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| Researchers study data collected from an experimenal explosive shot at PRL |
Description of Problem
All explosives generate carbon monoxide (CO) to one degree or another depending on their oxygen balance. Since 1988, there have been 17 reported incidents in which explosive-generated CO moved through the ground and accumulated in a nearby underground enclosed space. As a result, there have been 30 suspected or medically verified CO poisonings and 1 fatality.
Research and Development Activities
NIOSH expertise was called upon to identify the root cause of the CO poisoning among several likely proposed scenarios. NIOSH researchers evaluated the evidence and identified poor-quality explosive formulation as a major contributing factor. During the study, NIOSH researchers also recognized a need to better educate blasters and workers as to the hazards of CO and to develop guidelines to reduce the probability of future events when blasting near occupied dwellings. Subsequently, NIOSH researchers have been called upon to assist in other explosives and mining-related investigations involving toxic fumes. These include gas migration incidents in Dunmore, PA; Kittanning, PA; Lake Mills, WI; Derry, PA; Bristow, VA; and Amherst, NY.
R&D Outputs and Transfer Activities
NIOSH published papers to alert the public and industry about the possibility of CO poisoning due to nearby blasting. NIOSH researchers have also given presentations on this topic at national conferences for the International Society of Explosives Engineers (ISEE), local ISEE chapter meetings, the Penn State Drilling and Blasting Conference, and drilling and blasting seminars sponsored by the Mine Safety and Health Administration. For each gas migration incident, NIOSH researchers met with local and state officials to educate and advise them. For example, one explosives researcher worked with the New York State Department of Transportation (NYSDOT) in Amherst, NY. In this incident, blasting for the installation of new sewer lines had produced CO that migrated into nearby homes and businesses. This caused home CO monitors to alarm. Researchers recommended a change in explosive and advised NYSDOT on CO monitoring techniques. They also assisted NYSDOT in developing better safety requirements for blasters and steps to take to mitigate the effects of CO when detected in nearby homes. This was incorporated into the blast plan. NYSDOT also asked NIOSH to comment on the blast plan revisions, which included mitigation techniques to use in the event of high CO measured in nearby structures.
Description of Intermediate Outcome
In 2001, NIOSH Technology News No. 488 advised blasters to place CO monitors in basements of homes and businesses near blasting sites. Many blasters now routinely employ this practice. Since 2001 there have been no reported blasting-related CO poisonings. In the two most recent known incidents of CO migrating from blasts, home CO monitors alerted residents before they became sick. Blasters are now aware of the importance of using good-quality explosives to minimize generation of CO when blasting near occupied dwellings.