Polonius wrote:
Okay, well, this thread has spurred me to go on a dive into Cadmium safety. Here's what I found out:

Cadmium is toxic, with various ailments arising acutely after exposure. However, this is usually in an industrial capacity, and inhalation is far more dangerous than ingestion. The NIH does say that cadmium can cause lung cancer, which is a double whammy because smoking also increases your cadmium intake. https://www.cancer.gov/about-cancer/causes-prevention/risk/substances/cadmium

As for cadmium pigments, which are compounds with cadmium in them, the dry pigments are generally seen as toxic and dangerous, again especially when inhaled. Outside of a few fringe sources, nobody seems terribly concerned with the actual paint, since the emulsifier would really limit absorption. It's worth noting that the EU, despite having a hair trigger for banning even borderline toxic substances, still allows cadmium pigments.

For a fun read, this artist talks about the time his cat walked through cadmium paint, and began licking it up, all with no ill effects. https://www.danschultzfineart.com/is-cadmium-paint-toxic/

I found some sites very eager to link cadmium to cancer, but one was literally called "Cancer wisdom," and no kidding, talking about how a person had a filling improperly removed, and then got cancer on a finger the next day. https://www.cancerwisdom.net/heavy-metal-toxicity-and-cancer/

Okay, so looking at the actual warning here, it's easy to say, "well, better safe than sorry" and accept it at face value. And, sure, there's probably no real loss in utility to stop shaping brushes by mouth.

However, I think that the OP is either drastically overstating the certainty of his claim that hobby paint gave people cancer, or overstating his duty to avoid revealing more information. The reason I think that is because based on what I could find about cadmium, it's toxicity, it's pigments, and it's use, a claim that a hobby paint caused cancer requires a few leaps. First, it requires the leap that a compound which is generally seen as safe when not inhaled caused cancer through ingestion. Second, it requires medical certainty that this fairly uncommon metal caused the cancer, instead of any other factors. Third, it requires pigments, which are generally not absorbed when emulsified, to be absorbed at a higher rate than normal.

All of this seems unlikely, especially given the rationale provided by the OP in a follow up:

 MajorTom11 wrote:
But yes, reputable medical source, peer reviewed and proven with sufficient rigour and cause to stand in a court of law.

So, peer review is a term of art use in academics, which is unlikely here. Now, assuming the OP meant "verified by second opinion," that's fine, but what really worries me is that final clause. "proven with sufficient rigour and cause to stand in a court of law." That... does not mean much. That means that they had enough medical testimony to convince a finder of fact (jury or judge) that the paint, more likely than not, caused the cancer. Keep in mind that neither the judge nor jury knows anything about heavy metal toxicity or cancer.

Even if a hobby paint with cadmium caused cancer in a few people, that doesn't mean it will be generally dangerous. And based on what I've read, the biggest danger wouldn't be brush licking, which is essentially ingesting highly diluted pigment, but airbrushing, which would involve inhalation, the more dangerous route of absorption.

As for the "ethical quandary," I dunno. Usually people cannot reveal specifics due to ethical rules (medical or legal privacy), a signed NDA, or because they are a journalist who needs to protect a source. But he's not making a general warning. He's pretty clearly saying "Vallejo paints gave people cancer." And then saying, "but I can't tell you how I know that." Given what I've noted above, the only real way to know this would be a fairly extensive scientific study, if the OP had access to peoples medical files, or active litigation. The problem is, if he was involved in treatment or litigation, he shouldn't be saying anything. That's not an ethical conundrum, that's just the rules.

Based on the line about proving it in a court of law, I'm going to take a guess that the OP knows one or more people who have had cancer, and sued a paint company over it, and received a settlement with a non disclosure agreement. Which means that he wouldn't be able to say why he knows without risking those settlements. If this is the case, than there's all more reason to doubt the certainty of the claims. Company's settle cases all the time, especially if the settlement would be lower than the cost of litigation.

I know this was a lot, and I certainly don't think the OP is being malicious, but I think that the level of concern is both misguided and overstated.

 Orlanth wrote:
No matter what some think about raising controversy on this issue we should take a responsible attitude and disclose any safety concerns. Now armed with a 'suggestion' that Vallejo paints may be responsible I did a quick search and found this:

https://forum.reapermini.com/index.php?/topic/28534-toxicity-of-vallejo-paints/
https://www.reddit.com/r/minipainting/comments/9vx7q0/psa_recent_vallejo_model_color_paint_is/

....and did a search on GW paints, GW themselves list them as non-toxic and have found no evidence to the contrary. Frankly this didn't surprise me, I will not shy from bashing Geedubs when warranted, but also credit where credit is due. The company has always made product quality its watchword, and have an exemplary manufacturing safety record. GW were early adaptors of materials changes, being amongst others the first major manufacturer to stop using lead based metals, and also abandoning molten metal casting in favour of hot metal pressing, which releases far fewer volatiles. There are downsides to that, GW metal miniatures were not fully molten when cast, hence why the metal crumbles like metallic flapjacks when cut - and a metallurgist I encountered expressed strong concerns over product longevity. But it is a much safer and more healthy production process which is an acceptable counterpoint.