70.2—Definitions.
For the purpose of this part 70, the term:
(a)
Act means the Federal Mine Safety and Health Act of 1977, Pub. L. 91-173, as amended by Pub. L. 95-164.
(b)
Active workings means any place in a coal mine where miners are normally required to work or travel.
(c)
Certified person means an individual certified by the Secretary in accordance with § 70.202 (Certified person; sampling) to take respirable dust samples required by this part or certified in accordance with § 70.203 (Certified person; maintenance and calibration) to perform the maintenance and calibration of respirable dust sampling equipment as required by this part.
(e) Designated area.
An area of a mine identified by the operator under § 75.371(t) (Mine ventilation plan; contents) of this title and approved by the district manager.
(f)
Designated occupation means the occupation on a mechanized mining unit that has been determined by results of respirable dust samples to have the greatest respirable dust concentration.
(g)
District Manager means the manager of the Coal Mine Safety and Health District in which the mine is located.
(h)
Mechanized mining unit means: (1) A unit of mining equipment including hand loading equipment used for the production of material; or (2) a specialized unit which utilizes mining equipment other than specified in § 70.207(e) (Bimonthly sampling; mechanized mining units).
(i)
MRE instrument means the gravimetric dust sampler with a four channel horizontal elutriator developed by the Mining Research Establishment of the National Coal Board, London, England.
(k)
Normal production shift means (1) a production shift during which the amount of material produced in a mechanized mining unit is at least 50 percent of the average production reported for the last set of five valid samples; or (2) a production shift during which any amount of material is produced by a new mechanized mining unit, until a set of five valid samples is taken.
(l)
Production shift means (1) with regard to a mechanized mining unit, a shift during which material is produced, or (2) with regard to a designated area of a mine, a shift during which material is produced and routine day-to-day activities are occurring in the designated area.
(m)
Quartz means crystalline silicon dioxide (SiO2) not chemically combined with other substances and having a distinctive physical structure.
(n)
Respirable dust means dust collected with a sampling device approved by the Secretary and the Secretary of Health and Human Services in accordance with part 74 (Coal Mine Dust Personal Sampler Units) of this title. Sampling device approvals issued by the Secretary of the Interior and Secretary of Health, Education, and Welfare are continued in effect.
(p)
Valid respirable dust sample means a respirable dust sample collected and submitted as required by this part, and not voided by MSHA.