This paper presents results of tests performed on 35 materials, including woods, synthetic and textile materials, which have been submitted to thermal degradation at three different combustion temperatures. In addition, the interpretation and limitations of toxicological test results are discussed more generally.
INTRODUCTION -~Although fire fighting techniques have greatly developed and improved over the years and although the way in which buildings are designed as well as the types of materials available to build them have undergone a rapid evolution, the problem of toxicity caused by the burning of building materials, including furniture and decorating elements, remains a very important one.Referring only to a small country like Belgium the list of fire disasters since 1955 is impressive: This leaves out of consideration the family home fires in which one or several people die, as was the case in Deurne in November 1977 where a mother and five children died, or in Herstal in May 1978, costing the lives of five people. The number of such losses every year is serious and although such fires have less impact on the public, they are very important as it has been found that the majority of toxicity victims are to be found in fires in dwellings and that two-thirds of the fatalities are met in the room where the fire started.1 These statistics indicate a rapid incapacitation in which the victims fail to make use of possible excape routes. These facts are relevant to the elaboration of a test method imitating as closely as possible the early stages of fire during which the toxicological hazards play the most important role. The need for a biological assessment of the toxic hazards of fire has become generally acknowledged, and in recent years a great deal of research has been accomplished along these lines in a number of countries including Belgium, Germany, France, Japan, UK, USA etc. It is beyond the scope of the present paper to make reference to the numerous publications which have recently appeared in an increasing number of new journals covering the topic of combustion toxicology.Due to the complexity of the fire situation there are many different approaches possible when trying to establish a procedure for a small-scale test which explains the number of different methods in use at present. They can, in fact be divided into two categories, both systems having advantages and disadvantages as follows :1. In the first category, the animals are placed directly in the degradation chamber2 which may raise problems such as heat stress, oxygen depletion etc. 2. In the second category, degradation of the sample takes place in one apparatus (a moving tube system being used in most of the European c~u n t r i e s~-~) and the effluent products are transferred, with or without dilution, to animal chambers. This raises the problem of the effect of transfer on the composition of the toxic atmosphere.As far as the animal evaluation is concerned, methods Methods of the first type seem preferable in relation to the problem of acu...