Cost may seem the first difference when choosing between Treated and Inherent fabrics for your FR Workwear, but in this post we explain the difference.

Inherent or Treated Flame Resistant Fabrics?

HAZCHEM FR inherent vs treated infographic NOV 2021 01 scaled e1639693764855

Inherent or Treated – the meanings

What does Inherent mean?

In connection with Flame Resistant (FR) fabrics, the term ‘Inherent’ is used to describe a fabric whose FR properties are permanent and cannot be removed.

The structure of the fibres used to create the yarns and in turn fabrics are non-flammable and the resulting Inherent Fabric will not burn or melt when exposed to a heat source such as a fire or flame for it’s entire lifetime.

When used in Flame Resistant protective clothing, the FR properties can never be washed out or worn away resulting in a garment that guarantees your ongoing protection and long life spans for reduced cost-in-use.

Inherent fabrics are often either Modacrylic or Aramid and two well know brand names are Protal® (a Modacrylic) and Nomex® (an Aramid).

HAZTEC® Flame Resistant Workwear is produced using Protal® Modacrylic fibres in conjunction with other yarns including Cotton, Polyester and Elastane. The way these yarns are blended affects the resulting fabric’s technical and protective properties in addition to it’s comfort and washing performance.

What does Treated mean?

A Flame Resistant (FR) fabric that we refer to as being ‘Treated’ is a fabric that has been chemically treated to give it its flame resistant properties.

Unlike ‘Inherent’ fabrics, the properties of these fabrics can be washed out during the garment’s lifetime and can therefore be considered a risk to some organizations where safety is paramount.

The EN certification of Treated fabrics can be just the same as Inherent fabrics and can include IEC 61482 Protective Clothing against the Thermal Hazards of an Electric Arc or EN ISO 11612 Heat & Flame Protective Clothing.

A common and well know brand name for a chemical treatment is Proban®

The number of washes that Treated fabrics are generally tested to a point where they maintain their FR properties is typically 50 washes.

The important of flame resistant protective workwear

In high-risk work environments, the use of the correct protective workwear can be the difference between life and death.

Risks can include Radiant Heat (e.g. Welding), Flash Fires (e.g. Gas contractors), Arc Flash hazards (e.g. Electrical contractors) and general Heat or Flame hazards (e.g. Petrochemical or Utility contractors). In many of these situations, if an incident occurs, workers can have little or no time to escape or protect themselves further. The use of the correct flame resistant garments gives workers the extra protection they need to reduce potential injuries and the wearing of such clothing is regarded as a ‘last line of defence’.

Modern flame resistant fabrics as used in the HAZTEC® range of Technical Workwear can be demonstrated to provide exceptionally fast extinguishing properties after exposure to a Heat or Flame hazard.

The impact of washing on inherent or treated fabrics

Inherent Fabrics

Because the flame resistant properties in these fabrics are permanent, they cannot be washed out or removed from the garment, damaged under exposure to chemicals in your workplace, or by the laundering process. This results in a garment that as an employer, you can rely on knowing will always protect your member of staff.

Treated Fabrics

These fabrics may be damaged by the exposure to hazardous chemicals, some chemicals used in the laundering process, or the general washing process itself. As a result, the older the garment becomes, the less protection it potentially provides which cannot always be established from the garments visual appearance. Although some premium brands do offer certification test data for 50 or even 100 Industrial wash cycles, research has shown that after just 10 washes the Flame Resistant properties can be reduced to zero. Considering that some of these fabrics are 99% Cotton/1% Antistatic blends, the result could be that a worker requiring heat and flame protection is wearing an unprotected garment…

Note: You should also remember that a build up of dirt and grease on any FR garment, Inherent or Treated, should be avoided and garments should be washed on a regular basis.


Developed in conjunction with our wearers, the HAZTEC® Workwear range includes our renowned HAZTEC® Flame Retardant & Antistatic Workwear range, specifically designed for the Petrochemical industry

Summary – Inherent or Treated fabrics in FR workwear

Benefits of Inherent Fabrics:

  • The garments retain their flame resistant properties for life – they are unable to be washed out or removed.
  • They are often lighter than treated garments when comparing like for like protective data.
  • The cost-in-use is usually significantly lower as garments can be worn for a longer period of time.
  • Fabrics are often softer in comparison to Treated fabrics.

Benefits of Treated Fabrics:

  • Ideal for temporary workers requiring Flame Resistant Workwear.
  • Lower fabric cost resulting in a less expensive finished garment.

What fabric are HAZTEC® FR Garments made of?

We use a blend of yarns that result in a range of fabric blends we refer to as Modacrylic Plus+. The fibres are synthetic copolymers and are very strong, resilient, soft, and dimensionally stable. They share similar properties to acrylic, however, they do not combust and are difficult to ignite and will self-extinguish. They are also particularly effective in use on arc flash garments.

Many of our fabrics contain the Protex® brand of Modacrylic Fibres which is produced by Kaneka of Japan. This fibre is then woven into fabrics with the technical support of Waxman Fibres to produce the Protal® range of fabrics solutions which in turn is then used in the HAZTEC® garment range.

Modacrylic fibres do not make up the entire composition of the fabrics we use. They are combined with other fibres including Cotton, Antistatic Yarns, Viscose, Polyesters, Aramid Fibres. By adding these other fibres we gain other benefits to the finished fabric such as antistatic properties, dimensional stability, hi-visibility reflective characteristics and enhanced flame resistant performance.