View Full Version : Cadmium safety and cost
06-30-2002, 08:35 AM
Perhaps some kind soul will enlighten me on these two points.
I just purchased a 37 ml tube of WN Cad Yellow which contains Cadmium Zinc Sulphide in Safflower Oil. I got it at a half price(?) sale. The price marked on the tube was $23.95. Given that Cadmium based pigments are expensive the prices charged for the small quantities contained in a tube of paint puts it right up there with gold. I can't help but think that artist are getting ripped-off big time.
OK I know that Cadmium is very toxic and there is a certain amount of the material in the foods we eat and in tobacco as well.
However the actual amount ingested is in trace quanities and only a small percentage of that is retained in the body. So my intuition tells me that unless I'm adding Cad Yellow to my cooking for color as long as I use reasonable care the stuff is safe to use. Am I wrong?
06-30-2002, 10:28 AM
I'll be moving this thread to the oil forum. I'm sure someone there can answer your question.
06-30-2002, 11:53 AM
As long as you are not licking your paints or useing them in food, you are in no real danger. Though I personally prefer non-toxic paint. I think you'll live.
06-30-2002, 04:41 PM
Cadmium based oils are as toxic as any other paints, I am thinking of phthalos, leads, etc...
The same principle applies to ALL pigments, even those thought of as safe (you never know until someone finds out about them too):
No paint inhaled, eaten, through your skin, be careful at all times but as long as you take the normal precautions, there is nothing to worry about.
07-02-2002, 01:22 AM
yeah, take it from me. don't eat it or slather your body with it. It may feel nice on your body but the taste will make you cry.
07-03-2002, 11:57 PM
yes they are toxic.... but only if eaten... or inhaled. There are numerous warnings on acrylic tubes of paint about the dangers of inhaling cadmium. I guess the worry is someone using the paint in a spraygun or airbrush and then breathing in the vapors.
For us oil painters though, just don't eat it... and wash your hands well after painting with it and you should be fine.
FYI. Gamblin Colors, inc claims the cadmium in thier paints is so pure there is no reason to label it toxic... and the Arts and Crafts Materials Institute agrees with them. I think they are the only oil paint company who can get away with not labeling their cadmiums as toxic... i think.
Genuine Vermillion on the other hand should be handled VERY carefully.
07-05-2002, 02:05 AM
I wonder if they would be allowed the same leaway for a paint type that is more-commonly applied by airbrush (q.v. Golden's CP cadmiums)... I doubt it.
Luis, phthalos toxic???
07-05-2002, 03:02 AM
Originally posted by Einion
(...) Luis, phthalos toxic???
According to some sources, copper based phthalos are toxic.
Copper phthalocyanines are suspected to have molecules that are carcinogenic. The same applies to cobalt based phthalos. Studies seem to have indicated as much.
Interestingly enough, the Royal Mint replaced it with copper-free phthalo blue in the blue and green ink shades of the English 5 Pound note.
Not all phthalocyanines are carcinogenic. Pigment Blue 16 (74100)is a metal-free phthalo. Copper based but the finished pigment product is cleared from all metal components so the final pigment is safe.
For example, fluoraluminium phthalocyanine is currently being studied for the opposite reason: It is believed to have anti-carcinogenic properties that may prove useful in anti-cancer drugs.
Studies are still being carried out is the issues in regards to copper based phthalos are at least partially inconclusive.
Whatever the case, Artists should be made aware that safety rules must apply when handling the dry pigment. Phthalos suspended in oil are much safer (the same goes for lead white anyway), but safety precautions about inhaling, ingestion and skin absorbtion should apply.
07-05-2002, 10:44 AM
Originally posted by MrSpringGreen
.../FYI. Gamblin Colors, inc claims the cadmium in thier paints is so pure there is no reason to label it toxic... and the Arts and Crafts Materials Institute agrees with them. I think they are the only oil paint company who can get away with not labeling their cadmiums as toxic... i think. Genuine Vermillion on the other hand should be handled VERY carefully. PB15, PO48
Odd that they don't have to label, given that cadmium metal is carcinogenic...do you have any more info? And yes, for anyone using genuine vermilion, the mercuric compounds are quite toxic.
07-07-2002, 01:34 AM
Regarding phthalo pigments, I read in several places that they may be contaminated with PCBs due to the manufacturing process. One says that this was only the case before 1982, while others seem to suggest that some still might be.
If anyone has more definitive info about this, I'd appreciate it.
07-07-2002, 12:52 PM
Odd that they don't have to label, given that cadmium metal is carcinogenic...do you have any more info?
I got this tidbit of information from some of their literature. I thought that may be correct, or it may be some advertising semantics but I don't think there is a warning label on their paints. Perhaps this website might help:
If that's true, then excellent! It doesn't make any difference to me though as I treat all my colors as if they were vermillion and worthy of the utmost respect and caution... All the solvents and mediums as well.
