OSHA has specific requirements for manholes and the removal of manhole covers. Even before a manhole cover is removed, these relevant OSHA requirements come in to play. What are these manhole entry requirements? How does one comply with them?
Summary of OSHA Manhole Requirements
OSHA section 1926.953 covers the safety requirements confined space manholes. Before any manhole cover is removed, the employer shall determine whether it is safe to do so. Any conditions making it unsafe to remove the cover shall be eliminated before the cover is removed. When covers are removed from enclosed spaces, the opening shall be promptly guarded in order to prevent an accidental fall through the opening and to protect employees working in the space from objects entering the space.
OSHA Requirements Before Opening a Manhole
OSHA requires that before a manhole cover can be removed, even for routine maintenance, three potential hazards need evaluation where relevant. The three are (1) atmospheric pressure build up, (2) temperature build up, or (3) hazardous atmosphere.
For most of our customers, entry into street manholes, the third is the most likely hazard. This hazard is checked for with a Confined Space 4-Gas Detector. Atmospheric pressure build up or temperature build up are more common in manholes with sealed entry ways in vessels used to store liquids or gases.
Even before the manhole is opened, it is your responsibility to determine if any of these potential hazards are present and have a plan to mitigate them. Note that not all hazards can me mitigated before removing the manhole cover. For example, the presence of a hazardous atmosphere will required the introduction of forced air ventilation.
OSHA Requirements After Opening a Manhole
OSHA requires that "a railing, temporary cover, or other barrier" be erected around the manhole immediately after the manhole is safely removed. This is to prevent accidental falls into the space and to protect employees who enter the space from objects falling on them from above.
OSHA is not clear on what constitutes an "other barrier". Generally, either a manhole guard rail or even a confined space tripod system are adequate. Even pennant flagging can be used to cordon off the manhole entry way in most cases.
Manhole Entry Requirements Conclusion
In summary, before opening a manhole, evaluate for potential hazards, including a hazardous atmosphere. The plane of a manhole should never be broken by a human being before the atmosphere is tested with a 4-gas personal confined space meter.
After the manhole cover is removed, be sure to erect some sort of barrier to demarcate the manhole. It goes without saying that falling into a manhole could result in serious injury or even be fatal. These requirements are simple and easy to follow. They represent OSHA's best practices for opening up manholes.
One final and very important point: if entry into a manhole is done after the above guidelines are followed, OSHA's confined space standard 1910.126 is applicable. Before entry can be made, all of 1910.126's requirements must be understood and acted upon. This includes providing fall protection and rescue, continual gas detection, and possible force air ventilation. If you have an questions or need assistance, don't hesitate to reach out to us.