The so-called ‘Oddy Test’ is an inexpensive accelerated aging protocol for establishing the suitability of materials for museum use. The test conditions include exposure to high heat (60 ºC) and humidity (100% RH) over 28 days in a sealed glass jar containing ‘detector’ coupons made of lead, copper, and silver. The flint glass jars advocated in the Metropolitan Museum of Art’s ‘3-in-1’ Oddy test are shown to leach alkalis under these harsh accelerated aging conditions. The leached alkali is capable of neutralizing organic acids from samples which would otherwise have corroded the metal coupons, thereby calling into question materials that seemingly pass this accelerated aging test. The potentially erroneous conclusions from this widespread protocol are demonstrated using Delrin (polyoxymethylene) plastic. Delrin provisionally passed the Oddy test as conducted in the jar reactor, but an identical test performed in a non-leachable Pyrex boiling tube with an inert silicone stopper showed the material to be entirely unsuitable for long term museum use. In some cases, the Delrin samples degraded spectacularly in the Pyrex tubes, producing copious amounts of a brown viscous liquid that formed on the surface of the lead coupon. GC-MS of the solvent extractable portion of this brown degradation product showed the presence of organic acids, and infrared spectroscopy indicated the presence of a lead carboxylate moiety. Recommendations are made to utilize the modified 3-in-1 British Museum protocol for materials testing, which relies on non-leachable Pyrex glassware.