PVC and building fires
PVC and building fires - Vinyl Council Australia
| The increasing use of PVC in the construction and furnishing of buildings over the last 60 years has led to a thorough assessment of its fire performance. In a fire, the distinguishing characteristics of rigid PVC are: |
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| Although PVC will provide a source of carbon fuel to a fire once it has started, it will self-extinguish if the external heat or flame source is removed because of the chlorine present in PVC. This is a significant positive for fire safety. Additives may change the performance of PVC in a fire. Some plasticisers, for instance may increase the material’s impact during a fire. Alternatively, many PVC products are modified with fire retardants, increasing their safety. Plasticisers are used in the flexible PVC found in cable insulation. Electrical fires are potentially a major source of accidental building fire so extensive testing has resulted in high performance PVC sheathing and associated installation parts. One recent Australian development, ceramic PVC insulation, is a big breakthrough in fire performance technology. During processing, ceramic is mixed with the PVC polymer. When this new polymer is subject to the high temperatures of a fire, the insulation reverts to a solid ceramic shield thus protecting the cables and allowing the electric circuitry to continue to operate. It may have particular application on ships, trains and aircraft. |
| View more information on ceramic polymer. |
| Burning PVC releases hydrogen chloride gas. This may become corrosive and highly irritant when in contact with moisture. Hydrogen chloride has a very pungent odour and is, therefore, quickly detected. Burning PVC releases a heavy smoke. The overall toxicity of emissions from PVC in a building fire is comparable to that of some hardwood timbers. To our knowledge, no building fire fatality has ever been attributed to PVC by building fire authorities. |
