Don't Eat This

Even with the present craze of labeling every last ingredient and health hazard on common food and household items, many toxic artist materials fall outside of this jurisdiction. For about as long as artists have been using pigments to create works of art, they have been killing themselves in the process.
One of the most notorious artists, Vincent Van Gogh, was subject to spurts of madness (for lack of a better term) that have been contributed to everything as wide-ranging as syphillus to bipolar disorder to epilepsy and, of course, the obligatory accusation that the paints made him do it. Lead-based paints seem like one of the most likely culprits in this scenario. Lead poisoning is known to cause swelling of the eyes, which would cause the afflicted person to see halos around light...a technique that makes Van Gogh's paintings among the most unique and beautiful.
As of late, much of the lead once used to produce paints has been removed and replaced with less toxic ingredients. However, there is still a variety of hazardous chemicals present in paints, the most commonly known being cadmium pigments, a carcinogen. Less well known are the dangers present in the phthalo green and blue paints. During the manufacturing process of phatholcyanine, a chemical known Polychlorinated Biphenyl, or PCB is produced. Due to the expense of removing this toxic chemical, it is most commonly done only when the phthalocyanine is going to be used as a pigment for cosmetics. As well as being a carcinogen, PCB may cause dangerous alterations to the immune system, reproductive system, nervous system, and endocrine system. More specific side effects include poor short-term memory, hindered visual recognition, a decrease in thyroid hormone levels, a reduction in birth weight of the fetus in pregnant women, and an increased risk for contracting the Epstein-Barr virus. Pregnant women should be particularly cautious, because Phthalo Green also contains copper which can cause miscarriages. PCB is less of a risk in present day paints, because the US government has restricted the sale of products that contain PCB, including products that are imported from other countries. However, not all countries have established a ruling against PCB and it is a possibility that some Pthalo paints may still contain this toxin.
The jury is still out on certain paints, especially those made up of synthetic organic compounds, most of which are claimed to be safe yet whose toxicity levels have not been tested. Quinacridone Red is a synthetic organic paint which is said to be safe. Lithol Red, also a synthetic organic paint, has proven to be a carcinogen.
No dry pigment of any kind is 100 percent safe, as the dust particles are easily inhaled and adversly affect the respiratory system. Further, it is particularly hard to remove all traces of pigment dust from the area that they are used in, and may travel through the house through the air (albiet in trace amounts...there is no need to get too alarmed about this fact). A way of protecting against harming you lungs and air passageways would be to make sure that you contain your use of dry pigments such as paint pigments and chalk pastels to one area and to use a dust mask while working with them.
http://www.trueart.info/art_hardware.htm
http://www.epa.gov/pcb/pubs/effects.htm
http://www.epa.gov/pcb/pubs/about.htm
http://www.ci.tucson.az.us/arthazards/paint1.html
www.eggtempera.com/toxicity.html