This list covers 39 poisons, running alphabetically from “Sabadilla” to “Swainsonine.” They come from a wide range of sources, including plants, venomous animals, industrial chemicals, and synthetic compounds. Some show up in pest control and manufacturing, others in household products or even medicine, and a few exist only as weapons.
Poisons are substances that harm or kill living things when they enter the body in high enough amounts. Some, like sodium azide in car airbags or sodium fluoride in toothpaste, are perfectly safe in tiny doses but dangerous in larger ones. Others, like sarin and sulfur mustard, were developed specifically as chemical weapons and remain lethal even in trace exposures.
Below you’ll find the table with the poison, source, effects, antidote, and description.
Poison: the name of the toxic substance, so you can quickly identify what you’re looking at.
Source: where the poison comes from, whether it’s a plant, animal, mineral, or manufactured chemical.
Effects: the symptoms and health problems the poison causes, helping you understand its impact on the body.
Antidote: the treatment used to counteract the poison, or a note when no specific antidote exists.
Description: background on how the poison works, where it’s found, and any notable history behind it.
Poisons
| Poison | Source | Effects | Antidote |
|---|---|---|---|
| Sabadilla | Seeds of the Schoenocaulon officinale plant | Vomiting, tingling skin, irregular heartbeat | No specific antidote |
| Sago palm toxin (cycasin) | Seeds and all parts of the sago palm | Vomiting, diarrhea, liver failure | No specific antidote |
| Sanguinarine | Bloodroot plant sap and rhizome | Cell damage, glaucoma with chronic exposure | No specific antidote |
| Santonin | Wormseed and related Artemisia plants | Blurred or yellow-tinted vision, seizures | No specific antidote |
| Sarin | Synthetic nerve agent | Seizures, paralysis, respiratory failure | Atropine and pralidoxime |
| Saxitoxin | Marine algae, concentrated in shellfish | Numbness, muscle paralysis, respiratory failure | No specific antidote; supportive care |
| Scombrotoxin | Histamine buildup in spoiled fish like tuna or mackerel | Flushing, headache, hives, stomach cramps | Antihistamines |
| Scopolamine | Nightshade plants such as Datura | Delirium, hallucinations, memory blackout | Physostigmine |
| Scorpion venom (deathstalker) | Venom glands of the deathstalker scorpion | Intense pain, fever, paralysis | Scorpion antivenom |
| Sea wasp venom (box jellyfish) | Stinging cells of the box jellyfish | Excruciating pain, skin scarring, cardiac arrest | Box jellyfish antivenom |
| Selenium | Contaminated soil, water, or industrial waste | Hair and nail loss, nerve damage, garlic-like breath odor | No specific antidote |
| Silver nitrate | Industrial and medical caustic compound | Chemical burns, permanent skin discoloration (argyria) | No specific antidote |
| Skunk cabbage toxin | Calcium oxalate crystals in skunk cabbage leaves | Burning mouth, swelling, difficulty swallowing | No specific antidote |
| Snakeroot toxin (tremetol) | White snakeroot plant | Tremors, vomiting, “milk sickness” from tainted milk | No specific antidote |
| Soman | Synthetic nerve agent | Rapid paralysis, seizures, respiratory failure | Atropine and pralidoxime |
| Sodium arsenite | Pesticides and wood preservatives | Stomach pain, organ failure, skin lesions | Dimercaprol (chelation therapy) |
| Sodium azide | Airbag propellant, laboratory preservative | Low blood pressure, headache, seizures | No specific antidote |
| Sodium chlorate | Herbicide and industrial oxidizer | Destruction of red blood cells, kidney failure | No specific antidote |
| Sodium cyanide | Industrial mining and electroplating chemical | Rapid oxygen starvation at the cellular level, death | Hydroxocobalamin or sodium thiosulfate |
| Sodium fluoride | Pesticides, industrial processes, trace amounts in dental products | Nausea, seizures, cardiac problems in large doses | Calcium administration |
| Sodium fluoroacetate (Compound 1080) | Synthetic rodenticide and pest-control poison | Heart failure, seizures, metabolic collapse | No proven antidote |
