The Difference Between CAL 117 and CAL 133 Fire Ratings

Understanding fire ratings for furniture when sourcing in China
October 12, 2023 by
The Difference Between CAL 117 and CAL 133 Fire Ratings
Clemens Rudolph


When embarking on the selection of materials and external finishes for your forthcoming commercial or industrial construction project, it becomes paramount to ensure compliance with the minimum fire rating standards. Doing so is instrumental in upholding the overarching safety of any building. This fundamental requirement underscores the significance of rigorous quality inspections, particularly when considering purchases from new manufacturers.

In the context of procuring furniture for your project, two critical factors warrant attention: the fire resistance of the materials and their fire containment capabilities. The interplay between these elements significantly impacts the safety of materials in the face of fire incidents and their ability to swiftly suppress fire outbreaks.

In the realm of fire safety, there exist various types of fire ratings that encompass standards for diverse elements like sprinkler systems, insulation, and construction materials. Essentially, any material with the potential to ignite comes affixed with an assigned rating, reflecting its capacity to either withstand or curtail a fire event.

Understanding these fire rating standards is pivotal in guiding your material choices for your upcoming construction projects. This understanding is especially valuable if you are working in areas subject to stringent fire safety codes. In this article, we will delve into the differences between CAL 117 and CAL 133 fire ratings.

CAL 117 Fire Ratings

CAL 117, which stands for California Technical Bulletin 117, represents an industry-wide standard predominantly applicable to upholstered furniture items in the United States and Canada. Given the prevalence of flammable materials like wood in various settings, fire protection for furniture is of paramount importance. CAL 117's role is to evaluate the performance of fire-retardant paints and other fire-suppressing materials applied to furniture, particularly during fire incidents.

CAL 117 ratings involve a dual-stage evaluation. The first stage focuses on the material's ability to resist fire, labeled as the Fire Resistance Rating (FR). The FR ratings are as follows:

  • FR-0: The material offers no protection against fire.
  • FR-1: The material may extinguish a small fire and protect furniture from moderate heat.
  • FR-2: The material can resist moderate heat for a brief duration.
  • FR-3: The material can withstand extreme heat for a short period.
  • Products rated FR-4 or higher are deemed capable of enduring fire for an extended period.

The second stage, known as the Fire Containment Rating (CR), assesses how quickly the material can halt a fire's progress. CR ratings are as follows:

  • CR-0: The material lacks the capacity to contain a fire.
  • CR-1: It takes 30 minutes or more to suppress a fire.
  • CR-2: It takes 15 minutes or more to suppress a fire.
  • CR-3: The product can extinguish a fire within 10 minutes.

CAL 133 Fire Ratings

In comparison, CAL 133 is a fire rating standard stipulated by Underwriters Laboratories (UL) and is primarily directed at upholstered furniture intended for use in commercial settings. Although CAL 133 may share similarities with CAL 117 in the context of fire safety, it takes a more stringent approach, specifically regulating furniture materials employed in public spaces. These spaces encompass government buildings and private company offices housing at least ten employees. Consequently, CAL 133 stands out as one of the most rigorous fire rating standards for furniture.

The CAL 133 rating also consists of two stages that evaluate the material's ability to resist and contain fire. The Fire Resistance Rating (FR) categories are akin to those of CAL 117:

  • FR-0: The material does not offer protection from fire.
  • FR-1: The furniture material can extinguish a small fire.
  • FR-2: The material can resist moderate heat and protect itself from such heat.
  • FR-3: The material can endure extreme heat for a limited period.

Distinguishing CAL 117 from CAL 133

In essence, CAL 117 serves as the foundational standard for assessing the flammability of upholstered furniture in the United States and Canada. On the contrary, CAL 133 serves as a comprehensive rating system tailored for upholstered furniture intended for use in commercial settings.

Moreover, CAL 133 extends its scope to address upholstered furniture in high-risk public occupancies, which includes settings like hospitals, children's daycare centers, nursing homes, correctional facilities, public stadiums, auditoriums, and assembly areas. This wide-reaching application makes CAL 133 one of the most stringent fire rating standards in the furniture industry.

While CAL 117 primarily focuses on the filling materials and fabrics used in furniture, CAL 133 conducts a full-scale item test, assessing the fire resistance of the entire furniture structure. This more comprehensive testing method is one of the reasons CAL 133 is considered a more severe fire rating than CAL 117.

It is essential to recognize that CAL 133 poses a considerable challenge for furniture manufacturers. During testing, a piece of furniture, such as a chair, sofa, stool, ottoman, or bench, is subjected to ignition for 80 seconds using a gas burner. This rigorous testing process considers various factors, including temperature, carbon monoxide emissions, heat generation, smoke production, and weight loss. The measurements of these factors are meticulously compared to test criteria established by the regulating body to determine the compliance or non-compliance rating for the furniture item.

The demanding nature of this test, coupled with the associated costs, makes it a substantial financial burden for furniture manufacturers. Preparing the test item, shipping it to the testing laboratory, and covering testing fees that can amount to $500 to $600 contribute to the challenges and expenses manufacturers face in meeting CAL 133 standards.

Key Takeaway

While you might not be familiar with the intricacies of CAL 117 and CAL 133 fire ratings, it is crucial to recognize their pivotal roles as regulation protocols for furniture. These standards play a crucial part in safeguarding consumers by ensuring that furniture items meet stringent fire safety requirements.

Despite the financial challenges faced by manufacturers and project managers in meeting these standards, it is essential to acknowledge that these efforts substantially reduce the risk of fire spreading within commercial and industrial buildings. The fire resistance of furniture, as assessed by these standards, is instrumental in containing fires and, most importantly, saving lives during fire emergencies. Thus, it is incumbent upon individuals seeking commercial or residential furniture items to be vigilant and prioritize checking the fire ratings of materials before making their purchase decisions.


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