11/17/2025
Understanding toxicity and lethal dose thresholds
This chart ranks substances by their LD50, or the dose required to kill 50% of test animals (usually measured in mg per kilogram of body weight). It provides a standardized comparison of toxicity, showing how vastly potency differs among chemicals that range from essential nutrients to household compounds.
1️⃣ Super toxic compounds
Substances with extremely low LD50 values are lethal in microgram quantities.
🟢 Example: Botulinum toxin has an LD50 of 0.00001 mg/kg, making it the most potent biological toxin known. Just a few nanograms can cause fatal paralysis by blocking acetylcholine release at neuromuscular junctions.
2️⃣ Extremely to very toxic substances
Toxicity rises sharply among compounds that are safe at physiological levels but harmful when overdosed.
🟢 Example: Vitamin D has an LD50 around 10 mg/kg; while essential for calcium balance, excessive intake causes hypercalcemia and kidney damage.
🟢 Example: Caffeine and copper sulfate fall into the “very toxic” range, with lethal doses around 192–481 mg/kg, illustrating that natural origin does not imply safety.
3️⃣ Moderately toxic compounds
Common over-the-counter substances and minerals fall in this range, where toxicity depends on chronic exposure or extreme dosing.
🟢 Example: Acetaminophen (LD50 ≈ 1,944 mg/kg) can cause acute liver failure when overdosed due to depletion of glutathione.
🟢 Example: Sodium chloride (LD50 ≈ 3,000 mg/kg) is essential for fluid balance, yet large acute doses can disrupt osmotic regulation and lead to cardiac arrest.
4️⃣ Slightly to practically non-toxic substances
Compounds with high LD50 values require massive amounts to reach toxic levels.
🟢 Example: Glyphosate and ethanol are classified as slightly toxic, with LD50 values above 5,000 mg/kg, though chronic exposure to ethanol still produces systemic damage.
🟢 Example: Sucrose, with an LD50 around 30,000 mg/kg, is considered practically non-toxic acutely but contributes to metabolic dysfunction with habitual overconsumption.
LD50 values reflect acute toxicity, not long-term health effects. A compound’s danger depends on its dose, exposure duration, route of entry, and individual physiology. Even essential nutrients can become toxic when consumed far beyond the body’s regulatory capacity.