2007 ORS § 476.160¹
Circumstances under which warrant may be issued

(1) An inspection warrant shall be issued only upon cause, supported by affidavit, particularly describing the applicant’s status in applying for the warrant, the statute, ordinance or rule requiring or authorizing the inspection or investigation, the place, building or premises to be inspected or investigated and the purpose for which the inspection or investigation is to be made including the basis upon which cause exists to inspect. In addition, the affidavit shall contain either a statement that entry had been sought and refused or facts or circumstances reasonably showing that the purposes of the inspection or investigation might be jeopardized if entry were sought without an inspection warrant.

(2) Cause shall be deemed to exist in the following circumstances:

(a) There is probable cause to believe that a condition of nonconformity with a fire safety standard or order exists;

(b) A fire has occurred in a building or on premises the cause of which has not been determined; or

(c) For the purpose of carrying out a routine, periodic inspection. [1987 c.362 §3]