This part sets out requirements for MSHA approval of certain equipment and materials for use in underground mines whose product testing and evaluation does not involve subjective analysis. These requirements apply to products listed in the subparts following this Subpart A. After the dates specified in the following subparts, requests for approval of products shall be made in accordance with this Subpart A and the applicable subpart.

The following definitions apply in this part.

Applicant. An individual or organization that manufactures or controls the assembly of a product and that applies to MSHA for approval of that product.

Approval. A document issued by MSHA which states that a product has met the requirements of this part and which authorizes an approval marking identifying the product as approved.

Authorized company official. An individual designated by applicant who has the authority to bind the company.

Critical characteristic. A feature of a product that, if not manufactured as approved, could have a direct adverse effect on safety and for which testing or inspection is required prior to shipment to ensure conformity with the technical requirements under which the approval was issued.

Equivalent non-MSHA product safety standards. A non-MSHA product safety standard, or group of standards, that is determined by MSHA to provide at least the same degree of protection as the applicable MSHA product technical requirements in the subparts of this part, or can be modified to provide at least the same degree of protection as those MSHA requirements.

Extension of approval. A document issued by MSHA which states that the change to a product previously approved by MSHA under this part meets the requirements of this part and which authorizes the continued use of the approval marking after the appropriate extension number has been added.

Post-approval product audit. Examination, testing, or both, by MSHA of approved products selected by MSHA to determine whether those products meet the applicable technical requirements and have been manufactured as approved.

Technical requirements. The design and performance requirements for a product, as specified in a subpart of this part.

Test procedures. The methods specified in a subpart of this part used to determine whether a product meet the performance portion of the technical requirements.

(a) Application. Requests for an approval or extension of approval shall be sent to: U.S. Department of Labor, Mine Safety and Health Administration, Approval and Certification Center, 765 Technology Drive, Triadelphia, WV 26059.

(b) Fees. Fees calculated in accordance with part 5 of this title shall be submitted in accordance with § 5.40.

(c) Original approval. Each application for approval of a product shall include—

(1) A brief description of the product;

(2) The documentation specified in the appropriate subpart of this part;

(3) The name, address, and telephone number of the applicant's representative responsible for answering any questions regarding the application;

(4) If appropriate, a statement indicating whether, in the applicant's opinion, testing is required. If testing is not proposed, the applicant shall explain the reasons for not testing; and

(5) If appropriate, the place and date for product testing.

(d) Subsequent approval of a similar product. Each application for a product similar to one for which the applicant already holds an approval shall include—

(1) The approval number for the product which most closely resembles the new one;

(2) The information specified in paragraph (c) of this section for the new product, except that any document which is the same as one listed by MSHA in prior approvals need not be submitted, but shall be noted in the application;

(3) An explanation of any change from the existing approval; and

(4) A statement as to whether, in the applicant's opinion, the change requires product testing. If testing is not proposed, the applicant shall explain the reasons for not testing.

(e) Extension of an approval. Any change in the approved product from the documentation on file at MSHA that affects the technical requirements of this part shall be submitted to MSHA for approval prior to implementing the change. Each application for an extension of approval shall include—

(1) The MSHA-assigned approval number for the product for which the extension is sought;

(2) A brief description of the proposed change to the previously approved product;

(3) Drawings and specifications which show the change in detail;

(4) A statement as to whether, in the applicant's opinion, the change requires product testing. If testing is not proposed, the applicant shall explain the reasons for not testing;

(5) The place and date for product testing, if testing will be conducted; and

(6) The name, address, and telephone number of the applicant's representative responsible for answering any questions regarding the application.

(f) Certification statement. (1) Each application for original approval, subsequent approval, or extension of approval of a product shall include a certification by the applicant that the product meets the design portion of the technical requirements, as specified in the appropriate subpart, and that the applicant will perform the quality assurance functions specified in § 7.7. For a subsequent approval or extension of approval, the applicant shall also certify that the proposed change cited in the application is the only change that affects the technical requirements.

(2) After completion of the required product testing, the applicant shall certify that the product has been tested and meets the performance portion of the technical requirements, as specified in the appropriate subpart.

(3) All certification statements shall be signed by an authorized company official.

