Skip directly to search Skip directly to A to Z list Skip directly to page options Skip directly to site content

NIOSHTIC-2 Publications Search

Search Results

Hazard evaluation and technical assistance report: HETA-98-0020, carbon monoxide intoxication and death in a newly constructed sewer manhole.

Authors
Decker-JA; Deitchman-S; Santis-LD
Source
NIOSH 1997 Oct; :1-22
NIOSHTIC No.
10008222
Abstract
This report describes three cases of carbon monoxide (CO) poisoning in a manhole, including one fatality, from CO migrating through soil after nearby use of explosives. A municipal sewer project involved installation of new pipes and manholes. Work of the general construction contractor was interrupted when a subcontractor detonated 265 pounds of nitroglycerin-based explosive 40-60 feet south of the manhole to break up underlying rock. A construction worker who descended into the manhole 45 minutes after the explosion collapsed within minutes, and two co-workers descended into the manhole to rescue him. One rescuer retrieved the unconscious worker, and the other rescuer died in the manhole. All workers had elevated carboxyhemoglobin levels. In the subsequent NIOSH investigation, air monitoring was conducted with real-time instruments, and air samples were collected in Tedlar bags. Laboratory analyses of the bag samples collected near the bottom showed 1905 parts per million (ppm) CO, 19.5% oxygen, and 3% carbon dioxide. Direct reading instruments showed progressively higher concentrations as the sensor was lowered into the manhole. Subsequent chamber tests on sample explosive yielded 27 liters CO per kilogram detonated. Based on this value, the surface blast at the construction site may have produced about 3,250 liters (114.8 cubic feet) CO. The CO in this incident most likely was released from the nearby explosion and migrated through soil and fractured rock into the manhole. The blasting and construction industries should be made aware of this previously unrecognized CO exposure hazard associated with surface blasting. The extent of CO exposure from explosives used in construction is not known, and additional information on the extent of CO exposure must be collected. In addition, confined space entry procedures (including monitoring confined space atmospheres before entry) should be observed; CO monitoring of confined spaces in the presence of blasting can prevent future incidents such as this one.
Keywords
Explosive-gases; Explosive-hazards; Explosives; Explosives-industry; Toxic-gases; Confined-spaces; Construction-Search
CAS No.
630-08-0
Publication Date
19971030
Document Type
Hazard Evaluation and Technical Assistance; Field Studies
Fiscal Year
1998
NTIS Accession No.
PB2003-105471
NTIS Price
A03
Identifying No.
HETA-98-0020
NIOSH Division
PRL; DSHEFS; OECSP
Priority Area
Other Occupational Concerns
Source Name
National Institute for Occupational Safety and Health
State
PA
TOP