18 Pa.C.S.A. §305. Limitations on scope of culpability requirements.
(a) When culpability requirements are inapplicable to summary offenses and to offenses defined by other statutes.–The requirements of culpability prescribed by section 301 of this title (relating to requirement of voluntary act) and section 302 of this title (relating to general requirements of culpability) do not apply to:
(1) summary offenses, unless the requirement involved is included in the definition of the offense or the court determines that its application is consistent with effective enforcement of the law defining the offense; or
(2) offenses defined by statutes other than this title, in so far as a legislative purpose to impose absolute liability for such offenses or with respect to any material element thereof plainly appears.
(b) Effect of absolute liability in reducing grade of offense to summary offense.–Notwithstanding any other provision of existing law and unless a subsequent statute otherwise provides:
(1) when absolute liability is imposed with respect to any material element of an offense defined by a statute other than this title and a conviction is based upon such liability, the offense constitutes a summary offense; and
(2) although absolute liability is imposed by law with respect to one or more of the material elements of an offense defined by a statute other than this title, the culpable commission of the offense may be charged and proved, in which event negligence with respect to such elements constitutes sufficient culpability and the classification of the offense and the sentence that may be imposed therefor upon conviction are determined by section 106 of this title (relating to classes of offenses) and Chapter 11 of this title (relating to authorized disposition of offenders).