How can you safely disinfect your devices against the SARS-CoV-2 coronavirus?

What is the best procedure to keep surfaces clean?

You should clean and disinfect frequently touched surfaces using an EPA-registered disinfectant on the EPA List N. It is important to regularly clean frequently touched surfaces including doorknobs, faucets, light switches, handles, phones and keyboards. Most people will cautious and clean surfaces like countertops or tables, but then they pick up their devices, which is the most frequently touched object for many people. According to the CDC, the best way to keep hard electronic devices clean is to use a wipeable cover or case designed to make it easier to clean and disinfect. It’s important to follow the manufacturer’s instructions and recommendations for cleaning the electronic item¹.  

How do I know which disinfectants work on the virus causing COVID-19?

Not all disinfectants are effective against the novel coronavirus. During the initial outbreak of a new virus like COVID-19, no disinfectants existed on the market that could make claims to kill the virus, because the virus was simply not available for testing.

The CDC recommends that studies of cultures of novel SARS-CoV-2 should be conducted in a Biosafety Level 3 (BSL-3) laboratory using BSL-3 practices² but there is a limited number of BSL-3 labs in the world. Understandably, the immediate priority for research at these labs would focus on vaccines and treatments, so testing would have been a bottleneck. After that, it could still take more than one year to get a viral claim approved by a regulatory agency.

Since few disinfectants could be tested, the EPA took the approach of fast-tracking approvals of already approved disinfectants using a ‘hierarchy-based’ policy. This means that if a company’s product has been found to be effective against harder-to-kill viruses, it is likely to kill a virus like COVID-19.

The EPA expects the products on List N to kill SARS-CoV-2, the coronavirus that causes COVID-19, because they:

• Demonstrate efficacy against the coronavirus SARS-CoV-2 (COVID-19);
• Demonstrate efficacy against a pathogen that is harder to kill than SARS CoV-2 (COVID-19); or
• Demonstrate efficacy against a different human coronavirus similar to SARS-CoV-2 (COVID-19).

What do you mean by harder-to-kill virus? What are the different types of viruses and which disinfectants are effective against them?

Viruses can be generally categorized into three groups by virus structure. This affects the effectiveness of disinfectants in killing the viruses.³

• Enveloped viruses are easiest to kill. (Examples are Influenza A Virus. Herpes Simplex Virus, Human immunodeficiency virus (HIV))
• Large, non-enveloped viruses are more difficult to kill. (An example is Rotavirus or Adenovirus.)
• Small, non-enveloped viruses are hardest to kill. (Examples are Rhinovirus, Poliovirus, Coxsackie Virus, Parvovirus, and Norovirus.)
• Coronaviruses are enveloped viruses, meaning they are one of the easiest types of viruses to kill with the appropriate disinfectant product.

Since the novel coronavirus is lipid encapsulated, once you disrupt the lipid bilayer, it exposes the core proteins inactivating the virus, so it’s considered easier to kill vs. a non-enveloped virus.

A product that is likely to provide the greatest protection to you from COVID-19 will have claims against at least one non-enveloped virus such as Norovirus, Feline Calicivirus, Poliovirus, Rhinovirus, or Reovirus. This theory is the basis by which EPA has activated its Emerging Viral Pathogens Guidance for Antimicrobial Pesticides, regulating registrants that claim their products are effective against COVID-19⁴ .

Most of the disinfectants on EPA List N were already EPA-registered as hospital/healthcare or broad-spectrum disinfectant. Their directions included use on hard, porous or non-porous surfaces based upon claims and testing against at least one non-enveloped virus.

On July 6th, 2020, the US EPA announced it approved a test method for the SARS-CoV-2 virus, thus allowing disinfectants to get tested and submit their data to the US EPA for acceptance. If approved, they would be allowed to start the process of updating their chemical labels to include the SARS-CoV-2 claim.

You should stick to the products listed on the EPA List N. In reviewing a disinfectant for expedited review, the EPA would do a more thorough review of product chemistry, acute toxicology and appropriate efficacy studies. The efficacy data qualifies the product as a broad-spectrum or hospital hard surface disinfectant, and includes virucidal efficacy data for SARS-CoV-2 or another human coronavirus (e.g., ATCC 229E) or a non-enveloped virus.

Are there differences in the active ingredients in disinfectants?

There is no preferred active ingredient in disinfectants. All EPA-registered disinfectants must provide efficacy data against the organisms claimed on the label, but each has a different mechanism.

