Analysis of the effects of a proposed rule for the enforcement of respirable dust standards

Abstract

The effects of a rule for the enforcement of respirable dust standards proposed by the Mine Safety and Health Administration (MSHA) has been evaluated. Respirable coal dust sample data collected over a three year period by a mining company were used to represent the mining company's status of compliance with the current MSHA respirable dust standard (RDS) which bases noncompliance violations on the average of five full shift samples. Using the same data, the mining company's status of compliance was estimated for the proposed MSHA policy which bases noncompliance citations on a single, full shift respirable dust samples as well as multiple samples. Comparison of the results indicate that the mine operator would be 2.75 times as likely to be cited for violations of the MSHA respirable dust standard under the proposed rule. Furthermore, simulated citations of the mining company's respirable dust sample population for the proposed and current MSHA policy showed a factor increase in citations of 2.6 for the proposed policy versus the current policy. The simulation experiments also indicate that the proposed rule is unnecessarily complex. The single sample criterion alone could be applied to over 99.9% of citations. Finally, results show that the mines studied may expect to be in frequent violation of the proposed respirable dust standard despite achieving a long term average respirable dust concentration that falls below the current standard of 2.0 mg/m.