No more Vactrols in the U.K.?

[Mark Hammer]

Robin Vincent does a monthly roundup of synthesizer gear on his Molten Music Youtube channel.  This afternoon's February roundup had a rather disquieting item: the recent illegality of Vactrols in the U.K..  You can see the discussion here: https://www.youtube.com/watch?v=p6_bmERBAcU&t=757s  Apparently, the crux of the matter is the cadmium sulfide used in photocells.

Now, although cadmium is NOT good you, when it's sealed up inside an epoxy blob, it's not really dangerous to anyone.  That said, there is the matter of their safe disposal, and also the matter of their fabrication, and the exposure to workers.  Are there substitutes for it?  I have no idea.  I mean there ARE substitutes for Vactrols. but the question is whether there are substitutes for cadmium-sulfide photocells.  If one takes Robin's summary at face value, that would mean quite a few products made on the western side of the Atlantic could not be for sale in the UK, or in the EU.  Existing/legacy products would be excepted.  So if you play in a funk band in Birmingham, you won't have to surrender your Mutron III to the authorities, although you may have difficulty obtaining a new one.

Anyone across the pond have any other details to add?

[CheapPedalCollector]

If alarmists had control of everything, we wouldn't have guitar strings, most electronic parts we use and a multitude of other stuff. Meanwhile toxic chemicals are mined and used in batteries because "clean energy" ... I think it matters more who pays off who as to what is allowed anymore. Failure to have proper disposal of things is the issue and rather than fix that problem they just ban stuff. Maybe if we stop throwing things in the dump by the ton it wouldn't be such a problem. That brings up other issues with planned obsolescence and the right to repair. I'm still annoyed that lead solder is banned when it's clearly inferior when rapid temperature changes and vibrations are present. We should manufacture and dispose of/recycle responsibly instead of just banning everything because lazy/costly.

[ThePracticalPeasant]

If alarmists had control of everything, we wouldn't have guitar strings, most electronic parts we use and a multitude of other stuff. Meanwhile toxic chemicals are mined and used in batteries because "clean energy" ... I think it matters more who pays off who as to what is allowed anymore. Failure to have proper disposal of things is the issue and rather than fix that problem they just ban stuff. Maybe if we stop throwing things in the dump by the ton it wouldn't be such a problem. That brings up other issues with planned obsolescence and the right to repair. I'm still annoyed that lead solder is banned when it's clearly inferior when rapid temperature changes and vibrations are present. We should manufacture and dispose of/recycle responsibly instead of just banning everything because lazy/costly.

Such brilliance.

Unfortunate that the mob (masses) are less intelligent.
Prop65 in California had 2/3 voter support in the 80s.

Ever seen a label that says "Prop 65 says this causes cancer in California"?
Yeah; if the product in any way contains any from a near-endless list of potentially dangerous substances (lead obviously included), it must list the Prop65 cancer warning to be legal for sale. For efficiency sake, most manufacturers phrase the warning to apply only to California and print it on goods shipped everywhere.

This is what happens when alarmists number 2/3 of the population.

Thankfully, I live in Canaderp and can still by 50/50 lead/tin solder.

They recently legislated a minimum 10% ethanol in all gasoline sold here, to the chagrin of seals in my classic car, but I can still buy good solder. And likely vactrols, though I haven't checked.

Assuming your local customs doesn't search holiday gifts for stray electronic components, the Ur-A-Peein' folks around are welcome to have your dangerous goods shipped through me.

[Rob Strand]

I'll believe it if someone can post a link to a formal statement stating CdS is banned *for audio*.

CdS had been banned for some time.   It was used in many industries.  However when the ban was rolled out previously Audio applications were exempt.   Exemptions are common and are based on many factors.  For the case of vactrols in audio the reasons for not banning were:

- The total tonnage of CdS disposed from audio products is very low.

- Availability of alternative technologies.
  While we do have alternative technologies for audio, you cannot use those techologies in a tube amp.

The CdS cells were used in the lighting industry and building automation industries.  CdS were banned in these industries early on.   Firstly the size of the industry is much larger - more tonnage, and secondly, non CdS light sensors have been around for many years - they are more stable and reliable as well.

