ISO stands for the International Organization for Standardization. It is an international organization that sets forth a formula or best practice for a process or a product. For carpeting and floor textiles, the most common standard test is ISO 10361. The ISO 10361 is a simulation test that determines what level of foot traffic the carpet can withstand before it’s appearance deteriorates. There are many other ISO tests that rate a carpet’s performance based on castor chair use, slip resistance, or colorfastness, to name a few examples.

EN, from the German name Europäische Norm or “European Norm,” is the European Standard of requirements for products, processes, or services. An EN 1307 classification means that a carpet has been tested and meets EN’s standard for long term appearance retention. Based on the results, a carpet is then classified as suitable for domestic or commercial use. See Durability and Usage below. Another common EN test is EN 13501-1—this test establishes a carpet’s reaction to fire. See Fire Ratings below.

Formerly known as the American Society for Testing and Materials, ASTM International is a leader in establishing technical international standards for materials, products, systems, and services. For carpet, the most common ASTM tests determine a carpet’s reaction to fire. Test examples include the ASTM D-2859 (Flammability), ASTM E-648 (Radiant Panel), and the ASTM E-662 (Smoke Density). ASTM administers other tests as well that rate carpet delamination resistance or average pile weight, for example. Results from the Radiant Panel test classify a carpet as Class 1 (I) or Class 2 (II). See Fire Ratings below.

FCSS stands for Floor Covering Standard Symbols. This organization created standard pictograms or graphics that represent European Standards (EN), making floor classifications and ratings easy to understand. These pictograms are becoming more widely used among European and luxury carpet companies to represent a carpet’s technical specifications. The image at the top of this page shows a few of these pictograms.

Residential or Domestic Durability Ratings

“Residential” or “Domestic” is a general label that means the carpet is appropriate for residential settings. It may have further EN classifications like:

• Class 21: for residential areas with light to moderate use

  • Bedrooms, offices, and other rooms not frequented

• Class 22: for residential areas with medium, normal use

  • Living rooms, family rooms, hallways, dining areas

• Class 23: for residential areas with intensive, heavy use; also called Heavy Residential

  • Any of the rooms or areas listed above that experience intense, heavy foot traffic

Contract Grade Durability Ratings

“Contract Grade” is a general label that means the carpet is appropriate for commercial, public, or hospitality settings. It may have further EN classifications like:

• Class 31: for commercial areas with normal use, also called Light Contract or Light Commercial

  • Retail stores, hotel rooms, churches, meeting or conference rooms, restaurants

• Class 32: for commercial areas with medium public traffic, also called Medium Contract or Medium Commercial

  • Theaters, libraries, institutions, offices, restaurants, nursing or residential facilities, 

• Class 33: for commercial areas with intensive public traffic, also called Heavy Contract or Heavy Commercial

  • Lobbies, hotel or office building entrances, department stores, airport or other transportation terminals, service areas, elevators

Reaction to fire test methods from either EN or ASTM can be applied to floor coverings for classification purposes. The ASTM system classifies a carpet as Class 1 or Class 2, while the EN system is more stringent and detailed. 

With the EN system, letters A through F indicate how combustible the material is, with A being non-combustible to F being easily flammable. A “fl” abbreviation denotes flooring and the “s” is the level of smoke generation and speed, with s1 being low smoke quantity and speed and s3 being high smoke quantity and speed. Here is an example for a carpet that has earned an EN classification:

Cfl-s1 (EN 13501-1:2018): Cfl refers to a moderately flammable flooring material and the s1 means a low quantity and speed of smoke propagation. The “2018” refers to the test version used to establish the rating.

Fire rating requirements vary by region (please check your local building codes) and are more commonly required in commercial settings where carpet is installed wall-to-wall (fixture). Area rugs, which are an accessory, are generally not required to have stringent fire ratings.

Here are common fire ratings based on location and/or end use:

Fire Ratings for Residential or Domestic Settings

• Efl (EN): a normally flammable flooring material but suitable for residential use

• Class II fire rating applies to residential wool carpet and rugs since wool is naturally flame retardant

• If no rating is listed, the carpet has meet the standard for residential use but not commercial or public applications

• Any carpet fire rated for contract settings can be used in a residential setting if desired

Fire Ratings for Contract Grade Settings

• Class I (ASTM): the best fire rating that a carpet can achieve; indicates that if the carpet is exposed to fire, the flame spread rate is slow 

  • Required in commercial or hospitality corridors, entrances and exits

• Class II (ASTM): the second best fire rating that a carpet can achieve; indicates that if the carpet is exposed to fire, the flame spread rate is still slow, but not as slow as Class I 

  • A class 2 fire rated carpet is still considered appropriate for many contract grade settings

• Cfl (EN): a flame retardant flooring material that meets requirements for most commercial or hospitality settings

  • Cfl-s1 is a commercial standard; it is flame retardant with low smoke production

Castor Chair Suitability

Carpets without a favorable rating for use under castors will become damaged over time. There are different agencies that classify carpets are suitable for use under castors. For example, carpets that have passed the EN 985 test are rated either as suitable for occasional castor chair use or for intensive castor chair use (for a busy office or other business setting).

Stair Suitability

The quality and thickness of the carpet pile and face yarns impact stair safety and durability. Some fibers create a slippery surface on stairs and others deteriorate around the edges of the stairs with heavy traffic. The tests EN 1963 or ISO 12951 establish whether or not a carpet is suitable or not for stairs.

Luxury Class

Sometimes abbreviated “LC,” Luxury Class refers to the carpet’s comfort level and has a range from one to five. The more comfortable, soft, or plush a carpet is, the higher the LC number. On a pictogram, more crowns indicate more luxuriousness. This is part of the EN 1307 classification.