What is an Odour?

Odour – The science of smell:

Although the definition of ‘odour’ refers generally to any smell, it is regularly used to describe unpleasant smells or ‘malodour’.

Organic compounds make up the widest range of malodours. Other non-carbonbased odorants include hydrogen sulphide, and ammonia. As a substance evaporates, or is volatilised, compounds dissipate at very low concentrations and are carried by air currents beyond the boundaries of the originating site.

We perceive odours in three stages. Nasal olfactory receptors detect odour molecules. The stimuli are processed by the olfactory bulb, in the brain’s limbic system. This relays information to the olfactory cortex. Information is processed largely based on experience, (although individuals will react to odours from unknown toxins). Sometimes we even respond when we cannot detect a smell; (We respond to pheromones not consciously perceived).

This complex process and differences in individual’s responses, (based on age, gender, state of health and experience means that odour measurement was slow to develop; Chemical analysis for concentration of odour molecules has been unreliable. Olfactometers used with odour sampling and a panel of human subjects are commonly used to measure odour concentration.

Samples are diluted to the point where the odour is just detectable against an odour-free blank (usually n-Butanol) to 50% of the test panel. The recognition threshold is then measured. ( this is the concentration of the odour in air in which 50% of a test panel can discern or distinguish the sample odour from a baseline odour). Ability to distinguish is weaker than ability to detect by a factor of between 2 and 5.

The olfactory system recognises not one compound, but the odorous mix, although some individuals such as perfumers or food and drink tasters (flavourists) are trained to recognise certain odours, intensity, concentration and hedonic tone (Pleasant or unpleasantness). These experts are employed when more detailed analysis is required. Odours can change based on environmental conditions, for example odours tend to be more distinguishable in cool dry air. Hot days can increase evaporation of organic compounds leading to worsening of an odour nuisance in summer, (although intense sun can have the opposite effect).

Bespoke Odour Neutralisation Using Nature’s deodorants

Nature has its own way of dealing with odours. In the woods, we appreciate that there are surely hundreds of rotting creatures, animal waste and a mass of rotting vegetation. So why doesn’t it smell bad?

Natural resins created by trees, and other plants neutralise odourous compounds from the breaking down of organic matter.

This principle underpins Neutrapak’s effectiveness. We select plant oils which neutralise the specific odour being treated, enabling you and your neighbours to smell the roses a little easier.

Contact Renby for information on Neutrapak and how it can help neutralise odours without using power or water.