When selecting a disinfectant, try to select one appropriate for the surface it is intended to clean. There are advantages and disadvantages to every type of chemistry. Quaternary ammonium chemistry is a relatively surface-safe type of chemistry. It can act as a surfactant and help with the emulsification of soils and physical breakdown.

However, some disinfectants will chemically attack items being disinfected. Stainless steel can be pitted by strong acids and (in some conditions) halogen active disinfectants.

Bleach is a great oxidizer, but it is a corrosive with a high pH and not suitable for all surfaces. It also usually needs to be left on a surface for a long time to work, which has the potential to discolor the material. In some applications bleach can cause more damage than good.

Plastics can be affected by disinfectants containing organic solvents while various metals may be attacked by strong acids or alkalis, halogen active substances or disinfectants containing electrolytes.

Alcohol is a great anti-septic, but it is flammable and can flash off surfaces quickly.

Hydrogen peroxide can also be a good cleaner, however peroxide chemistry is acidic and not all surface are acid resistant, so it may not be compatible with many materials.

What should you consider in choosing a disinfectant?

A broad spectrum of disinfectants should be selected based upon FDA approval for efficacy against the specific HAI, whether SARS-CoV-2 (COVID-19), Multidrug-Resistant (MDR) pathogens such as Methicillin-Resistant Staphylococcus aureus (MRSA), Vancomycin-Resistant Enterococci (VRE), Extended-spectrum β-lactamase (ESBL) producing Gram-negative bacteria, Carbapenem-resistant Enterobacteriaceae, Multidrug-resistant Gram-negative rods (MDR GNR) such as Enterobacter species, Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, Clostridium difficile, Pseudomonas aeruginosa, emerging pathogens like the fungus Candida auris.

A wide range of disinfectants is required, however for each disinfectant to be effective, it is important to consider how you can adhere to the manufacturer’s instructions for mixing, prep and dwell time. Contact exposure time must be long enough to effectively kill the pathogen, but easy for Healthcare Workers to follow and not break down materials of the product being disinfected.

Most disinfectants have toxic properties and some are also highly corrosive, causing damage if they come into contact with skin or eyes. Some products are less suitable for contact with skin such as products with a high level of alkalinity or highly oxidizing products, such as sodium hypochlorite (bleach), hydrogen peroxide, chloroxylenol, or quaternary ammonium or bleach. 

Some disinfectants e.g. glutaraldehyde and hypochlorites may also have irritant properties and so cause respiratory problems if used in poorly ventilated areas. Some disinfectants may react with other chemicals causing the release of hazardous gases e.g. bleach and acids or bleach and cleaning agents containing ammonia.

Precautions should be given for handling both concentrated disinfectants and made up in-use dilutions. When handling concentrated disinfectants care should be taken to avoid splashing, and goggles or a full-face visor and gloves should be worn. 

Furthermore, the choice of disinfectant is an issue as most housings are not designed for disinfection and are not designed to be repeatedly disinfected using a wide range of disinfectants. 

In terms of the materials of a housing, it is important to test chemical compatibility against surfaces and to consider long dwell times and frequency of exposure. 25% of housing failures result from stress cracking of the materials that results from a combination of chemical exposure, environmental conditions and part design.

If using wipes, the composition of disinfectant changes over time as the main solve evaporates quickly. While the volatile organic compounds evaporate, the residual low volatility components accumulate on the housing surface if you do not wash after wiping, leaving a long contact exposure, which may chemically attack housing materials.

Also, even if you test a disinfectant that contains a specific active ingredient, every formulation is different and the solvents, surfactants, detergents, fragrances, stabilizers and additives may chemically attack the surfaces of the material you are disinfectant, hence materials need to be re-tested.

Part design also plays a factor as some cases are not waterproof, as they have areas that can harbor pathogens and accumulate disinfectant, leading to stress cracking.

Some housings either don't fully seal the internal device or components, leading to damaged devices or components that may not be easily repaired or replaced.

Other sealed housings claim to be waterproof, but use permeable membranes with tiny holes that allow air to pass through the membrane. These small holes can accumulate bacteria leading to biofilm growth. These membranes are delicate and not designed to be disinfected as they are not easy to clean. Any abrasion would damage the tiny holes, especially with any contaminant matter, causing leaks.

How should I use a disinfectant?

When using these disinfectants, follow the manufacturer’s instructions to properly use the disinfectant, such as recommended use-dilution (if applicable), material compatibility, storage, shelf-life, and safe use and disposal.

