222nm lamps kill pathogens but sell only a few hundred a year — the bottleneck isn't the technology
Far UVC uses 222nm light to inactivate pathogens in the air while leaving human skin unharmed; a South African TB trial has already seen 90% suppression, yet the world sells only a few hundred units a year. The real bottleneck is awareness.
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The argument · timestamps estimated from transcript position
222nm is safe for humans because of a layer of dead skin
The 200–235nm band of far UVC (especially 222nm) is absorbed by pathogens' DNA, RNA and nearly all proteins, inactivating airborne pathogens — equivalent to 30–50 extra air changes per hour. The reason it's safe for humans is mainly mechanical: human epidermis has a dead-cell layer about 20 microns thick, full of protein, that absorbs almost all far UVC; conventional UVC at 254/265nm lacks that strong protein absorption and shouldn't be exposed. The eyes are protected by eyelids, eyelashes and other structures, tolerate a lower dose than skin, but long-term damage risk is very low.
— VivianA corner-mounted lamp is a proof of existence, not the final form
Current products are mostly corner-mounted because the beam angle is narrow, and firing from a diagonal maximizes path length and average dose. The emitter is only about 100 milliwatts, decaying to near zero at the other end of the room; but the dose needed to kill is very small. Misha calls the current lamp a "proof of existence": there's no insurmountable technical or logistical obstacle, ordinary people can buy and install it, and in the future it becomes an ordinary ceiling fixture. The real obstacle isn't cost or regulation — it's that too few people know about it.
— MishaElementary schools need it most, but workplaces get it first
Vivian thinks the biggest payoff is probably elementary/middle schools: ventilation is usually poor and children's immune systems aren't mature; but parents demand high safety, schools are conservative, and workplaces, long-term care centers and hospital waiting rooms will go first. The economics: each lamp covers about 250 square feet, a normal classroom needs 2–3, a university needs hundreds; a small building costs only four to five figures for the whole thing, a large building reaches six figures; professional installation costs about as much as the lamps. Patrick adds that waiting rooms have high foot traffic, so any one person's cumulative dose is low, but total dwell time is very high.
— VivianTB is the most UV-resistant, yet its transmission has been cut 90%
Preliminary results from the South African TB ward trial have already seen 90% transmission suppression: guinea pigs were exposed to patients only through the air. Tuberculosis is not especially sensitive to far UVC, with roughly 10 times the resistance of influenza/coronavirus, so the effect on common respiratory viruses may be even better. TB hotspots and nursing homes will be among the first sources of strong evidence. Vivian says pandemic prevention is the most exciting scenario: the more transmissible the pathogen, the bigger the leverage of environmental intervention; old-style UVC once successfully controlled measles with R0≈20, so pushing R from slightly above 1 to slightly below 1 is enough to avert a pandemic.
— VivianOnce it's in building codes, UVC is the cheapest path to compliance
ASHRAE 241 is currently the only infection-prevention standard, but it hasn't yet been widely adopted by any jurisdiction with authority; once it's written into building codes, UVC becomes the cheapest way to comply and enters the existing building stock on a ten-year renovation cycle. The alternatives don't suffice: upgrading HVAC in existing buildings is often impossible or extremely expensive; portable filters (MERV 13 is enough) work, but pathogens are only one of many air pollutants and need to be used alongside UVC. In high-density large spaces like auditoriums and gymnasiums, meeting clean-air standards through ventilation alone is basically cost-infeasible — you have to use UVC.
— VivianLamp prices can fall like LEDs, but adoption doesn't depend on price
The best emitters today are made by a single Japanese company, with a high-margin business model; even if you cut all profit, a single emitter costs 15–20 dollars, and manufacturing uses hydrofluoric acid gas, making it harder to scale than LEDs. The end market is still tiny; some sell lamps for 2000 or even 3500 dollars, AeroLamp prices at 500 dollars, targeting around 100 dollars within a year or two, with no technological innovation required. Patrick judges that going from a few hundred units a year to a billion-dollar market, unit prices will fall as fast as LEDs; Misha cautions that falling prices won't automatically change willingness to deploy — information is the bottleneck.
