The emission of toxic gaseous combustion products from timber constructions influences on the time required for evacuation of people from a building during a fire. In order to prolong the time interval until inflammation of timber constructions, fire retardant solutions are used. It is relevant and very important to determine how the emission of toxic gaseous combustion products from pine timber non-treated and treated with fire retardant solutions used in Lithuania differs during thermal destruction. Measuring carbon monoxide (CO) emissions, the paper focuses on toxicity analysis determined by nonstandard and standard research methods of smouldering and flaming pine timber, both non-treated and treated with fire retardant solutions. The description comprises specimens used in research and their preparation, nonstandard and standard research equipment and methods determining toxicity of smouldering and flaming pine timber, both non-treated and treated with fire retardant solutions. The article presents the analysis of experimental results processed by statistical methods.

In order to investigate the impact of some inorganic additive flame retardants on the selected fire properties of the materials based on polyester resin Polimal 1033 APy, small-scale fire testing techniques have been used. Seven samples have been studied: unmodified PES, PES modified with MoO3 (7, 14 and 21 wt%) and PES modified with Sb2O3 (7, 14 and 21 wt%). The following flammable properties of materials have been determined: the heat of combustion (HOC), the ignition temperature of volatile thermal decomposition products (Tig), self-ignition temperature and oxygen index. A cone calorimeter method has been used for determining heat release rate (HRR), mass loss, specific extinction area (SEA) and other combustion parameters. The toxicological analysis of combustion products has been conducted. Based on the obtained results, the following conclusions have been made: (1) MoO3 and Sb2O3 added to the studied material change its flammable properties and fire parameters. It can be indicated by higher HOC, higher Tig and self-ignition temperature, as well as by lower HRR and SEA. Modified materials become safer in terms of fire hazard. (2) A significant reduction in HRRmax of approx. 40% in the content of 7 wt% has been observed. The lowest HRRmaxof approximately 300 kW/m2 and 450 kW/m2 have been obtained for 21 wt% in a range of 200–600 s at 30 kW/m2 and 100–400 s at 50 kW/m2 respectively. Except for a sample containing 7 wt% of Sb2O3, a clear local reduction in HRR (from 50 to 150 kW/m2), in case of all modified samples has been noticed. (3) Sb2O3 has a greater impact on the thermostability of the studied materials compared to MoO3 in all cases of heat flux density and additive concentrations. The effectiveness of Sb2O3, as a flame retardant is the most evident at 21 wt%.

Fire safety is one of the main requirements with respect to the regulations on the buildings involved into the category of human hazards. Human safety measures are applied equally to inhabitants, users, customers, spectators, etc., as well as to fire brigades taking part in the activities connected with rescue actions. Methods for emission research were applied to estimate thermo-kinetic parameters related to smoke and toxic gases. The methods fall into two types: full scale methods reflect fire conditions and small laboratory scale methods having a significantly lower degree of reflection. This paper presents the results of studies on the influence of BAK-1 and Flamasepas-2 fire retardants produced in Lithuania and applied for timber on the selected parameters of the fire environment. Experimental studies were conducted using a cone calorimeter (small scale) in the closed compartment equipped with measuring devices (full scale). The undertaken studies have demonstrated that considering some parameters, such as heat release rate (HRR), a positive effect of the lower amount of the released heat can be obtained. Unfortunately, in case of the major part of the studied parameters, including time to ignition, CO concentration and extinction parameter reflecting smokiness, worse results (shorter time, higher CO values and higher extinction coefficient) have been observed for the treated timber rather than for the non-impregnated one. The obtained results have showed combustion with piloted ignition. In case of no piloted ignition, the results were slightly different. For all studied specimens treated with fire retardants, no ignition was observed and tests were terminated following 15 minutes. CO concentration and extinction parameter (smokiness) were higher for non-impregnated timber. Full scale experiments have confirmed the above provided information; moreover, it has been found that the application of fire retardant has no significant impact on temperatures in the compartment.

