abnormally dangerous activity
abnormally dangerous activity. An undertaking that necessarily carries with it a significant risk of serious harm even if reasonable care is used, and for which the actor may face strict liability for any harm caused; esp., an activity (such as dynamiting) for which the actor is held strictly liable because the activity (1) involves the risk of serious harm to persons or property, (2) cannot be performed without this risk, regardless of the precautions taken, and (3) does not ordinarily occur in the community. • Under the Restatement (Second) of Torts, determining whether an activity is abnormally dangerous includes analyzing whether there is a high degree of risk of harm, whether any harm caused will be substantial, whether the exercise of reasonable care will eliminate the risk, whether the activity is a matter of common usage, whether the activity is appropriate to the place in which it occurs, and whether the activity’s value to society outweighs its dangerousness. Restatement (Second) of Torts § 520 (1977). — Also, esp. formerly, termed extrahazardous activity; ultrahazardous activity. See strict liability under LIABILITY. [Cases: Negligence 305. C.J.S. Negligence §§ 176–179.]