Wednesday, March 3, 2010

Ask Stape, Mad cow disease and ivory black


Dear Stape

As I told you before, I am a one armed widow living down here in the container docks.I have to eat, so I have been running a trap line for meter readers in my neighborhood. I caught one the other day, well at least I did for a while. It was a bizarre young women all dressed in black, wearing black lipstick. She was flopping about hideously, barking like a dog, and screaming threats in ancient Aramaic. I have heard that a coyote will chew off its leg to escape a leg hold trap, but this woman actually chewed through the steel trap itself! She appeared to be wearing some sort of black dentures!

By the time I could get back with the net and the ether, she was gone. She also ran off with the black plastic eyeglasses and cheap narrow brimmed fedora I was using as bait.
When I retrieved my damaged trap there was black paint everywhere. It was all over the meter and the stairs. Frankly the whole thing makes me nervous. Now I am starting to worry, could I get mad cow disease from all of that ivory black paint? I know it is made from animal bones. Is Ivory black dangerous?

signed Oneulna


Oneulna:

I did some research on the question of "Mad Cow Disease and ivory black, actually, I did a lot of research. I contacted the CDC in Atlanta ( no kidding) and an expert on BSE ( as they like to call it) answered the question. Their opinion is that the risk is "vanishingly small".

The odds of getting it from carbonized bone that is handled and not ingested would be extremely small. While it is theoretically possible for the prions that cause this disease (called Creutzfeldt Jakob in humans) to survive the extreme heat used in making the pigment, it is not likely, given the temperatures to which the bone material is heated and the length of time that heat is maintained. Oddly enough the CDC already had researched this question for the potters, who use bone ash in the making of china and certain sorts of pottery. People would of course be eating from those products. There are no food grade bone black pigments, but there are bone black pigments approved for the cosmetic industry.. Incidences of the disease in humans even where there have been cattle with BSE are extremely rare.
The disease is carried in the nerve tissue and not in the bone. A major paint manufacturer when contacted about this explained that as a precaution the bone used to make ivory black doesn't include skulls or vertebra.

So Oneulna, I would go ahead and use ivory black without reservation, but I don't think you should eat it. Even if you did, I think the odds of your getting "mad cow" are very,very small.

I also think you need to be far more careful about where you set your traps though. Not everyone is nice.
.......................Stape

19 comments:

willek said...

Just a terrific post, Stape. I knew it came up at Snow Camp W but my hearing is not what it was, I have shot so many ducks, you see. But I also stopped listening because I knew heat was involved in the process of making the pigment. So it was big news to me that the Pryons could survive the heat!. Wow!. I try not to think too much about the insideous dangers of painting, it is hard enought to think about what the painting needs. I have so much painting to do and very little time before the kids stick me in the nursing home.

Gregory Becker said...

That was a good question and answer. Especially since that is my black of choice. I have a tube of Lamp black also. No danger there I hope.

mariandioguardi.com said...

Hey, you should see the nice fedora and black rimmed eyeglasses I found last night down by the docks..all that and a new anklet.

The most common entry of all the toxic pigments is through ingestion. So, make sure you don't have pigment on that cigar, coffee cups etc. Next common is breathing in aerated pigments from sanding (pastels). Never sand inside without a ventilator and a dust collector or sand outside.

Pigment molecules, like cadmium, cobalt, are to large to go through your skin. But solvent molecules are small, go through skin, to the blood stream and into the liver. If you don't like gloves, use a plastic bag on the hand where you hold the solvent rag. I saw what happened to a friend of mine after a day of painting and holding a solvent rag in his left hand for eight hours. He was in bad shape and never did that gain. Beware you thinners!

Deb said...

I'm with Willek here - good grief! There is enough to worry about just trying to paint the dang painting without having to also consider
what dangers lurk on our palette!
Willek - move several thousand miles away from your kids - then it is harder for them to find you to put you in the nursing home!
I never knew that Ivory Black was made from bones. wow. Thanks for researching it and for the info.
My liver is shot, I just know it.