Anotacija. Daugelyje šalių mediena yra plačiai naudojama statybai, o kai kada ji yra pagrindinis statybinių konstrukcijų elementas. Pastato konstrukciniams elementams, apdailai naudojama mediena ir jos produktai privalo atitikti priešgaisri-nės saugos reikalavimus. Straipsnyje aptariami veiksniai, kurie turi įtaką medienos užsiliepsnojimui: antipireninių tirpalų įtaka degimo fazei, medienos tankis ir drėgnumas. Taip pat nagrinėjama antipireniniais tirpalais impregnuotos medienos užsiliepsnojimo priklausomybė nuo medienos tankio. Tyrimai atlikti pagal LST ISO 5657:1999 standarto ,,Reagavimo į ugnį bandymai -statybinių gaminių užsidegimas veikiant juos šilumine spinduliuote" reikalavimus. Impregnuotos medienos užsiliepsnojimo priklausomybė nuo medienos tankio vertinama pagal laiką iki bandinio užsiliepsnojimo.Reikšminiai žodžiai: medienos tankis, medienos drėgnumas, impregnavimas, antipireninis tirpalas, užsiliepsnojimas. ĮvadasMediena ir jos produktai dažnai naudojami pastatų konstrukcijoms ir apdailai (Stevens et al. 2006), o kai kuriose šalyse mediena yra pagrindinis statybinių konstrukcijų elementas (Grexa 2000).Medienos apsauga nuo ugnies poveikio yra labai aktuali (Gu et al. 2007). Ši teiginį patvirtina ir R. Stevens (2006). Jis pabrėžia, kad mediena, jos produktai privalo atitikti vis griežtėjančius ir tobulėjančius priešgaisrinės saugos reikalavimus.Yra nemažai impregnavimo būdų ir cheminių junginių, naudojamų impregnuoti. Jie ilgina medienos laiką iki užsiliepsnojimo. Tačiau laikui iki užsiliepsnojimo įtaką turi ir medienos struktūra, drėgnumas ir kiti dalykai.Tiriant antipireniniais tirpalais impregnuotą medieną, buvo tirtas ir Lietuvoje sertifikuotų antipireninių tirpalų efektyvumas ( Darbo tikslas: ištirti antipireniniais tirpalais impregnuotos medienos užsiliepsnojimo priklausomybę nuo medienos tankio. Bendrosios žinios, tyrimo objektasŠilumos srautu veikiamoje medienoje vyksta terminis skilimas -pirolizė, kurios rezultatas -lakių, mažos molekulinės masės produktų išsiskyrimas (Nassar et al. 1999). Lakūs produktai reaguoja su aplinkos ore esančiu deguonimi -vyksta oksidacijos reakcija, vadinama degimu (Shafizadheh et al. 1979). Medienos degimas susideda iš trijų pagrindinių pakopų: kaitimo, pirolizės, smilkimo ir (arba) užsiliepsnojimo (Di Blasi et al. 2008). Antipireniniai tirpalai kelia degimo fazei inicijuoti reikalingą aktyvacijos energiją (Nassar 1990; Tang 1967), kartu ilgina iki medienos užsiliepsnojimo laiką.Mediena -poringoji medžiaga, kurios ląstelių sienelės ir vidus yra pripildytas oro arba vandens (Wazny et al. 2001). Medienos charakteristikas galima pristatyti analizuojant jos makroskopinę, mikroskopinę, cheminę sandarą, fizikines savybes. Pagrindinės fizikinės medienos savybės yra tankis, drėgnumas, sugeriamumas ir kita. Šios ypatybės, veikiamos aplinkos veiksnių, ilgainiui gali kisti. Medienos tankį veikia medienos poringumas, drėg-numas, medžio rūšis, metinių žiedų plotis, amžius, augimo sąlygos. Tos pačios medienos tankis gali skirtis 10-20 %. Daugelio rūšių tankiausia mediena yra k...

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