Lies, Damn Lies, and Far-UVC Marketing

How to buy safe and effective Far-UVC in a dishonest marketplace.

Far-UVC light has the potential to revolutionize global biosecurity and indoor air quality, as well as significantly improve public health. Unfortunately, as with many cutting-edge technologies, it tends to attract profiteers and opportunists.

If you follow the air purifier channel HouseFresh on YouTube, then you know that the air purifier industry is plagued by dishonest marketing tactics. Similarly, the lack of regulation in the Far-UVC industry means devices that are ineffective or even dangerous can be sold for enormous profit with little risk to manufacturers.

Far-UVC technology has been extensively researched. It has been shown to be extremely safe and incredibly effective. However, the way it is often sold and advertised leaves much to be desired.

You can absolutely find high-quality, safe, and effective Far-UVC products, but you must be an educated consumer and not simply accept marketing claims at face value. In this article, we're going to go over what you need to know before you buy.

Hitchens's razor
What can be asserted without evidence can also be dismissed without evidence.

First, it’s important to understand that claims alone are worthless unless there are consequences for fraudulent and deceptive ones. As it will become clear below, this is common practice in the Far-UVC industry, where there are no consequences- only greater profits.

Currently, a Far-UVC company can make nearly any claim about the effectiveness or safety of its product with little risk of verification and almost no risk of negative consequences if those claims are proven untrue. Therefore, any claim made by a Far-UVC seller that is not accompanied by evidence should be ignored. This evidence should include unredacted, downloadable test results from independent labs; the method used to calculate the claimed performance numbers; the software stack and parameters used to model outcomes; and links to peer-reviewed research papers.

Trust is irrelevant- don't blindly trust anyone when it comes to your health. You wouldn't buy unrated climbing equipment based on "trust" or the nationality of the seller because your health and life relies on it, just as they rely on clean air. If a company told you that their climbing equipment "supports up to 300 kg" based on their word alone and some drawings, with no load certifications, you would go elsewhere. Claims are worthless- only verifiable data matters.

In this article, we will be covering:

• Spectral Analysis

• Input vs. Output

• Optical Filtration

• Pathogen Chamber Testing

• Excimer Lamp Life

• Ozone Emission

• Disinfection Claims

• Why Do They Lie?

• Conflicts of Interest

Spectral Analysis

The first and most important document you should review before purchasing any Far-UVC product is the spectral assay. This document provides a complete description of the light output of the Far-UVC emitter. This includes the power, shape, and spectrum covered. Any light fixture can be mailed in by a third party and measured by the lab, there is no proprietary data in a spectral assay. There is also no valid reason for a company to hide it, demand non-disclosure agreements, or refuse to make it available for download on the product page- unless they know their product is substandard.

Obviously, in-house tests or tests by labs with commercial relationships to the seller or manufacturer are unacceptable. Only a few truly independent test laboratories offer complete spectral assays for Far-UVC products. We use Lightlab International in Pennsylvania. The cost is $1,000, which is very reasonable for ensuring a safe, effective product.

Input vs. Output

Often, when a Far-UVC fixture (luminaire) is sold, the input wattage is quoted as a power metric, but what we need to know is the total output wattage. Different fixtures have different levels of efficiency depending on their design. The output power of a Far-UVC fixture is only very loosely correlated with its power input. Therefore, the first thing we examine in the spectral assay is the fixture's Radiant Power Output.

The Nukit Lantern has a Radiant Power Output of 30.5mW (PDF):

This means that the fixture emits a total power of 30.5 mW (milliwatts) when measured in all directions.

To determine this and create a spectral analysis, the testing lab uses a device called a goniophotometer to measure the light output of the fixture from every angle:

The Far-UVC fixture (luminare) is rotated on the vertical and horizontal axis, and measurements are taken at 0.5º increments with a UV spectrometer. This allows the lab to build a three-dimensional chart of the fixture's power output, which can be displayed as a polar plot:

The red outlined area represents the Lantern's beam spread from a top view (X Axis), the blue outlined area represents the beam spread from a side view (Y Axis):

Many people and even some Far-UVC companies, confuse Radiant Power Output with Irradiance at Nadir. This is the Nukit Lantern's Irradiance Plot:

Below is an interactive model that shows the difference between Radiant Power Output with Irradiance at Nadir. Irradiance at Nadir (black vertical line) measures power at just one angle, directly in front of the lamp, not total power output. Radiant Power Output (white mesh) tells us the total number of watts emitted, making it a much more useful number for determining how many Far-UVC fixtures are needed in a room. 

