Information about UV Blocking for Tinted Windows

[rafacq]

UV is very important, and they are many reasons why tint is good, if not necessary, I am for heat, I am in San Antonio, Texas and, let me tell you, all the other values are important. However, Lumar seems the best all around for what I have been reading. How expensive was Lumar? I have a quote for SunTek for 800 plus 150 for Sunroof, I like the numbers from SunTek for protection/Heat/UV and color density. I tend to see the spec sheet and look what calor and intensity, and other values, SunTek protection looks great... I am not sure why many people prefer Lumar the specs are similar, but the price seems quite different, so I dont want to regret paying for something is not the best I can use for the car

I paid a little less for Llumar on the front windshield, and Autobahn Ceramic i3 on the sides and back. I got a 10% discount for being a member of the North Texas Tesla Owner’s Club. The front windshield does make a difference .

 

[Fusion]

Also keep in mind that a thin sheet of film vs a actual glass is not the same comparison.

 

[turnem]

UV is very important, and they are many reasons why tint is good, if not necessary, I am for heat, I am in San Antonio, Texas and, let me tell you, all the other values are important. However, Lumar seems the best all around for what I have been reading. How expensive was Lumar? I have a quote for SunTek for 800 plus 150 for Sunroof, I like the numbers from SunTek for protection/Heat/UV and color density. I tend to see the spec sheet and look what calor and intensity, and other values, SunTek protection looks great... I am not sure why many people prefer Lumar the specs are similar, but the price seems quite different, so I dont want to regret paying for something is not the best I can use for the car

I just did Llumar Formula One on the sides and back from Llumar Air 80 on the front and it was around $600. Looks great and the heat rejection has been superb in my opinion.

 

[EdisonDrvr]

I had Autobahn Ceramic i3 installed on the side and back windows. Had Llumar 80% on the windshield. It makes such a difference. Car is SO MUCH COOLER. I used Glacier Window Tinting in Arlington, TX. If you are in the DFW area, strongly recommended!

View attachment 408040

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Looks great! Super choices and a beautiful looking car.

 

[rafacq]

Looks great! Super choices and a beautiful looking car.

Thanks! Next is to do a PPF on the front. Been working on restoring the hood and getting it ready for the protection film. Certainly want to do it before going on our next road trip.

 

[Lanzer]

I've been doing more tests and research, and I've purchased an UV flashlight rated 365nm, and when I tested my window tint with 365nm UV light, I found that all of them does a great job in blocking 99% of UV light at that wavelength. (3M, Alpine, Suntek)

So things started to make sense. The first UV flashlight I used is rated at 390nm, and that is the wavelength the window tint had trouble with. So I started to wonder: "Why do tint manufacturer not care about UV at 390nm?" My UV reading glasses thinks 390nm UV is important enough to block, but is there some inherent problem where a sheet of tint can't block above a certain wavelength?

I don't have a real answer, but I can only make some assumptions:

• in the 80's we discovered that besides UVB, UVA is also harmful to us, so the FDA began putting in standard for measuring UVA absorption rates. Ince that time, other countries had improved on the method to measure UVA protection, and Japan's standard is the most widely used in the world today, and is a standard that measures the 320nm to 400nm wavelength called the "In vitro PPD method". Meanwhile in America we have been slow to adopt the new standard, with their old system being focused on the 370nm as the "critical wavelength" for UVA.
• Companies making products to block UV probably ended up using 370nm as the standard for testing and rating their products. Blocking 99% of 370nm UV = 99% UV protection. Ability to block UV at 380 to 400nm were mostly omitted by sunscreen manufactures, and I think the same happens for window tint manufacturers.
• Not knowing any history, I assumed that UVA is 320nm to 400nm, and I assumed that all "UV blocking" products will block those wavelengths, but I had been mistaken. It seems to suggest that the 380 to 400nm range is harmless, therefore blocking this wavelength is not needed, but that sounded a bit too convenient, so I did more research.
• In 1996 Japan devised a standard for rating UV blocking products called "in vitro persistent pigment darkening (PPD)", it covers UVA from range 320 to 400nm, and is widely used around the globe today. Except that the FDA is not adopting this standard. Some articles states that the aging FDA ratings are putting Americans in health risk as today's sunscreens are often lacking in UVA protection, and many popular sunscreens from the US were rejected by the UK because of their performance.
• A scientific paper published in 2018 states that: "The effects of very long-wave UVA (>380 nm) and visible radiation (≥400 nm) are much less known. Sunscreens have been beneficial in inhibiting a wide range of photodamage, however most formulations provide very little protection in the long wave UVA region (380–400 nm) and almost none from shortwave visible wavelengths (400–420 nm)." The conclusion suggest that UVA at 380 - 400 nm are still harmful. And if that's only been suggested in 2018, I can assume that most industries are not putting this range of UV as a focus.
• (source: The UV/Visible Radiation Boundary Region (385–405 nm) Damages Skin Cells and Induces “dark†Cyclobutane Pyrimidine Dimers in Human Skin in vivo)

