California Code, Labor Code - LAB § 7151

If the working platform of any scaffolding swung or suspended from an overhead support is more than 10 feet above the ground, floor or area to which an employee on the scaffolding might fall, it shall have a safety rail of wood or other equally rigid material of adequate strength.The rail shall comply with the applicable orders of the Division of Occupational Safety and Health.

Suspended scaffolding shall be fastened so as to prevent the scaffolding from swaying from the building, or structure, or other object being worked on from the scaffolding. All parts of the scaffolding shall be of sufficient strength to support, bear, or withstand with safety any weight of persons, tools, appliances, or materials which might reasonably be placed on it or which are to be supported by it.