33. Operating conditions: Scaffolds shall be designed for the type of work to be performed and the probable risks. They shall meet the following conditions:
(1) be so designed, constructed, trussed, braced and maintained as to support any loads and stresses they may be subjected to, and resist wind action;
(2) have a safety factor of at least 4 for each constituent element;
(3) rest on firm ground or foundations;
(4) be provided with guardrails when workers are exposed to a danger of falling more than 3 m.
The guardrails of the scaffolds may be temporarily removed if they prevent the carrying out of work that cannot reasonably be performed otherwise. In these cases, the wearing of a safety harness is compulsory for the worker and the worksite shall be marked off to prevent access to those persons not working there.