Richard J. Luschek II said...

I had heard rumors of this mad cow thing in association with Lamp Black which is why I have assistants make my own brand of Lamp black. It is made from the horns of endangered elephants and pygmy rhinos. I prefer it to "ivory" black made from cows. It is a bit blacker and more evil.

Jim Nolan said...

Dear Stape
I am relatively new to oil painting and have been following your blog avidly since discovering it a few months ago. More useful information than all of the art instruction books sold on Amazon ( most of which I foolishly bought).
I am especially interested in your comments yesterday on BSE since I happen to be a retired pathologist. The outbreak in the UK in the 80's was caused by the changes in animal husbandry whereby tissue from slaughtered herbivores was used in modern industrial cattle farming. (cows and artists have a natural affinity for grass). In the UK the processing temperature for these tissues was reduced thereby allowing the vector prions to survive. This did not happen in Germany where the disease was minimal. A reason that Bovine Spongifom Encephalopathy (and its associated Creutzfeld-Jacob Disease) was uncommon in the US was the feed used was the much cheaper and plentiful soybean meal. Therefore if lamp black is produced within the US it is safe.
As a pathoogist my most terrifying moment occurred many years ago when I doing my residency and fellowships at The University of Minnesota Hospitals. I was asked to perform an autopsy on a patient thought to have CJ disease to verify the diagnosis. Ethically I couldn't refuse and I ended up with as many protective suits and masks as an astronaut. Fortunately I am here to tell the tale and I don't think I have a spongiform brain. An interesting footnote - CJ disease is named after the South African physicians who discovered the disease among tribal warriors who believed, by eating the brains of their slain foes, they gained wisdom. These brave physicians didn't know anything at that time about prions but they correctly deduced that the disease was transmitted in neural tissue.
Sorry for the lengthy comment

barbara b. land of boz said...

Aw Stapleton.... It's good to know you care about our health. Kidding aside, the world of a painter can be hazardous to your health. As you have shown in the last couple of posts. I'm glad I mix my own black.

Thank you once again for this blog.

barbara b.

mariandioguardi.com said...

PS.
No danger in Lamp Black. It's a carbon black too but made from burning oils. Hence the name "Lamp" black. It was originally made from the soot of oil burning lamps.

Mars Black is a black Iron Oxide. It's inorganic where the other two are organic (carbon based). I just read that it is the only black that is considered non-toxic.

willek said...

Where are you now, Stape adn what are you painting?

Stapleton Kearns said...

Willek:
As the man said, the odds of your getting BSE are very very small.I have called the kids by the way.
...............Stape

Stapleton Kearns said...

Gregory:
I wouldn't lose any sleep over that either.
...............Stape

Stapleton Kearns said...

Marian;
I have no skin.
...............Stape

Stapleton Kearns said...

Deb;
The government is going to provide you with a new liver.
...................Stape

Stapleton Kearns said...

Richard;
Mail me your teeth.
..................Stape

Stapleton Kearns said...

Jim:
The got Kuru I learned about that as an undergrad (briefly) at the University of Minnesota.
.....................Stape

Stapleton Kearns said...

Barbara:"
You will just get something else. No one gets out alive!
...............Stape

Stapleton Kearns said...

Marian:
I don't like mars black though. It is too inky.I wonder if it could be stepped on with something to make it better?
..................Stape

Stapleton Kearns said...

Willek;
I am in Charleston South Carolina. I will post one tonight so you can see what I am doing.
.................Stape

Jim Nolan said...

Stape
You are a remarkable man - your knowledge base extends far beyond art. I was surprised to see you mention Kuru. You probably know it was identified in Papua-New Guinea among members of the Fore tribe. BSE, C-J Disease, and Kuru are all the same disease entity caused by transmission of prions. There is another variant affecting sheep which is called SCRAPIE. I know there are a lot of sheep in New Hampshire but I don't think artists use any of the by-products????? The name comes from the fact that as the disease progresses the affected animal scrapes itself against rocks to relieve itching.