Radiant Power Output

Irradiance at Nadir

View in your space

Click the above image, wait for the 3D model to load, then click and drag to move it, pinch to zoom in and out. Note: UV fixture size and output plot are not to scale.

Irradiance at Nadir (black vertical line), Radiant Power Output (white mesh)

A Far-UVC fixture with a very wide emission angle can have a higher Radiant Power Output (total power output), but lower Irradiance at Nadir (power output directly in front) than a fixture with a narrow emission angle. 

Imagine a spotlight and a floodlight. They can have the same power output in watts, but if you stand directly in front of the spotlight, it will seem brighter than the floodlight that is spreading that same power over a wider area. So one power measurement, from one position, is not enough to determine total output power.

When using germicidal UV against bioaerosols, a wider spread is better. This can be accomplished either by using wider beams or more emitters.

A Far-UVC manufacturer that only provides the power level at the center of a fixture's output, i.e., its Irradiance at Nadir, is not telling you the fixture's total power output or much about the product's effectiveness against bioaerosols. Disinfection is dose-dependent, so you need the total Radiant Power Output to calculate an effective dose for pathogen inactivation. Irradiance at Nadir is important for surface disinfection, and when calculating safe limits for the eyes and skin.

According to the above Irradiance Plot, the Nukit Lantern emits 4.6 µW/cm² of 222 nm light at a distance of 75 cm (µW is pronounced "microwatts") at nadir. So, a square centimeter that is 75 centimeters directly in front of the fixture will be hit by approximately 4.6 microwatts of Far-UVC light.

That gives us power, but UV exposure risk (and pathogen inactivation) is determined by power over time. We've created a simple spreadsheet so you can calculate safe exposure limits using the ACGIH standard.

We enter 4.6 µW/cm² under "Irradiance (µW/cm²)", and it tells us that we can safely look at the Lantern for about 9 hours and 42 minutes (75cm away).

We can then use the Inverse Square Law calculator to check other distances. We enter the "Irradiance at Current Distance" as 4.6 µW/cm², the "Current Distance" to 75 cm, and set the desired distance to 100 cm:

It tells us the Lantern's approximate Irradiance at Nadir at 100 cm is 2.58 µW/cm².

Going back to the ACGIH TLV calculator and putting in 2.58 µW/cm², we can see that if you are 100 cm away, you have 17 hours and 18 minutes of eye-safe operation:

You can use this calculator for any filtered Far-UVC fixture for which you have an Irradiance Plot.

Next, we will examine third-party spectral assays of three popular, portable Far-UVC emitters. Lightlab International conducted these tests independently on brand-new, unopened units.

Krypton MVP (Spectral Assay PDF)

Krypton MVP Pro (Spectral Assay PDF)

Ergo X-One (Spectral Assay PDF)

Far UV Technologies' sales page claims a radiant power output of ~12 mW for their Krypton MVP product and ~24 mW for the Krypton MVP Pro.

They provide no spectral analysis, whether from a third party or otherwise, and offer no evidence to support their claim. This is understandable because lab results show that the actual radiant power output of the Krypton MVP is 4.8 mW instead of 12 mW:

….and that the Krypton MVP Pro is just 8.8 mW instead of 24 mW:

This is a fraction of what buyers are told the products offer.

What makes this more than just a simple mistake is the accompanying charts on the sales page:

This shows 4 µW/cm² at 42cm for the Krypton MVP Pro and 2 µW/cm² at 42cm for the MVP Pro. This is consistent with the Irradiance at Nadir results from the Lightlab spectral assay. But you can't have that Irradiance at Nadir, and what they claim is the total Radiant Power Output, unless the polar plot was completely different from what it is.

Clearly, Far UV Technologies is in possession of accurate spectrographic data and knows exactly how much power their MVP devices really output. They even check the devices before packaging them. However, they chose to claim a total Radiant Power Output number that was less than half of what these products actually produce. (We contacted Far UV Technologies for comment or explanation several months before publishing, and did not get a response.)

