Dr Clo Disinfectant Sticks : Do They Work Against COVID-19?

Dr Clo Disinfectant Sticks : Do They Work Against COVID-19?

Dr Clo sterilisation sticks from South Korea are being marketed as a way to prevent COVID-19.

Let’s take a look at their claims, and find out what the FACTS really are!


Dr Clo Disinfectant Sticks : Chlorine Dioxide Sanitisers

Dr Clo disinfectant sticks, also known as Dr Clo sterilisation sticks, were developed by NON Corporation from South Korea.

Originally sold as a sanitising deodorant, it started being marketed as 99.9% effective against the COVID-19 virus, SARS-CoV-2.

That brought them a lot of attention, and many of our readers asked us to fact-check their claims. That was the basis of our original fact check.


Dr Clo Disinfectant Sticks : Claims Removed

Dr Clo Malaysia recently reached out to us, and explained that they made mistakes in their marketing materials.

Those mistakes have been corrected based on what I addressed in my original article, removing these claims :

  • 99.9% effective against COVID-19
  • Tested, verified and approved by US FDA
  • Disinfects a space of up to 16 feet in radius

However, Dr Clo Philippines continues to make the claims above, so we will address them below as well.

They also shared new test reports from Korea, to prove that Dr Clo is both safe and effective.

I would like to thank Mr. Ng Lyp Hau, the Director of Dr Clo Malaysia, for sharing the new information with us.

Let’s check out what’s changed and what’s new with Dr Clo Disinfectant Sticks!


Dr Clo Disinfectant Sticks : TLDR Summary

Here is a quick summary on Dr Clo disinfectant sticks :

  1. They are registered with the US FDA as a general purpose sanitiser.
  2. Class I refers to the low risk devices, not the quality or efficacy of the product.
  3. They were registered as 510(K) exempt from proving safety or efficacy, so they were not tested or approved by the US FDA.
  4. The KR Biotech lab test only proves that an aqueous chlorine dioxide solution can kill SARS-CoV-2 virus, not the actual chlorine dioxide gas released by the disinfectant sticks.
  5. The Seoul National University lab test showed that the chlorine dioxide gas they release inside a small sealed chamber can reduce SARS-CoV-2 virus load completely in one hour, .
  6. Their internal test shows that they emit between 0.01 and 0.02 ppm of chlorine dioxide, below the NIOSH / OSHA limit of 0.1 ppm for 8 hours.

There does not appear to be enough evidence to prove that the Dr Clo Disinfectant Sticks can protect you against COVID-19, and I’m glad to note that they have mostly removed this claim.

Happily, they also shared some evidence that the chlorine dioxide gas released is below the NIOSH / OSHA limit.

If you wish to purchase these sanitising deodorant sticks, you can do so at the official Dr Clo store.

Make sure you buy the original ones, because at least we know that they emit low levels of ClO2 gas.


Dr Clo Warning : Do NOT Hang It On Your Body!

According to the Dr Clo’s FAQ 2.0 (posted March 2021), Dr Clo is not meant for users to hang on their bodies. The correct way to use it is to place it indoors.

Yet many of Dr Clo influencers love showing how easy it is to strap it around their necks.


Dr Clo Disinfectant Sticks : Do They Work Against COVID-19?

Dr Clo made a number of claims about their disinfectant sticks, including being over 99.9% effective against the COVID-19 virus.

Let’s examine each claim, and see what the FACTS really are!

Claim #1 : Dr Clo Is US FDA Approved / Tested / Verified
Verdict : Registered, But Not Tested, Verified Or Approved

When we first fact-checked their claims, Dr Clo’s Facebook posts claimed that their sanitisation sticks were tested, verified and approved by the US FDA.

Dr Clo told us that it was a mistake, and they removed all references to US FDA approval, verification or testing.

However, a quick check revealed that at least their subsidiary in the Philippines continues to make this claim (here, here, here), as well as the Dr Clo official store.

So let us make it very clear – Dr Clo disinfectant sticks were NOT TESTED , NOT VERIFIED and NOT APPROVED by the US FDA.

Dr Clo was only registered as a 510(K) exempt general purpose disinfectant, with the Registered Establishment Number of 3013383068.