Now, although cadmium is NOT good you, when it's sealed up inside an epoxy blob, it's not really dangerous to anyone.  That said, there is the matter of their safe disposal, and also the matter of their fabrication, and the exposure to workers.  Are there substitutes for it?

You can't trust people to follow the rules.   I see people dumping stuff all the time.   They don't care.   That's one reason minor things get banned and new laws get made.   For example, new rules for various medicines have been imposed here either for reasons of uncontrolled used, illegal use, yadda, yadda, yadda.

In general Joe public has no idea how various chemicals are used.  No idea what happens when they get disposed of, either correctly or incorrectly.    No idea of the damage they do.   In the world or the rising narcissist everyone knows better than the experts.    There are experts out on this topic and they know their shit.   They model the whole process of production to disposal on a world scale and make decisions based on it.   The Europeans are far more proactive and less corrupt about it than the US.

[Rob Strand]

Here's the only information I could find regarding the exemptions.

I haven't hunted down any new statements but since I can only see the use of CdS photoresistors under an exemption I don't expect to find anything.

Here are the RoHS exemption lists:

As of 2017,  Item 40,  CdS used for Audio, exemption expired 2013,
https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:02011L0065-20171211&rid=1

As of 2022, Item 40,  CdS used for Audio, exemption expired 2013,
Table of Contents - IPC 1752A Appendices B C D E and F - January 2022.pdf
https://www.ipc.org/media/5277/download

UK and Australia have been aligned with RoHS for some time.
So what has changed recently?  nothing is coming up in searches (not that I'm surprised).

There could be some subtlety regarding RoHS components and RoHS products.   Also there are countries that don't follow RoHS and your country could make products to be sold in those countries.   Your component supplier would probably ask for a declaration that you would not be selling products to RoHS compliant countries.   It's hard to find info on these finer points.   The companies I work for only care about RoHS compliant products because they sell into major countries.


EDIT:

Here's some info justifying expiration of the exemption (art. February 5 2013 ):

https://www.lexology.com/library/detail.aspx?g=06b3bc64-d2c6-4283-90ea-638588021101
http://eurlex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2012:348:0018:0019:EN:PDF
"However, the exemption is limited in time, since the Commission considers that the research for cadmium-free technology is in progress and substitutes could become available by the end of 2013."

But no additional info about what happens if the cadmium-free technology doesn't eventuate.

[PRR]

The other thing is: who is making CdS today? Not the old-school production lines. And it isn't like water or salt, a simple ratio of pure elements. Especially the time-decay of CdS requires control of charge centers(?) with impurities or defects. (I have not looked at this stuff in a decade.)

Yes, the Chinese will sell you dusk/dawn light controllers with a CdS in them. No, it won't even be the inconsistent stuff we got from the Old Guys.

Boutiquer I know in Euro-zone makes an opto-compressor, he sells the box but only "loans" the CdS cell. You are contractually required to return the cell on demand or when disposed. Will this avoid legal trouble? So far he has snuck under EU's radar.

[bartimaeus]

makes me wonder how chase bliss keeps on selling in europe... under the radar?

[ElectricDruid]

Xvive claim that their RoHS vactrols are free of both Lead and Cadmium, and are therefore legal to sell. They provide a legal RoHS declaration to this effect, which is (sometimes) necessary to show customs in order to be able to import the devices into the EU. Prior to Brexit, that would have been the same rules in the UK. Now, they'll do the same thing, but it'll be much better because Brexit improved everything, right?

Do I believe the Chinese when they hand me a legal declaration saying there's no cadmium in the product? Well, my experience is that Chinese cultural practice is to tell you what they think you want to hear, and the truth is not seen as an impediment to that. Have you *ever* seen a parcel coming from China that declared the correct value on the outside for customs purposes? So I have a degree of scepticism.

But legally, I think I've done what's required of me. I don't think it's up to me to enforce the rules by getting expensive independent testing of the devices done to find out whether they are compliant with the declaration made by the manufacturer. What I can honestly say is that I've got no reason to believe that they're *not* compliant, and I was assured by the manufacturer that they *are* compliant, and I've got the paperwork to prove it.

