Passive fire protection is the primary measure integrated within the constructional fabric of a substrate, structure or building to provide inherent fire safety and protection by responding against flame, heat and smoke to maintain the fundamental requirements of structures or building compartmentation, structural stability, fire separation and safe means of escape.
Passive Fire Protection is usually spray applied and is used extensively for protection of structural steelwork in a fire environment to help preventing the collapse of structures and allowing safe evacuation of the facility. In the early days of spray applied fire protection the products were based on cement usually containing vermiculite. These were typically used in both commercial building structures and in the oil and gas hydrocarbon processing industries.
Over many years both industries changed and in the oil and gas industry the realisation that a standard cement-based fireproofing material would not provide enough adequate fire protection in severe oil and gas fires became evident.
In the mid to late 1980s the advantages and benefits of the epoxy based intumescent materials became more understood and in a short period of time epoxy intumescent materials replaced cement-based materials, particularly for use on offshore installations. Along the way further appreciation of the dangers of offshore fire and explosion were put into focus in 1987 with the Piper Alpha disaster in the North Sea in which 170 people lost their lives after a major fire and explosion.
In the commercial and public building market, or built up environments the so-called ‘thin-film’ intumescent materials, either water or solvent-based, have become very extensively used particularly where the structural steelwork is exposed to view.
Passive fire protection measures achieve their intended purpose by raising the fire resistance of the structure, protecting the structure against the effects of fire, reducing fire spread through secondary ignition, limiting the movement of flame and smoke, and minimising the danger of fire-induced collapse or structural distortion.
Passive fire protection design, incorporating passive fire protection materials, systems and assemblies, serves by fire containment to protect life, safeguard the building structure, protect assets, maintain building serviceability after fire, minimise rebuild costs, and facilitate quick business recovery and continuity
The protection of any structural steel or substrate from the effects of Fire requires a specialised coating or Solvent Free Plural or Single Component Intumescent material (PFP). This material requires being applied using specialist application equipment to provide a Passive Fire Barrier Coating. A thick film or coating of in excess up to 20mm is applied with reinforcing mesh between the coats for plural component intumescent or several thin layers of single component itumescent. In the event of a fire the coating provides a heat resistant barrier to protect the steel substrate from the effects of the fire. As a result of this reaction they swell and provide an expanded layer of low conductivity char.
Intumescent coatings are paint like materials which are inert at low temperatures but which provide insulation as a result of a complex chemical reaction at temperatures typically of about 200-250°C. At these temperatures the properties of steel will not be affected.