The Science Behind Fireproofing Clothing

We’ve talked about the science behind waterproofing and insulation, but what about the magic that turns ordinary clothing into flame retardant workwear? In this blog post, we will be taking a look at the process of creating garments that protect you when things get a little hot under the collar, so to speak.

The Tech Specs

It’s important to get the terminology right when talking about fireproof clothing. Fire retardant materials are designed to burn slowly, whilst fire resistant materials are designed to not catch alight at all. The latter are mainly worn by fire-fighters, whilst flame-retardant clothing is designed to be worn by industrial workers.

Dickies Workwear’s range of flame-retardant workwear is rated in line with specifications outlined by the International Organization for Standardization (ISO), who is the world’s largest developer of voluntary international standards.


The EN ISO 11611 specification refers to the minimum basic safety requirements and test methods for protective clothing “...intended to protect the wearer against spatter (small splashes of molten metal), short contact time with flame, radiant heat from the arc, and minimizes the possibility of electrical shock by short-term, accidental contact with live electrical conductors at voltages up to approximately 100 V in normal conditions of welding”.

This rating comes in two grades - Class 1, which refers to protection against less hazardous welding techniques, and Class 2, which provides a higher grade of protection.

The EN ISO 11612 rating provides the wearer with protection against brief contact with heat and flame. According to ISO, the heat can be radiant, convective, molten or a combination thereof.

The specification contains the following sub-ratings:

(A1) Limited flame spread

(A2) Limited flame spread, hemmed specimens

(B) Convective heat, scale 1-3 where 3 is the best

(C) Radiant heat, scale 1-4, where 4 is best

(D) Molten aluminium splash, scale 1-3 where 3 is the best

(E) Molten iron splash, scale 1-3 where 3 is the best

(F) Contact Heat, scale 1-3 where 3 is the best  

fire hazard icon

Dickies Flame-Retardant Workwear

Flame-retardant clothing can either be treated with chemicals to enhance its resistance to fire, or can be made from fireproof fibres or materials. Dickies manufacture and sell a selection of flame retardant and fire resistant garments, treated with Proban and Pyrovatex.

These are suitable for welding and foundry environments. Proban is a flame retardant solution, developed to give cotton (or cotton rich fabrics) reliable flame retardant properties that meet industry fire regulations. Pyrovatex, meanwhile, is one of the most widely used flame retardant treatments for 100% cotton fabrics.

Pyrovatex not only affords regulation protection for the whole life of the garment, but the cotton retains its comfort and durability.

 man with hosepipe

The Hottest Gear 

  • The Dickies Pyrovatex Coverall offers excellent protection against heat or flames, and also provides high visibility for dark or smoky working environments.
  • The Dickies Flame Retardant Polo Shirt has natural wicking properties to ensure comfort and dryness whilst working in hot conditions.

dickies insulated pyrovatex cverall     dickies modacrylic polo shirt

Whether you need gear to keep you safe in the workplace, or require fire retardant clothing for leisure activities such as motor racing, Dickies Workwear has you covered – literally.