I’ve been looking into the eye safety of the LEDs on the Triad Spectroscopy Sensor (AS7265x) and wanted to share what I found and ask a few follow-up questions.
From the schematics the two emitters:
IR: SIR19-21C/TR8 (875nm)
UV: VLMU3100-GS08 (405nm)
Using the typical radiant intensity values from both datasheets and a basic inverse square law calculation (E = I/d²):
These calculations assume 20mA drive current, but I have a few questions:
What current does the firmware actually drive the IR and UV LEDs at by default, and what is the maximum? The AS7265x LED_DRV pin supports up to 100mA, but the SIR19-21C is rated for 65mA DC max. so is the driver operating in pulsed mode at higher settings to stay within the LED’s absolute maximum rating?
Has SparkFun or ams performed any formal or informal eye safety assessment on this board, for example against ICNIRP 2013 guidelines or IEC 62471? Both emitters are largely invisible (875nm has no aversion response, and 405nm is barely visible), which means there is no natural protection if someone looks directly into them.
For the UV LED specifically: 405nm falls within the ICNIRP photochemical retinal hazard action spectrum (300-550nm), where damage is cumulative over time. Has any assessment been done on safe exposure duration at typical working distances?
1 - The hookup guide and the data sheet both cover this. Drive current is programmable, you select what you want in your code. There is example code but you are free to customize it.
2 - Sparkfun, doubt it, it’s not meant to be a consumer product. Sparkfun pretty much assumes you’ve done your homework as far as safety goes. AMS, definitely no. AMS only makes the sensor chip, they don’t make the LEDs or the assembled board.
3 - Seriously doubt it. It’s not meant to be used on a human. Avoid exposure, especially long term exposure. Wear protective gear, do not stare into laser with remaining eye.
Typically with this sensor, one might use the LEDs as light sources for measurement of reflection or fluorescence emission spectra from sample surfaces.
In that case, potential interference from external illumination (and consequently light leakage from the LEDs) must be eliminated by a suitable enclosure for the sample and sensor. So there should be no exposure.
I get your point, but I think there’s still some responsibility on their side. Even if SparkFun targets hobbyists, a lot of the audience isn’t made up of experts, and not everyone is fully aware of the risks associated with things like IR or UV exposure.
I’m not saying they need to treat it like a consumer appliance, but at least some basic safety guidance or risk acknowledgment would be reasonable, especially when the hardware can potentially impact eye or skin safety if misused.
As for ams-OSRAM, I understand they only manufacture the sensor itself, but even at the component level, manufacturers often still document safe operating conditions and potential hazards. So I don’t think it’s entirely fair to say there’s no responsibility at all.
If you are worried about your own safety, build an enclosure.
If you are worried about the safety of others, why bother with LEDs? Consider focusing your crusade on the vastly more dangerous UV and IR laser diodes flooding the market.
That’s a strawman. I’m not comparing LEDs to laser diodes or going on a “crusade.” and honestly, your reply just comes across as dismissive and defensive rather than addressing that point.
I’m trying to figure out whether using this sensor is actually safe, especially since when people experiment with it, it’s right next to them while they test different functions, including turning all the LEDs on.
Companies like SparkFun sell to hobbyists, not experts, so basic safety guidance around IR/UV exposure is reasonable. “Just remove the LEDs” assumes people already know there’s a risk, which is exactly the issue.
…the LED operates at ~0.2w, so likely RG 0-1. Are you planning on arranging an array and looking directly at them inches away at full power?
It just frankly not a safety concern under anything resembling normal use - knocking a component off the board and accidentally inhaling it, something physically popping into your eye, etc are all more likely in the grand scheme. The boards are made from fiberglass, many components are sharp…the list of perceived dangers can be endless
It is odd to be concerned with these without a basic understanding of the power at-play and to then suppose that we as a company haven’t performed such due diligence - what’s prompted these threads? We don’t assume the users to be experts and take great care to ensure our products are safe.
In at least one other thread there was attempt to disregard the advice given…I’d guess the ‘dismissive’ nature could be stemming from a lack of respect for the time and effort it takes for someone to offer help only for it to immediately be disregarded.
If by your estimation you feel unsafe we have a fairly generous return policy
“there was attempt to disregard the advice given…lack of respect for the time and effort…”
That’s a pretty unfair characterization. Asking follow-up questions or trying to better understand safety implications isn’t “disregarding advice,” it’s how people learn,especially when dealing with something like IR, UV exposure that isn’t visible. If you read the thread, you would’ve noticed that one commenter basically said that :”Sparkfun pretty much assumes you’ve done your homework as far as safety goes”
Framing that as a lack of respect comes across as dismissive in itself and shifts the discussion away from the actual question.
I’m not questioning whether due diligence was done or trying to waste anyone’s time. I’m trying to understand whether close-range exposure during typical hobbyist use is safe. That’s a reasonable question, and it shouldn’t be treated as if it’s inherently misguided.
Implying that asking for clarification is disrespectful isn’t. It just discourages people from asking when they have questions.
Just proffering why a sleight may have been perceived; the folks around here are volunteers (also, referring to a separate thread)
They mention ‘that you’ve done your research’ in regards to using our devices in an uncommon/non-prescribed manner. If there are safety concerns (like with some of our devices) we go pretty far to indicate such so that users are abreast.
The tone does not come off as ‘curiosity’ in this thread Eye safety assessment for AS7265x IR and UV LEDs - #4 by any It has the air litigiousness (which in this case would fall to the manufacturer of the LED as mentioned above, if used in a design conforming to their specs). If we packaged it in an overdriven or somehow unsafe way, then perhaps…but our engineers have already done the research for these type of things
Anyhow you’re not in danger is the point throughout. But don’t put it like RIGHT in front of your eye either
I’m going to be very clear here: asking about safety isn’t wrong, and I reject that framing.
These are invisible IR/UV sources, fully exposed, and people often work with them at close range 30 40 cm is a pretty typical distance during testing. Asking what that means in terms of actual exposure is reasonable.
This isn’t about liability or trying to assign blame. I did the math, and the result looked concerning to me, so I’m trying to sanity check whether I’ve made a mistake.
10cm : 2.5e-3 W in 0.01 m^2 : 0.25 W/m^2
5cm : 2.5e-3 W in 0.0025 m^2 : 1 W/m^2
2cm : 2.5e-3 W in 0.0004 m^2 : 6.25 W/m^2
1cm : 2.5e-3 W in 0.0001 m^2 : 25 W/m^2
So, at a distance of 1cm, you would exceed the IEC 62471 (2006) limit for an exposure of >= 1000 seconds. At 2cm, you’re OK.
I’ve been eating these for several weeks now and hadn’t noticed any problems but that was before I was aware of this glaring safety risk. I insist this public nuisance be removed from the catalog at once.