So, for now at least, there are plenty of no-cadmium, no-lead, RoHS-compliant vactrols you can use in the EU and UK.

[Phend]

How many people can you name who have died from cadmium?
Nicotine?
New Zealand is smart on that one.

[Mark Hammer]

I didn't wish to start a "political" thread.  Let's please keep it that way.  This is about the implications for design and manufacture.

Tom, although XVive (and perhaps others) can produce photocells that are Cds-free, one of the things we like about vactrols - commercial or homebrew - is their "bouncy" qualities, to quote Robin Vincent.  That is, the speed and manner in which they change resistance, in response to illumination and dimming.  Do LDRs using alternate materials have these same qualities or is this something specific to Cds?

[ElectricDruid]

Tom, although XVive (and perhaps others) can produce photocells that are Cds-free, one of the things we like about vactrols - commercial or homebrew - is their "bouncy" qualities, to quote Robin Vincent.  That is, the speed and manner in which they change resistance, in response to illumination and dimming.  Do LDRs using alternate materials have these same qualities or is this something specific to Cds?

Good point. Whether they're entirely equivalent to the types they claim to clone, I can't say. I haven't got any old PerkinElmer vactrols to compare them with. Anecdotally, they seem to do the same job. They certainly have a short-but-definitely-not-zero turn-on time, and a much-slower turn-off time, with the dark resistnce continuing to rise for minutes afterwards (exponential, so to be expected). That fits with what I know about "classic" vactrols.
I had one customer write to me complaining that they didn't work as a replacement in some vintage studio compressor, iirc. But that was probably a *very* specific part originally, and could well have been selected to boot.

For my purposes, for stuff like the FilterFX vactrol-controlled SVF or adding modulation to a PT2399, they're great. I imagine most people here would be in a similar situation.
For manufacture, I'd say that you need to design around the inherent variability of vactrols of any type. If you've got a design that depends on some specific characteristic of a specific device, you're going to end up having to hand-select them. Better to avoid that if possible through intelligent design.

[Mark Hammer]

Point well taken.  The rate-of-change sought, or exploited, in a photocell depends on the application.  So, CdS-free LDRs may continue to be absolutely acceptable substitutes for some applications but perhaps less than adequate for others.

Part of why we love them is because of how they can provide a nicely isolated function that can make a circuit feasible.  But, we also love them because of how they can compensate for the inadequacies of simpler rectifier circuits.

[GibsonGM]

You get what you vote for.   

[Fancy Lime]

...  There are experts out on this topic and they know their shit.   They model the whole process of production to disposal on a world scale and make decisions based on it.   The Europeans are far more proactive and less corrupt about it than the US.

Sadly, that's not how it works. In reality, the experts no their shit and make (usually) sound recommendations to politicians based on that. Then lobbyists scare the politicians into ignoring the experts. Many of the inconsistencies in health hazard prevention legislation come from the fact that some lobbyists are more successful than others, not from experts disagreeing.

Fun Cadmium Fact #1: Smoking is the biggest contributor to chronic Cd poisoning for smokers.

Fun Cadmium Fact #2: Many areas in Europe and probably elsewhere as well are massively contaminated with Cadmium, Lead, Arsenic, Thallium, and a bunch ot other toxic heavy metals as a result of medieval mining and smelting operations (mainly for silver). This is so bad in some places that certain vegetables are illegal to grow for sale because they enrich these elements further to the point that the vegetables are considered toxic waste.

Andy

[Phend]

Not a problem if you wear gloves. Vintage RS .
(Soldering bench is in the beer box, wood boards act like vice(s))

[StephenGiles]

This sounds to me like another winkie wankie wokie nonsense!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[bartimaeus]

Xvive claim that their RoHS vactrols are free of both Lead and Cadmium, and are therefore legal to sell. They provide a legal RoHS declaration to this effect, which is (sometimes) necessary to show customs in order to be able to import the devices into the EU. Prior to Brexit, that would have been the same rules in the UK. Now, they'll do the same thing, but it'll be much better because Brexit improved everything, right?

interesting! do you know what they use instead of Cadmium? i'm surprised that nobody else makes Cadmium-free photocells if it's possible... i know the datasheet says "Cd-free", but i have to wonder if they're ROHS by (expired) exception rather than using a different material.

