Petitioner Occupational Safety and Health Division (OSHD) seeks review of an order of the Workers’ Compensation Board1 holding that employer did not violate safety rules adopted by the Department of Insurance and Finance (DIF),2 pursuant to the Oregon Safe Employment Act. We review for errors of law, ORS 183.482(8), and reverse.

On June 14,1991, an OSHD safety compliance officer inspected employer’s worksite where a large metal roof was under construction. The officer cited employer for not complying with OAR 437-03-040(1), which provides:

“All employees shall be protected from fall hazards when working on unguarded surfaces more than 10 feet above a lower level or at any height above dangerous equipment, except when connecting steel beams as stipulated in OAR 437-03-040(2).”

The officer saw four employees on the roof, which was 28 feet above the concrete surface. Two of the employees were walking on beams and cross beams without being attached to a safety fine. The officer assessed employer a $2,000 fine, which included a penalty for a repeat violation. OAR 437-01-165.

Employer requested a hearing on the citation. The referee found that the workers were not tied to the safety fine. The referee concluded, however, that OAR 437-03-040(1) was not violated, because the rule does not specifically require employees to be attached to a safety line; rather, it requires protection from “fall hazards.” The referee found that the severity level of falling 24 feet to the concrete below was “death,” but reasoned that the working conditions were not hazardous, because the employees were experienced and the compliance officer had delayed his inspection for several days.

OSHD argues that the referee erred, as a matter of law, in concluding that employer did not violate OAR 437-03-040(1). We agree. The rule expressly requires that employees shall be protected from fall hazards when working *550on unguarded surfaces more than 10 feet above a lower level. See, e.g., Oregon Occupational Safety v. Affordable Roofing, 125 Or App 99, 102, 865 P2d 439 (1993). The legislature has adopted a strong safe-employment policy and requires employers to equip workplaces with reasonably necessary “devices and safeguards.” ORS 654.003; ORS 654.010.3 OAR 437-03-040(1) does not provide, and the legislature did not intend, that an employee’s work experience shall constitute a safety device or safeguard.4 The referee erred in concluding that an employee’s experience, rather than a physical device, provided adequate fall protection.5

Employer nonetheless argues that we cannot reinstate the citation, because OAR 437-03-040(1) is unconstitutional under the Fourteenth Amendment to the United States Constitution. Employer explains that the rule violates its rights under the Due Process Clause, because it fails to provide notice of the type of fall protection required. Because employer faded to preserve that argument at the hearing, we do not address it. Llewellyn v. Board of Chiropractic Examiners, 318 Or 120, 127, 863 P2d 469 (1993).

Reversed and remanded with instructions to reinstate Citation No. C5730-094-91.