07-07-2002, 03:00 PM
Patrick, the only mention of PCBs in relation to the phthalos I have seen was on the 'Net. It's not mentioned in any reference book I have or have read, which probably says a lot about the validity of the issue.
Luis, incidentally the issue of copper in this regard is also not mentioned, in fact most sources state unequivocally that phthalos are not toxic, hence they don't require health labelling - even in California, tee hee. We have to remember that we're talking about an organic compound with a copper atom in it, not a metallic salt, so personally I think this is one of those types of warning - caffeine causes cancer etc. About the mint, I'd bet money (sorry!) they switched to metal-free phthalos because of cost, since their lower lightfastness is obviously irrelevant in this application.
Garry, Gamblin's MSDSs for their cadmium pigments explains why they don't required health labelling.
07-07-2002, 04:06 PM
if you go to the Ciba-Geigy site, there is
much mention of % content of PCBs per
So it is an accountable factor.
I wrote to Ciba-Geigy, but never got a
response.That was about a year ago.
I switched to Bismuth Vanadate as my
yellow [ also available as red and green].
Because the Bismuth site has it listed as
It is Rembrandt's Permanent Lemon Yellow in oils
and I believe water-colours.
It is W and N's acrylic Bismuth Yellow [ cheap
Anything you can add on would be appreciated.
07-09-2002, 08:54 PM
i don't have any definitive studies or scientific papers to cite, but here's the commonly held beliefs of the paintmakers i know vis-a-vis various pigments. if any of these beliefs are wrong, i'd love for the more scientifically minded folks here to disabuse me of the following notions:
- a lot of the pigments we use are heavy metal compounds. this goes for cadiums, cobalts, titaniums, manganeses. cobalts and cadmiums can be harmful if ingested. these molecules are too large to be passed through the human system easily, once ingested. exposure is cumulative. cadmium in particular is carcinogenic.
- cobalt blue is mildly radioactive.
- lead white is lead carbonate. overexposure or ingestion can lead to lead poisoning.
- zinc white is zinc oxide. it is a common additive to many whites. overexposure can lead to zinc poisoning. a household treatment for zinc poisoning is to drink a glass of milk.
- most modern organic pigments (quinacradones, azos) are nontoxic.
- breathing any particulate matter is harmful. overexposure to pigment or any other type of dust can lead to emphysema.
- zinc yellow is zinc chromate which is poisonous to mammals.
- vermilion is mercury sulfate, extremely poisonous. this is the most toxic pigment i have ever handled. extreme caution should be used. many vermilion substitutes are cadmium sulfate or mercury cadmium compounds. these should also be handled with all appropriate caution.
- a careful artist who wears gloves when painting and washes her hands after painting has little to fear from even the most toxic pigments. the most danger is presented to those handling pigment in its raw dust form. air filters, respirators, etc should be employed. most of these dangerous chemicals are too large to be absorbed through the skin.
- i've heard various things about the toxicity of phthalos, i'm not taking any chances. i treat them like any other pigment, i use precautions.
- sanding paintings can be another source of danger. wear a dust mask. lead grounds should not be sanded.
07-09-2002, 09:00 PM
and yes, cadmium does rival the cost of many other precious metals, ounce for ounce. i am usually able to get it wholesale, where it ranges between $12 and $25 per pound.
camium sulfate and cadmium selenide (red and yellow cadmium compounds) do occur naturally, but most of the natural cadmium in the world has been mined. natural cadmium is far more expensive than synthetic cadmium, though chemically identical.
07-09-2002, 09:44 PM
I don't think Titanium is a heavy metal
and Ti02 is pretty unreactive.Ti02 I believe
does have a drying , irritating effect on
skin and naturally lungs.
Zinc Oxide at 40 % is an ingredient in
Diaper Rash cremes.Usage is apply liberally.
You should check into the reaction of cobalt,
manganese, cadmium and lead in oil.See if
any organic compounds are formed and if
in the oil vehicle, these organic compounds can
enter the skin.
Someone using a White blend of Ti02 and Zn0
would not be able to use cobalt or manganese
as the paint film would become brittle with age.
Organic pigments have to be well read up on,some
are listed as very toxic .
Why not just look up Monona Rossol on a search
engine and write to her.She is an Industrial Hygienist
, very helpful and very knowledgeable.
You might also do a search on Bismuth Vanadate and
it's use as a replacement for Cadmium, comes in yellows
, reds and greens.
There was also some research into Cerium for yellows
It is supposed to be the blends of metals [ the cocktail]
that does the most harm and the combined sources
you get the metals from, water, glazes, washing powders
, residue on foods, car exhausts, solvents , cleansers and
so on. As well as pesticides, glue fumes and other modern
The body can handle a good deal, but not the cocktails.