Meanwhile, the Ergo X-One sales page simply claims a “UV intensity” of “1500 µW/cm²”. It is not uncommon for Far-UVC resellers to not understand the metrics they quote. “1500 µW/cm²” alone, without stating that it is a nadir measurement and without providing the distance at which the measurement was taken, is an example of this. They quoted part of a measurement without realizing that it doesn't mean anything without the missing data point or knowing whether the device would offer any protection to buyers.

The actual measured Irradiance at Nadir for the Ergo X-One is 2.2 µW/cm² at 50 cm:

We can then use the Inverse Square Law calculator again, trying different Desired Distances, and can then see that Ergo X-One is only 1500 µW/cm² at 1.9 cm- measured almost directly against the glass filter:

While this odd measurement method is probably well-intentioned, it unfortunately does not tell us the actual total Radiant Power Output of the device or its effectiveness. 

The spectrographic assay reveals that the Ergo X-One's total power output is just 8.9 mW- about the same as the Krypton MVP Pro:

To illustrate how far below the threshold for effectiveness these output numbers are, we can run the spectrographic assay through physics modeling software using computational fluid dynamics to see the exact impact that it would have when compared to the now-discontinued portable Nukit Torch kit (PDF), which emitted 95.6 mW (23.9 mW per emitter):

(This model is sped up; the timer on top shows the elapsed time. You may have to pinch and zoom on mobile or view the video in landscape mode in the YouTube app.)

In the above model, we measure two key areas to determine effectiveness:

The Breathing Zone: According to ASHRAE standards, this is the air volume from 8 cm (3.14 in) to 180 cm (70.86 in) above the floor, 60 cm (23.62 in) away from each wall. The air the room occupants inhale and exhale primarily comes from inside this area. This is represented by the large cube, outlined in green, located in the middle of the room.

The Breathing Box: A 500 cm³ (30.51 cubic inches) volume right below your nose tip. By counting infectious particles inside versus outside this tiny space, we get a pseudo "fit factor"- similar to how we test mask effectiveness. This is also sometimes called "Exposure Reduction Factor". This is represented by a small cube outlined in orange in front of each person's mouth.

As you can see, these devices, which output less than 10mW, provide almost no protection from infection.

For those of you who might ask, no, wearing them or putting them next to/under/over your face will not have any effect. We ran the CFD models, and the output wattage is simply far too low- but please support Rebirth Garments' and their other products.

(This model is sped up; the timer on top shows the elapsed time. You may have to pinch and zoom on mobile or view the video in landscape mode in the YouTube app.)

Unfortunately, the Nukit Torch kit is no longer available- although a new, even more powerful version should be ready in Q4 2025. You can add your email to the original Torch product page to be notified using the "Notify When Available" link.

Optical Filtration

Currently, all commercial Far-UVC products use krypton-chloride excimer bulbs as their light source. Perhaps in the future we’ll have LEDs or other alternatives, but for now, the technology just isn’t ready. 

KrCl excimer bulbs are excellent at producing 222 nm light. But, they also produce light well outside of the safe Far-UVC range- harmful UVC, and light well up into the UVA and UVB bands. To address this, Far-UVC fixtures use optical bandpass filters. This optical filter allows safe 200-230 nm Far-UVC light through while blocking almost all of the light in the unsafe bands. With a good quality filter, a Far-UVC emitter is incredibly safe.

The problem is that these optical filters are extremely expensive, often costing as much as the KrCl bulb itself. Consequently, the KrCl bulbs used in commercial Far-UVC fixtures often have undersized filters, which restrict light output and limit effectiveness.

Omitting the bandpass filter or substituting plain quartz glass can also allow unscrupulous sellers to make high-power output claims without mentioning that much of that output is in the form of extremely harmful UV rays outside the safe Far-UVC range.

Fortunately, a standard spectral assay makes it possible to determine whether a Far-UVC emitter is equipped with a bandpass filter (although a precise determination of the quality of that filter needs more specialized measurements). Ideally, the assay will show leakage above 240 nm. However, you can also get a good idea even if the cutoff is at 250 nm.

Here’s a filtered Nukit Lantern (Spectral Assay PDF) with minimal leakage above 250 nm:

By subtracting the "UV-C 200-250" (99.8%), from the "Total UV" (100%), we can see the Lantern "leaks" 0.2% UV over 250 nm- that's 0.1mW, very little and still safe.