1. Check that your product is EPA-approved. To do this, find the EPA registration number on the product. Then, check to see if it is on EPA’s list of approved disinfectants at: epa.gov/listn. It’s important to note that EPA expects that all products on the list will be effective against SARS-CoV-2 (the coronavirus that causes COVID-19) on surfaces, ONLY when you follow the instructions with the listed contact time for the specified harder-to-kill virus. You can look under the column “Follow the disinfection directions and preparation for the following virus” to find which harder-to-kill viruses the EPA used in its assessment, and find the recommend minimum contact time.⁵ The EPA list also tells you the types of surfaces on which you can safely use a disinfectant product. You can see this by clicking on the green plus sign next to a product's registration number and looking at the Surface Type.
2. You can also find this information on the product label. For the product you are disinfecting, it’s important to know if the surface has any chemical compatibility problems with the materials of the surface or device. As we’ve noted, some disinfectants will degrade or damage the surface or change its color or properties. The product manufacturer should be able to provide you with recommendations on which disinfectants can be safely used on surfaces.
3. Read and follow the disinfectant product’s directions for the specific virus listed on EPA List N. Check “use sites” and “surface types” to see where you can use the product. You can use certain products on surfaces that touch food, such as dishes, cooking utensils, and countertops. For these products, the surface type in List N will include the phrase “Food Contact.” Read the “precautionary statements.” Note that a disinfectant can be approved with different instructions for different types of viruses or bacteria so it is important to follow the instructions for the specific virus listed on EPA List N. If there are use directions for enveloped viruses, follow those directions. EPA recommends that if the directions for use for viruses/virucidal activity list different contact times or dilutions, use the longest contact time or most concentrated solution.
4. Pre-clean the surface. Make sure to wash the surface with soap and water if the directions mention pre-cleaning or if the surface is visibly dirty. Keep in mind that dirt, germs, or blood on the surface may reduce the effectiveness of a disinfectant otherwise. Organic matter in the form of serum, blood, pus, or fecal or lubricant material can interfere with the effectiveness of disinfectant by reacting with it to form a complex that is less effective or not effective, leaving less disinfectant available to attack microorganisms^6. Chlorine and iodine disinfectants, in particular, are prone to such interaction. Organic material can alternatively act as a physical barrier for inorganic material. Studies show that inorganic material can be occluded in salt crystals blocking access to disinfectants to work. Both organic and inorganic soils are easily removed by washing. While there are one-step disinfectants that have been verified by the EPA to be effective against named organisms in the presence of 5% blood serum solution, these products generally do not require pre-cleaning in order to disinfect a hard surface as long as dwell time is observed. However, related to COVID-19, the CDC recommends a multi-step cleaning process including pre-cleaning prior to disinfection.
5. Follow the contact time listed to expose the virus on the surface. You can find the contact time in the directions. The surface should remain wet the whole time to ensure the product is effective. Let the surface air dry. Do not spray, and immediately wipe the surface as that won’t be effective. Many consumers are not aware they you need to leave the disinfectant on the surface long enough to effectively kill the contaminant. Most EPA-registered hospital disinfectants have a label contact time of 10 minutes. However, multiple scientific studies have demonstrated the efficacy of hospital disinfectants against pathogens with a contact time of at least 1 minute. By law, all applicable label instructions on EPA-registered products must be followed. If the user selects exposure conditions that differ from those on the EPA-registered product label, the user assumes liability from any injuries resulting from off-label use and is potentially subject to enforcement action under FIFRA⁶.

6.  Wear gloves and wash your hands. Some disinfectants are not skin safe, can be irritants or have toxicity when ingested, cause allergies or other health hazards. For some disinfectants, the directions will that you rinse the surface after disinfecting and this will be listed on the EPA List N as Food Contact Surfaces, Post-Rinse Required. In some cases, if you’re not wiping or rinsing the product off the surface, you can leave a chemical build-up over time which can lead to skin burns. It’s always best to wipe the surface post-cleaning to make sure it is not left with chemical residue. When a rinse is not necessary, this will be noted on EPA List N as Food Contact Surfaces, No Rinse. You can find out whether you need to rinse the surface after disinfection by reading the directions on the product label, however if you can’t tell, it’s best practice for you to wear gloves. For disposable gloves, discard them after each cleaning. For reusable gloves, dedicate a pair to disinfecting COVID-19. Wash your hands after removing the gloves. In our recommendations for disinfectants to be used on our waterproof cases, we recommend using a skin safe disinfectant.

7.  Lock up the disinfectant after use. Keep lids tightly closed and store out of reach of children⁷. It is best practice to separate any After carefully removing so that you don’t touch the contaminated portions of the PPE that you have been wearing, it should be disposed of in a trash liner that is then is sealed up and disposed of with your normal waste.