With the exception of certain reserved devices, the US FDA does NOT require Class I products to even prove that they are safe and effective.

As a 501(K) exempt device, “a premarket notification application and FDA clearance is not required before marketing the device“.

The US FDA only requires the manufacturer “to register their establishment“, which was what Dr Clo did.

Therefore, Dr Clo disinfectant sticks were registered, but not tested, verified or approved by the US FDA.

Claim #2 : Dr Clo Is Class 1 Medical Device
Verdict : Correct, Because It Doesn’t Require FDA Approval

Most people will assume that Class 1 products are superior to Class 2 or Class 3 products. That’s not true.

Dr Clo is a Class 1 product because it’s just a disinfectant, and therefore, does not require FDA testing or approval!

Class 1 products are those that are the least likely to pose a risk to our safety. Hence they generally do not require testing or approval by the US FDA. Examples of Class 1 products include :

  • Toothbrush – manual or electric
  • Tongue depressor
  • Bandages
  • Disinfectants

Class 2 products are those that pose more risk because they come into contact with your internal organs, or are diagnostic tools, etc. Examples of Class 2 products include :

  • Blood pressure cuffs
  • Pregnancy test kits
  • Syringes
  • Surgical gloves
  • Contact lenses

Class 3 products are those that either sustain / support life, are implanted, or could potentially pose risk of injury. Examples of Class 3 products include :

  • Breast implants
  • Pacemakers
  • Cochlear implants
  • Ventilation machines

Claim #3 : Dr Clo Is Medical Grade / Hospital Grade Disinfectant
Verdict : Not Until They Are US EPA Certified

Dr Clo claims that their disinfectant sticks are Hospital / Medical Grade Disinfectants. That would true, if their disinfectant sticks are registered with the US EPA.

This is important because hospital-grade disinfectants are certified based on DIS/TSS-1 Jan 22, 1982 EFFICACY DATA REQUIREMENTS Disinfectants for Use on Hard Surfaces.

At the very minimum, a hospital-grade disinfectant must be tested against Pseudomonas aeruginosa and Staphylococcus aureus, and their efficacy approved by the US EPA.

As per Dr Clo’s FAQ 2.0 (posted March 2021), their disinfectant sticks are not registered with the US EPA.

Claim #4 : Dr Clo Was Certified Effective Against COVID-19 Virus
Verdict : Only In Labs, Using Solution / Sealed Chamber

Konkuk University : Using Solution

In December 2020, NON Corporation announced that their Dr Clo disinfectant sticks were proven to be 99.9% effective against SARS-CoV-2, the COVID-19 virus.

This was based on a laboratory test conducted by KR Biotech Co. Ltd under the Institute of Infectious Disease Control of Konkuk University.

In that test, KR Biotech dissolved an entire Dr Clo disinfectant stick in 100 ml of warm water for 24 hours, to create an aqueous chlorine dioxide solution.

That concentrated chlorine dioxide solution reduced the SARS-CoV-2 virus titre (amount of virus) by 99.93% after just 30 seconds.

However, the actual Dr Clo disinfectant stick works by releasing small amounts of chlorine dioxide gas over 50 days, so the laboratory test was completely pointless.

The KR Biotech test results do not prove that the chlorine dioxide gas from Dr Clo disinfectant sticks can actually destroy the SARS-CoV-2 virus in the air, much less prevent you from getting infected.

Lots of things can kill the SARS-CoV-2 virus, including ordinary soap! But that does not mean these substances can effectively kill SARS-CoV-2, or prevent an infection, when dispersed into the air.

Seoul National University : Using Sealed Chamber

A month after we published our fact check on 3 February 2021, NON had Professor Cho Nam Hyuk from the Seoul National University test the efficacy of their Dr Clo sanitisation stick against the SARS-CoV-2 virus.

In that test, Professor Cho used a sealed chamber measuring 25 centimetres on each side, with a cubic capacity of 15.625 litres.

He ran two tests – one with a Dr Clo disinfectant stick attached to the top of the sealed chamber, and one without.

At first glance, the results are impressive, showing a steady drop of plaque-forming units (p.f.u.) with the Dr Clo disinfectant stick active in the sealed chamber.

