Friday, August 5, 2011

Health, Safety, & Copper-Based Metal Clay [Copper I]

by Mary Ellin D'Agostino
Technical Advisor

This is part 2 of my ongoing series on Metal Clay Health and Safety.

Many of us have been using copper-based base metal clays for for a while and, while there have been a few complaints from people who have skin sensitive to the copper, no-one has reported any major illnesses. Still, I have wondered since the beginning about the health and safety issues associated with copper and bronze clays. I have sporadically researched this issue over the past two years. Even though I don’t feel I have fully grasped the issues and I have yet to find a definitive answer, I am going to pass on what I have learned and it is going to take at least a couple of posts, so stay tuned for more after this....

Natural Copper. Photo from

Copper is one of the first malleable metals humans learned to work and is abundant in our lives. We use copper for everything from water pipes to jewelry. Copper is an important trace element our bodies require, but it is also a heavy metal and overexposure to it can have serious health consequences. Exposure routes are through skin absorption, ingestion, and inhalation

For the most part absorption through the skin, one of the main exposure routes for metal clay artisans, does not appear to cause serious health problems. Some people’s skin is sensitive to copper. If you suffer from a rash or itching after using copper containing base metal clays, you will want to take precautions (wearing gloves) or discontinue use of the product. One of the biggest drawbacks to making copper and bronze jewelry is the reactive nature of the copper. In addition to irritating skin, it may turn the wearer’s skin green as copper oxides are formed and rub off onto the skin. While this is not a health hazard, it is unsightly and many people refuse to wear copper and bronze jewelry for this reason. The resistance to copper jewelry can be partly resolved by making sure that copper elements do not come into contact with the wearer’s skin or by placing a silver barrier, such as a ring liner, to prevent copper-skin contact.

The largest hazard associated with skin contact for metal clay users is the potential for ingestion of copper-based clay residue on hands. Always be sure to wash hands thoroughly after using copper or bronze clays and before eating. Avoid eating picnic or finger foods after working with copper and bronze clays. The possibility of ingestion of residue on hands is the main reason I do not recommend allowing children to work with copper or bronze clays.

I highly discourage teachers from doing children’s classes using copper and bronze clays. Stick to the silver clays when working with kids.

Most copper absorption is through the digestive system, so ingestion (eating or drinking) of too much copper can cause stomach upset, nausea, and diarrhea. More serious health risks are associated with very high levels of copper toxicity and will be discussed, along with inhalation in my next blog. In the meantime, if you can’t wait, you can read this basic Wikipedia article on Copper in Health.

Part 1 of the series on Metal Clay Health and Safety.

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