Help For Designers & Specifiers

Textile Fibres and Flammability Requirements

The following section contains information which may be of some help when specifying materials for a project. In particular, emphasis is given to the fibre types which textiles are made from and how they are considered by domestic legislation with regard to the levels of flammability testing required. Much of this information is contained within the table below.

A guide to fibre types, how they are considered by domestic fire safety legislation and their suitability for flame retardancy treatment.

Fibre Category
Composition
Fibre Name

Domestic
Legislation†

Possible to Flame Retard‡
Domestic Upholstery
Contract Upholstery
Contract
Curtains
Natural Fibres Cellulose Cotton
Exempt Fibre
Yes
Yes
Yes
Cellulose Flax
Exempt Fibre
Yes
Yes
Yes
Keratin (protein) Wool
Exempt Fibre
Yes
Yes
Yes
Fibroin (protein) Silk
Exempt Fibre
Yes
Yes
Yes
Keratin (protein) Mohair
Not exempt
Yes
Yes
Yes
Man-made (1) Regenerated cellulose Viscose
Exempt
Yes
Yes
Yes
Regenerated cellulose Polynosic (modal)
Exempt
Yes
Yes
Yes
Regenerated cellulose Cuprammonium (cupro)
Not exempt
Yes
Yes
Yes
Cellulose acetate Acetate or Triacetate
Not exempt
Yes if mixed with natural fibres
Yes if mixed with natural fibres
Yes if mixed with natural fibres
Man-made (2) At least 85% acrylonitrile Acrylic
Not exempt
Avoid
Avoid
Avoid
At least 35% acrylonitrile & other materials * Modacrylic
Not exempt
Yes
Yes
Yes
Polyethylene glycol terephthalate Polyester
Not exempt
Yes if mixed with natural fibres
Yes if mixed with natural fibres
Yes
Polyhexamethylene diaminoadipate Nylon (6,6)
Not exempt
Yes if mixed with natural fibres
Yes if mixed with natural fibres
Yes if mixed with natural fibres
polyethylene Polyethylene
Not exempt
Avoid
Avoid
Avoid
Polypropylene Polypropylene
Not exempt
Avoid
Avoid
Avoid
Man-made (1): Fibres derived from materials found in nature.
Man-made (2): Fibres made from materials not found in nature.
† If exempt, fabric composed of at least 75% by weight of this fibre alone or in combination with other exempt fibres, does not have to comply with the match test provided it is used with a flame retardant (schedule 3) interliner. It must pass the cigarette test. Exempt fibres can be treated to comply with the match test in the same way as non-exempt ones. See the sections on domestic legislation for more details.
‡ The suitability of a fabric for flame retardancy processing depends on many factors other than fibre type alone. Therefore, the comments regarding the suitability of processing specific fibre types is a general guide only.
* Other materials means not more than 65% of various types of chemical dependant on the fibre to be manufactured.

Things to Avoid

Fibres: Whilst in many instances the fibres listed below may be flame retarded, experience has shown that problems may be encountered either during the application of the flame retardant treatment or at some time following treatment. The causes of the problems are numerous. From a flame retardancy point of view, we would recommend that fabrics containing significant proportions of any of the fibres listed below be avoided when selecting materials for a project.

There seems to be an increasing number of man made fibres which we simply are unable to identify. These may be familiar fibres but finished in a way that imparts burning characteristics quite unlike those we have seen previously. This unfortunately makes them unsuitable for flame retardancy treatment.

Dye Types: Some dyes will have an adverse reaction to some flame retardants. One class of dye in particular seems sensitive to certain types of flame retardant. Fabrics which include reactive dyes in the composition have been shown to discolour following treatment. The discolouration may occur soon after treatment or may not manifest itself until some time (often many months) after treatment. From a flame retardancy point of view, avoiding the use of this class of dye may help eliminate possible long term problems. We have included more information on dyes and colour fastness which can be found here.