Benzalkonium chloride solutions are rapidly acting biocidal agents with a moderately long duration of action. They are active against bacteria and some viruses, fungi, and protozoa. Bacterial spores are considered to be resistant. Solutions are bacteriostatic or bactericidal according to their concentration. Gram-positive bacteria are generally more susceptible than Gram-negative. Activity is not greatly affected by pH, but increases substantially at higher temperatures and prolonged exposure times.
Newer formulations using benzalkonium blended with various quaternary ammonium derivatives can be used to extend the biocidal spectrum and enhance the efficacy of benzalkonium based disinfection products. This technique has been used to improve virucidal activity of quaternary ammonium-based formulations to healthcare infection hazards such as hepatitis, HIV, etc. Quaternary ammonium formulations are now the disinfectants of choice for hospitals. This is on account of user and patient safety even on contact with treated surfaces and the absence of harmful fumes. Benzalkonium solutions for hospital use tend to be neutral to alkaline, non-corrosive on metal surfaces, non-staining and safe to use on all washable surfaces.
The use of appropriate supporting excipients can also greatly improve efficacy and detergency, and prevent deactivation under use conditions. Formulation requires great care as benzalkonium solutions can be readily inactivated in the presence of organic and inorganic contamination. Solutions are incompatible with soaps, and must not be mixed with anionic surfactants. Hard water salts can also reduce biocidal activity. As with any disinfectant, it is recommended that surfaces are free from visible dirt and interfering materials for maximal disinfection performance by quaternary ammonium products.
Although hazardous levels are not likely to be reached under normal use conditions, it is important to remember that benzalkonium and other detergents can pose a hazard to marine organisms. Quaternary ammonium disinfectants are effective at very low ppm levels, so it is important to avoid excess in use. Responsible care ensures that the fragile marine ecosystems that sustain us are not disrupted.
Some products have been reformulated in light of this research, but it is still widely used in eyewashes, hand and face washes, mouthwashes, spermicidal creams, and in various other cleaners, sanitizers, and disinfectants. Manufacturers of over-the-counter artificial tears and eye washes became concerned about chemical sensitivity from long-term daily use and have in some products substituted EDTA as a preservative. Some have added "for sensitive eyes" to labeling. There has also been concern that long-term use of benzalkonium as a preservative in nose sprays may cause swelling of mucosa and lead to rhinitis medicamentosa. Some manufacturers have put 3-day limits on safe use of such nose sprays.
A disinfectant containing benzalkonium chloride and the related compound didecyl-dimethyl ammonium chloride (DDAC) has been identified as the most probable cause of birth defects and fertility problems in caged mice.
Cetostearyl alcohol/benzalkonium chloride/hydrocortisone: Allergic contact dermatitis following application of preparations containing cetostearyl alcohol and benzalkonium chloride: case report
Nov 15, 2008; Cetostearyl alcohol/benzalkonium chloride/hydrocortisone Allergic contact dermatitis following application of preparations...
WIPO ASSIGNS PATENT TO BISCO FOR "BENZALKONIUM CHLORIDE COMPOSITIONS FOR INHIBITING THE HYDROLYTIC ACTIVITY OF ENDOGENOUS MATRIX METALLOPROTEINASES IN DENTAL RESTORATIONS" (AMERICAN INVENTOR)
Sep 06, 2011; GENEVA, Sept. 6 -- Publication No. WO/2011/106089 was published on Sept. 01. Title of the invention: "BENZALKONIUM CHLORIDE...