Peracetic acid and coronavirus

The current coronavirus pandemic (COVID-19) has been caused by the SARS-CoV-2 virus. This is an encapsulated coronavirus, formed by a single strand of RNA, which is principally transmitted through the air by infected persons and via contact with surfaces. For this reason, surface disinfection is, along with personal hygiene and protective measures (masks, safety distances, quarantine, confinement, etc.), a priority strategy in the fight against the pandemic, as it acts on one of the infection pathways.

Surface disinfection and coronavirus

Research published on 17th March in The New England Journal of Medicine concludes that SARS-CoV-2 is more stable on plastic surfaces and stainless steel than on copper or cardboard. On plastics, the virus was detected up to 72 hours after being applied to the surfaces, although the viral load decreased considerably during this time (from 103.7to 100.6 TCID50 per millilitre of medium). On stainless steel the drop was faster, and in 48 hours the viral load had fallen from 103.7 a 100.6 TCID50 per millilitre of medium. On copper surfaces no viable SARS-CoV-2 was detected after 4 hours, while on cardboard the virus was not detected after 24 hours (van Dolremalen et al., 2020).

Due to the ability of the coronavirus to persist on different types of surfaces, disinfection should be rigorously applied in the food distribution and retail industry in general and individual establishments in particular, as it is essential to ensure the supply of safe food to the population while, at the same time, avoiding infection among personnel working in these places.

Surface disinfection should be carried out in production, distribution and retail facilities as well as in all related spaces, including corridors, floors, offices, toilets, changing rooms, vehicles, and so on. Suitable biocidal products should be used for this purpose. In a previous post, we gave recommendations for disinfecting surfaces and some suitable products for this purpose. In addition, the United States Environmental Protection Agency has published an extensive list of disinfectants that have viricidal activity and are recommended against the SARS-CoV-2 virus (EPA 2020).

Due to the recent emergence of SARS-CoV-2, there are still no specific tests that check the efficacy of disinfectant products against this virus. However, some of the current viricidal efficacy tests include reference viruses that are morphologically similar to SARS-CoV-2. In fact, SARS-CoV-2 is not particularly resistant to conventional biocides (quaternary ammonium compounds, alcohol, chlorine, etc. (ECDC, 2020)). During the current COVID-19 pandemic, one of the biocide substances being recommended to inactivate the coronavirus is peracetic acid-based disinfectant, referred to as PAA (Wang et al.2020).

The scientific literature, as well as recent recommendations issued by various health authorities, provides data on the efficacy of active substances in PAA-based products (PAA and hydrogen peroxide) against SARS-CoV-2. These tests have been performed using encapsulated viruses (like SARS-CoV-2), other comparable coronaviruses, or under conditions that prove generic viricidal efficacy. The table below presents the data available in the literature, as well as the official recommendations.

Virucidal Action Active ingredient and concentration Time Source
Activity against encapsulated viruses (EN14476 – Vaccinia) Peracetic acid 0.01% 1 min (Rabenau 2010)
Limited spectrum virucidal activity (EN14476 – Adenovirus and murine norovirus) Peracetic acid 0.04% 5 min (Becker 2017)
General virucidal activity (EN14476 – Poliovirus, adenovirus and murine norovirus) Peracetic acid 0.15% 5 min (Becker 2017)
Decontamination of SARS-CoV-2 on surfaces Hydrogen peroxide 0.5% 1 min (Spanish Ministry of Health, 2020)
Activity against human coronavirus (HCov-229E) Hydrogen peroxide 0.5% 1 min (Kampf 2020)

Disinfectant products containing PAA

PAA, also known as peracetic or peroxyacetic acid, is an organic compound with the following chemical structure:

PAA is a product of the reaction between acetic acid and hydrogen peroxide. It is commercially available as an equilibrium between PAA, acetic acid and hydrogen peroxide. Thanks to its high oxidising potential, which acts on the external membrane of bacteria, endospores, fungi, viruses and yeasts, it has many industrial applications as a disinfectant in the food industry as well as in laundry products and water and wastewater treatment. Its oxidation mechanism involves electrons being transferred from the oxidised form of the acid to the microorganisms, thereby inactivating them. Its biocidal efficacy, the absence of hazardous residues and its easy application in aqueous solution, makes PAA an increasingly necessary antimicrobial in the food and beverage industries.