(a) All products submitted for approval under this part shall be tested using the test procedures specified in the appropriate subpart unless MSHA determines, upon review of the documentation submitted, that testing is not required. Applicants shall maintain records of test results and procedures for three years.

(b) Unless otherwise specified in the subpart, test instruments shall be calibrated at least as frequently as, and according to, the instrument manufacturer's specifications, using calibration standards traceable to those set by the National Bureau of Standards, U.S. Department of Commerce or other nationally recognized standards and accurate to at least one significant figure beyond the desired accuracy.

(c) When MSHA elects to observe product testing, the applicant shall permit an MSHA official to be present at a mutually agreeable date, time, and place.

(d) MSHA will accept product testing conducted outside the United States where such acceptance is specifically required by international agreement.

(a) An applicant shall not advertise or otherwise represent a product as approved until MSHA has issued the applicant an approval.

(b) MSHA will issue an approval or a notice of the reasons for denying approval after reviewing the application, and the results of product testing, when applicable. An approval will identify the documents upon which the approval is based.

(a) Each approved product shall have an approval marking, as specified in the appropriate subpart of this part.

(b) For an extension of approval, the extension number shall be added to the original approval number on the approval marking.

(c) Applicants shall maintain records of the initial sale of each unit having an approval marking. The record retention period shall be at least the expected shelf life and service life of the product.

Applicants granted an approval or an extension of approval under this part shall—

(a) Inspect or test, or both, the critical characteristics in accordance with the appropriate subpart of this part;

(b) Unless otherwise specified in the subparts, calibrate instruments used for the inspection and testing of critical characteristics at least as frequently as, and according to, the instrument manufacturer's specifications, using calibration standards traceable to those set by the National Bureau of Standards, U.S. Department of Commerce or other nationally recognized standards and use instruments accurate to at least one significant figure beyond the desired accuracy.

(c) Control production documentation so that the product is manufactured as approved;

(d) Immediately report to the MSHA Approval and Certification Center, any knowledge of a product distributed with critical characteristics not in accordance with the approval specifications.

(a) Approved products shall be subject to periodic audits by MSHA for the purpose of determining conformity with the technical requirements upon which the approval was based. Any approved product which is to be audited shall be selected by MSHA and be representative of those distributed for use in mines. The approval-holder may obtain any final report resulting from such audit.

(b) No more than once a year except for cause, the approval-holder, at MSHA's request, shall make an approved product available at no cost to MSHA for an audit to be conducted at a mutually agreeable site and time. The approval-holder may observe any tests conducted during this audit.

(c) An approved product shall be subject to audit for cause at any time MSHA believes that it is not in compliance with the technical requirements upon which the approval was based.

(a) MSHA may revoke for cause an approval issued under this part if the product:

(1) Fails to meet the applicable technical requirements; or

(2) Creates a hazard when used in a mine.

(b) Prior to revoking an approval, the approval-holder shall be informed in writing of MSHA's intention to revoke approval. The notice shall:

(1) Explain the specific reasons for the proposed revocation; and

(2) Provide the approval-holder an opportunity to demonstrate or achieve compliance with the product approval requirements.

(c) Upon request, the approval-holder shall be afforded an opportunity for a hearing.

(d) If a product poses an imminent hazard to the safety or health of miners, the approval may be immediately suspended without a written notice of the agency's intention to revoke. The suspension may continue until the revocation proceedings are completed.

(a) MSHA will accept non-MSHA product safety standards, or groups of standards, as equivalent after determining that they:

(1) Provide at least the same degree of protection as MSHA's applicable technical requirements for a product in the subparts of this part; or

(2) Can be modified to provide at least the same degree of protection as those MSHA requirements.

(b) MSHA will publish its intent to review any non-MSHA product safety standard for equivalency in the Federal Register for the purpose of soliciting public input.

(c) A listing of all equivalency determinations will be published in this part 7. The listing will state whether MSHA accepts the non-MSHA product safety standards in their original form, or whether MSHA will require modifications to demonstrate equivalency. If modifications are required, they will be provided in the listing. MSHA will notify the public of each equivalency determination and will publish a summary of the basis for its determination. MSHA will provide equivalency determination reports to the public upon request to the Approval and Certification Center. MSHA has made the following equivalency determinations applicable to this part 7.

