The concept of strict liability for engaging in ultrahazardous activities has long been recognized. In Green v. General Petroleum Corp. (1928) 205 Cal. 328, where an oil well suddenly erupted, showering the defendant's neighbor's property with oil and mud, the court held that liability would be imposed without proof of negligence. In Luthringer v. Moore (1948) 31 Cal. 2d 489, the court explained the principle which underlay its holding in Green: "The important factor is that certain activities under certain conditions may be so hazardous to the public generally, and of such relative infrequent occurrence, that it may well call for strict liability as the best public policy." (Luthringer v. Moore, supra, at p. 500.) The factors to be considered in determining whether a particular activity is abnormally dangerous or ultrahazardous are: "'(a) existence of a high degree of risk of some harm to the person, land or chattels of others; (b) likelihood that the harm that results from it will be great; (c) inability to eliminate the risk by the exercise of reasonable care; (d) extent to which the activity is not a matter of common usage; (e) inappropriateness of the activity to the place where it is carried on; (f) extent to which its value to the community is outweighed by its dangerous attributes.'" (SKF Farms v. Superior Court (1984) 153 Cal. App. 3d 902, 906, 200 Cal. Rptr. 497.) Only a limited number of activities have been classified as ultrahazardous, including blasting with explosives in the vicinity of populated areas (Balding v. D.B. Stutsman, Inc. (1966) 246 Cal. App. 2d 559, 564), fumigating with industrial strength pesticide (Luthringer v. Moore, supra, 31 Cal. 2d at p. 500), and crop dusting with toxic chemicals (SKF Farms v. Superior Court, supra, 153 Cal. App. 3d at p. 905). The act of discharging a firearm has been held not to constitute an ultrahazardous activity. (Orser v. George (1967) 252 Cal. App. 2d 660, 672, citing Jensen v. Minard (1955) 44 Cal. 2d 325, 328-329, and Tucker v. Lombardo (1956) 47 Cal. 2d 457, 463.)