Hypochlorous Acid in the Fight Against COVID-19
Alan G. Kabat, OD, FAAO
As news of COVID-19, the worldwide pandemic associated with severe acute respiratory syndrome coronavirus-2 (SARS CoV-2) continues to dominate the headlines well into April of 2020, eye care providers have witnessed a tremendous alteration of their practices and lifestyles. Upon recommendations from both the American Academy of Ophthalmology and the American Optometric Association, ophthalmologists and optometrists have been advised to restrict their care to urgent and emergent cases only. This has resulted in many eye care practices across the country closing entirely, not only because of fear of the virus, but because of difficulties in obtaining personal protective equipment (PPE) and lacking appropriate protocols for patient flow and disinfection. Protection against this unforgiving virus has become a paramount concern for healthcare providers and patients alike.
At present, the United States Centers for Disease Control and Prevention (CDC) have made the following recommendations for all individuals to slow/stop the spread of COVID-19: 1
1. Wash your hands often with soap and water for at least 20 seconds. If soap and water are not readily available, use a use a hand sanitizer that contains at least 60% alcohol. Avoid touching your eyes, nose, and mouth with unwashed hands.
2. Stay home as much as possible. Practice social distancing by keeping at least six feet (2 meters) between yourself and other people.
3. Cover your mouth and nose with a cloth face cover when around others, and especially if you go out in public.
4. If you do not have a face covering, remember to always cover your mouth and nose with a tissue when you cough or sneeze, or use the inside of your elbow.
5. Clean and disinfect frequently touched surfaces daily. This includes tables, doorknobs, light switches, countertops, handles, desks, phones, keyboards, toilets, faucets, and sinks.
As a disinfectant, the CDC recommends dilute household bleach solution (5 tablespoons per gallon of water) or solutions containing at least 70% alcohol. The agency has also endorsed a litany of other common Environmental Protection Agency (EPA)-registered household disinfectants which, although not formally tested against the SARS CoV-2 pathogen, have shown efficacy against harder to kill viruses (e.g. Norovirus and Hepatitis A).1,2 If one reviews the published list, he may recognize several active ingredients that have broad antiseptic properties, including hydrogen peroxide, quaternary ammonium and thymol in addition to many alcohol and bleach derivatives. But of particular interest, especially to eye care providers, is the inclusion of hypochlorous acid.
Most of us will recognize hypochlorous acid (chemical formula: HOCl) as a now widely-utilized agent for the management of blepharitis in the United States. First introduced for ophthalmic use in 2014, HOCl is a natural antibacterial agent that is produced during the human immune response as white blood cells target pathogens within the body.3,4 This simple chemical compound has a broad spectrum of activity and exhibits rapid kill kinetics against a wide range of bacterial and viral organisms.5 Despite their efficacy however, ophthalmic formulations of HOCl are safe and extremely well-tolerated by patients.
Some of the earliest information regarding HOCl being used to contain the spread of COVID-19 came in the form of reports from South Korea. On March 3, 2020, a story by CNN about workers at drive-through corona testing stations reported that “When their shifts ends, they step fully clothed into a small portable booth called the ‘Clean Zone,’ in which they are showered in hypochlorous acid disinfectant.”6
In reviewing the EPA’s listing,2 HOCl appears a total of six times in unique products; these include such names as Cousteau (Reckitt Benckiser; Parsippany, NJ), Excelyte VET (Paradigm Convergence Technologies; Little River, SC), Danolyte (Danolyte Global; Overland Park, KS) and Cleansmart (Simple Science Limited; Edina, MN). The amount of HOCl in each of these products varies, with some as high as 500 parts per million (0.05%), but both Cousteau and Cleansmart weigh in at 0.017%. If we compare this concentration with that of known ophthalmic products containing HOCl, HypoChlor (OCuSOFT; Rosenberg, TX) meets and exceeds this percentage in that it contains 0.02% HOCl.
To be clear, at this date, none of the commercially available hypochlorous acid eyelid formulations have been specifically tested for efficacy against SARS CoV-2, either in vitro or in vivo. Nonetheless, as doctors and patients alike look for alternative disinfection solutions that are safe and well-tolerated on human skin – including the face and skin around the eyes – this information is very compelling. Gloves and masks provide excellent barriers to COVID-19 spread, but contamination remains an issue when removing these items. Moreover, the CDC has warned individuals that touching the nose, mouth or eyes increases the risk of potential infection. Since products like HypoChlor are readily available and easily applied to the face via a convenient spray bottle, this provides great peace of mind for those of us who still need to venture out into the community during this challenging time. Admittedly, due to the overwhelming evidence, this author has been regularly using HypoChlor on both his face and precious N95 masks following trips to the supermarket or other vital destinations where the potential for contamination exists.
Until we have effectively “flattened the curve” and social distancing can be relaxed, we must remain diligent in the fight against this unparalleled pandemic. Sometimes, in order to do that, we need to be creative. It is nice to know that a simple product like HypoChlor, which many of us employ routinely for blepharitis, may have additional utility against this potentially deadly disease.
Dr. Kabat is a Professor of Optometry at Salus University in Philadelphia, Pennsylvania. He is a member of OCuSOFT’s Optometric Scientific Advisory Board.
1. Centers for Disease Control and Prevention. Coronavirus disease 2019 (COVID-19) – Prevention & treatment. Updated April 4, 2020. Available at: https://www.cdc.gov/coronavirus/2019- ncov/prevent-getting-sick/prevention.html. Accessed April 7, 2020.
2. United States Environmental Protection Agency (EPA). List N: Disinfectants for use against SARS-Cov-2. Updated April 2, 2020. Available at: https://www.epa.gov/pesticide-registration/list-n-disinfectants-use-against-sars-cov-2. Accessed April 7, 2020.
3. Stroman DW, Mintun K, Epstein AB, et al. Reduction in bacterial load using hypochlorous acid hygiene solution on ocular skin. Clin Ophthalmol. 2017;11:707-714.
4. Hurst JK. What really happens in the neutrophil phagosome? Free Radic Biol Med. 2012;53:508–520.
5. Wang L, Bassiri M, Najafi R, et al. Hypochlorous acid as a potential wound care agent: part I. Stabilized hypochlorous acid: a component of the inorganic armamentarium of innate immunity. J Burns Wounds. 2007;6:e5.
6. Watson I, Jeong S. CNN. South Korea pioneers coronavirus drive-through testing station. CNN. Updated March 3, 2020. Available at: https://www.cnn.com/2020/03/02/asia/coronavirus-drive-through-south-korea-hnk-intl/index.html. Accessed April 8, 2020.