— MishaWhether home use is worth it depends on whether disease spreads at close range
Misha thinks ordinary households don't have much transmission, 500 dollars isn't worth it, and 100 dollars is justifiable; Vivian counters: she just had a baby, keeps two lamps at home on during gatherings and when guests come, and once a baby gets a fever it's the ER, hospitalization or even a spinal tap — preventing a few illnesses pays for itself. Behind this disagreement is the biggest failure mode: if most common illnesses spread mainly at short range within two feet at high dose, environmental intervention can only do so much, reducing severity rather than preventing infection; but even then, lowering viral load may make the course of illness milder.
The first money should buy global awareness, not more lamps
Misha thinks the first money should go to building global awareness: the world may sell only a few hundred lamps a year, and almost no one has heard of 222nm. Vivian leans toward formal trial deployments, arguing that hype can backfire and expansion must be responsible; Paris Hilton is a better spokesperson than Taylor Swift. The commercial shortcut doesn't require convincing the public: companies have already internalized the cost of sick leave and caregiving absences, companies like Google have people dedicated to employee health, and they'll install once the math is clear; building owners can decide unilaterally, bypassing the "blocker veto."
— MishaIn their own words · checked verbatim
So on a chemical, biological level, the special thing about far UVC is it is absorbed by the DNA and RNA of pathogens, as well as by essentially all proteins. And this is very important, because the fact that it's so heavily absorbed by proteins is a thing that makes it much safer than other germicidal UV wavelengths.
Vivian0:58
Essentially, it's not good for living cells to be exposed to UVC of any wavelength. But the difference is that humans have a 20-micron-thick layer of dead skin cells that are chock-full of proteins that essentially absorb all far UVC.
Vivian3:25
One of the big benefits of it being more effective than sunlight as a disinfectant is that you can actually use it at pretty low power levels. So the emitters we're using, they're putting out like 100 milliwatts, right? Which is really not a lot.
Misha9:24
So there's going to be some critical coverage point within a community where the suppression really takes off. And we have modeling on this, but yeah, I think it's really, really uncertain.
Vivian21:48
And also I should point out that we have some really encouraging results on tuberculosis specifically. There's a trial going on in South Africa that already has preliminary results, and they're seeing 90% transmission suppression in these TB wards.
Vivian23:24
No, I definitely think that's a huge benefit. I also think because it's part of the built environment, you need a lot fewer people to be involved in the prevention process, right?
Misha32:49
And if a certain amount of infection prevention gets written into building codes, and then these are broadly adopted in whatever the authority having jurisdiction is — that might be on the state level or on the county level — this means that these interventions just get built into buildings on a ten-year renovation cycle.
Vivian34:23
So I would much rather my kid catch whatever it is that's going around at ten than at five, and I'd rather it happen at five than at one. But I'd really rather it just not happen. There's just no benefit.
Vivian56:09
Figures
| Thickness of the dead-cell layer in human epidermis | about 20 microns | 3:25 |
| AeroLamp emitter output power | about 100 milliwatts | 9:24 |
| Coverage per lamp | about 250 square feet | 17:31 |
| Lamp price and installation cost | lamp about 500 dollars each, installation about equal to the lamp price | 17:31 |
| South African TB trial result | 90% transmission suppression | 23:24 |
| TB relative resistance | about 10 times that of influenza/coronavirus | 23:24 |
| Measles R0 | about 20 | 27:16 |
| Estimated global annual sales | possibly only a few hundred lamps per year | 39:11 |
| AeroLamp target price | about 100 dollars per lamp | 45:14 |
Glossary
- far UVC
- Ultraviolet light at 200–235nm, mainly 222nm, absorbed by proteins, germicidal and safe for human surfaces.
- krypton chloride excimer lamp
- The main current far UVC emitter; its manufacturing process is more complex than LEDs and requires hydrofluoric acid gas.
- ASHRAE 241
- An indoor infection-prevention standard set by the American Society of Heating, Refrigerating and Air-Conditioning Engineers, not yet widely incorporated into building codes.
- R0
- The average number of people one infected person infects; above 1 it spreads exponentially, below 1 it dies out on its own.
- hygiene hypothesis
- The idea that being too clean causes allergies and asthma; the modern version holds that immune training comes from environmental bacteria, not from actually getting sick.
How to listen
Founders working on respiratory disease prevention, building/HVAC professionals, hospital operators, and parents who want to upgrade the air in their kids' schools.
The intro and the two ad breaks in the middle can be skipped; the main content starts at 00:58 with no filler.