Essential oil
Essential oils can be extremely toxic when taken internally. Doses as low as 2 ml have been reported to cause clinically significant symptoms and severe poisoning can occur after ingestion of as little as 4 ml. A few reported cases of toxic reactions like liver damage and seizures have occurred after ingestion of sage, hyssop, thuja and cedar oils. Accidental ingestion may happen when oils are not kept out of reach of children. As with any bioactive substance, an essential oil that may be safe for the general public could still pose hazards for pregnant and lactating women.