Inherent vs Retardants:
Which is the best fire protection?
As a result of the dissemination of articles on comparisons and explanations about inherent flame retardant fabrics and retardant flame retardant fabrics, we have received inquiries due to the uncertainties generated in this regard. Let’s clear up these doubts. We will start with the meaning of the keywords and then turn to chemistry to obtain answers.
Inherent: adj. That by its nature it is so united to something that it cannot be separated from it; inseparable, innate, proper, constitutive, etc.
Delay: To defer, stop, dilate. Flame retardants are various substances that are added to different materials, especially combustible ones, to reduce or prevent the spread of flames.
Now it’s time to mention the Fire Triangle and explain the LOI (Oxygen Limit Index). To cause combustion we need three elements:
- An activation energy source (flame, melting metal spatter, electric arc, etc.).
- A fuel (in this case, the PPE clothing item).
- An oxidizer, a means that makes combustion possible. It is the main element, “oxygen” that we find in the troposphere or where we live on the planet, in a concentration of approximately 21%.
These three elements form the Triangle of Fire. Any material that requires a higher percentage of the O2 we breathe in the environment to burn will make it difficult to burn. (See LOI list of fibres).
How is it achieved?
By using synthetic fibers or they are in intimate mixture with other fibers (natural or artificial). As a result, we will obtain fabrics that, regardless of their traceability of maintenance or the number of wash cycles, will always guarantee that the PPE will not burn.
Therefore, what is a retardant fabric?
It is a fabric based mainly on natural fibres such as cotton that, by means of a chemical sizing in its spinning or on the fabric itself, will achieve a higher LOI (Oxygen Limit Index) than the original of the fibres themselves to avoid or delay combustion.
Nowadays there are retardant fabrics that achieve excellent results of permanence after multiple washes, always following the manufacturer’s maintenance instructions because the aggressiveness of the washes (detergents, temperatures, drying, etc.) can reduce the flame retardant properties of the material.