[Phend]

Silicon
ie;
Photodiodes CADMIUM-FREE LIGHT SENSOR
Type   High Sensitive Light Sensor
Photodiode Material   Silicon
Peak Wavelength   580 nm
Maximum Dark Current   0.3 uA
Fall Time   8.5 ms
Light Current   260 uA
Maximum Operating Temperature   + 85 C
Minimum Operating Temperature   - 30 C
Mounting Style   Through Hole
Packaging   Reel
Power Dissipation   40 mW
Product   Light Sensor
Reverse Voltage   6 V
Rise Time   8.5 ms

[ElectricDruid]

Xvive claim that their RoHS vactrols are free of both Lead and Cadmium, and are therefore legal to sell. They provide a legal RoHS declaration to this effect, which is (sometimes) necessary to show customs in order to be able to import the devices into the EU. Prior to Brexit, that would have been the same rules in the UK. Now, they'll do the same thing, but it'll be much better because Brexit improved everything, right?

interesting! do you know what they use instead of Cadmium? i'm surprised that nobody else makes Cadmium-free photocells if it's possible... i know the datasheet says "Cd-free", but i have to wonder if they're ROHS by (expired) exception rather than using a different material.

No, I don't know, sorry. The RoHS declaration is pretty clear that they're Lead and Cadium *free*, not just covered under some exemption. Here's an example test report:

https://electricdruid.net/wp-content/uploads/2023/02/Opto-coupler-RoHs-testing-report-by-SGS.pdf

My understanding was that there are quite few non-cadmium photocells out in the world, along with phototransistors, photoFETs, and many other types of non-cadmium photosensitive devices. So I don't think we're out of options any time soon! It's just that we're often trying to reproduce circuits from 30/40/50 years ago, when cadmium photocells were the go-to option.

[Rob Strand]

The RoHS declaration is pretty clear that they're Lead and Cadium *free*, not just covered under some exemption.

Yes, it's a very different thing.

FWIW, you can still buy leaded components but you can't sell products with leaded components (unless the product falls under an exemption category.)

My understanding was that there are quite few non-cadmium photocells out in the world, along with phototransistors, photoFETs, and many other types of non-cadmium photosensitive devices. So I don't think we're out of options any time soon! It's just that we're often trying to reproduce circuits from 30/40/50 years ago, when cadmium photocells were the go-to option.

The thing that reduces the choices is the CdS cell is a photoresistor (photoconductive cell).  The common sensors are silicon based but they aren't used as photoresistor they either generate current or voltage like a solar cell.  That's because they are junctions (with an energy gap).   In fact you can use an LED in reverse like this.  Put a multimeter across an LED and shine a bright into it (IIRC green LEDs works better if the light source is a white LED, less problems with incandescent/halogen torches).  These things have been around a long time and that's the parts used in the lighting industry - and many Lux (light) meters.  You can make photoresistive cells from silicon, I've got no idea how they behave.

For audio, even if we found another material we would also like to keep the same kind of time constants.

interesting! do you know what they use instead of Cadmium? i'm surprised that nobody else makes Cadmium-free photocells if it's possible... i know the datasheet says "Cd-free", but i have to wonder if they're ROHS by (expired) exception rather than using a different material.

If you look at the periodic table and think about how Germanium was replaced by Silicon in semiconductors you can see that elements in the same column can be swapped.   However as we all know that silicon doesn't behave exactly like germanium.  People have also made semiconductors from carbon (C), also Gallium (Ga).



For the sulfur (S) part you can see selenium (Se) can be swapped and you do see selenium been used in photocells.   For the cadmium part (Cd) part you are only left with Zinc (Zn).   As a side note Cadmium plating is now replaced by (passivated) Zinc.      The period table thing does work.

Another thing which is done is add other elements around the one you want to use in order to "bend" the final result. For Zinc (Zn) that would be Galium (Ga) and Indium (In).

Finding the right combination is where the research is.

An alternative is optical MOSFETs but they have a limit voltage range when used as a resistor - just think of the issues with those CMOS Phasers.