Next is a well-filtered Krypton Shield that uses a Ushio emitter (Spectral Assay PDF). Doing the same math as above, we can see it "leaks" 0.3% UV over 250 nm- that's a bit more than the Lantern, but still very safe.

Here’s a Sterilray "GermBuster" Sabre that uses an unfiltered KrCl bulb (Spectral Assay PDF). 4.1% of its UV output is above 250nm, 19.7 mW. This means it emits UVA, UVB, and UVC at levels that require a distance of about three meters for even marginally safe operation:

The spectral output of a filtered Ushio B1 emitter and an unfiltered Sterilray are compared here:

To be clear, unfiltered KrCl bulbs have been conclusively shown to be harmful:

A Pilot Study of the Effect of 222-nm UVC Phototesting on Healthy Volunteer Skin
https://sci-hub.ru/10.1111/phpp.12156
https://onlinelibrary.wiley.com/doi/abs/10.1111/phpp.12156

Isla Rose Mary Barnard, Ewan Eadie, and Kenneth Wood confirmed that this damage was due to Sterilray being unfiltered:

Extreme Exposure to Filtered Far-UVC: A Case Study
https://sci-hub.ru/10.1111/php.13385
https://pmc.ncbi.nlm.nih.gov/articles/PMC8638665/

Further evidence that Far-UVC for disinfection is unlikely to cause erythema or pre-mutagenic DNA lesions in skin
https://onlinelibrary.wiley.com/doi/10.1111/phpp.12580

No study has ever demonstrated the safe implementation of Far-UVC produced by an unfiltered krypton chloride (KrCl) excimer bulb. No patent has ever been issued for a "safe" form of Far-UVC produced by an unfiltered KrCl bulb.

While you can prevent immediate visible short-term skin and eye damage from unfiltered KrCl bulbs by using them at a significant distance, you cannot mitigate the hidden, accumulated harm of high-intensity, broad-spectrum, long-term UV exposure. 

Many online "clean air influencers" lack a firm understanding of Far-UVC technology and the tools necessary to measure and evaluate UV output. Unfortunately, some of these influencers have been persuaded to promote unfiltered Far-UVC products to their followers. Unseen but cumulative UV harm has led many unfiltered Far-UVC device users to insist these products are safe. This puts the public at substantial risk and could lead to Far-UVC being discredited as a safe, effective tool for clean air.

Third-party test results and peer-reviewed research should always take precedence over corporate marketing claims. If you are using unfiltered KrCl excimer bulbs, all available evidence indicates that you are exposing yourself and those around you to harmful UV rays- even if the consequences of that exposure are not immediate. 

In addition, even if a Far-UVC seller is honest and means well, if they cannot show you a third-party spectral assay (not one supplied by the factory), they do not actually know that the Far-UVC product they ordered or had manufactured is actually filtered and safe.

It is extremely common for factories to cut costs and substitute cheap, plain quartz glass for expensive bandpass filters because they look identical, and few buyers have the required testing equipment. Alibaba is full of unfiltered 222nm fixtures. Even after the initial spectral assay, every Far-UVC shipment needs to be checked with a spectrometer by an outside agent or non-factory employee to verify filtration and output power as part of the QA process.

Pathogen Chamber Testing

While a spectral assay provides us with data on filtration, radiant power output, and beam geometry needed for evaluating and deploying Far-UVC, and CFD modeling lets us simulate that performance in software, a final check ensures that the results are accurate in the real world.

Elevators are rated for various weights, and each of their components is tested before final assembly to ensure those ratings. However, because elevators are used for such critical applications, test weights are often loaded into them during installation and maintenance to confirm that everything works together properly and that the ratings translate into real-world performance.

Pathogen chamber testing serves a similar purpose- it provides a final check to ensure that the measurements and data of a device that we rely on for safety are accurately reflected by its real-world performance.

To accomplish this, we place the Far-UVC in a room-sized, hermetically sealed chamber, introduce a pathogen, and measure the inactivation rate. This type of test is included in both the GB/T 18801-2022 air cleaner standard and the AHAM AC-5-2023 standard.