So now I have a clear picture to why I'm getting the results that I did. I understand potentially why all the window tint I came across do not block 390nm UVA, and I hope that in the future, either as FDA updates their ruling, or when we discover better formulas, we will have a truly "broad spectrum" window tint on the market. Meanwhile, there are still many window tint that I haven't tested, so maybe something is out on the market already.

Lastly, the FDA had proposed new sunscreen rules to make sunscreen safer, but it still haven't addressed any changes to the SPF standard. FDA is rigorously testing the 16 sunscreen ingredients available in the states, but somehow still doesn't test any of the popular ingredients in Europe and Asia. For now, I'm buying better sunscreen from overseas. Thanks Amazon!

Some graphic so show the performance of sunscreen. I think the window tint performs similar with a gradual drop off:

(EWG's 2019 Guide to Safer Sunscreens)

I also need to state that many of these info are completely new to me, and I still have a lot to learn. Also there might have been errors on my understanding, so apologies in advance if I've gotten anything wrong.

I've also updated my blog on this subject: (UV Test on Window Tint)

* Other sources
(Sunscreen Regulations Haven’t Aged Well)
(After More Than A Decade, FDA Still Won’t Allow New Sunscreens | May 18, 2015 Issue - Vol. 93 Issue 20 | Chemical & Engineering News)

 

[rsg123]

Does the tint sold in Japan block 320-400nm UV?

 

[pandap]

I found the email from tesla. They claim UV blocking from factory as on a 3:

front and rear 98%
side glass 74%
roof 99%

How much of this is true? This seems like a concrete answer but no one really responded to him...
If the OP is primarily concerned about UV blockage then it seems to me that it may not be worth to install aftermarket tints for the purpose of UV blockage?

Although, it doesn't specify UVA/UVB and OP also was looking into the 390nm range

 

[pandap]

This thread also mentions that all windows are UV coated.

 

[SigNC]

How much of this is true? This seems like a concrete answer but no one really responded to him...
If the OP is primarily concerned about UV blockage then it seems to me that it may not be worth to install aftermarket tints for the purpose of UV blockage?

Although, it doesn't specify UVA/UVB and OP also was looking into the 390nm range

It's straight from tesla when i inquired about uv blocking from factory. I assume it's true.

Edit: after reading the last post about how we measure UV blocking it very well may be just at a specific wavelength.

 

[tander]

No. You can’t get a sunburn in a car if the windows are up. Glass—any glass—blocks UVB, which is what causes tanning and sunburns. You’ll never get tan on a cloudy day for the same reason; UVB is easily blocked even by clouds.

But! But! Normal auto side window glass does NOT block UVA, which is the wavelength that’s most carcinogenic. So that’s where the tint comes in. You’d never sit in the sun for three hours in mid summer with no sunblock—you’d cook and blister—but you can take a three hour drive in the summer sun and your left arm gets the same UVA cancer-blast and you don’t even know it.

(This is the same reason dermatologists are adamant that you put on sunblock even on cloudy days. You can get a whole day’s midsummer UVA exposure and not even notice because you won’t tan or burn.)

And that’s why this thread is important. Because if tint companies are faking their UV protection, people could be getting exposed and not know it. I had midlevel 3M tint on an old car and took for granted that the whole 3M line was “99.9%” protective. Thanks, OP, for making me think twice!

I had an experience that kind of relates to this. I did a two day bike ride that was like 8+ hours outside each day. I wore a short sleeve jersey, maybe applied sunscreen once a day but don't remember so probably not, especially on my arms. After the 2nd day, taking off my jersey I noticed a very distinct color change where the jersey sleeve stopped, just a dark line all the way around my arm. It looked more like a scar than a burn, it peeled but the scar remained for either months or years, hopefully it doesn't come back to bite me when I'm older.

