What Is Cyanide, and Are Apple Seeds Poisonous?
Cyanides are a group of compounds containing a highly reactive cyanide anion, according to the Agency for Toxic Substances and Disease Registry, and cyanide is produced naturally in many plants, fungi, bacteria and millipedes, with some compounds made by people. ATSDR calls cyanide a well-known poison that can cause death at very high levels, and says breathing hydrogen cyanide may also cause breathing difficulty, nervous system changes such as dizziness, headache, weakness and tingling, and impaired thyroid gland function.
Apple seeds matter if they are chewed. ATSDR says people may be exposed to higher levels of cyanide if they eat foods that potentially contain cyanogenic compounds, such as the pits or seeds of apples, apricots and peaches, or unprocessed cassava root, and that most products of concern in the US are processed to remove those compounds. The Maryland Poison Center says swallowing a whole seed, pit or kernel will not cause harm but chewing or crushing them may, because digestive enzymes then react with the amygdalin inside and cause cyanide to form.
For most people, ATSDR says general exposure to cyanide is expected to be low, and it lists people who smoke cigarettes or live with a smoker among those who may be exposed. Its public health statement says smoke from burning plastics in a building fire contains cyanide and carbon monoxide and can lead to unconsciousness or death, which is why families should evacuate a burning building immediately.
Sources checked September 15, 2026. Every point below links the page it came from.
The sources behind this answer
- Government sourceATSDR says cyanides are a group of compounds containing a highly reactive cyanide anion, and that cyanide is produced naturally in many plants, fungi, bacteria and millipedes, with some compounds human-made. ATSDR, CDC ↗
- Government sourceATSDR says cyanide is a well-known poison that can cause death at very high levels, and that breathing hydrogen cyanide may also cause breathing difficulty, dizziness, headache, weakness, tingling and impaired thyroid function. ATSDR, CDC ↗
- Government sourceATSDR says eating pits or seeds of common fruits such as apple, apricot and peach, or unprocessed cassava root, may expose people to higher cyanide levels, and that most products of concern in the US are processed to remove cyanogenic compounds. ATSDR, CDC ↗
- Medical referenceThe Maryland Poison Center says swallowing a whole fruit seed, pit or kernel will not cause harm but chewing or crushing them may, because digestive enzymes react with amygdalin inside and form cyanide. Maryland Poison Center ↗
- Government sourceATSDR says general population exposure to cyanide is expected to be low, and that people who smoke cigarettes or live with a smoker may be exposed to cyanide. ATSDR, CDC ↗
- Government sourceATSDR says families should evacuate a building fire immediately, because smoke from burning plastics contains cyanide and carbon monoxide and breathing it can lead to unconsciousness or death. ATSDR public health statement for cyanide ↗
Sources checked September 15, 2026. A brand statement is the company’s own claim, which we report but have not verified. Our grades are model-based estimates, not lab tests.