Because it is a synthetic textile that burns and can drip molten material.

Aircraft cabins and rail vehicles prohibit it.

Marine interiors, theatres and public buildings do too.

Fire behaviour in enclosed spaces is strictly controlled.

Escape time depends on materials not accelerating a fire.

Smoke is frequently the more dangerous product rather than flame.

Whatever the applicable standard defines rather than a general description.

Ignition resistance and flame spread rate are typically covered.

So is self-extinguishing behaviour once the flame is removed.

Smoke density and toxicity are frequently included too.

Which standard applies depends on sector and jurisdiction.

They differ substantially between transport, marine and building applications.

Certification, because performance cannot be seen by looking at the product.

Test certificates referencing the specific standard are the deliverable.

Specifiers generally require them rather than a claim.

A product called fire-retardant without a named standard proves nothing.

Documentation has to be retained for the project.

It is frequently required at handover as well as at purchase.

It can - and that distinction matters for laundered items.

Some materials carry a flame-retardant finish.

That finish can be reduced by washing and ageing.

Others use inherently flame-resistant fibres.

Their performance does not wash out.

For anything laundered in service, the inherent type is the safer specification.

As much as the tape itself.

Fire-retardant tape with a flammable adhesive is not a fire-retardant assembly.

Nor is it if stitched with ordinary thread onto untreated fabric.

The specification has to cover the whole construction.

Adhesives and threads have their own certifications.

Specifying only the tape is a common and consequential gap.

Noticeably, and availability is narrower.

Fewer manufacturers produce certified material.

Colour and size ranges are more limited.

Lead times can be longer than for standard tape.

Specifying it where genuinely required rather than by default is reasonable.

Where it is required, no cheaper alternative is acceptable regardless of price.

Fully - fire performance is additional rather than instead.

Peel and shear strength still matter.

Cycle life and lint contamination still apply.

Adhesive-backed versions still depend on surface preparation.

Sew-on versions still need proper perimeter stitching.

The material has to work as a fastening as well as satisfy the standard.