erred in receiving exhibits showing OSHA trench safety standards and in instructing on them over his objections on relevancy, hearsay, and foundation grounds. Because the relevancy objection depends on his theories of nondelegability and absence of evidence of delegation, it fails for the same reasons those theories fail. Exhibits 5 and 6 were copies of the standards taken from the Federal Register. As such, they were subject to judicial notice. 44 U.S.C. § 1507 (1970); See Fed. R. Evid. 201; C. McCormick, Handbook of the Law of Evidence § 335, at 777 (E. Cleary 1972) (“When such documents are published in the Federal Register it is provided that their contents shall be judicially noticed.”). No hearsay problem is presented. Cf. Jorgensen v. Horton, 206 N.W.2d 100, 103 (Iowa 1973) (<HOLDING>). Finally, we find no merit in the foundation
holding that an objection on hearsay grounds did not preserve for appeal an exception to the hearsay rule that was not specifically raised holding that evidence of customer inquiries is admissible under the state of mind exception to the hearsay rule holding that private safety codes are admissible as an exception to the hearsay rule on the basis of trustworthiness and necessity holding that the admission of evidence under an exception to the hearsay rule is reviewed for abuse of discretion holding that otherwise hearsay evidence disclosing the basis of an expert witness opinion should be admissible if  the impeaching evidence has sufficient guarantee of reliability that the prophylactic effect of the hearsay rule is not necessary to ensure trustworthiness