How does the toxicity of FBM media compare to TBE?
FBM media are less toxic than TBE. The major toxicant is boric acid (and borate). Although few reports exist, it appears that the acute ingestion of 30 grams of boric acid can be lethal if untreated. To reach this lethal dose, one would need to ingest 2.7 liters of 1X TBE, or 12 liters of 1X SB or LB. Boric acid and borate are not significantly absorbed through skin. Lithium is somewhat less toxic than the borate, given the amounts used in FBM media. Indeed, lithium used to be a component of 7-Up and some lithia beers. Ingesting 12 liters of 1X LB would be expected to provide moderate toxicity from the lithium alone (but a potentially fatal quantity of boric acid). The same dose of lithium, supplied by LA, would require the acute ingestion of 24 liters of a 1X solution. These are not likely scenarios. Considering the above numbers, any realistic danger of toxicity would have to come from acute ingestion of a few hundred milliliters of concentrated solutions of these conductive media (f