While you can use several different pathogens for testing, at Nukit, we use human coronavirus HCoV-229E because its UV sensitivity and inactivation characteristics are similar to those of SARS-CoV-2. We test in a 30 m³ room-sized chamber rather than a small 1 m³ box because testing in a smaller space does not reflect real-world performance.

The performance of a Far-UVC product tested this way directly reflects why consumers are buying it- no extrapolation is required; it provides direct proof of effectiveness. A pathogen chamber test removes almost all abstraction. It demonstrates a product's real-world performance and proves that it does what it claims to do.

The now-discontinued Nukit Torch kit emitted  95.6 mW (23.9 mW per emitter) and reduced the pathogen load by 73.66% in a 30 m³ chamber (PDF):

Two Nukit Lanterns, offering a total of 60 mW, reduced the pathogen load by 74.66% in the same 30 m³ chamber (PDF):

Four Nukit Lanterns for a total of 120 mW get us to 89.07% (PDF):

The nice thing about having pathogen chamber tests is that we can then compare those to our software models, confirm our spectral assays are accurate, the math is solid, and we are getting the same results in our software tests as in our real-world tests:

(This model is sped up; the timer on top shows the elapsed time. You may have to pinch and zoom on mobile or view the video in landscape mode in the YouTube app.)

Although a pathogen chamber test isn’t as essential as a complete spectral assay, we believe it provides consumers with an extra level of confidence by demonstrating precisely how the product performs against real pathogens in an actual room in the real world when sold as is- not just on paper. 

As with a spectral assay, if a company won't provide the results of a relatively inexpensive pathogen chamber test, it's likely because they are fully aware their product cannot perform as advertised, or do not want it benchmarked against Far-UVC products that offer the same performance at far lower cost. 

Excimer Lamp Life

The krypton-chloride excimer bulbs used to generate Far-UVC have a significant downside: a relatively short lifespan. On average, they last just 3,000–5,000 hours. Currently, no filtered Far-UVC fixture allows for easy bulb replacement*, and once the bulb dies, the entire fixture- including the electronics and bandpass filter- becomes e-waste. This leads to a high hourly operating cost, which gives many buyers pause.

Far-UVC sellers have responded to this concern with bold marketing claims that their excimer bulbs last 10,000 to even 20,000 hours. Given that this is at least a year away from the date of purchase, when the device is well out of warranty, why not? There’s no downside to the claim.

As with other dubious marketing copy, there are no third-party test results verifying the claimed operating life. There are also no peer-reviewed studies in which a KrCl excimer bulb was successfully operated for this length of time while staying within specifications. Additionally, there are no patents covering the necessary technology. Some companies cite poorly documented and vague "internal testing."

If your product is so revolutionary and has such a huge edge over the competition, why not have a credible third-party lab confirm it? Or patent it? They can't. Far-UVC companies can claim anything, and people will believe them, assuming there is some risk of misrepresentation- there isn't. It's just profit.

According to all the independent data currently available, KrCl excimer bulbs last between 3,000 and 5,000 hours before experiencing performance degradation.

If a company expects you to calculate ownership costs based on a claimed operating life that contradicts all current knowledge about the technology, then it's reasonable to expect them to provide solid third-party data proving that their product can actually offer that. Reputable companies don't make claims they can't support with credible data.

Falsus in uno, falsus in omnibus
One who falsely testifies about one matter is not credible to testify about any matter
-Latin legal maxim

Once you see a company engage in dishonest business practices, such as making unsupported claims, they have shown their character. It would be foolish to then accept any other claim they make about any of their products at face value. Always demand proof.

*Nukit's next model Far-UVC fixture will have replaceable bulbs to address this.

Ozone Emission

Some have expressed concern about the potential for ozone emission from Far-UVC fixtures. However, this is only a potential issue with rooms with serious pre-existing ventilation issues, and has not been observed in any real-world Far-UVC installation. This is because even modest ventilation rates cause ozone to dissipate almost immediately, keeping in-room levels well below NIOSH safety limits and often below ambient outdoor levels.

Still, it’s reasonable to want to keep ozone levels as low as possible. For this reason, the Nukit Lantern is validated by United Laboratories as having Zero Ozone Emissions.

 
If you are concerned about ozone emissions, ask your Far-UVC vendor for the results of their UL 2998 test for Zero Ozone Emissions. It is inexpensive, and the results- pass or fail, will show exactly how much ozone the device creates.

