It has been well established that odours have powerful links to memory and emotion. People tend to experience, rather then simply detect them. Fire odours are no inherently unpleasant (the aromas of an outdoor barbecue, or a crackling fireplace may be attractive) but once these are linked to personal disaster, the response may swing to revulsion. For that reason, the presence of smoke odours tends to be obnoxious to fire victims and its elimination commands high priority. For this reason, it can be classed as either real or client heightened awareness of the fire odour which may be psychological. The most difficult to deal with is psychological, as the client perceives an odour.
Odour is one characteristic of smoke. It is conveyed with smoke and deposits as components of combustion residues. Even when residues are too fine to be visible their presences may be indicated by odour. Combustion residues may continue to emit odours as long as they are present. The retention of odour is directly related to surface textures and porosity.
General Principles Relating to Odour;
- Human nose – the only odour detection device.
- Types of odours – real and heightened awareness (psychological)
- Humidity – odour is amplified by temperature and humidity (moisture)
- Smoke particle size – mass median diameter (MMD) of smoke odour particles is 0.1 to 4 microns.
- Overkill – they key to successfully, permanent deodorising