Chemical Dose Type Target water 8 kg inorganic nervous system lead 500 g inorganic nervous system alcohol 500 g organic kidney/liver ketamine 226 g drug cardiovascular table salt 225 g inorganic nervous system ibuprofen (e.g., Advil) 30 g drug kidney/liver caffeine 15 g biological nervous system paracetamol (e.g., Tylenol) 12 g drug kidney/liver aspirin 11 g drug kidney/liver amphetamine 9 g drug nervous system nicotine 3.7 g biological nervous system cocaine 3 g biological cardiovascular methamphetamine 1 g drug nervous system chlorine 1 g element cardiovascular arsenic 975 mg element digestive system bee sting venom 500 mg biological nervous system cyanide 250 mg organic causes cell death aflatoxin 180 mg biological kidney/liver mamba venom 120 mg biological nervous system black widow venom 70 mg biological nervous system formaldehyde 11 mg organic causes cell death ricin (castor bean) 1.76 mg biological kills cells VX (nerve gas) 189 mcg organophosphate nervous tetrodotoxin 25 mcg biological nervous system mercury 18 mcg element nervous system botulinum (botulism) 270 ng biological nervous tetanospasmin (tetanus) 75 ng biological nervous system

Poisons: Lethal vs Toxic

Looking at the list of poisons, you might be tempted to think lead is safer than salt or bee sting venom is safer than cyanide. Looking at the lethal dose can be misleading because some of these chemicals are cumulative poisons (e.g., lead) and others are chemicals your body naturally detoxifies in small amounts (e.g., cyanide). Individual biochemistry is also important. While it might take half a gram of bee venom to kill the average person, a much lower dose would cause anaphylactic shock and death if you're allergic to it.

Some "poisons" are actually necessary for life, such as water and salt. Other chemicals serve no known biological function and are purely toxic, such as lead and mercury.

Most Common Poisons in Real Life

While it's unlikely you'll be exposed to tetrodotoxin unless you eat improperly prepared fugu (a dish prepared from pufferfish), some poisons routinely cause problems. These include: