Is it acceptable to work from a folded stepladder leaned against a wall?
Using a standard (foldable) stepladder in a closed position is not a safe practice because it’s more likely to slip on surfaces such as concrete and wood than a straight ladder. Standard stepladders are designed for use only when the spreader arms are open and locked. If a standard stepladder doesn't meet your needs, choose an appropriate straight ladder or a combination ladder. (A combination ladder is designed for use as a stepladder, extension ladder, single ladder, or trestle ladder.)
Wondering what Oregon OSHA rule applies for the construction industry? Subdivision 3/X, (Stairways and Ladders) 1926.1053(a)(8) says, “A metal spreader or locking device shall be provided on each stepladder to hold the front and back sections in an open position when the ladder is being used.”