What should I do to clean my device in a Catalyst case?

If the surface is visibly dirty, wash it first with soap and water. Then, follow with an EPA-approved disinfectant, paying attention to proper contact time – the surface should remain wet the whole time to ensure the disinfectant is effective⁸.

It’s the manufacturer’s responsibility to provide a recommended disinfection protocol, and as you can tell, we’ve done our homework to come up with a recommendation.

Catalyst Waterproof Cases have been tested to sustain repeated disinfection with 70% isopropyl alcohol and 70% ethanol. These have proven to work against similar coronaviruses like SARS and MERS by a study by the Journal of Hospital Infection.⁹

According to the World Health Organization, in general, alcohol-based disinfectants (ethanol, propan-2-ol, propan1-ol) have been shown to significantly reduce infectivity of enveloped viruses like SARS-CoV-2, in concentrations of 70-80% with one minute exposure time.¹⁰

After cleaning, the following disinfectants and defined concentrations can be used on environmental surfaces to achieve a >3 log10 reduction of human coronavirus. They are also effective against other clinically relevant pathogens in the health-care setting:

• Ethanol 70-90%
• Chlorine-based products (e.g., hypochlorite) at 0.1% (1000 ppm) for general environmental disinfection
• 0.5% (5000 ppm) for blood and body fluids large spills.¹¹

In recommending a disinfection method, we needed to understand the toxicity of disinfectants & determine what was safe given the frequent skin contact to your devices.

The Catalyst Waterproof Case allows safe disinfection your phone or electronic device using 70% isopropyl alcohol or 70% ethanol. These are amongst the few disinfecting methods that are effective, skin-safe, and did not leave harmful chemical residue build-up that could pose a health hazard. 

We also looked at the chemical compatibility of disinfectants that were proven to work against coronaviruses to determine if any of the materials in our cases would be degraded. Some disinfectants chemically attack items being disinfected, e.g. various metals (may be attacked by strong acids or alkalis, halogen active) or plastics (affected by solvents), which are what your device or cases may be made of. Choosing the wrong disinfectant would affect the performance of our cases, possibly making it no longer waterproof or drop proof.  In some of our cases such as our Waterproof Case for the iPhone 11, there are 46 component parts. That’s a lot of reviewing, testing and evaluation!

Check out how to clean your phone case with our Total Protection range safely here.

Why are hand sanitizers not on the EPA’s list N?

EPA List N only includes EPA-registered, non-critical, hard non-porous surface disinfectants. At EPA, products used to kill viruses and bacteria on surfaces are registered as antimicrobial pesticides¹². An antimicrobial product or pesticide is intended to disinfect, sanitize, reduce, or mitigate growth or development of microbiological organisms ¹³.

Sanitizers and disinfectants are two types of antimicrobial pesticides¹⁴. Hand sanitizers, antiseptic washes and antibacterial soaps are not regulated as pesticides, because they are used to kill microbes in or on a person, and are regulated by the FDA. Antimicrobial hand hygiene products are regulated by FDA, which specifies the acceptable active ingredients and their use level. The two most popular on the market today are Ethanol (Alcohol) and Benzalkonium Chloride. 

Sanitizers used on inanimate objects such as countertops and floors are regulated as pesticides. EPA-registered surface disinfectants, including surface wipes, should not be applied on the skin or ingested, but only used on surfaces.

Unlike EPA registered disinfectants, products regulated by the FDA, such as antimicrobial handwashes or antibacterial hand sanitizers, do not undergo viral efficacy testing. The FDA monograph (the “rule book”) assumes the active ingredients have antimicrobial activity, and responsible manufacturers will self-verify their formula’s efficacy against a list of 26 organisms including bacteria, yeast, and mold. This list of organisms is recommended by the FDA. Making anti-viral claims or reduction in illness claims are considered false and misleading under the monograph, leading to enforcement by the FDA.

What does log reduction mean?

Log reduction or 99.9% or 99.9999% effectiveness are terms used to correlate to efficacy provided by a specific disinfectant or sanitizer. This means the percent of pathogens able to be killed from a hard non-porous surface as long as all label directions are followed properly.

What is the difference between a disinfectant and sanitizer?

Disinfection is 100% kill of the claimed organism. A sanitizer claim for nonfood contact surfaces is 99.9% of the claimed organism, or reducing the level of bacteria to a level considered safe by public health standards or requirements.

