NDFR- Non Durably Flame Retardant
These fabrics are chemically treated with a water soluble solution and if wetted in any way it is essential to retreat the fabric to meet flammability requirements. This may also apply after cleaning or a long period of use in a high humidity atmosphere.
DFR- Durably Flame Retardant
These fabrics are chemically treated to withstand a number of cleanings.
IFR- Inherently Flame Retardant
These fabrics are woven from a high percentage of yarn fibres that are flame retardant. It is the chemical make up of the raw fibre and not an after treatment to the cloth that renders the finished material Flame Retardant.
Flame Retardant Standards
B1 = German DIN 4102 B1
M1 = French NFP92 503-505 M1
EN 13773 = Class 1,2 or 3 European Standard Textile burning behaviour for curtains and drapes.
BS 5867 = British Standards “Fabrics for curtains and drapes.”
BS 4790 = British Standards Hot metal nut test.