After one hour, no more SARS-CoV-2 p.f.u. could be detected.

However, I have to point out a few troubling points about this study :

A. The sealed chamber is very small – measuring just 25 cm x 25 cm x 25 cm.

It would not be an accurate reflection of the real world discharge of the Dr Clo disinfectant stick, which promises a protective radius of 16 feet (4.88 metres).

The sealed chamber has a cubic capacity of 0.01562 m³ – much smaller than the rated protective volume of 17,157 cubic feet or 486 m³.

B. The Dr Clo disinfectant stick appeared to be activated for 16 hours, prior to the test.

That would have led to a very significant accumulation of chlorine dioxide within the sealed air chamber.

If true, it would not be an accurate reflection of the real world concentration of chlorine dioxide released by the Dr Clo disinfectant stick.

C. It took about 252 seconds for the chlorine dioxide gas to reduce the virus load in the air chamber by half.

While better than the baseline of 11 minutes, 4 minutes is still a long time because SARS-CoV-2 is a highly-contagious virus that infects in SECONDS.

A normal person takes about 12 to 20 breaths a minute. That’s an average of 67 breaths in the 4 minutes 12 seconds it takes for the chlorine dioxide gas to cut the viral load by half.

It does not appear that the chlorine dioxide gas from the Dr Clo disinfectant stick can destroy the SARS-CoV-2 virus fast enough to matter.

Claim #5 : Dr Clo Passed EU REACH SVHC Test
Verdict : Absolutely, Chlorine Dioxide Is Not Even In The List

To prove that Dr Clo is safe, NON Corporation had it tested by the Korea Testing and Research Institute (KTR) for toxins and carcinogens.

What KTR did was test the Dr Clo disinfectant sticks against the Candidate List of Substances of Very High Concern (SVHC) from the European Chemicals Agency (ECHA).

This is a red herring because the SVHC is a list of chemicals that are “carcinogenic, mutagenic or toxic for reproduction“. In other words, it is limited to chemicals that could cause cancer.

Just because a chemical is not in that list, does NOT mean it is safe to breathe in.

In fact, the same ECHA warns that chlorine dioxide is dangerous, and can be fatal if inhaled, is toxic if swallowed, and can cause severe skin burns and eye damage.

The ECHA dossier for chlorine dioxide gas lists its LC50 (lethal concentration over 4 hours) at 32 ppm. In other words, it is considered a “very toxic” gas at 32 ppm.

The US FDA has also warned about the dangers of chloride dioxide, calling it “a powerful bleaching agent that has caused serious and potentially life-threatening side effects“.

But of course, it all boils down to the dose. After all, even oxygen and water can be toxic at high doses.

Claim #6 : Dr Clo Emits 0.01-0.02 ppm ClO2 – 10X Safer Than WHO Guidelines
Verdict : Not Quite, But Should Be Safe

WHO does not actually have guidelines for ClO2 gas limits. However, both NIOSH and OSHA in the United States set ClO2 exposure limits at 0.1 ppm (up to 8 hours).

Dr Clo shared with us a document on their internal measurement of chlorine dioxide, showing ClO2 readings of 0.01 ppm and 0.02 ppm.

That would certainly make it safe to breathe in, albeit not quite “10X safer”, because the NIOSH and OSHA exposure limits are based on an 8-hour work session.

While we have no reason to doubt the accuracy of their internal test, it would be good if Dr Clo can verify it with an independent test that they can release publicly.

It would also be good for Dr Clo to share with us the concentration of ClO2 gas over time inside a sealed gas chamber.

This would assure the public that there won’t be a dangerous build-up of chlorine dioxide gas inside their car, home or even the refrigerator.


Help Support My Work!

If you would like to support my work, you can do so via bank transfer /  PayPal / credit card.

Name : Adrian Wong

Credit Card / Paypal : https://paypal.me/techarp
Bank Transfer : CIMB 7064555917 (Swift Code : CIBBMYKL)

Thank you in advanced! 


Recommended Reading

Go Back To > Health | Fact CheckHome


Support Tech ARP!

If you like our work, you can help support us by visiting our sponsors, participating in the Tech ARP Forums, or even donating to our fund. Any help you can render is greatly appreciated!

Leave a Reply