Disinfects up to…

One of the most insidious and dishonest phrases in air purifier marketing is the dreaded "up to..."

Imagine you went to your local hardware store to buy a light fixture. You ask the salesperson how powerful it was, and they respond, "It illuminates up to 500 square feet!" or "It eliminates up to 99% of darkness!". You'd probably ask, "Okay, well, how much illumination? Can I see my hand? Can I read a book? How does this compare to that other light fixture over there?" If they said they couldn't tell you, you'd move on.

Claims such as "up to 98% pathogen reduction" should raise immediate red flags. At what distance, over how long, inactivating what pathogens? Surface or air? With the device held 3 cm from a Petri dish for an hour, or mounted near the ceiling in a room? Any claim without the total Radiant Power Output is dishonest and meaningless- just marketing doublespeak designed to sound impressive without offering actual data quantifying what you are getting for your money.

Similarly, people want to know how large an area a single device can effectively treat. But at what dose? Providing only square footage or meters covered without stating the degree of protection offered is meaningless. Knowing the total milliwatts of output from a spectral assay allows you to determine this.

We provide pathogen chamber test results for our products on our sales pages. This allows you to see the real-world results and decide how many fixtures are right for your space.

Unfortunately, people continue to buy indoor air quality tools based on a manufacturer's evasive "protects up to..." claims without verifying the accuracy of the claim, asking what the number is based on, or inquiring about the level of protection offered for a given space. They assume that companies can't lie and that there is some kind of oversight that would prevent them from doing so. This is simply not the case. Ask to see the math and for third-party data. If you don’t receive it, they are hiding something.

Why Lie?

Why do companies do this? Not just with Far-UVC, but also air purifiers? In short, engineering, R&D, and manufacturing are expensive; copywriting is cheap. It costs far more to develop an effective product than it does to write persuasive marketing language that simply claims the same effect.

A company that provides exaggerated or even fictitious specifications for its products gets all the benefits of actually having those specifications, without the cost- provided no one checks, and so far, they don't.

For some companies' leadership, it makes more economic sense to invest in better marketing that will never be fact-checked either by customers or investors, rather than better engineering. 

All this is particularly grim for vulnerable people buying Far-UVC while under the impression that these costly products are doing something, and who may become infected while unknowingly unprotected.

Conflicts of Interest

Why does this epidemic of dishonesty persist? Isn't there a group or impartial body that can expose these practices? Aren't there enforceable regulations?

Unfortunately, they are few and far between. There are billions of dollars at stake as the world begins to look towards large-scale biosecurity measures to protect against current and future threats. Competing interests are looking to make their mark- or their fortunes- on what technologies eventually see widespread adoption. Non-profits are reluctant to take unpopular positions that might interfere with future funding.

Some groups are invested exclusively in filtration-based indoor air quality solutions and are determined to discredit UV technologies, which they feel compete with this (while actually UV perfectly complements filtration). Conversely, there are groups invested in the future of Far-UVC who feel that acknowledging any downsides, including problematic industry practices and conflicts of interest in academia, would hinder its adoption. This code of silence persists even when those practices clearly endanger public health and the credibility of Far-UVC as a technology. Many of these groups and individuals receive generous grants to do exactly this kind of advocacy, or public funds, and so should act in the public interest. Yet, they remain silent- and a lie by omission is still a lie.

The firewall that should exist between Far-UVC manufacturing and academia is instead a revolving door. Far-UVC companies often give researchers generous grants and paid advisory positions. ICFUST, the largest Far-UVC conference, is funded by the same companies that researchers should be able to evaluate impartially for the public good.

Ironically, conference organizers and academic participants will insist that they can't push for transparency or address the rampant misinformation and mislabeling that pose a risk to public health because they "have to remain impartial"- all while sporting more banners than a race car from the very companies responsible for that misinformation that also fight against regulation and greater transparency. Their job is not to be impartial but on the side of evidence, science, and public health- not protecting their corporate sponsors.

Unsurprisingly, in study after study, the Far-UVC products of the sponsoring companies are shown to perform flawlessly and without caveat. No studies are conducted to verify marketing claims, even when people are clearly being misinformed and possibly left unprotected. Studies promote only the most costly- and so profitable for manufacturers- Far-UVC implementations, not the highest ROI and most cost-effective ones that would benefit the most people. There is no push for greater transparency. Public health researchers and advocates only act when it is convenient and unproblematic, not when it might put them at odds with the industry contacts who fund their work.

