Employes shall not enter a manhole unless a temporary cover is placed over the opening or a watchman is stationed at the surface. If any gas may be present employes shall see that the watchman is stationed at the surface. If any hazard is involved no employe shall leave a manhole unwatched until all workmen are out.
34 Pa. Code § 39.434
This section cited in 34 Pa. Code § 39.431 (relating to general provisions); 34 Pa. Code § 39.441 (relating to general provisions); 34 Pa. Code § 39.461 (relating to general requirements); 34 Pa. Code § 39.471 (relating to general requirements); and 34 Pa. Code § 39.491 (relating to general requirements).