During COVID-19 prevention and control, people’s hands are constantly exposed to objects contaminated with viruses and bacteria, especially doctors and nurses in hospitals. Therefore, keeping hands clean is one of the effective ways to reduce the risk of novel coronavirus infection.

The main characteristic of Polyhexamethylene guanidine hydrochloride (PHMG) disinfectant is its effective sterilization. It can quickly kill a variety of bacteria, sterilization rate up to 99.999%, no drug resistance, safe and non-toxic.

In the prevention and control of COVID-19, PHMG disinfectant has played a major role in hand and object surface disinfection. Especially in mucous membrane and wound surface application advantage, is alcohol disinfection products can not be replaced.

The sterilization mechanism.

The guanidine end of PHMG is high activity. It can make the polymer positively charged and easily adsorbed by bacteria and viruses. Thus, the division function of bacteria and viruses is inhibited. It disables their ability to reproduce. Moreover, the formation of polymer blocks the respiratory channel of microorganisms, which suffocates them and kills them.

The mechanism of cell membrane damage of Escherichia coli by PHMG was investigated by β-galactosidase activity analysis, confocal laser scanning microscopy with fluorescein isothiocyanate, automated scanning electron microscopy and transmission electron microscopy.

The results showed that low doses of PHMG slightly damaged the outer membrane of the bacteria and increased the permeability of the cell membrane. However, no significant morphological damage to the cells was found. The high dose of PHMG collapsed the membrane structure and led to the formation of transmembrane stomata, which severely damaged the intracellular structure, ruptured the cell membrane and leaked the intracellular material.

Feature Comparison.

PHMGAldehydePhenolicQuaternary ammonium saltChlorine-containing disinfectantIodineAlcohols
Sterilization effectGreatGreatNormalGoodGreatGoodNormal
Mucosal irritationNoneMediumMediumMediumStrongMediumWeak
ToxicityNoneMediumMediumMedium~weakVery strongMediumWeak
Long-term effectLongMediumMediumMediumVery shortMediumShort
OdorNoneStrongStrongWeakVery StrongMediumMedium
Environmental pollutionNoneMediumMediumMediumStrongMediumWeak

PHMG has excellent performance and is used in a wide range of applications, and only a few examples of applications are given below for reference.

Medical Sterilization.

PHMG disinfectants have good bactericidal effect on bacterial propagules, fungi and some viruses. However, due to many factors affecting the single-sided aqueous solution, PHMG is currently used as a medical disinfectant mainly in combination with alcohols and other synergistic components.

The compounded guanidine disinfectants not only improve the bactericidal effect, but also reduce the adverse reactions, which is more convenient to promote the application.

Household scenario use.

PHMG has many advantages such as non-toxic, colorless, odorless, non-corrosive and wide sterilization spectrum, which is very suitable for household disinfection. It can be used for sterilization and cleaning of fruits and vegetables; for sterilization and cleaning of clothes, towels, bed sheets and other kinds of fabrics; and directly for sterilization and disinfection of furniture, carpets, sofas, kitchen utensils, sanitary ware and other object surfaces and air.

Skin wound disinfectant.

PHMG is colorless, non-corrosive and long-lasting, so it can be easily used for cleaning and disinfection of skin, wounds, obstetrics and gynecology, and urology, especially for some medical supplies that cannot be disinfected by high temperature, just soak or spray with 1‰ concentration solution, and it can achieve satisfactory sterilization effect in a short time. The composition of the product can also be used for the disinfection of air, walls and floors of wards.

Textile industry.

PHMG can be developed for antibacterial textiles and knitted products, such as towels, underwear, baby clothes, bedding, woolen fabrics, gauze, etc. The textiles are simply immersed in a special solution of PHMG before the final finishing stage.

When bacteria fall on the PHMG treated textiles, the trace amount of moisture causes the active substances contained in it to dissolve, rapidly killing the bacteria and achieving the effects of antibacterial, anti-moth, anti-mildew, non-shrinking and non-sheeting. After testing, properly treated textiles still have antibacterial properties when washed in water up to 120 times.

Laundry products.

Laundry products with disinfection function are generally added with chlorine as the disinfection ingredient. There are defects such as corrosiveness to fabrics, fading, short sterilization period and can only be used for white fabrics.

Polyhexamethylene guanidine hydrochloride (PHMG) is water-soluble, non-toxic, colorless, odorless, non-corrosive, non-fading, non-irritating to skin and mucous membrane, and has a long validity period. It can develop high-tech environmental protection disinfection and sterilization laundry powder, detergent, dry cleaning agent and other products for washing any color fabrics.

Sterilization and disinfection have become an essential part of people’s daily life. The market prospect of PHMG will be very broad.