BS 4790 Method for Determination of the effects of a small source of ignition on textile floor coverings (hot metal nut method)

1 Scope

This British Standard describes a method for the determination of the effects of a small source of ignition on textile floor coverings using a hot metal nut. It is applicable to all types of textile floor coverings whether loose-laid or fully adhered and used with or without an underlay.
NOTE The titles of publications referred to in this standard are listed on the inside back cover.

2 Definitions

For the purposes of this British Standard the following definitions apply.
NOTE Definitions 2.1, 2.2 and 2.3 have been extracted from BS 6373.

2.1
afterglow
persistence of glowing of a material, under specified test conditions, after cessation of flaming or, if no flaming occurs, after removal of the ignition source

2.2
flame (verb)
to undergo combustion in the gaseous phase with emission of light

2.3
smouldering
the combustion of a material with or without emission of light and generally evidenced by smoke

2.4
loose-laid
a specimen placed on a horizontal substrate and subsequently held in position only by the mass of the clamping ring