 

[tander]

I've been doing more tests and research, and I've purchased an UV flashlight rated 365nm, and when I tested my window tint with 365nm UV light, I found that all of them does a great job in blocking 99% of UV light at that wavelength. (3M, Alpine, Suntek)

So things started to make sense. The first UV flashlight I used is rated at 390nm, and that is the wavelength the window tint had trouble with. So I started to wonder: "Why do tint manufacturer not care about UV at 390nm?" My UV reading glasses thinks 390nm UV is important enough to block, but is there some inherent problem where a sheet of tint can't block above a certain wavelength?

I don't have a real answer, but I can only make some assumptions:

• in the 80's we discovered that besides UVB, UVA is also harmful to us, so the FDA began putting in standard for measuring UVA absorption rates. Ince that time, other countries had improved on the method to measure UVA protection, and Japan's standard is the most widely used in the world today, and is a standard that measures the 320nm to 400nm wavelength called the "In vitro PPD method". Meanwhile in America we have been slow to adopt the new standard, with their old system being focused on the 370nm as the "critical wavelength" for UVA.
• Companies making products to block UV probably ended up using 370nm as the standard for testing and rating their products. Blocking 99% of 370nm UV = 99% UV protection. Ability to block UV at 380 to 400nm were mostly omitted by sunscreen manufactures, and I think the same happens for window tint manufacturers.
• Not knowing any history, I assumed that UVA is 320nm to 400nm, and I assumed that all "UV blocking" products will block those wavelengths, but I had been mistaken. It seems to suggest that the 380 to 400nm range is harmless, therefore blocking this wavelength is not needed, but that sounded a bit too convenient, so I did more research.
• In 1996 Japan devised a standard for rating UV blocking products called "in vitro persistent pigment darkening (PPD)", it covers UVA from range 320 to 400nm, and is widely used around the globe today. Except that the FDA is not adopting this standard. Some articles states that the aging FDA ratings are putting Americans in health risk as today's sunscreens are often lacking in UVA protection, and many popular sunscreens from the US were rejected by the UK because of their performance.
• A scientific paper published in 2018 states that: "The effects of very long-wave UVA (>380 nm) and visible radiation (≥400 nm) are much less known. Sunscreens have been beneficial in inhibiting a wide range of photodamage, however most formulations provide very little protection in the long wave UVA region (380–400 nm) and almost none from shortwave visible wavelengths (400–420 nm)." The conclusion suggest that UVA at 380 - 400 nm are still harmful. And if that's only been suggested in 2018, I can assume that most industries are not putting this range of UV as a focus.
• (source: The UV/Visible Radiation Boundary Region (385–405 nm) Damages Skin Cells and Induces “dark†Cyclobutane Pyrimidine Dimers in Human Skin in vivo)

So now I have a clear picture to why I'm getting the results that I did. I understand potentially why all the window tint I came across do not block 390nm UVA, and I hope that in the future, either as FDA updates their ruling, or when we discover better formulas, we will have a truly "broad spectrum" window tint on the market. Meanwhile, there are still many window tint that I haven't tested, so maybe something is out on the market already.

Lastly, the FDA had proposed new sunscreen rules to make sunscreen safer, but it still haven't addressed any changes to the SPF standard. FDA is rigorously testing the 16 sunscreen ingredients available in the states, but somehow still doesn't test any of the popular ingredients in Europe and Asia. For now, I'm buying better sunscreen from overseas. Thanks Amazon!

Some graphic so show the performance of sunscreen. I think the window tint performs similar with a gradual drop off:

(EWG's 2019 Guide to Safer Sunscreens)

I also need to state that many of these info are completely new to me, and I still have a lot to learn. Also there might have been errors on my understanding, so apologies in advance if I've gotten anything wrong.

I've also updated my blog on this subject: (UV Test on Window Tint)

* Other sources
(Sunscreen Regulations Haven’t Aged Well)
(After More Than A Decade, FDA Still Won’t Allow New Sunscreens | May 18, 2015 Issue - Vol. 93 Issue 20 | Chemical & Engineering News)

This was a great post, thanks, would love to hear more about those upper ranges. I would like to know why it's not mandated for auto manufacturers to make sure all auto glass offers the most protection, especially considering for many if not most people driving is where they get the bulk of sun exposure.