The article presents data of the analysis of scientific literature on the toxicity and danger of polyhexamethylene guanidine (PHMG) and based on it disinfectants, which have been widely used for several decades. The COVID-19 pandemic has contributed to a sharp increase in the use of disinfectants, making it important to study the safety of these substances. The presented materials confirm the effectiveness of PHMG and its compounds against a wide range of bacteria, viruses and fungi. The article discusses the mechanism of the bactericidal action of guanidine polymers, based on the destruction of the bacterial cell wall due to the electrostatic effect of positively charged substance molecules on anionic groups on the cellular wall. Methods for using disinfectants based on PHMG for sanitizing various surfaces and media are shown.
 The results of toxicological studies show that polyhexamethyleneguanidine compounds have low toxicity when taken orally, but pose a great danger to the respiratory system. With chronic exposure, they cause pulmonary fibrosis, a serious lung disease, associated with irreversible destruction of the lung architectonics, pulmonary insufficiency and impaired gas exchange due to excessive accumulation of proteins in the extracellular matrix. The use of disinfectants based on polyhexamethylene guanidine is not recommended for aerosol disinfection of indoor air in the presence of people. The presented data also indicate the need for additional toxicological studies to establish threshold doses of PHMG under inhalation exposure.