S-2.1, r. 4 - Safety Code for the construction industry
3.5.2. A ladder shall:
(a) be designed, built, maintained and used so as not to endanger the safety of workers;
(b) always be used in such a way that the loads applied do not cause any part of the ladder to be stressed beyond allowed stresses; and
(c) be suitable for the type of work to be performed, with regard to its type as well as to its length and accessories.
R.R.Q., 1981, c. S-2.1, r. 6, s. 3.5.2.