Working in Manholes, Utility Tunnels, and Vaults

DOE-HDBK-1092-2004

flammable liquids, corrective measures shall be taken before work in the manhole is allowed

to proceed.

7. When nitrogen is used in manholes or confined areas, approved atmosphere testing devices

shall be placed in operation where they can be observed by people in the manhole. When

the testing devices show a deficiency of oxygen, all personnel shall leave the manhole until

the proper atmosphere is restored.

8. The manhole shall be ventilated continuously when occupied.

9. An attendant is required topside with the means to summon help without leaving his or her

station. The attendant shall be capable of instituting a rescue without entering the manhole.

The attendant on the surface is responsible for the safety of the persons in the manhole.

10. The topside attendant can perform other duties outside of the enclosed space if these duties

do not distract the attendant from monitoring employees within the space. All manholes over

4 ft. deep should be entered with the use of a ladder as required by 29 CFR 1910.269 (t)(1).

11. Workers should open all entrance bars or chains on the topside of manhole guards before

entering or leaving a manhole. All chains or bars should be closed at all other times, except

when raising or lowering tools or materials.

12. Operations involving chemical cleaning agents, solvents, volatile chemicals, cutting and

welding equipment, and other hazardous agents or tools require additional consideration.

Consultation with and concurrence of appropriate industrial safety and industrial hygiene

personnel are required.

13. The employee shall enter or leave a manhole by means of a ladder. The employer shall not

use a cable, cable hanger, or manhole rack as a support for climbing. A manhole ladder

should never be removed while a worker is in the manhole unless absolutely necessary. In

the instance of a ladder being removed to make it easier to rescue a worker, the topside

attendant shall fully devote his or her attention and efforts to instituting a rescue using the

worker's body harness and lifeline if necessary. The ladder shall be replaced as soon as

practical.

Note: The other workers in the hole should be warned that the ladder is to be removed in

time to allow him or her to exit the hole if necessary.

14. Materials, tools, and equipment should be kept at a sufficient distance from the entrance to

the manhole to avoid any hazard to the occupant from falling objects or from hot metal or

spilled compounds.

15. Blowtorches and furnaces should be ignited before being lowered into manholes unless this

creates additional hazards.

16. Rags, tape, refuse, and combustible and flammable materials should not be allowed to

accumulate in a manhole.

17. Instrumentation shall be calibrated per manufacturer's instructions. [See 29 CFR

1910.269(e)(8)]. A record of calibration should be maintained.

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