S109: Technical Specifications for Flame-Resistant Fabrics in Canada

CAN/ULC-S109 is the mandatory flame test standard for fabrics and films used within buildings and specific outdoor structures in Canada. Developed by ULC Standards (Underwriters Laboratories of Canada) and directly referenced by the National Building Code of Canada, this standard assesses the flame propagation characteristics of materials when exposed to flame sources of varying intensities.

Background and Regulatory Status of the CAN/ULC-S109 Standard

The full title of CAN/ULC-S109 is the Standard Method for Flame Tests of Flame-Resistant Fabrics and Films. Within the Canadian regulatory framework, it stands as a standard with independent jurisdiction. Unlike American standards, CAN/ULC-S109 serves as the primary basis for textile compliance in public spaces under Federal and Provincial Fire Codes. Products that fail to meet this standard are typically legally prohibited from installation in Canadian hotels, schools, theaters, or places of public assembly.

Core Definitions and Interpretation of CAN/ULC-S109

CAN/ULC-S109 defines a dual-test procedure designed to measure the flame resistance of textiles and films in a vertical orientation. The standard does not evaluate toxicity or smoke generation; instead, it focuses on three core physical metrics: Afterflame (time the material continues to burn after the ignition source is removed), Damaged Length (length of char or destruction), and Flaming Drippings (whether molten residue ignites the floor). Its core logic involves evaluating fire safety through two simulated scenarios: a small ignition source (e.g., a match) and a large ignition source (e.g., a wastebasket fire).

CANULC-S109
CANULC-S109

Scope of Application: Materials Requiring CAN/ULC-S109 Certification

The standard explicitly applies to soft materials used in a vertical orientation or as coverings within places of Public Assembly. If a product falls into the following categories, compliance with CAN/ULC-S109 is generally mandatory:

  • Interior curtains and draperies
  • Theater stage curtains, backdrops, and soft scenery materials
  • Blackout shades and decorative hangings in public spaces
  • Tents, awnings, and related temporary fabric structures
  • Flexible films used in air-supported or tensioned membrane structures
  • Temporary partition fabrics for exhibition halls or event centers

Grading System: The Dual Small and Large Flame Architecture

CAN/ULC-S109 does not utilize an “A/B/C” classification system similar to ASTM E84; instead, it operates on a strict “Pass/Fail” model. The standard comprises two independent test procedures. Most curtains and decorative fabrics are required to pass both procedures to ensure safety across different fire scales:

  • Small-Flame Test: Designed to evaluate the ignitability and flame spread speed of the material when in contact with a minimal ignition source (e.g., a lighter or candle).
  • Large-Flame Test: Designed to evaluate the flame resistance of the material when exposed to a larger fire source, specifically assessing heat accumulation effects in multi-layer or folded configurations.

Specific Test Methods and Parameters for CAN/ULC-S109

Testing must be conducted in a controlled laboratory environment, covering samples in both the warp (machine) and weft (cross) directions. The specific test parameters are as follows:

  • Small-Flame Test Method: A butane flame with a height of 40mm is applied to the bottom edge of a vertically suspended 70mm x 250mm specimen for a duration of 12 seconds.
  • Large-Flame Test Method: A high-output burner with a flame height of 280mm is applied to vertically suspended large-format specimens for a duration of 120 seconds (2 minutes).
  • Large-Flame Configuration: In addition to flat specimens, the Large-Flame Test mandatorily requires testing of folded specimens. These consist of four layers of material overlapped to simulate the actual pleated state of drapery.

Pass/Fail Criteria: Quantitative Compliance Requirements

A product must simultaneously meet all the following quantitative metrics to be deemed compliant. Exceeding the limit value in any single category results in a failure.

Test TypeMetricMaximum Allowable Limit
Small-Flame TestAfterflame Time (Single Specimen)2.0 Seconds
Small-Flame TestFlaming DrippingsResidue shall not burn on the floor for more than 2.0 Seconds
Small-Flame TestAverage Damaged Length (10 Specimens)165 mm
Small-Flame TestMaximum Damaged Length (Single Specimen)190 mm
Large-Flame TestAfterflame Time (Single Specimen)2.0 Seconds
Large-Flame TestFlaming DrippingsResidue shall not burn on the floor for more than 2.0 Seconds
Large-Flame TestDamaged Length – Flat Specimen250 mm
Large-Flame TestDamaged Length – Folded Specimen635 mm

Technical Comparison with NFPA 701 (USA)

Although CAN/ULC-S109 and the US NFPA 701 standard share similar testing principles, significant differences in test configuration and strictness exist, meaning certificates are generally not interchangeable.

