Putrescine is a chemical compound recognized for its potent and unpleasant smell. This article explores its characteristic odor, chemical origins, common environments where it is found, and important safety considerations.
Describing the Distinct Odor
Putrescine emits a foul, decaying aroma, often described as similar to putrefying flesh, sour rot, or a fishy-ammoniacal smell. This odor is strongly associated with decomposing animal tissue and is a component of the “smell of death.” The human nose is highly sensitive to putrescine, processing its scent as a warning signal. Its presence can signal potential threats, prompting avoidance behaviors in both animals and humans.
What is Putrescine and How Does it Form?
Putrescine is an organic compound classified as a diamine, with the chemical formula C4H12N2. It primarily forms through the breakdown of amino acids, particularly the decarboxylation of ornithine, a process often carried out by microorganisms. This microbial action is a significant part of the putrefaction of organic matter. Putrescine is closely related to cadaverine; both are biogenic amines produced during the breakdown of amino acids in living and dead organisms.
Common Sources of Putrescine
Putrescine is widely found in various natural and processed environments. It is prominently present in decaying organic matter, such as dead animals, rotting meat, and decomposing plant material, where it serves as a byproduct of microbial activity. Beyond decomposition, putrescine occurs in certain fermented foods, including some cheeses, fish products, sauerkraut, and soy sauce. It is also found in small amounts in some bodily fluids, contributing to odors like bad breath and certain vaginal infections. Its presence often acts as an indicator of spoilage in food products.
Safety Considerations for Putrescine
In typical environmental concentrations, such as those found from decaying organic matter, putrescine is generally not harmful to humans. However, at higher, concentrated exposures, such as in laboratory or industrial settings, it can cause irritation. Direct contact can lead to burns on the skin and eyes, and inhalation may cause severe irritation of the respiratory tract, including symptoms like sore throat, coughing, and shortness of breath. While its smell is potent, putrescine has a low acute oral toxicity in rats, with a no-observed-adverse-effect level of 2000 ppm (180 mg/kg body weight/day).