Though the risk of transmission of COVID-19 through touching surfaces is not considered the main way the virus spreads by the Centers for Disease Control and Prevention, it has not been ruled out. As a result, we must continue to eliminate common points of touch and regularly disinfect those that cannot be eliminated. Like you, I have had much more experience with workplace disinfecting over the last few months and wanted to share a few quick tips that I have learned personally and from clients. Also, due to many questions and conversations about hypochlorous acid and where it fits into the disinfecting world, I did a bit of research to share.

Tips on disinfecting...

When deciding on which products to use for workplace disinfection, the following may be helpful considerations:

1. Clean first then disinfect – organic material can quickly consume the active ingredient in disinfectants leaving invisible bacteria or viruses to live on. Remove organic material from a surface by cleaning with soap and water and then apply the disinfectant to kill the viruses and bacteria.
2. Consider product availability – the pandemic has placed huge demands on suppliers of disinfectants. The ideal products are not always available, but it is important that you select a product that has efficacy against the virus. The Health Canada website is a great place to start and then work with your suppliers to ensure you are using the right products. Disinfectant suppliers are currently run off their feet. They may not have time to review who is using products on Health Canada’s list and who is not. It is the employer’s responsibility to protect their workers, patrons and brands by ensuring they are using products with efficacy against COVID-19.
3. Practicality of the contact time needed to kill the virus – the contact time for the disinfectants to kill bacteria or viruses ranges from 15 seconds to 30 minutes. Depending on the job at hand, workers may not be able to wait 30 minutes to disinfect a surface. If you’ve already chosen your disinfectants, ensure you read and follow the instructions for contact time on the label. If you need to source a product that acts faster, the US Environmental Protection Agency’s (EPA) new List N Tool, allows you to easily search on contact times to obtain a list of products that may suit your needs. And to ease the demand for supply of disinfectants, Health Canada has made it possible for certain products, such as hard surface disinfectants and hand sanitizers, to be imported and sold in Canada as an interim measure.
4. Applying the product – the active ingredients in quaternary ammonium products can bind to certain types of clothes, reducing their effectiveness by 85%! This is known as “Quat Binding”. Ensure that you read the label and apply the product properly for maximum effectiveness.
5. Consider the hazards of the product – remember that disinfectants are meant to kill organisms. For this reason, they are regulated in most countries. When considering the cost of the products, be sure to review the product label and safety data sheet. While one product may be cheaper than another to purchase, when you consider any PPE required to properly protect the workers who are using these products, the economics may change.
6. Availability of personal protective equipment – further to point 4, if the proper PPE is not available, other products must be chosen.
7. Plan ahead for the supply of the product – products like wipes may be used at high frequency. Ensure that your supply can be maintained once you have done the work to select the product and determined how to use it safely.
8. Disposal of the product – products like wipes or environmental hazards can create secondary issues if disposed of improperly. Ensure that your method of communication for the disposal of the product is clear and sustainable.
9. Storage of the product – ensure the product can be stored properly, if it is flammable or hazardous, and out of reach of vulnerable people who may not understand or be able to read about the hazards.
10. Engage and train your workers – frontline workers are handling disinfectants with much higher frequency. They trust employers to train them, as is required by law, to handle chemicals safely. These workers can be stressed or be working many jobs with different disinfectants in each location. Keep their training simple, clear and accessible for refreshing memories.
11. Audit your protocols – set a frequency to review the protocols you have put implemented. Talk to workers for feedback on ease of use, issues with PPE, etc. and adjust as needed.

There are many types of active ingredients in disinfectants, but the remainder of the blog will focus on hypochlorous acid-based disinfectants.

What is hypochlorous acid?

Hypochlorous acid is one of the disinfection agents that forms when chlorine dissolves in water. It is a weak acid with a pH of 3 to 6, according to Hypochlorous Acid: A Review¹, which is a very interesting, recently published paper on the use of hypochlorous acid as a disinfecting agent in the dental and medical sectors.

In everyday life, a good example of where hypochlorous acid is useful is with saltwater swimming pools. These types of pools use electrolysis (electric current to stimulate a chemical reaction) with dissolved salt (NaCl) to generate hypochlorous acid (HClO) and sodium hypochlorite (NaClO) as the sanitizing agents for the pool.

Is hypochlorous acid effective against COVID-19?

To find an independent answer to this question, I looked at disinfecting products that are included on Health Canada’s List of disinfectants with evidence for use against COVID-19 and the US Environmental Protection Agency’s COVID-19 disinfectants, known as List N. At the time of writing, the Health Canada list contained 1 product while the EPA List N contained 12 products where hypochlorous acid is listed as the active ingredient.

Are hypochlorous acid-based disinfectants safe to use in the workplace?

Aside from the paper cited in footnote 1, I looked to the European Chemicals Agency (ECHA), whose mission is to “work for the safe use of chemicals”.  ECHA defines a biocide as a product that is “used to protect humans, animals, materials or articles against harmful organisms like pests or bacteria, by the action of the active substances contained in the biocidal product”. Since active chlorine, which is released from hypochlorous acid, is an effective biocide, I was able to find opinion pieces completed by ECHA’s Biocide Products Committee on hypochlorous acid. There are detailed evaluations for several product types and I encourage those who are considering use of hypochlorous acid-based products to review these informative opinions. However, a summary table from opinion EC 232-232-5 Product Type 4 is useful for this discussion as it considers the risk associated with the “active chlorine released from hypochlorous acid used as hard surface disinfection/disinfection in food and feed industry (professional use, 200-300 mg/L active chlorine) and cleaning in place/cleaning in food and beverage industry (professional use, 200-300 mg/L active chlorine).” These scenarios define the typical use scenarios for hard surface disinfectants in the average workplace.

To me, hypochlorous acid-based disinfectants seem to be inexpensive to produce, effective and relatively safe for workers. Keeping in mind that our bodies also have good bacteria on the surface, I would still use gloves to handle the disinfectant, as I do all disinfectants, but I will definitely consider using these products as they become more available on the market.

If you need help selecting disinfectants or performing risk assessments for safe use of these products, please feel free to contact us. We would be happy to conduct an assessment of the disinfectants you are using against COVID-19 and provide guidance to mitigate risk.

1 Block, Michael S, and Brian G Rowan. “Hypochlorous Acid: A Review.” Journal of oral and maxillofacial surgery : official journal of the American Association of Oral and Maxillofacial Surgeons vol. 78,9 (2020): 1461-1466. doi:10.1016/j.joms.2020.06.029