Transmission from hard surfaces and disinfection strategies

  • …Physicochemical processes and surface science underlying the adsorption and transfer of virus between surfaces, as well as their inactivation, are important in understanding how the disease is transmitted, and in developing effective interception strategies.

Castaño N et al. Fomite transmission and disinfection strategies for SARS-CoV-2 and related viruses arXiv:2005.11443 May 2020.

Effective for hours

  • This study used … a polymeric surfactant containing QAC … sprayed on the surfaces following … cleaning. …None of the bed units (0/18, 0.0%) were contaminated with MRSA following the treatment. This was in contrast to 4/18 (22.2%) of sites cleaned with hypochlorite, …(OR=0.11 [CI95% 0.01-2.21], p=0.1501) …. Continue using currently utilized products approved for use in healthcare.

Yuen JWM et al. Methicillin-Resistant Staphylococcus aureus (MRSA) Contamination in Bedside Surfaces of a Hospital Ward and the Potential Effectiveness of Enhanced Disinfection with an Antimicrobial Polymer Surfactant, International Journal of Environmental Research and Public Health 2015, 12(3), 3026-3041.

Effective against CoV-2

  • Several readily available quaternary ammonium formulations were evaluated and proved to be effective … after drying on both metal and plastic surfaces. A silinated quaternary ammonium compound that left a residual on the surface was capable of inactivating SARS-CoV-2 for at least seven days …. Studies on the finger transfer of coronavirus from various surfaces showed that the amount of virus transfer to the finger varied from 0.46 to 49.0% depending upon the surface. Little or no virus transfer occurred from treated surfaces compared to the untreated controls. …Various quaternary ammonium disinfectant formulations are effective against human coronaviruses. Finger transfer tests showed that transmission of coronavirus from surfaces can be prevented, reducing the risk of fomite [hard surface] transmission.

Gerba CP Efficiency of Quaternary Ammonium Disinfectants against SARS-CoV-2 and Coronavirus 229E, Open forum infectious diseases ; 8(Suppl 1):S488-S489, 2021.

Illness cost-estimates, survey results on continued disinfection practices and tips for selecting effective products

  • Nearly 345 million school days are lost annually due to illness. …CDC estimates this costs the U.S. economy $120 billion in lost productivity….75% of American adults are likely to continue key hygiene behaviors in the coming months, like ... disinfecting frequently touched surfaces…. Products that say “disinfectant” on the label … meet government specifications. …Check for an EPA Registration Number on the label. Disinfectants: …Effective against the germs indicated on their labels. Surfaces should be clean prior to disinfecting. Disinfectant cleaners…contain ingredients that help remove soil, as well as kill germs.

Clean Link Cleaning Fundamentals to Prevent Colds and Flu Dec 17, 2021

Quat-based products highly effective and practical for healthcare use

  • We evaluated the virucidal activity of two quaternary ammonium compounds (QAC) disinfectants…. Two QAC disinfectants are highly effective for the inactivation of SARS-CoV-2, which makes them practical for use in healthcare settings and laboratories where prompt disinfection is important. The low-level … present in commonly available household hygiene agents is also able to inactivate SARS-CoV-2.

Haung Y et al. Evaluating the Virucidal Activity of Four Disinfectants Against SARS-CoV-2, American Journal of Infection Control Nov 11, 2021

Effective against COVID

  • Quaternary ammonium compounds (QAC) are common disinfection agents with a wide range of microbicidal action. Disinfectant wipes containing 0.75% didecyl-dimethyl-ammonium chloride associated with 0.5% hydrogen peroxide can …can prevent transmission to secondary surfaces. …Surface disinfection solutions containing 0.5% benzalkonium chloride with laurylamine can reduce viral titres after 30 minutes of exposure while 0.5% benzalkonium chloride associated with glutaraldehyde and didecyldimonium chloride showed reduction of SARS-CoV titres also in 30 minutes. QAC was shown to be active against SARS-CoV-2 in contact times of 5 minutes or less.

Martins CPV et al. Disinfection methods against SARS-CoV-2: a systematic review Journal of Hospital Infection Oct 18, 2021

Silanated quats could play a role in Covid 2 transmission from surfaces

  • Silane-anchored quaternary ammonium compound treated surfaces could play an important role in mitigating the communicability and fomite transmission of SARS-CoV-2.

Caschera A et al. Evaluation of Virucidal Activity of Residual Quaternary Ammonium-treated Surfaces on SARS-CoV-2.


  • One group of the QACs family that is widely used as a biocidal agent is the alkyldimethylbenzylammonium chloride …. These are active against coronaviruses at less than 1% concentration and within an exposure time of a minute or less (Saknimit et al. 1988; Pratelli 2008; Kampf et al.2020). …Dialkyl quaternaries retain biocidal activity in the presence of anionic residues and hard water (Rutala, W., Weber, D. & Healthcare Infection Control Practices Advisory Committee 2019).

Mohammad Hussein Al-Sayah Chemical disinfectants of COVID-19: an overview Journal of Water and Health (2020) 18 (5): 843–848

Effective Against COVID-19

  • …Consumers should feel confident that products on …the Environmental Protection Agency’s (EPA) List N: Disinfectants for Coronavirus, will kill the novel Coronavirus upon application and stop its spread

American Chemical Council Commercial Disinfectants Equally As Effective Against New COVID Strains, According to CBC (Center for Biocides Chemistries) Jan 11, 2021

Alcohol-Free Sanitizers Work

  • Researchers from Brigham Young University discovered …quaternary ammonium compounds found in disinfectants…in most cases … wiped out at least 99.9% of the virus within 15 seconds.

European Cleaning Journal Study shows alcohol-free sanitiser is effective against Covid-19 Dec 10, 2020

What Do Quats Kill

  • …Quaternary ammonium compounds (QACs) are among the most commonly used disinfectants. .Selection of formulations and methods of application have been shown to affect the efficacy of QACs. Their hydrophobic activity also makes them effective against lipid-containing viruses.

El-Badry M et al. Epidemiological and Disinfectants as Controlling Aspect on COVID-19 Journal of Advanced Biomedical and Pharmaceutical Sciences 4 (2021) 37-41

Hand Sanitizers Are Effective

  • Quats rapidly inactivate SARS-CoV-2, making them potentially useful for controlling SARS-CoV-2 spread in hospitals and the community

Ogilvie BH et al. Alcohol-free hand sanitizer and other quaternary ammonium disinfectants quickly and effectively inactivate SARS-CoV-2 Journal of Hospital Infection Short Report (2021) Volume 108, P142-145