Ricin (from Ricinus communis)

Ricin is a highly toxic protein derived from the seeds of the castor bean plant, Ricinus communis. Although the castor oil extracted from the seeds is safe and used for various purposes, the residue contains ricin, which can be lethal if ingested, inhaled, or injected. Symptoms of ricin poisoning may include severe abdominal pain, vomiting, diarrhea, and organ failure. There is no specific antidote for ricin, making it particularly dangerous. Due to its potential use in bioterrorism, ricin is classified as a hazardous substance in many countries.