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Odor threshold value (OTV) (also aroma threshold value (ATV), Flavor threshold) is defined as the most minimal concentration of a substance that can be detected by a human nose. Some substances can be detected when their concentration is only few milligrams per 1000 tonnes, which is less than a drop in an Olympic swimming pool. Odor threshold ...
Odour activity value (OAV) is a measure of importance of a specific compound to the odour of a sample (e.g. food). It is calculated as the ratio between the concentration of individual substance in a sample and the threshold concentration of this substance (odour threshold value, the minimal concentration that can be detected by human nose).
Many gases have toxic properties, which are often assessed using the LC 50 (median lethal concentration) measure. In the United States, many of these gases have been assigned an NFPA 704 health rating of 4 (may be fatal) or 3 (may cause serious or permanent injury), and/or exposure limits (TLV, TWA/PEL, STEL, or REL) determined by the ACGIH professional association.
The odour quality of a (odour-active) compound is assessed using odour descriptors in sensory descriptive analyses. [4] It shows the sensory–chemical relationship in volatile compounds. The odour quality of a compound may change with its concentration. [1] The absolute threshold of a compound is the minimum concentration at which it can be ...
Key odorants can be identified by comparing the concentrations of the odorants with their respective flavor threshold. The resulting unit is the odor activity value (OAV). Every key odorant has an OAV higher than 1. Values lower than 1 are not perceived.
Enforcement efforts will be paused over the next several months while the city collects data, though Des Moines residents are encouraged to continue reporting foul smells to the Odor Complaint ...
0.00047 ppm or 0.47 ppb is the odor threshold, the point at which 50% of a human panel can detect the presence of an odor without being able to identify it. [67] 10–20 ppm is the borderline concentration for eye irritation. 50–100 ppm leads to eye damage.
The recognition odor threshold is usually a factor of two to five higher than the detection threshold. [22] The measurement of odor concentration is the most widespread method to quantify odors. It is standardized in CEN EN 13725:2003. [23] The method is based on dilution of an odor sample to the odor threshold. The numerical value of the odor ...