(1) MSHA will accept applications for motors under Subpart J designed and tested to the International Electrotechnical Commission's (IEC) standards for Electrical Apparatus for Explosive Gas Atmospheres, Part 0, General Requirements (IEC 60079-0, Fourth Edition, 2004-01) and Part 1, Electrical Apparatus for Explosive Gas Atmospheres, Flameproof Enclosures “d” (IEC 60079-1, Fifth Edition, 2003-11) (which are hereby incorporated by reference and made a part hereof) provided the modifications to the IEC standards specified in § 7.10(c)(1)(i) through (ix) are met. The Director of the Federal Register approves this incorporation by reference in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. The IEC standards may be inspected at the U.S. Department of Labor, Mine Safety and Health Administration, Electrical Safety Division, Approval and Certification Center, 765 Technology Drive, Triadelphia, WV 26059, or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html. These IEC standards may be obtained from International Electrical Commission, Central Office 3, rue de Varembé, P.O. Box 131, CH-1211 GENEVA 20, Switzerland.

(i) Enclosures associated with an electric motor assembly shall be made of metal and not have a compartment exceeding ten (10) feet in length. External surfaces of enclosures shall not exceed 150 °C (302 °F) in normal operation.

(ii) Enclosures shall be rugged in construction and should meet existing requirements for minimum bolt size and spacing and for minimum wall, cover, and flange thicknesses specified in paragraph (g)(19) of § 7.304 Technical requirements. Enclosure fasteners should be uniform in size and length, be provided at all corners, and be secured from loosening by lockwashers or equivalent. An engineering analysis shall be provided for enclosure designs that deviate from the existing requirements. The analysis shall show that the proposed enclosure design meets or exceeds the mechanical strength of a comparable enclosure designed to 150 psig according to existing requirements, and that flamepath clearances in excess of existing requirements will not be produced at an internal pressure of 150 psig. This shall be verified by explosion testing the enclosure at a minimum of 150 psig.

(iii) Enclosures shall be designed to withstand a minimum pressure of at least 150 psig without leakage through any welds or castings, rupture of any part that affects explosion-proof integrity, clearances exceeding those permitted under existing requirements along flame-arresting paths, or permanent distortion exceeding 0.040-inch per linear foot.

(iv) Flamepath clearances, including clearances between fasteners and the holes through which they pass, shall not exceed those specified in existing requirements. No intentional gaps in flamepaths are permitted.

(v) The minimum lengths of the flame arresting paths, based on enclosure volume, shall conform to those specified in existing requirements to the nearest metric equivalent value (e.g., 12.5 mm, 19 mm, and 25 mm are considered equivalent to 1/2 inch, 3/4 inch and 1 inch respectively for plane and cylindrical joints). The widths of any grooves for o-rings shall be deducted in measuring the widths of flame-arresting paths.

(vi) Gaskets shall not be used to form any part of a flame-arresting path. If o-rings are installed within a flamepath, the location of the o-rings shall meet existing requirements.

(vii) Cable entries into enclosures shall be of a type that utilizes either flame-resistant rope packing material or sealing rings (grommets). If plugs and mating receptacles are mounted to an enclosure wall, they shall be of explosion-proof construction. Insulated bushings or studs shall not be installed in the outside walls of enclosures. Lead entrances utilizing sealing compounds and flexible or rigid metallic conduit are not permitted.

(viii) Unused lead entrances shall be closed with a metal plug that is secured by spot welding, brazing, or equivalent.

(ix) Special explosion tests are required for electric motor assemblies that share leads (electric conductors) through a common wall with another explosion-proof enclosure, such as a motor winding compartment and a conduit box. These tests are required to determine the presence of any pressure piling conditions in either enclosure when one or more of the insulating barriers, sectionalizing terminals, or other isolating parts are sequentially removed from the common wall between the enclosures. Enclosures that exhibit pressures during these tests that exceed those specified in existing requirements must be provided with a warning tag. The durable warning tag must indicate that the insulating barriers, sectionalizing terminals, or other isolating parts be maintained in order to insure the explosion-proof integrity for either enclosure sharing a common wall. A warning tag is not required if the enclosures withstand a static pressure of twice the maximum value observed in the explosion tests.

(2) [Reserved]

(d) After MSHA has determined that non-MSHA product safety standards are equivalent and has notified the public of such determinations, applicants may seek MSHA product approval based on such non-MSHA product safety standards.