Over the past 25 years, the frequency of blasting-related injuries and fatalities at mining operations has dropped significantly. In 1978, 140 miners were killed or injured in U.S. blasting accidents. By 1998, this number had dropped to 22 and continued to decline to 7 in 2001. Factors contributing to increased blasting safety include the development of nonelectric initiation systems; the change from the use of cartridged explosives to bulk explosives; increased use of safer, non-nitroglycerine explosives; development of safer blasting practices; and an increase in the knowledge and professionalism of the average blaster. Industry, labor, and government all contributed to the improved safety record.

NIOSH conducted research to help eliminate injuries and fatalities resulting from blasting accidents. When high-detonation pressure (HDP-1) explosive boosters and Detaline initiation systems marketed by Explosives Technologies International (ETI) seemed to play a role in explosives accidents, the Mine Safety and Health Administration (MSHA) asked for technical assistance. Following a research project in which the accidents were simulated, NIOSH researchers identified the problem and advised the manufacturer and MSHA on how to modify the booster to make it safer.

During the 1990s there were a number of cases of carbon monoxide (CO) poisoning near blasting sites. Whether this type of accident had not occurred before the 1990s or whether it had occurred but had gone unrecognized is uncertain. The latter seems the more likely scenario. NIOSH became aware of the problem when a congressman asked for assistance in the investigation of a nonfatal CO poisoning incident in Dunmore, PA. As word of the incident and NIOSH assistance spread, requests came in from state and local officials who suspected that they might have cases of CO poisoning near blasting sites. NIOSH researchers became recognized as experts on the issue. Cases of CO poisoning near blast sites have essentially disappeared as NIOSH made blasters aware of the problem. Blasters now routinely place CO monitors in any structure at risk for CO infiltration.

The heavy equipment at all mining sites leads to the generation of quantities of waste motor oil. In past years, mines had no choice but to pay someone to dispose of this oil. Some in the industry realized that the waste motor oil could become a resource rather than a liability if it were used to make ammonium nitrate fuel oil (ANFO) blasting agent. MSHA regulations prohibited this practice because of concerns that contaminants in the oil could lead to the production of unusually sensitive, insensitive, or thermally unstable ANFO. MSHA would consider allowing mines to use the waste oil in explosives if this were approved on a case-by-case basis. Mines proposed procedures to use the waste oil in ANFO and asked for approval. There was no precedent for knowing which of these practices was safe. MSHA asked NIOSH to conduct research to evaluate the safety of waste oil-produced ANFO and help them develop safety guidelines for this practice. These guidelines were adopted by industry and are now used every time a mine uses waste oil in ANFO.

Mines in the Powder River Basin of Wyoming asked for NIOSH assistance when concerns arose about the orange or red product clouds rising from large-scale surface blasts. These blasts contained up to 8 million pounds of blasting agent. The orange to red color resulted from high concentrations of nitrogen dioxide (NO2), a highly toxic gas, in the product cloud. NIOSH researchers met with mine safety personnel to discuss the problem and conducted in-house research to determine the factors that lead to excessive NO2. NIOSH advised the mines on the results of the research and recommended practices that might reduce NO2 production. The mines and explosives suppliers adopted some of the recommendations and, in some cases, used them as the starting point for their own research to solve the problem.

NIOSH research has contributed to making blasting at mines safe and will continue to aid industry in maintaining this good safety record in the future.