Smoke formation from materials

Meszaros, Gy. Scientific Report. Method for evaluation of smoke formation from materials (in Hungarian). Fire Resistance Laboratory, Institute of Quality Control for the Building Industry, Budapest, Part I (1984) and Part II (1985)... 

Besides the development of test methods, some relationships between the type of burning material and the smoke density have also been discovered. On this basis, a number of additives are marketed for the suppression of smoke formation from plastics. 

Ascertainment of smoke formation from a material is rather difficult due to the uncertainties in testing and evaluation. The measurement of smoke generation is to some extent dependent on the measurement technique i.e. whether smoke has been collected in a chamber or is streaming in a pipe whether gravimetric or optical evaluation is used and in the case of optical density, whether specific optical density, mass optical density, or a different measure is to be considered. 

Apart from the specific techniques for testing smoke formation, a great number of the methods devoted to flammability testing (mainly for building materials) are also capable of ascertaining smoke formation. 

In their search for incandescence inhibitors, they screened a number of known organic catalyst poisons but without success, probably due to insufficient thermal stability. Inorganic additives proved more promising. Ammonium polyphosphate (APP) was found to be very effective but suffers from water sensitivity problems and was rejected on this basis. Surprisingly antimony trioxide, which is often regarded as an incandescence promoter itself, was found to be very effective and was their preferred material. Unfortunately, the effectiveness of antimony trioxide on flame retardancy and smoke formation was not reported on. 

Minimize stocks and segregate from other chemicals and work areas. Where appropriate, keep samples dilute or damp and avoid formation of large crystals when practicable. Add stabilizers if possible, e.g. to vinyl monomers. Store in specially-designed, well-labelled containers in No Smoking areas, preferably in several small containers rather than one large container. Where relevant, store in dark and under chilled conditions, except where this causes pure material to separate from stabilizer (e.g. acrylic acid). 

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