What 29 CFR 1926.61 requires (plain English)
29 CFR 1926.61 has no paragraphs of its own. The whole construction section is a note: "The requirements applicable to construction work under this section are identical to those set forth at § 1910.1201 of this chapter." So the rule a contractor follows is 1910.1201, Retention of DOT markings, placards and labels.
1910.1201 covers hazardous materials that arrive marked, labeled or placarded under the Department of Transportation's Hazardous Materials Regulations (49 CFR Parts 171 through 180). A package keeps its markings, labels and placards until the packaging is sufficiently cleaned of residue and purged of vapors to remove any potential hazards (a). A freight container, rail freight car, motor vehicle or transport vehicle keeps its markings and placards until the hazardous materials that require them are sufficiently removed to prevent any potential hazards (b). They are maintained so they are readily visible (c).
The section meets the Hazard Communication Standard at the drum. For a non-bulk package that will not be reshipped, a label or other acceptable marking affixed in accordance with 1910.1200 meets the rule (1910.1201(d)). On a shipped container that already carries the DOT pictogram for a hazard, the HazCom pictogram for that same hazard is not required on the label (1910.1200(f)(5)(iii)). And the workplace may not remove or deface labels on incoming containers of hazardous chemicals unless the container is immediately marked with the required information (1910.1200(f)(9)).