How long are flame retardants effective?


Flame retardant agents are contained in some materials or are attached chemically, so that they can’t be washed out.

For textiles, this applies to all permawash (WP) products (silk decoration material WP, SunSat CS, Sunlight CS, SunBlockSoft WP, Bolton WP etc.) all Trevira CS® products and all polyester FR products.

SEMI-PERMANENT FIRE PROTECTION: Fireproof until the first wash or rinse.

Nowadays, most flame retardant materials made of natural fibres belong to this group, for instance cotton, wool, but also viscose. Regardless of whether the material is high quality cotton stage velvet or inexpensive decorating material – in most cases, flame retardant is effective for the duration of the product life, as long as these materials don’t get wet.

Even superficial contact with waters dissolves the flame retardant agent. As the water is absorbed by the material, it drives the protection agent out. A similar effect can be observed if you write on a piece of paper, with ink or an ordinary felt-tip and then let the paper absorb a drop of water.

After drying, sharp white edges are often visible. Also, patches of the material can harden. In this case, the patches of material, where the flame retardant agent was driven out, no longer contain a sufficient amount of the flame retardant agent and therefore are flammable.

If the material is thoroughly rinsed or even washed, the flame retardant agent is removed completely and the material becomes flammable, like before treatment with an agent. In many cases, flameproofing can be restored by re-impregnation.

The above-mentioned doesn’t apply for dampening the material, by spraying it evenly with water. This method is often used for stretched materials, to make last creases disappear. Even dampening of the surface does not affect the flame retardant effect. The flame retardant effect is only affected or removed when so much water is applied, that it drips or surrounding dry areas absorb water.


The flame retardant agent in the material trickles or produces dust. This type of transient flame retardant is not to found in any Tüchler product. Our modern fire proofing agents ensure the semi-permanent flame retardant qualities described above.