The Oddy test is a procedure created at the British Museum by conservation scientist Andrew Oddy in 1973, in order to test materials for safety in and around art objects. Often, materials for construction are evaluated for safety. However, though materials may be safe for building purposes, they may emit trace amounts of chemicals that can harm art objects over time. Acids, formaldehyde, and other fumes can damage and even destroy delicate artifacts if placed too close.
This test calls for a sample of the material in question to be placed in an airtight container with three coupons of different metals—silver, lead, and copper—that are not touching each other or the sample of the material. The container is sealed with a small amount of de-ionized water to maintain a high humidity, then heated at 60 degrees Celsius for 28 days. An identical container with three metal coupons acts as a control. If the metal coupons show no signs of corrosion, then the material is deemed suitable to be placed in and around art objects. The Oddy test is not a contact test, but is for testing off-gassing.
Each metal detects a different set of corrosive agents. The silver is for detecting reduced sulfur compounds and carbonyl sulfides. The lead is for detecting organic acids, aldehyde, and acidic gases. The copper is for detecting chloride, oxide, and sulfur compounds.
The Oddy test has gone through many changes and refinements over time. Whereas Andrew Oddy proposed to place each metal coupon in a separate glass container with the material to be tested, Bamberger et al. proposed a "three-in-one" test, where all three metal coupons shared one container, simplifying the procedure. Robinett and Thickett (2003) refined the "three-in-one" test by stabilizing the metal coupons.
One of the main issues with the Oddy test is that there is some subjectivity to the interpretation of the results, since it is primarily a visual determination.
- W.A.Oddy, "An unsuspected danger in display", Museum Journal 73, 1973, p.27-28
- Schiro,Mara "Oddy Test Protocols" http://www.conservation-wiki.com/index.php?title=Oddy_Test_Protocols&oldid=4830 Accessed February 6, 2012.
- Studies in Conservation, Vol. 44, No. 2 (1999), pp. 86-90.
- Studies in Conservation, Vol. 48, No. 4 (2003), pp. 263-268.