Comparison DimensionCAN/ULC-S109 (Canada)NFPA 701 (USA)
Test CombinationUsually mandates both Small-Flame and Large-Flame tests simultaneously.Selects either Method 1 or Method 2 based on fabric density/use; rarely requires both.
Folded TestingMandatory testing of folded specimens in the Large-Flame test; high difficulty.Method 1 excludes folded testing; only Method 2 involves a similar concept.
Damage CriteriaExtremely strict millimeter-level limits for the Small-Flame test.Method 1 relies on weight loss percentage; Method 2 relies on char length; relatively more lenient.
Territorial ValidityMandatory standard across Canada.US Standard; accepted in Canada only at the discretion of specific local authorities.

Usage Scenarios: Application Requirements in Canadian Public Spaces

According to Canadian provincial fire codes, fabrics within any facility classified as “Public Assembly” must hold a CAN/ULC-S109 certificate. Typical scenarios include:

  • Hospitality Industry: Guest room curtains, lobby draperies, banquet hall decorations.
  • Healthcare and Senior Living: Cubicle curtains, privacy screens, blackout shades.
  • Educational Institutions: School auditorium stage curtains, classroom window treatments, dormitory textiles.
  • Entertainment Facilities: Acoustic felts surrounding cinema screens, theater stage drapery.
  • Exhibitions and Events: Temporary construction materials in convention centers.

Specific Fabric Requirements and Pre-Treatment

Fabrics submitted for CAN/ULC-S109 testing must demonstrate flame resistance not only in their original state but also after cleaning or weathering. The standard prescribes specific sample preparation protocols:

  • Size Requirements: Given the need for warp/weft directions and flat/folded configurations, it is recommended to prepare at least 3-5 linear meters of full-width fabric.
  • Inherently Flame Retardant (IFR): If the fiber itself is flame-resistant, testing is typically conducted in the “as received” state.
  • FR Treated Materials: If the fabric achieves flame resistance through chemical immersion or coating, it must undergo accelerated aging. This typically involves standard washing or dry-cleaning cycles. Laboratories must test the fabric after these cleaning procedures to verify the durability of the treatment.
  • Outdoor Weathering: Fabrics intended for outdoor use may require pre-treatment involving UV exposure and water leaching.

Common Misconceptions and Compliance Cautions

When implementing the CAN/ULC-S109 standard, buyers and suppliers often confuse scope and certificate validity. The following technical misconceptions require correction:

  • Misconception 1: Confusing S109 with S102. Vertically hung fabrics (e.g., curtains) must undergo S109. Materials adhered to walls, such as wallpaper, hard acoustic panels, or carpeting, fall under CAN/ULC-S102 (Surface Burning Characteristics). These are not interchangeable.
  • Misconception 2: Assuming US reports act as a pass. While some remote Canadian fire marshals may accept NFPA 701, major urban centers like Toronto or Vancouver strictly require S109. Lack of an S109 report carries a high risk of inspection failure.
  • Misconception 3: Testing must be done by ULC laboratories. Compliance depends on “Laboratory Accreditation,” not the organization’s name. Reports issued by any third-party laboratory accredited to ISO 17025 with a scope including CAN/ULC-S109 are legally recognized.

Frequently Asked Questions (FAQ)

Q: Does a CAN/ULC-S109 test report have an expiration date?

A: The standard itself does not specify a hard expiration date. However, Authorities Having Jurisdiction (AHJ) typically require reports issued within the last 1 to 3 years to ensure the tested sample represents current production quality. If the manufacturing process or raw materials change, re-testing is mandatory immediately.

Q: Does digital printing or dyeing affect CAN/ULC-S109 compliance?

A: Yes. Inks, dyes, and transfer papers are often flammable chemicals. A base fabric that passed the test may fail after being printed. Therefore, the standard requires the final product (after printing or dyeing) to be tested to ensure the added chemicals have not compromised flame resistance.

Q: Can I submit a small sample (A4 size) for testing?

A: No. The Large-Flame test requires specimens that are 750mm long, and the folded test requires wide panels to form the necessary layers. An A4 sample is insufficient for the mandatory testing configuration. Full-width yardage is required.

Q: What happens if my fabric fails the test?

A: If the fabric is FR treated (chemically coated), it may be possible to re-treat the material with a higher concentration of flame retardant and re-test. However, if the fabric is an untreated natural fiber (like standard cotton or linen) without any chemical finish, it will almost certainly fail; it cannot pass without the application of an FR treatment.

Q: Is CAN/ULC-S109 required for residential homes?

A: Generally, the National Building Code does not mandate S109 for single-family private residences. However, it is mandatory for high-density residential buildings (such as condos or apartments) in common areas like lobbies and corridors, as well as for all commercial and public institutional buildings.