California Code of Regulations
Title 8 - Industrial Relations
Division 1 - Department of Industrial Relations
Chapter 4 - Division of Industrial Safety
Subchapter 6 - Elevator Safety Orders
Group II - Elevator Installations for Which the Installation Contract Was Signed Before October 25, 1998
Article 12.3 - Special Purpose Personnel Elevators
Section 3085.1 - Hoistways and Hoistway Enclosures [Rule 1500.1]

(a) Hoistways adjacent to and within 4 ft. (1.22 m) of areas permitting passage of people (e.g., passageways, stairwells, elevator landings) shall be enclosed to a height of not less than 8 ft. (2.44 m) above the floor or stair treads. The enclosure shall be of sufficient strength to prevent contact between the enclosure material and the car or counterweight when the enclosure is subjected to a force of 250 lbs (113 kg) applied at right angles at any point over an area of 4 in. (102 mm) by 4 in. (102 mm). Openwork enclosures may be used and shall reject a ball 1 in. (25 mm) in diameter and shall be so located as to provide at least 4 in. (102 mm) between the outside of the enclosure and the closest member of any moving object inside the enclosure. Enclosures within 4 in. (102 mm) of moving equipment shall have no openings exceeding 1/2 in. (13 mm) in diameter.

(b) The Division shall be provided with engineering details and drawings approved by a California registered engineer, competent in this field, showing the adequacy of the supporting members, foundations and building attachments to safely withstand the forces generated during normal operation and safety tests. The installation of the elevator shall be in conformance with these plans and details.

(Title 24, Part 7, Section 7-3085.1)