Plaintiff appeals as of right from a jury verdict of no cause of action. We affirm.

Plaintiff injured his elbow when he fell on an interior stairway at defendant’s business. Plaintiff claimed that his fall was caused by defendant’s negligent maintenance of an unsafe stairway. In support of his claim, plaintiff attempted to elicit testimony of his safety expert that if the stairway were five degrees steeper it would be termed a "ladder” rather than a stairway under National Safety Council standards. The trial court precluded such testimony. Plaintiff claims this was error. We disagree.

This Court affirms a trial court’s evidentiary ruling unless it constituted an abuse of discretion. Guider v Smith, 157 Mich App 92, 103-104; 403 NW2d 505 (1987), cert den — US —; 108 S Ct 1079; 99 L Ed 2d 238 (1988), aff'd 431 Mich 559; 431 NW2d 810 (1988). A tried court does not abuse its discretion by excluding evidence of safety regu*567lations where the purpose of introducing the regulatory codes was already fulfilled by other evidence and where any peripheral reference which the regulations may have to the parties’ conduct "would certainly be far outweighed by the confusion to the jury.” Gagnon v Dresser Industries, Corp, 130 Mich App 452, 462; 344 NW2d 582 (1983), aff'd 424 Mich 166; 380 NW2d 440 (1985). Here, plaintiff asserts that the "ladder” testimony would have served as a "critical frame of reference” for determining whether the stairway was too steep. However, plaintiff successfully introduced evidence comparing the steepness of the subject stairway with osha recommended steepness and the "critical angle” of unsafe steepness, providing the jury a frame of reference. The "ladder” evidence therefore would have been cumulative at best. We find no abuse of discretion.

Plaintiff further contends that the trial court abused its discretion by excluding evidence that one of defendant’s employees fell on the stairway approximately twenty-two months after plaintiff’s fall. Plaintiff argues that the subsequent accident evidence should have been admitted both for purposes of establishing defendant’s liability and for impeachment. The evidence was clearly incompetent to establish defendant’s liability. See Branch v Klatt, 173 Mich 31, 35; 138 NW 263 (1912). Moreover, we find no abuse of discretion in the trial court’s refusal to allow plaintiff to impeach defendant’s witnesses on an irrelevant issue. Plaintiff’s argument that the trial court’s ruling creates "a wide open invitation to misrepresent facts” during discovery is misplaced. We are satisfied that the existing sanctions for intentionally lying under oath are a sufficient deterrent for the misconduct plaintiff fears.

Finally, plaintiff claims that the trial court *568abused its discretion in refusing to admit as party admissions plaintiffs proposed Exhibit 10, certain interrogatories answered by defendant’s controller approximately IV2 years before trial. The question whether to admit interrogatories at trial is a matter within the sound discretion of the trial judge. Marchand v Henry Ford Hospital, 398 Mich 163, 169-170; 247 NW2d 280 (1976). We find no abuse of discretion on this record. The interrogatory answers were cumulative of testimony adduced at trial. A trial judge does not abuse his discretion by refusing to admit interrogatories at trial which have already been answered by testimony, or which are irrelevant to the issues. Masters v Highland Park, 97 Mich App 56, 59-60; 294 NW2d 246 (1980), lv den 409 Mich 937 (1980).

Affirmed.