The best protection is Awareness.
07-15-2002, 12:58 AM
Hi Khaimraj, I don't doubt that PCBs might be present in some phthalo colours (although at least two sources stated that they had been eliminated in the last twenty years or so, one is even specific to 1982) but what I was referring to was the potential threat they might pose in use even if they were present - all the printed sources say the same thing: non-toxic, without qualifiers (even some which are a bit more rabid about the issue of toxicity!) hence its ACMI status and as indicated in its MSDS. The toxicity of PCBs, as I understand it, is open to debate anyway and is usually linked to significant long-term exposure.
Nothing much to report on Bismuth Vanadate. Bismuth and vanadium are both heavy metals but the stability of the compound is the main issue and appears very good. It's health labelling class is the same as Bone Black's so it must be pretty safe.
BTW, titanium is classed as a heavy metal but then so are iron, silver, platinum and rhodium so I'm not exactly losing sleep ;)
Sarkana, TiO2 is about as non-toxic as it's possible to get for a pigment - it's used in oral medication and toothpaste, heck, it's probably safer than some actual foods! Zinc Oxide is the primary ingredient in total sunblocks - including lipstick types - so it can't be much of a risk. Again for both, as you mention, it is probably as a lung irritant where most threat lies.
Isn't cobalt considered more carcinogenic than cadmium? Cadmium is a threat largely by inhalation while cobalt is a significant risk via ingestion too, if I remember correctly the warnings are a bit more dire on Cobalt Blue than they are on Cadmium Red.
Not all heavy metals build up in the body in the same way but it is a good reminder of the real threat they pose. By the way, you might be interested in something I just discovered, for ingested lead compounds absorption rates in children can be as high as 50% while for adults it's around 10%.
As you say, breathing any particulate matter is harmful and a careful artist... has little to fear from even the most toxic pigments to which I'll add treat everything as toxic and you can't go far wrong.
Oh, sorry to be such a pedant but Vermilion is mercuric sulphide, not sulphate :)
To put the toxicity of any pigment used in paint into perspective: people have worn flake white makeup on their skin (not to mention kohl, which is an antimony compound, was used around eyes!) without dropping like flies left and right so we have little worry about from the contents of our tubes!
07-15-2002, 04:17 AM
You have scared me !
Do you think cadminum and cobalt paints (oil, watercolor)
are really dangerous ??
07-15-2002, 08:44 AM
Yes, Enion your correct.
I had to research this one .
Heavy metals are elements having atomic weights between 63.546 and 200.590 (Kennish, 1992), and a specific gravity greater than 4.0 (Connell et al., 1984).
Titanium only fits in here because the specific gravity is
4.5. Atomic weight is 47.90
Iron has the same situation -S.G 7.86[Iron is however
easily eroded ]
So now we will have many people running around
claiming Titanium and Titanium Dioxide are Toxic.
I wear Titanium surgical grade as a ring, the metal
is implanted into the body and I use titanium dioxide
as a non-toxic ingredient in my enamels and glazes.
BUT if everyone runs around just blindly shouting
I give up.
Thanks for the important heads up.
*I am presently staying away from Inorganic pigments
until I ask Monona Rossol for a definition of safe.
AND which colours.
** Lead based make-up often evolved sores and other
skin damage on the face.
Ah,the price of beauty.
Lead white use is a complicated issue, is highly individual
,and should be discussed by professionals connected
with Industrial Hygiene or other.
07-15-2002, 08:57 AM
I have asked by czech producent of oil, watercolor and tempera paint (brand UMTON). Mr.Krejcarek wrote me (shorted and translated):
"Our pigments are based on such two cadmium compounds, that are not clasiffied like dangerous substance (list of dangerous substances by law). (sulf-selenid of cadmium, sulf-cadminum-zinc, sorry I don't know how translate it corectly). Those pigments are indissoluble, so they cannot harm.
Other cadmium compounds are not used.
I personally know 90 years old painter, who mixes watercolors using his own finger, licking it without washing rests of paints :)
And he is fit and healthy.
Alternatives based on anorganic pigments are really toxic and alternatives based on organic pogments are less bright and less permanent. Red and yellow cadmium based pigments are still best solution.
So don't be afraid to use cadmium paints"
07-15-2002, 10:12 AM
I didn't reply to your request because I didn't
know which paint type you used - water-colour
The problem with cadmium is one's studio practice.
I wouldn't encourage "licking your fingers" and
painting even with poster paints meant for children.
You should contact Monona Rossol [ Industrial
Hygenist - do an on-line search for her e-mail address]
or read Patty's Industrial Safety or look up in your
See Sinopia.com for comments on Cobalt, Nickel and
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