It depends on the type of poison
https://www.google.com/search?q=can+poison+expire&rlz=1CAHZJV_enUS951&ei=SveKYLX6HIuDtQaUyKPoBg&oq=can+poison+e&gs_lcp=Cgdnd3Mtd2l6EAMYADICCAAyAggAMgYIABAWEB4yBggAEBYQHjIGCAAQFhAeMgYIABAWEB4yBggAEBYQHjIGCAAQFhAeMgYIABAWEB4yBggAEBYQHjoHCAAQRxCwAzoECAAQQ1CWAljzG2D4KGgAcAV4AYAB5giIAZokkgEFNi0zLjKYAQCgAQGqAQdnd3Mtd2l6yAEIwAEB&sclient=gws-wiz&safe=active&ssui=on
