Correlations based on linear regressions between data as time to ignition and heat release in the cone calorimeter and time to flashover in the room fire test have been developed. They are a further development of an earlier approach which has been modified and extended to a wider range of surface W i n g s . The correlations apply 90 far only to surface linings on both walls and ceilings. When the density of the linings as a simplifien measure of the thermal inertia is included, the correlations are improved significantly.The new correlations are based on data readily available from the cone calorimeter test at one heat flux level, 50 kW m-2. The correlation coefficient for the basic relationship, including the density of the linings, is now 0.98 when applied to the 13 linings investigated earlier. This is slightly better than the previous study, in which the best correlation coefficient was O. %. When applied to 28 linings, the correlation coeaicient remains about the same (097). Very similar regression equations have been obtained when analysing only 13 products and all 28. This is a strong indication of the general predictive capacity of this approach. The inclusion of other data such as thickness of linings or mass loss during fire does not improve the correlation coefficients. The approach is quite straightforward and simple. However, it has provided a useful prediction which is also valid for an extended range of linings.

The combustibility of timber is one of the main reasons that many building regulations strictly limit the use of timber as a building material. Fire safety is an important contribution to feeling safe, and an important criterion for the choice of building materials. Historically, the combustibility aspect of wood has been a disadvantage for using timber as a construction material. The main precondition for an increased use of timber in buildings is providing adequate fire safety. This paper reviews the opportunities and challenges to reach this goal by implementing Fire Safety Engineering and Performance Based Design principles.

Fire retardants may considerably improve the 5re properties of wood products, but the durability, e.g. in exterior applications, has not been addressed fully. This paper reviews the existing knowledge and experience mainly from the USA with the aim of supporting further development in Europe. The review is concentrated on pressure impregnated 5re retardant treated wood products which have the best opportunities for increased durability.

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Kraft lignin wood fiberboards ± The effect of kraft lignin addition to wood chips or board pulp prior to fiberboard production M. Westin, R. Simonson, B. O È stman Kraft lignin is a by-product of kraft pulping with great potential as an additive for wood composites. Kraft lignin was added to wood chips prior to de®bration and alternatively to ®bers to improve the properties of ®berboards. Lignin-wood ®berboards were produced on both laboratory and semi-industrial scale using different methods of adding the lignin and ®xing it with metal salt solutions. Both wet-formed (hardboards) and dry-formed (MDF) boards were produced. The properties of lignin hardboards without a post-heat-treatment were slightly better than heat-treated control hardboards. This indicates that addition of kraft lignin in combination with a di-or trivalent metal salt can be an economic alternative to heattreatment of boards. Results for MDFs indicate that boards with improved dimensional stability could be produced at relatively low cost without need of major investments in equipment.