The chemistry of foot odor involves the study of the properties of some organic compounds, the ways in which they can originate and how we can prevent them from being formed.
We are constantly in contact with the bad smell , be it from any source. In these situations, the brain makes a quick association with an unpleasant situation or environment. When we are in a forest, for example, and we smell a very strong and unpleasant odor, we immediately imagine that there may be a dead animal in that place. This is because the brain relates the smell to some other situation already experienced by us with that same odor. Thus, when we encounter the smell, for example, of vomiting, feces, foot odor, among others, even without seeing them, we immediately identify what it is about.
Each bad smell, chemically speaking, is related to a certain chemical substance that has the following characteristics:
- Organic (mainly contains carbon and hydrogen in its structure);
- Of molecular weight up to 294 g / mol;
- Good solubility in water;
- It is in the gaseous state;
- High vapor pressure (evaporates very easily);
- It has low molecular interaction (this substance being in the gaseous state);
- Ability to perform an intermolecular interaction with the sensory receptors of the nose.
The bad smell is also related to the concentration of the substance when it reaches the nose receptors, as it is common for the same substance to promote a pleasant or unpleasant odor, depending on its concentration when it reaches the nostrils.
Example : The substance Geraniol, when reaching the nose in high concentration, promotes the odor of animal feces; but if it is in low concentration, it will cause the odor of jasmine. Just out of curiosity, see the chemical structure and characteristics of geraniol:
Structural formula of geraniol
- Organic acid;
- Monocarboxylic (has a carboxyl group, COOH);
- Saturated (has simple bonds between carbon atoms);
- Molar mass of 102 g / mol;
- It belongs to the series of fatty acids.
As there are several bad smells and the substances that cause them, in this article we will deal with one in particular and its chemical characteristics: foot odor , a very characteristic odor and known to all of us. Not only known, but feared, since nobody wants to be remembered for bringing that smell with them.
The foot odor receives the scientific name bromidrosis and is caused by the valeric acid, whose chemical structure is shown below:
Structural formula of valeric acid
Don’t stop now … There’s more after the publicity;)
Valeric acid is formed in the region of the feet by the action of bacteria in the presence of high humidity, absence of light and heat , since these factors favor its proliferation. These microorganisms feed on dead skin and sweat components (water, mineral salts, urea, phenols and nitrogen wastes) , which results in the formation of acid.
In some people, there is also the presence of a cheese odor associated with foot odor. This occurs through the formation of an organic compound called ethanethiol , a thioalcohol that has the following chemical structure:
Structural formula of ethanethiol
A curiosity about ethanethiol involves the fact that it is widely used to detect leaks in natural gas pipelines, since it has no odor and, when it leaks, it cannot be detected without the presence of that.
The most common habits that favor the formation of foot odor in an individual are:
- Use the same shoes for consecutive days;
- Wear closed shoes (increase heat and sweat);
- Do not wash your feet well (especially between the toes);
- Do not dry your feet well after washing them;
- Use rubber or plastic shoes frequently (they increase sweat and retain moisture);
- Use nylon stockings;
- Presence of diseases, such as mycoses, in the region of the feet.
Plastic shoes favor the development of foot odor
To avoid foot odor or even fight it, some measures are very interesting and effective:
- Use more ventilated shoes;
- Use fabric or leather shoes;
- Wash the feet and the area between the toes well;
- Dry your feet well after washing;
- Use cotton socks;
- Iron the socks with an iron (to sterilize, that is, to kill bacteria);
- Treat mycoses or chilblains present on the feet with a doctor;
- Use antiseptic talc on the feet after cleaning them (it absorbs moisture);
- Leave the used footwear resting in a ventilated and sunny place and only use it again after at least 24 hours.