| Sodium hydroxide (lye) | Household drain cleaners, industrial chemicals | Severe caustic burns to skin and throat | No antidote; dilution and supportive care |
| Sodium nitrite | Food preservative, industrial chemical | Blocks oxygen transport in blood, bluish skin, collapse | Methylene blue |
| Solanine | Green or sprouted potatoes, nightshade plants | Nausea, vomiting, confusion | No specific antidote |
| Spurge sap | Milky sap of Euphorbia plants | Skin blistering, eye irritation, GI upset if swallowed | No specific antidote |
| Stachybotrys mycotoxins (black mold) | Toxins produced by Stachybotrys chartarum mold | Respiratory irritation, fatigue, immune suppression | No specific antidote; remove exposure |
| Star of Bethlehem toxin | Ornithogalum plant (cardiac glycosides) | Vomiting, irregular heartbeat | Digoxin-binding antibodies in severe cases |
| Stibine | Industrial byproduct, antimony hydride gas | Destruction of red blood cells, kidney and lung damage | No specific antidote |
| Stonefish venom | Venom glands along the stonefish’s dorsal spines | Excruciating pain, swelling, paralysis | Stonefish antivenom |
| Strontium-90 | Nuclear fallout and radioactive waste | Bone cancer, leukemia from long-term radiation exposure | No antidote; limiting absorption helps |
| Strychnine | Seeds of the Strychnos nux-vomica tree | Violent muscle spasms, convulsions, respiratory failure | No specific antidote; diazepam eases seizures |
| Sulfolane | Industrial solvent used in oil refining | Central nervous system depression, seizures | No specific antidote |
| Sulfur dioxide | Burning fossil fuels, volcanic gas | Coughing, throat irritation, lung damage | No antidote; oxygen and supportive care |
| Sulfur mustard (mustard gas) | Synthetic chemical warfare agent | Severe skin blistering, blindness, lung damage | No antidote; decontamination and supportive care |
| Sulfur trioxide | Industrial chemical, forms sulfuric acid with moisture | Severe respiratory and tissue burns | No antidote; supportive care |
| Sulfuric acid | Industrial and laboratory chemical | Severe chemical burns, tissue destruction | No antidote; irrigation and supportive care |
| Sulfuryl fluoride | Structural fumigant gas used in pest control | Nausea, seizures, lung irritation | No specific antidote |
| Suxamethonium (overdose) | Synthetic muscle-paralyzing drug | Full-body paralysis, respiratory arrest | Mechanical ventilation until the drug wears off |
| Swainsonine | Locoweed and milkvetch plants | Nerve damage, disorientation (“locoism”) in livestock | No specific antidote |
Descriptions
Sabadilla
An old-fashioned insecticide made from crushed lily seeds; the alkaloids inside irritate mucous membranes and can throw off heart rhythm if swallowed.
Sago palm toxin (cycasin)
Found throughout this popular ornamental plant; even a couple of seeds can cause serious liver damage in pets and people alike.
Sanguinarine
This reddish alkaloid from bloodroot was once used in “black salve” cancer cures; it kills cells indiscriminately and can scar skin and eyes.
Santonin
Once prescribed to expel intestinal worms, this plant compound has a narrow safety margin and can cause vision changes and convulsions in overdose.
Sarin
A colorless, odorless nerve agent developed as a chemical weapon; it overwhelms the nervous system within minutes and is lethal in tiny doses.
Saxitoxin
The toxin behind paralytic shellfish poisoning; it builds up in clams and mussels that feed on toxic algae blooms and can paralyze the diaphragm.
Scombrotoxin
Not a single chemical but histamine that accumulates in fish left unrefrigerated too long; cooking doesn’t destroy it, so spoiled fish stays dangerous.
Scopolamine
Extracted from thorn-apple and related plants, this compound has legitimate medical uses in tiny doses but causes dangerous confusion and disorientation in excess.
Scorpion venom (deathstalker)
One of the most dangerous scorpion species, its sting delivers a potent cocktail of neurotoxins that can be fatal to children and the elderly.
Sea wasp venom (box jellyfish)
Considered one of the most venomous marine animals, its tentacles can deliver enough venom to stop a swimmer’s heart within minutes.