There are various formulations that include PAA as an active ingredient and which can be used for disinfecting surfaces. Some relevant PAA formulations, containing PAA and hydrogen peroxide as active ingredients and commercialised by CHRISTEYNS, are listed in the table below. These products are registered as biocide in different European countries. These compositions can be compared with the information presented in the table above to evaluate their potential capability to inactivate SARS-CoV-2. The viricidal efficacy tests carried out for some of these products are also indicated.

Product name % PAA % H2O2 Other
Oxysan 5 4.9 23
Mida Chriox F2 2.4 7.3 Foaming, for use on open surfaces
Oxysan 15 14.9 25.7
Phago’Spore 0.034 3.25 Ready to use for surface disinfection

The virucidal efficacy of Oxysan 5 has been tested against Adenovirus, Influenza H1N1, Influenza H5N2, Poliovirus and Vaccinia virus, by means of the tests EN 14476 (Quantitative suspension test for the evaluation of viricidal activity). The test on Vaccinia virus indicates efficacy against encapsulated viruses. The viricidal capacity of Oxysan 15, a product similar to Oxysan 5 but with a higher concentration, can be deduced from the tests carried out with the latter. Additionally, Phago’Spore (direct application disinfectant) has been tested (EN14476) against Poliovirus, Adenovirus and Murine Norovirus, showing general viricidal activity.

With the exception of Phago’Spore, which is a ready-to-use product, the other formulations must be diluted in water in the proportions indicated in the corresponding technical information. In all cases, the indications and precautions detailed in the technical and safety data sheets for each product must be followed.

Conclusions

At the time of writing, there have already been over 1.5 million cases of COVID-19 confirmed in the world, and number of people who are infected but not confirmed is probably several times higher. It is therefore crucial, in addition to healthcare effort and other important control measures, to implement one of the main strategies for preventing the many infections that occur daily. This strategy is the frequent and proper cleaning and disinfection of the surfaces that people come into direct contact with on a daily basis. Although the virus becomes progressively inactivated over time, it can remain on surfaces for relatively long periods (several hours or even days). To avoid this source of propagation and infection, there are many products that we can use to inactivate the virus in a simple way: alcohol, chlorinated products, quaternary ammonium, and so on. These products include those based on PAA and hydrogen peroxide which, at both the industrial and institutional levels, can be extremely helpful in reducing infections. The suppliers specialised in this type of products are able to offer the most appropriate alternatives for each case, as well as products that are registered as biocides and have undergone rigorous efficacy tests.

NOTE: The technical information corresponding to the products listed in the above table can be consulted on the CHRISTEYNS website or by sending a request to: [email protected]

Bibliography

  1. Becker et al. (2017) Virucidal efficacy of peracetic acid for instrument disinfection. Antimicrobial Resistance and Infection Control, 6:114

BETELGEUX-CHRISTEYNS, Equipo Técnico (2020). Cuestiones frecuentes sobre el coronavirus en alimentos y superficies. URL: www.betelgeux.es/blog/2020/03/23/cuestiones-frecuentes-sobre-el-coronavirus-en-alimentos-y-superficies/ 23 de marzo de 2020.

ECDC, European Centre for Disease Prevention and Control (2020) Interim guidance for environmental cleaning in nonhealthcare facilities exposed to SARS-CoV-2. https://www.ecdc.europa.eu/sites/default/files/documents/coronavirus-SARS-CoV-2-guidance-environmental-cleaning-non-healthcare-facilities.pdf

EPA, United States Environmental Protection Agency, 2020. Disinfectants for Use Against SARS-CoV-2. URL: https://www.epa.gov/pesticide-registration/list-n-disinfectants-use-against-sars-cov-2 Consultado el 1 de abril de 2020.

  1. Kampf, D. Todt, S. Pfaender, E. Steinmann (2020) Persistence or coronaviruses on inanimate surfaces and their inactivation with biocidal agents. Journal of Hospital Infection, 104:246-251.
  2. F. Rabenau, I. Rapp, J. Steinmann (2010) Can vaccinia virus be replaced by MVA virus for testing virucidal activity of chemical disinfectants? BMC Infectious Diseases, 10:185
  3. van Doremalen, et al. (2020). Aerosol and surface stability of HCoV-19 (SARS-CoV-2) compared to SARS-CoV-1. The New England Journal of Medicine. DOI: 10.1056/NEJMc2004973.
  4. Wang et al. (2020). A precision medicine approach to managing 2019 novel coronavirus pneumonia. Precision Clinical Medicine, Volume 3, Issue 1, March 2020, Pages 14–21, https://doi.org/10.1093/pcmedi/pbaa002