The peace lily (Spathiphyllum) is a widely favored indoor plant, prized for its glossy green foliage and elegant white spathes. It is popular due to its tolerance for low light and its reputation as an air purifier. Despite its tranquil name, this common houseplant is toxic to both humans and pets if ingested or chewed. The toxicity is generally mild to moderate, but immediate discomfort and localized reactions are highly predictable.
Confirmation of Toxicity and the Responsible Compound
The peace lily’s toxic properties are due to a physical mechanism, not a chemical poison affecting internal organs. All parts of the plant contain microscopic structures called insoluble calcium oxalate crystals. These crystals are bundled into specialized cells, acting as a defense mechanism against herbivores. When the plant is chewed, pressure releases these needle-shaped crystals, known as raphides, which penetrate the soft tissues of the mouth and throat.
This process causes immediate, intense, localized irritation and inflammation. The instant pain typically prevents the ingestion of large quantities, making the incident self-limiting. While the peace lily is often confused with true lilies (Lilium and Hemerocallis), Spathiphyllum does not cause the life-threatening kidney failure seen in cats that ingest true lilies. The physical irritation is unpleasant and painful, but it is rarely fatal in humans or common household pets.
Recognizing Symptoms in Humans and Pets
Symptoms begin almost instantly after contact with the plant tissue due to the crystal-induced injury. In humans, common symptoms include an intense burning sensation in the mouth, lips, and tongue, followed quickly by localized swelling. This irritation can lead to temporary difficulty swallowing or speaking. Contact with the sap may also cause localized dermatitis in sensitive individuals.
In pets, particularly dogs and cats, the reaction manifests as visible distress and discomfort in the oral cavity. Owners often observe excessive drooling or foaming at the mouth as the animal attempts to clear the irritants. Pets may paw repeatedly at their face or mouth due to the intense pain. Other signs include vomiting, refusal to eat or drink, and decreased appetite due to soreness.
Emergency Response and Safe Plant Placement
If a child or pet is suspected of chewing on a peace lily, the first priority is to clear any remaining plant material from the mouth. For humans, rinsing the mouth thoroughly with water is recommended. Drinking milk or consuming a cold dairy product can help soothe the irritation by coating the sharp crystals. Seek immediate medical attention if severe swelling impedes breathing or swallowing. For guidance, contact the national Poison Control Center (1-800-222-1222).
For pets, immediate contact with a veterinarian or the ASPCA Animal Poison Control Center (888-426-4435) is advised, even if symptoms appear mild. The vet can recommend specific supportive care, such as offering ice chips or a small amount of water to help manage the oral discomfort. Preventative measures are the most reliable strategy for avoiding exposure, especially in homes with curious pets or young children.
Safe Plant Placement
Safe plant placement involves positioning the Spathiphyllum on high shelves, utilizing hanging planters, or placing it in rooms inaccessible to vulnerable individuals. When handling the plant for pruning or repotting, wearing gloves is prudent to prevent skin irritation from the sap. Promptly sweeping up and discarding any fallen leaves or blooms removes attractive material a pet or child might encounter on the floor.