U.S. government, miners settle diesel rule lawsuits

Diesel Fuel News, July 22, 2002

U.S. Mine Safety & Health Administration (MSHA) last week announced the second part of a series of lawsuit settlements over its diesel[ exhaust control rules for underground metal/non-metal mines.

The settlement requires mine operators to "develop and implement good-faith compliance strategies to meet the interim DPM [diesel particulate matter] concentration limit" that just took effect this month.

It also requires MSHA to re-start rulemaking on some disputed provisions in rules first adopted last year. These provisions cover requirements for mines to get prior MSHA approval before allowing miners to work in areas with DPM exceeding the standards, and a current ban on the use of "personal protective equipment" (such as masks and respirators) to comply with the standards.

MSHA earlier settled another group of lawsuits covering new-engine emissions and maximum PM exposure limits (see Diesel Fuel News 7/9/01, p12, 5/28/01, p10). That settlement triggered an air sampling study at 31 mines; MSHA is close to finishing its final report based on that study.

An "interim" exposure limit of 400 micrograms of total carbon per cubic meter of air officially triggers non-compliance fines starting next July, but MSHA will prod mine operators to adopt technologies for early compliance, while using an SKC sampler to determine DPM concentrations.

While not mandatory today, ultra-low sulfur diesel (ULSD) is expected to become part of the mine DPM reduction equation since ULSD enables high-efficiency diesel particulate filters (DPFs).

Under the settlement, "MSHA will consult with NIOSH [National Institute for Occupational Safety & Health], industry and labor representatives on the performance of the SKC sampler and the availability of practical mineworthy filter technology," MSHA says.

If engine and exhaust aftertreatment controls aren't sufficient, then MSHA would require personal protective devices. "Rotation of employees will not be allowed as an administrative control for compliance with this [DPM exposure] standard," MSHA says.