QHow much antifreeze would someone have to drink before it would be likely to kill him? Would the ME be able to differentiate between brands of antifreeze, maybe in traces left in the victim’s stomach, so the perpetrator could be tracked down?
Cat Waldron
Sarasota, Florida
AAntifreeze is a general term for many different types of engine coolants. The most common ingredient in these products is ethylene glycol, a toxic substance.
In toxicology, LD50 stands for lethal dose 50% or the dose that will kill 50% of people who take it. Most of the studies on ethylene glycol have been done in animals so the true LD50 in humans is not known. It is estimated to be 110 grams, roughly four ounces. This varies greatly from person to person, and alcoholics are notorious for being able to tolerate the consumption of antifreeze without killing themselves. Drunks are hard to kill. Ask any emergency room physician. So about four ounces could be lethal in your story.
If the coroner tested the stomach contents and found residual antifreeze, it is possible that he could send it to a specialized lab, perhaps the FBI lab or a sophisticated state lab, and have it tested for the other ingredients that are added to ethylene glycol to make antifreeze. Most antifreeze products contain at least 90% ethylene glycol, so it is the other 10% that would be of interest. Since different companies use various solvents, alcohols, coloring agents, and other chemicals in their products, it is conceivable that the manufacturer could be determined. This might be helpful in tracking down the killer.