The careful skeptical inquirer considers . . .
Did a bioplastic growth on the fibers cause an error in the carbon 14 dating?
Certainly not! There have been claims that a biological polymer was growing on the Shroud and that this could have affected the date. This "theory" has received a lot of play in books about the ST and in many magazine articles. It is repeated on dozens of web sites.
The National Science Foundation Mass Spectrometry Center of Excellence at the University of Nebraska, using highly sensitive pyrolysis-mass-spectrometry, could not detect any such polymers on Shroud fibers.
Furthermore, it is well known that a biopolymer product would show the same carbon age as the Shroud because the organism, as it grew and formed, would use fixed carbon from the cellulose fibers and not from the atmosphere.
Nonetheless, the argument involving bioplastic growth persists. One reason is that ancient textiles that have been grossly misdated, especially in the earliest days of radiocarbon testing, and some suspect it is because of bioplastic growths. Most notable of these is mummy 1770 of the British Museum, whose bones were dated some 800–1000 years earlier than its cloth wrappings. Proponents also point out that the corner used for the dating would have been handled more often than other parts of the shroud, increasing the likelihood of contamination by bacteria and bacterial residue. Bacteria and associated residue (bacteria by-products and dead bacteria) carry additional carbon and would skew the radiocarbon date toward the present.
Harry E. Gove of the University of Rochester, who developed Mass Spectrometry Analysis for carbon 14 dating, the particular radiocarbon test used, has stated, "There is a bioplastic coating on some threads, maybe most." According to Gove, if this coating is thick enough, it "would make the fabric sample seem younger than it should be."
Others disagree. One reason is that an error of 1300 years resulting from bacterial contamination would have required a layer approximately doubling weight of the tested samples. This can be shown mathematically.
Sadly many authors, (including highly esteemed and reputable authors like Ben Witherington III writing in Christianity Today) have picked up on this hypothesis and a scorching fire hypothesis and given them traction.
See: Did a scorching fire, in 1532, possible affect the results of the carbon 14 dating? Is it possible that the images were formed by a biological growth mechanism?