Sanitizers cannot claim viricidal data. For food service, a sanitizer should reduce the level of bacteria on a surface by 99.99%. Sanitizing does not necessarily clean dirty surfaces or remove germs. Most sanitizers, as well as disinfectants, require a clean surface in order to be effective at killing germs.

Can I use an alternative disinfection method?

CDC only recommends use of the EPA List N: Disinfectants for Coronavirus (COVID-19) against the virus that causes COVID-19. In their guidelines for disinfection, the CDC does not recommend alternative disinfection methods, including UVC devices, because their efficacy is unknown against the virus that causes COVID-19 and the EPA does not routinely review the safety or efficacy of these devices.¹⁵

Studies using UVC to disinfect and reuse masks show that even when using this alternative disinfection method, it is still important to supplement this with the primary recommended method to clean and disinfect. Consumers should continue using a disinfectant on the EPA List N Disinfectants for Coronavirus, since UVC may not be fully effective on all materials.

Check out our other articles around dispelling the myths about alternative disinfection methods such as antimicrobial products and UVC lamps.

1. Cleaning and Disinfection for Households. https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/cleaning-disinfection.html USA Center for Disease Control and Prevention (2020).
2. Interim Laboratory Biosafety Guidelines for Handling and Processing Specimens Associated with Coronavirus Disease 2019 (COVID-19), https://www.cdc.gov/coronavirus/2019-ncov/lab/lab-biosafety-guidelines.html USA Center for Disease Control and Prevention (2020).
3. American Chemistry Council. Center for Biocide Chemistries Answers Your Questions About COVID-19, https://blog.americanchemistry.com/2020/03/cbc-answers-your-questions-about-covid-19/ American Chemistry Council, (2020).

• Guidance to Registrants: Process for making claims against emerging Viral Pathogens not on EPA-Registered Disinfectant Labels, https://www.epa.gov/sites/production/files/2016-09/documents/emerging_viral_pathogen_program_guidance_final_8_19_16_001_0.pdf

5. What does the column "Follow the disinfection directions and preparation for the following virus" mean? Why are viruses other than the human coronavirus listed in that column?, https://www.epa.gov/coronavirus/what-does-column-follow-disinfection-directions-and-preparation-following-virus-mean-why, Environmental Protection Agency (2020)
6. Factors Affecting the Efficacy of Disinfection and Sterlization. Guideline for Disinfection and Sterilization in Healthcare Facilities https://www.cdc.gov/infectioncontrol/guidelines/disinfection/efficacy.html, Centers for Disease Control and Prevention (2008)
7. Chemical Disinfectants. Guideline for Disinfection and Sterilization in Healthcare Facilities (2008), https://www.cdc.gov/infectioncontrol/guidelines/disinfection/disinfection-methods/chemical.html, Centers for Disease Control and Prevention (2008) (2020).
8. 6 Steps for Safe & Effective Disinfectant Use. https://www.epa.gov/sites/production/files/2020-04/documents/disinfectants-onepager.pdf Environmental Protection Agency (2020).
9. The Journal of Hospital Infection. Persistence of coronaviruses on inanimate surfaces and their inactivation with biocidal agents, https://www.journalofhospitalinfection.com/article/S0195-6701(20)30046-3/fulltext Healthcare Infection Society (2020).
10. ECDC Technical Report. Disinfection of environments in healthcare and non-healthcare settings potentially contaminated with SARS-CoV-2 https://www.ecdc.europa.eu/sites/default/files/documents/Environmental-persistence-of-SARS_CoV_2-virus-Options-for-cleaning2020-03-26_0.pdf European Center for Disease Prevention and Control (2020).
11. Cleaning and disinfection of environmental surfaces in the context of COVID-19: interim guidance, 15 May 2020, https://apps.who.int/iris/handle/10665/332096, World Health Organization (2020).
12. List N: Disinfectants for Coronavirus (COVID-19). https://www.epa.gov/pesticide-registration/list-n-disinfectants-coronavirus-covid-19 USA Environmental Protection Agency (2020).
13. List N Appendix: Supplemental Residual Antimicrobial Products for Coronavirus (COVID-19). https://www.epa.gov/pesticide-registration/list-n-appendix-supplemental-residual-antimicrobial-products-coronavirus USA Environmental Protection Agency (2020).
14. What’s the difference between products that disinfect, sanitize, and clean surfaces? https://www.epa.gov/coronavirus/whats-difference-between-products-disinfect-sanitize-and-clean-surfaces (2020).
15. Cleaning and Disinfecting your Facility. https://www.cdc.gov/coronavirus/2019-ncov/community/disinfecting-building-facility.html Centers for Disease Control and Prevention (2020).