The Difference Between CAL 117 and CAL 133 Fire Ratings

When you are choosing materials and external finishes for your commercial or industrial construction project, it is essential that you meet the minimum fire rating standards to maintain the overall safety of a building. This is one of the reasons why quality inspections are important when buying from a new manufacturer.

While purchasing furniture for the project, you need to consider two major factors: the fire resistance of the materials and the fire containment capacity of the materials used. Both of these factors will impact how safe the material is from fire and how quickly it can contain the fire if one does start.

There are several different types of fire ratings, including standards for sprinkler systems, insulation, and construction materials. In general, any material that may catch fire has an assigned rating based on its ability to resist or contain a fire.

Understanding these standards can help you choose safer materials for your next construction project — especially if you work in an area that requires such codes. Here’s what you need to know about the differences between CAL 117 and CAL 133 fire ratings.

CAL 117 Fire Ratings

CAL 117 (California Technical Bulletin 117) is an industry-wide standard for upholstered furniture items in the United States and Canada. All furniture items need to be protected from fire, as it is a major hazard in any setting where flammable materials like wood are present. The CAL 117 rating is used to evaluate the performance of fire-retardant paints and other materials applied to furniture material, especially during a fire.

The materials are rated in two stages: the first is based on their ability to resist fire, and the second takes into account their ability to contain the fire once it starts. The first stage is referred to as the Fire Resistance Rating or FR. The rating system for this is as follows:

If a product is rated FR-4 or above, then it is considered to be able to resist fire for an extended period of time.

The second stage is referred to as the Fire Containment Rating, or CR. These ratings are based on how quickly the material can stop a fire once it starts.

CAL 133 Fire Ratings

The CAL 133 rating is a UL standard for upholstered furniture in commercial settings. In many cases, the fire rating is similar to CAL 117. The only difference is that CAL 133 specifically regulates furniture materials used in public spaces, such as government buildings and private company offices with at least ten employees. CAL 133 is a more rigorous fire rating standard than any other rating standard for furniture.

The CAL 133 rating is broken down into stages as well. Like the CAL 117 rating, it determines how well the materials resist fire and how well they can contain it after it starts.

The FR rating system for CAL 133 is as follows:

·       FR-0: The material does not protect from fire

·       FR-1: The furniture material can extinguish a small fire

·       FR-2: The material can resist moderate heat and can protect itself from moderate heat

·       FR-3: The material can resist extreme heat for a short period of time

What is the Difference?

CAL 117 is the basic standard to rate the flammability of upholstered furniture in the United States and Canada. On the contrary, the CAL 133 is a standard rating system for upholstered furniture in commercial settings.

The CAL 133 is a fire regulation that rates upholstered furniture in high-risk public occupancies such as hospitals, children’s daycare centers, nursing home jails, public stadiums and auditoriums, and assembly areas.

While CAL 117 is a fire rating system for filling materials and fabrics used in furniture, CAL 133 is a full-scale item test of the whole furniture structure.

CAL 133 is considered a more severe fire rating than CAL 117 fire rating and is highly criticized by the furniture manufacturing industry. In CAL 133, a furniture item is placed in the test room and is ignited for 80 seconds using a gas burner.

Various factors, such as temperature, carbon monoxide emission, heat generation, smoke, and weight loss, are taken into account during the testing. The measurements of these factors are compared with the test criteria established by the bureau to provide the compliance or non-compliance rating for the item.

The test poses a real challenge for furniture manufacturers because a furniture item such as a chair, sofa, stool, ottoman, or bench is made from a combination of different fabrics, frames, and foams. When these materials are ignited, they produce different results.

In addition, the cost of preparing the test item and shipping it to the testing lab for the test, along with the testing fee of $500-$600, is very expensive.

Burning test with and without flame retardant.
Image by: NIST

Key Takeaway

You may not be familiar with the CAL 117 and CAL 133 fire ratings, but these are important regulation protocols for furniture that aim to protect consumers. While the cost of testing the furniture item places an extra burden on manufacturers and project managers, it reduces the risk of fire spreading in commercial and industrial buildings.

The fire resistance of furniture is important for containing the fire and saving lives during a fire breakout. A furniture item with a high level of fire resistance will be able to prevent spreading the fire for longer and protect other structures in the building from damage.

So, next time when you shop for a commercial or residential furniture item, make sure to look out for the fire ratings on the material before buying.

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