MSHA Ratings

The MSHA is a government agency that oversees mine safety.

In 1977, 272 miners lost their lives on the job. In response to the mortality rates of those who work in American mines, the Department of Labor created the Mine Safety and Health Administration in 1978. As a result of this regulation, the number of miner fatalities had been reduced to 34 miners in 2009.

History

The Department of Interior created the Bureau of Mines in 1910. In 1952, the Federal Coal Mine Safety Act required annual safety checks for underground mines. The Federal Mine Safety and Health act of 1977 ensured that all mines, coal, metal and non-metal, were covered under the same law.

Flame-Retardant Material

In compliance with the MSHA is the rating of flame-retardant material used in the construction of the mine; for instance timber used in mine entrances. A testing agency must verify the material as a flame spread rating of 25 or less. The manufacturer might also request that MSHA rate the material. It is up to MSHA's Approval and Certification Center to accept any testing documents for compliance.

Voltage Limitations

MSHA also requires voltage limitations for equipment used by miners. Hand-held tools and switches that make contact with the body should not have a nameplate rating that would exceed 300 volts DC or AC. Also disallowed is direct-current equipment with a nameplate rating that exceeds 550 volts and battery operated equipment with a nameplate rating exceeding 240 volts.

References

• MSHA.gov: Fact Sheet: Legislative History
• MSHA.gov: Code of Federal Regulations
• MSHAHelp.com: Standards and Regulations
• MSHA.gov: Program Policy Manual