Odor Investigations


Our sense of smell can be amazing and annoying at the same time.  Many of us can detect certain odors that are annoying, bothersome, and can even make us sick.  More importantly determining the source of the smell can drive us crazy!  We come into contact with many scents all throughout our day.  What happens if the odor is in our home or work environment where we spend a majority of our time?  Some VOCs can be odorless but many do have an odor & odor threshold.  To remove the source of the offensive odor we must first find what it is coming from.


An odor, smell, scent, or fragrance is caused when one or more volatile chemicals enter our nasal passages and are detected by specialized receptors.  These can be interpreted as pleasant or unpleasant, as well as variations in description such as flowery, spicy, ethereal, acrid, musky, etc.

Prism provides an answer to the odor woes.  Our knowledgeable technical staff and solutions based analyses can help to determine the point source odor and vapor problems.  Prism offers varying levels of odor detection/solution analyses from our Survey line of products to our 500+ compound Comp-Air report. 

For help determining which analysis option best matched your application, contact us at prism@pati-air.com or 989-772-5088.

How Smell Works

Our sense of smell, also known as olfaction, is activated when certain volatile chemicals dissolve into the mucus lining as they pass through the nasal passages and bind to olfactory receptors in the nasal cavity which transmit signals to the olfactory bulb which is part of the brain structure directly above the nasal cavity.  How these signals get interpreted by the brain as different smells is still being researched, but essentially these olfactory receptors break down the smell because each receptor that is activated recognizes only a specific characteristic of the odorant and the combination of the different receptors that are activated is what allows us to recognize and identify specific smells.  Odor molecules transmit messages to the limbic system, which is the area of the brain that governs emotional response.  Therefore, odors can be tightly linked to specific emotions and trigger memories.

Odor Classification

The range and complexity of odors makes characterization of them challenging. Prism uses the chemical class, or functional groups, of individual chemical compounds to estimate the odor effect those compounds will have on those exposed to them.

Odors can be difficult to classify since everyone perceives odors differently.  However, there are some classification methods that help to define the odor. One of the common classification schemes includes: fragrant, woody/resinous, fruity (non-citrus), chemical, mint/peppermint, sweet, popcorn, lemon, pungent, and decay. Despite numerous studies in this area there are no universal descriptors for odor as there are for taste.

The odor threshold is the lowest concentration of a chemical compound at which an odor is perceptible.  There are a number of ways to measure the odor threshold, leading to a wide range of threshold concentrations from different organizations.  An individual’s specific threshold to a particular odor depends on the frequency, concentration, and duration of the odor.

Odor Thresholds