Quaternary Ammonium Compound
Quaternary ammonium compounds («quaternaries» or «quats») are a family of cationic surfactants with a disinfectant effect: their positive charge binds to the membrane of bacteria, fungi and enveloped viruses and destabilises it. They work on clean surfaces; grease, soap residues and hard water reduce their effectiveness. A common example on data sheets is didecyldimethylammonium chloride.
Chemically, a quaternary ammonium compound is a salt with a nitrogen atom bonded to four organic groups, at least one of them a long chain. The positively charged part binds to the negatively charged cell surface, and the long chain penetrates the membrane and disrupts it. The most common in disinfection are didecyldimethylammonium chloride and alkylbenzyldimethylammonium chlorides (benzalkonium chloride).
They are less effective against non-enveloped viruses and bacterial spores. Because they are cationic, they are neutralised by the anionic surfactants in many detergents, so it is advisable to rinse between cleaning and disinfection unless the products are formulated to be used together. As with any disinfectant, effectiveness is only proven at the dose and contact time stated on the data sheet.
Instaquim products containing didecyldimethylammonium chloride, according to their technical data sheets:
- InstaBact® 3000 (4.5 %; pH 7; bactericidal at 2 % and 5 min; UNE-EN 13697; registration 22-20/40-11678-HA): walls, equipment, utensils and surfaces, environmental use and in the food industry.
- Bacter (4.5 %; pH 11.5; bactericidal at 4 % and 5 min; UNE-EN 13697 and UNE-EN 14476; registration 22-20/90-04313 and 19-20/90-04313 HA): disinfectant and deodorising detergent.
- InstaBact® DS (1 % with isopropyl alcohol 10.30 %; ready to use, at least 5 min; registration 20-20/40-10631-HA): disinfectant surface cleaner.
- Bacter 200 (4.5 %; UNE-EN 13623 against Legionella pneumophila; registration 21-100-04598): cooling towers and evaporative condensers, by specialised professional staff.
- Sanitex (pH 7; 4 g per kg of dry laundry in the penultimate rinse, minimum 5 min): laundry hygiene in professional washing.