1 Pa. Code § 35.173
Official notice may be taken by the agency head or the presiding officer of such matters as might be judicially noticed by the courts of this Commonwealth, or any matters as to which the agency by reason of its functions is an expert. Any participant shall, on timely request, be afforded an opportunity to show the contrary. Any participant requesting the taking of official notice after the conclusion of the hearing shall set forth the reasons claimed to justify failure to make the request prior to the close of the hearing.
1 Pa. Code § 35.173
This section cited in 1 Pa. Code § 35.205 (relating to contents of proposed reports); 4 Pa. Code §265.3 (relating to level II hearings); 7 Pa. Code §131.33 (relating to evidence); 7 Pa. Code §179.62 (relating to Commission official notice); 34 Pa. Code §131.101 (relating to briefs, findings of fact and close of record); 37 Pa. Code §21.55 (relating to evidence); 37 Pa. Code §171.104 (relating to limitation on matters considered); 40 Pa. Code §15.52 (relating to official notice of facts); and 52 Pa. Code §5.408 (relating to official and judicial notice of fact); 52 Pa. Code §1005.148 (relating to official and judicial notice of fact); 58 Pa. Code §494a.4 (relating to report or recommendation of the presiding officer); 61 Pa. Code §702.6 (relating to formal rules of evidence); and 61 Pa. Code §703.34 (relating to hearing procedure).