Peace lily ingestion in cat

Due to my negligence while closing the door to my room, my 6 year old, 5kg cat got inside and ingested about 3 centimeters of a peace lilies leaf 30 minutes ago. I read they arent as deadly as true lilies but are still toxic. He is otherwise in good health and currently isn't showing any signs of discomfort. Will he be okay due to a small amount? I am located in Slovenia and cannot reach the vet as of this moment. Any advice is truly appreciated.