Tuesday, February 3, 2009

Good News & Bad News

From Troy McFarland: Art From Scratch


I've been reading The Materials & Techniques of Medieval Painting By Daniel V. Thompson on the bus for a couple of weeks now.

I'm pleasantly surprised that some of the techniques I came up with to create a pigment are listed in here. For example, I took a patina recipe on the web (salt, ammonia, & vinegar), and experimented with it until I found that using just vinegar produces the best pigment. This was done a variety of ways in Medieval times for the same reason. The pigment is called 'Verdigris', also described in the book as an 'acetate of copper'.

That's the good news.

The bad news is that I just did an MSDS search on the effects of Copper (II) acetate, and it is not safe at all. Here's the MSDS, and here is the wiki entry on it.

By the way, vinegar fumes will create lead white pigment, which is potentially even scarier than copper (but not by much, it would seem)

I may continue to use this green pigment, but maybe it would be safer to stick with ground malchite.

Hazards listed on the MSDS site (thankfully I've been using a resperator & keeping Ravenna out of the garage with working with it):
Emergency Overview
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DANGER! CAUSES EYE BURNS. HARMFUL IF SWALLOWED. CAUSES IRRITATION TO SKIN AND RESPIRATORY TRACT.

SAF-T-DATA(tm) Ratings (Provided here for your convenience)
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Health Rating: 2 - Moderate (Life)
Flammability Rating: 1 - Slight
Reactivity Rating: 1 - Slight
Contact Rating: 3 - Severe
Lab Protective Equip: GOGGLES & SHIELD; LAB COAT & APRON; VENT HOOD; PROPER GLOVES; CLASS D EXTINGUISHER
Storage Color Code: Green (General Storage)
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Potential Health Effects
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Inhalation:
Causes irritation to respiratory tract, symptoms may include coughing, sore throat, and shortness of breath. May result in ulceration and perforation of respiratory tract. When heated, this compound may give off copper fume, which can cause symptoms similar to the common cold, including chills and stuffiness of the head.
Ingestion:
May cause burning pain in the mouth, esophagus, and stomach. Hemorrhagic gastritis, nausea, vomiting, abdominal pain, metallic taste, and diarrhea may occur. If vomiting does not occur immediately systemic copper poisoning may occur. Symptoms may include capillary damage, headache, cold sweat, weak pulse, kidney and liver damage, central nervous excitation followed by depression, jaundice, convulsions, blood effects, paralysis and coma. Death may occur from shock or renal failure.
Skin Contact:
May cause irritation with redness and pain.
Eye Contact:
Corrosive. May cause irritation, redness, pain, blurred vision, discoloration, and damage.
Chronic Exposure:
Prolonged or repeated skin exposure may cause dermatitis. Prolonged or repeated exposure to dusts of copper salts may cause discoloration of the skin or hair, blood and liver damage, ulceration and perforation of the nasal septum, runny nose, metallic taste, and atrophic changes and irritation of the mucous membranes.
Aggravation of Pre-existing Conditions:
Persons with pre-existing skin disorders, impaired liver, kidney, or pulmonary function, glucose 6-phosphate-dehydrogenase deficiency, or pre-existing Wilson's disease may be more susceptible to the effects of this material.

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