Fire Resistance Information

FACT: Cast iron Is one of the safest materials for above ground drainage! How do we know?
Because we have test evidence to support it.

Fire Safety Comparison Test

Commissioned by IZEG in 2004 (association of cast iron manufacturers in Germany) to understand the effects and behaviour of fire on different drainage systems in industrial, commercial & public buildings and carried out at MPA, North-Rhine Westphalia Laboratory.

1.Establish how different materials react on exposure to fire
2.Establish ability of different materials to contain fire within a compartment

Systems Installed

  • Cast iron soil and waste system to BS EN 877
  • Acoustic HDPE system (composite material made up of 80% HDPE and 20% stone powder).
  • Twin-walled acoustic plastic system
  • Polypropylene (PP) sanitary system


  • Each system comprised two vertical stacks in the fire compartment penetrating through the floor above, and a vertical and horizontal stack in the basement below
  • All the pipework was installed to the relevant manufacturers’ guidelines and in accordance with local building regulations
  • Systems were simultaneously exposed to a fire in the compartment
  • Systems 2, 3 and 4 were fitted with fire collar passive fire protection solutions only.


  • Within 3 minutes polypropylene systems began to melt
  • Within 10 minutes molten droplets from polypropylene system and Acoustic HDPE system bypass the intumescent fire collars (which failed to deploy) and ignite in basement area
  • Within 15 minutes the plastic systems generate dense smoke in test compartment
  • Within 25 minutes fire spreads to the basement below the test compartment as a result of the molten droplets from the Acoustic HDPE and PP systems and dense smoke and gases continue to be generated
  • After 35 minutes test aborted in the interests of safety


  • Fire collars on plastic systems prevented fire spreading upwards from compartment
  • Fire collars on all plastic systems in the basement failed to deploy
  • PP and the Acoustic HDPE systems burned and released molten droplets spreading fire to the compartment below
  • All plastic systems emitted a high density of smoke - a consideration when when smoke is recognised as the biggest killer in the first 30 minutes of every fire
  • All plastic systems were destroyed in the fire
  • The non-combustible cast iron pipework did not propagate the fire to either floor


  • In the event of a fire in a multi-storey building, there is a potential risk of people being cut off by the fire propagating down through a building
  • Tests proved that intumescent fire collars activate through heat but only in the compartment and NOT on the floor below
  • The PP and Acoustic HDPE system installed in this laboratory test burned and released molten droplets which could pose a potential fire risk even if fitted with the traditional fire collar passive fire protection solution
  • Non-combustible cast iron does not burn, melt, drip, emit toxic smoke or gas or propagate fire - cast iron was the only system to survive the fire intact
Fire Classification
Saint-Gobain have gone further than any other cast iron manufacturer - by adopting the voluntary CE mark in conjunction with BS EN 877 - which requires the compulsory attainment of a fire rating from an independent accredited laboratory.

New CE Marking Fire Rating Test
Carried out at Warrington Fire Research Establishment


  • To test the reaction to fire in accordance with BS EN 13501-1

Products Tested

  • Ensign cast-iron above and below ground system to BS EN 877
  • Ensign EEZI-FIT push-fit sanitary system to BS EN 877
  • Timesaver soil to BS416 and Timesaver drain system BS437

Results :

  • Cast iron individual components would be classified as A1
  • Tested as a system it has achieved the Euroclass classification A2 s1, d0 - the highest classification permitted under BS EN 877
  • Saint-Gobain PAM UK has obtained an excellent ranking for its complete ranges of pipes, fittings, couplings, accessories and other components of wastewater pipe systems
  • Cast iron remains one of the safest materials in the event of fire - Building Regulations Doc B stipulates that cast iron requires no protection up to 160mm diameter. Saint-Gobain PAM UK cast iron systems are proven among the safest on the market in their reaction to fire.

>> Find out more, contact us today.