Fire Ratings

What is the difference between Class 1 and Class II ?

Both are classifications of the surface spread of flame test (BS 476 part 7).  They refer to the degree of flame spread on an ignited panel 900mm x 230mm cut from a laminate.  The panel is exposed at right angles to a radiant panel to reproduce the effect of a fire on an adjoining wall or ceiling.  It is ignited at the hotter end and allowed to burn for 10 minutes.  Flame spread is measured along a line 75mm from the base.   A Class 1 rating is given if the spread of flame is no greater than 165mm   A Class II rating is given if the spread of flame is no greater than 215mm in the first 1½ minutes and on overall spread of no more than 455mm.

Fire Ratings, the Diference

What is Class 0 ?
Class 0 is a Building Regulations rating and not a British Standard Classification.  To attain Class 0, a sample must meet Class 1 for spread of flame and also meet the fire propagation requirements of BS476 Part 6.  (Hence we quote Class 1/0 as our product meets both criteria - this rating also complies to CLASP spec). The Part 6 test was introduced because investigations into the growth of building fires showed that spread of flame was not the only significant factor.  Fire propagation (or the amount of heat added to a fire by the energy output of burning materials) was also an important consideration.

Phenolic (Phenclad)
Phenol Formaldehyde (Phenolic) resins have been in commercial use for just under 100 years.  Recent advances in resin / catalyst technology and continuing improvements in glass fibre production techniques combined with unique processing methods have made the manufacture of PHENCLAD possible.  This product has undergone relevant tests by an internationally recognised Fire Research Centre.  It is one of the most effective FIRE RESITANT sheet materials available producing comparatively minute quantities of smoke and toxic fumes when exposed to fire - well within the most stringent limits of any international fire standard - while still retaining excellent physical properties at high temperatures. Phenclad sheets and Phenolic Anti Slip Stair Treads have been approved for use by the likes of London Underground and Offshore Installations.

BS 476: Part 22
On 17th December 1991 Smyth Composites satisfied the BS 476: Part 22 Standard when a piece of 6mm thick Fybagard (smooth faced Georgian Wired GRP - 602mm x 602mm) was installed in an aperture cut in to a door blank, between timber glazing beads.  The 54mm thick door blank (1150mm x 1150mm) was clamped in place on a concrete lined restraint frame to form a panel for exposure to the furnace conditions.

The test item was installed within a fire resistance furnace.  The specimen was found to satisfy the criteria of the Standard by retaining its integrity for 39 minutes.  The test was terminated at 41 minutes.