Selenium
An essential trace mineral in small amounts, but excessive exposure damages the nervous system and causes a distinctive garlicky breath odor.
Silver nitrate
Used medically to cauterize wounds, this caustic salt burns tissue on contact and can turn skin a bluish-gray with repeated exposure.
Skunk cabbage toxin
The needle-like crystals in this swamp plant’s leaves irritate the mouth and throat instantly, discouraging animals from grazing on it.
Snakeroot toxin (tremetol)
Cattle that graze on white snakeroot pass the toxin into their milk, historically causing deadly “milk sickness” in frontier communities, including Abraham Lincoln’s mother.
Soman
A fast-acting nerve agent related to sarin, developed for chemical warfare; it binds to nerve enzymes almost irreversibly, making treatment a race against time.
Sodium arsenite
An arsenic-based compound once common in weed killers and wood treatments; chronic exposure damages nearly every organ system in the body.
Sodium azide
Best known as the chemical that inflates car airbags, this compound is also highly toxic if ingested, disrupting blood pressure and cell respiration.
Sodium chlorate
A powerful weed-killing oxidizer that, if swallowed, breaks down red blood cells and can shut down the kidneys.
Sodium cyanide
One of the fastest-acting poisons known; it stops cells from using oxygen, causing collapse and death within minutes without prompt treatment.
Sodium fluoride
Safe in the tiny amounts used in toothpaste, but concentrated industrial forms can cause seizures and heart problems if ingested.
Sodium fluoroacetate (Compound 1080)
This odorless, tasteless pesticide blocks a key step in cell metabolism, making it extremely lethal and notoriously hard to treat.
Sodium hydroxide (lye)
A highly corrosive chemical used in cleaning products; swallowing even a small amount can burn through the esophagus.
Sodium nitrite
Used safely in tiny amounts to cure meats, but a large dose leaves blood unable to carry oxygen, a condition called methemoglobinemia.
Solanine
The bitter, toxic compound that forms in potatoes exposed to light; peeling away green skin removes most of the risk.
Spurge sap
The milky latex inside spurge stems is intensely irritating on contact and can cause temporary blindness if it gets in the eyes.
Stachybotrys mycotoxins (black mold)
Often called “toxic black mold,” it thrives in water-damaged buildings and releases mycotoxins linked to breathing problems and chronic fatigue.
Star of Bethlehem toxin
This pretty white flowering plant contains heart-affecting compounds similar to foxglove, dangerous to livestock and curious pets that nibble it.
Stibine
A toxic gas sometimes released accidentally in battery manufacturing and metal refining; it destroys red blood cells and can shut down the kidneys.
Stonefish venom
Considered the world’s most venomous fish, its camouflaged spines deliver venom so painful that victims have begged doctors to amputate the affected limb.
Strontium-90
A radioactive byproduct of nuclear fission that mimics calcium, letting it settle into bones and teeth where it irradiates the body for years.
Strychnine
A notorious poison from a tropical tree’s seeds; it causes painful, whole-body convulsions while leaving the victim fully conscious until the end.
Sulfolane
A widely used industrial solvent that has contaminated groundwater near refineries; heavy exposure can dull brain activity and trigger seizures.
Sulfur dioxide
A sharp-smelling gas released by burning coal and oil, or by volcanoes; breathing it in irritates airways and can trigger asthma attacks.
Sulfur mustard (mustard gas)
A World War I-era chemical weapon that causes horrific blisters on skin and lungs, often with delayed symptoms that appear hours after exposure.
Sulfur trioxide
An extremely reactive industrial gas that turns into sulfuric acid on contact with moisture, burning skin and lungs almost instantly.
Sulfuric acid
One of the most widely produced industrial acids; it destroys tissue on contact and has tragically been used in acid attacks.
Sulfuryl fluoride
A colorless, odorless gas pumped into buildings to kill termites; accidental exposure can cause seizures, making ventilation before re-entry critical.
Suxamethonium (overdose)
A fast-acting paralytic used safely in surgery under monitoring, but a deliberate overdose can stop breathing while the victim remains conscious.
Swainsonine
Found in locoweed, this toxin disrupts brain and nerve cell function, causing grazing animals to wobble, stagger, and act erratically.