When it comes to flame retardancy, fabrics are classified into a few basic categories. Below we explain the difference between FR, IFR (PFR), DFR and NFR

Flame Retardant Certificates

S&K Theatrical Draperies, Inc. issues flame retardant certificates with all flame retardant fabric and custom curtain purchases.

These fabrics are commonly woven from natural and/or synthetic yarns and then topically treated with a flame retardant chemical so that the material meets fire safety codes. The flame retardant chemicals are dissolved in a water solution and then applied to the fabric by immersion process (dipping) or by spraying. After applying the FR chemicals the soft goods are allowed to dry so the chemicals cure and adhere to the fabric fibers. 

Prior to FR treating –by topical treatment or dipping process- the material is classified as non flame retardant or widely known as “NFR”. Once the fabric has gone through the FR process and appropriate testing has been done it can be classified as Flame Retardant or “FR” (also known as fire retardant).

All fabrics that undergo this process are considered an FR treated fabric or chemically made FR fabric. Since most FR chemicals are water soluble, the topical treatment will wear out in time and repeated dry cleanings will cause the FR treatment to dissipate sooner. The fabrics then will require periodical testing and re-treatment to meet fire safety codes. These chemicals are also removed by washing. Any accidental wetting of the fabric will dissolve and possibly remove the chemicals rendering the fabric Non Flame Retardant (NFR). 

If this happens the material should be thoroughly washed with water and then the FR chemicals should be re-applied to restore the flame resistance.

A fabric that is woven from innately noncombustible fibers and without the addition of chemicals is categorized as IFR (aka Inherently Fire Retardant). Since the FR properties are woven into the fabric fiber itself, these materials are expected to remain fire retardant throughout the product’s lifetime, even after repeated washings or dry cleanings.

These materials are also often referred to as PFR (Permanently Flame Retardant) and also known as Permanently Fire Retardant.

Some synthetic fabrics are considered Durably Flame Retardant (a.k.a. Durably Fire Retardant).

Manufacturers and chemist laboratories have developed textiles from polymer extruded filament fibers along with non-water soluble chemical compounds that bind into the fibers providing flame resistance. 

When laundered properly the flame retardancy typically withstands many washes, rendering these fabrics flame resistance for the life of the product, depending on the specific fabric application. While there are solvents and chemicals that can impact the flame retardant properties of these materials, such products are not usually present when fabrics are used for curtains or space decoration, thus these fabrics are categorized as “DFR”.



These fabrics can be woven from natural, synthetic and or recycled fibers and are flammable, thus not compliant to fire safety codes.

Some materials simply cannot be made fire retardant and should not be used on public spaces. This applies to certain metallic and synthetic fabrics.

Even though some fabrics are not specifically produced as flame retardant, they can be topically treated for fire retardancy, either by spraying a flame retardant chemical onto the fabric or by dipping the fabric into a flame retardant solution (natural fibers and some synthetic blends).