In law, this refers to a class of wrong that arises out of unreasonable, unwarranted or unlawful use by a person of his own property, whether that property be real or personal or from his own improper, indecent or unlawful personal conduct and producing an annoyance, inconvenience, discomfort or hurt to others or to their property that the law would presume a consequential damage. In insurance claims, it is most frequently met as a cause of action, arising from the escape of some obnoxious substance.