Invented in the 1920’s by Eli Lilly, thimerosal is 49.6% ethlymercury by weight, a neurotoxin known to be more than a hundreds times more lethal to tissue than lead.
Eli Lilly’s safety testing of the product consists of a 1930 study of 22 patients dieing from mengiococcal meningitis in an Indiana hospital. Patients are injected with the solutions and followed until their death, which is within days. Because the patients die of meningitis, they are declared to show no adverse reaction to thimerosal and the product is declared safe for use. Thimerosal is subsequently introduced for use in vaccines and in over the counter remedies as a preservative to kill bacteria in the product.