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Record of Individual Exposure to Radon Daughters


The operator shall calculate and record complete individual exposures to concentrations of radon daughters. 30 CFR 57.5040(b) requires the operator to maintain MSHA Form 4000-9, or an equivalent form acceptable to the Administrator of Metal and Nonmetal Mine Safety and Health. Specific information required by the form with respect to each person's time-weighted current and accumulative exposure to concentrations for radon daughters shall be recorded. Each form shall be available for examination by the Secretary or his authorized representative. On or before February 15 of each calendar year, or within 45 days after the shutdown of mining operations for the calendar year, each mine operator shall submit to the Mine Safety and Health Administration a copy of the "Record of Individual Exposure to Radon Daughters" (Form 4000-9), or acceptable equivalent form, showing the data required by the form for all personnel for whom calculation and recording of exposure was required during the previous calendar year. The operator's records of individual exposure to concentrations of radon daughters and copies of "Record of Individual Exposure to Radon Daughters" (Form 4000-9) or acceptable equivalent form or true legible facsimiles thereof (microfilm or other), shall be retained at the mine or nearest mine office for a period as specified in paragraph 9.8, ANSI N13.8-1973, or shall be submitted to the Mine Safety and Health Administration. These records, if retained by the operator, shall be open for inspection by the Secretary of Labor, his authorized representative, and authorized representatives of the official mine inspection agency of the State in which the mine is located.
    Chief, Division of Health
    Metal and Nonmetal Mine Safety and Health
    Mine Safety and Health Administration
    Room 2406
    1100 Wilson Boulevard
    Arlington, Virginia 22209-3939
Mine I. D. Number, is the number assigned to the operation by the Mine Safety and Health Administration (MSHA). If this number is not known with certainty, contact the nearest MSHA office and request confirmation.

Mine. The name normally used for this mine in correspondence and legal documents.

Section, Township, Range. Information used to legally describe the geographical location of the mine. Survey and section numbers may be used in states where that system is practiced.

County and State are the county and state in which the mine is located.

Operator, fill in the name of the operator.

Period. Calendar year for which individual exposures are reported.

Name, Identification Number. Self-explanatory terms. These items shall be entered on the same line that an individual's exposure is reported under working level months. The Identification Number is not required, but may be provided to assist identification.

Exposure, WIM. This section contains the calculations of each listed individual's exposure to radiation hazards from radon daughters, expressed as working level months (WLM), computed as follows:
    To calculate an individual exposure in WLM for a given period of time, multiply the total exposure time (hours to the nearest half-hour) in an active working area by the average concentration of airborne radon daughters for the applicable active working area (average working level calculated to the nearest hundredth working level), and divide the product by the constant, one hundred seventy-three (173) hours per month.

    An average airborne radon daughter concentration for a designated active working area shall be determined by averaging all sampling results for that working area during the time that persons are present. Any sample taken by Federal or State mine inspectors, which represents exposure to miners and reported to the operator within three (3) days of being taken, shall be included in the average concentration; except that if the mine operator samples simultaneously with the inspector, he may use his own sample results.
Current Year. For the operator submitting this report, "current year" shall reflect the sum of exposures incurred by each individual employed at this operation for all or a part of the calendar year of this report.

Cumulative Total. "Cumulative total" shall be the sum of the current year exposure plus exposure incurred prior to the current year for all periods in which the individual was in your employ. Do not report exposures obtained by another operator.

If questions arise, the nearest MSHA office may be contacted for clarification.

This report is required by law (30 CFR, Part 57). Failure to report can result in assessment of a civil penalty under Section 110 and institution of a civil action for relief under Section 108 of the Federal Mine Safety and Health Act of 1977. Knowingly making a false statement or concealing a material fact can result in criminal prosecution under Section 110 of the Federal Mine Safety and Health Act of 1977 and 18 U.S.C. 1001.