One of the main inventors responsible for much of current Far-UVC technology, while undeniably brilliant, is also a co-author on many of the most cited studies on Far-UVC- all while working for the university that licenses that same Far-UVC technology to the world's largest Far-UVC emitter manufacturer.

That university and its researchers are hardly going to shine a light on the dishonest marketing practices of the companies that pay millions in licensing fees to use university IP in their products.

The same university published a glowing adver-study of a Far-UVC product after receiving a generous “research gift” from the manufacturer.

Even if their conduct were completely above reproach, the very fact that this university is attached to so much research on what they sell and directly profit from has already been seized upon by Far-UVC detractors to discredit large bodies of data that have yet to be replicated by parties without similar conflicts of interest.

These practices jeopardize Far-UVC's potential for large-scale deployment as a life-saving technology. They have not, and will not, remain unnoticed or unaddressed by detractors or those conducting meta-studies. If left uncorrected, it will inevitably undermine the credibility of all Far-UVC research.

Having repeatedly called for this vulnerability to be addressed (even resorting to light-hearted memes), in response, some researchers, rather than look inward at this state of affairs, have blamed the messenger and now try to find fault in Nukit’s products on behalf of their sponsors. 

We welcome any scientific scrutiny. We invest in R&D and engineering, not copywriting, cronyism, and thinly veiled bribery. Nukit has always aimed for complete transparency and is up to the challenge of meeting any engineering standard set. We would just like to see all Far-UVC products subject to the same level of scrutiny and offer the same transparency that Nukit does.

Takeaways

1. Without a spectral analysis, a Far-UVC product can be anything from useless to dangerous. There's no way to know whether it's safe or effective. Major manufacturers have been caught lying with no consequences, so they will continue to do so.
   
   

2. There is currently no regulatory enforcement. Researchers and non-profits have not, and given the current perverse incentives, likely will not, be speaking up to inform and protect the public from dangerous or ineffective Far-UVC products.
   
   

3. A complete photometric assay from LightLab International costs $1,000 and provides a wealth of data. If a company does not make one available for download on its product page, or if there is data omitted, there's a reason for that.
   
   

4. In terms of overall effectiveness, the first metric you want to look at is Radiant Power Output. Keep in mind that broader coverage- either by using more emitters, wider beams, or ceiling placement- can often trump sheer output wattage for pathogen inactivation.
   
   

5. The Irradiance at Nadir only provides a very rough estimate of a fixture's power and is mostly useful for safety calculations.
   
   

6. Far-UVC is very powerful, but it is also very expensive. If a Far-UVC company is selling a device and can’t prove with independent lab results that it is as powerful as advertised, will work as advertised, for as long as advertised, don’t waste your money. Invest in a quiet but high CADR air filter. It can't offer the same protection from near-field transmission as Far-UVC, but at least you know what you are getting.
   
   

7. Trust no one- not appearances, not nationality, not Nukit. Trust hard data from credible, impartial sources.

Despite all this, here at Nukit, we believe that Far-UVC is not just positioned to drastically revolutionize public health, but is an essential tool for global biosecurity that cannot be replaced by any other available technology. The millions of lives Far-UVC could potentially save every year make it worth coming together, working through these issues, doing better, and making sure bad practices do not undermine eventual large-scale adoption.

If you've enjoyed this article and found it informative, please share it as widely as you are able. The more public support there is for honesty and transparency in Far-UVC, the more people will benefit from this remarkable technology.

-Nukit

All device specifications come from third parties. All of the above models are provided with the caveat that "all models are flawed, but some models are useful." While they are not perfect, they offer a helpful guide for non-academics looking to protect themselves from airborne pathogens.  

The following methods, software, and parameters were used to generate the "Cafe Tabletop CFD Model, Krypton MVP Pro vs. Nukit Torch" and "Wearable Krypton MVP Pro vs. Ergo One X" models featuring exhalation and breathing box/zone boundaries and the "Nukit Lantern, Four Emitters, 30 m3 Chamber, HCoV-229E Inactivation Efficacy" model featuring simulated  GB/T 18801-2022 Air cleaner Appendix H, full room inactivation:

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