As used in this part, unless the context clearly requires otherwise:
(a) Act means the Williams-Steiger Occupational Safety and Health Act of 1970 (84 Stat. 1590).
(b) Assistant Secretary of Labor means the Assistant Secretary of Labor for Occupational Safety and Health;
(c) Employer means a person engaged in a business affecting commerce who has employees, but does not include the United States or any State or political subdivision of a State;
(d) Employee means an employee of an employer who is employed in a business of his employer which affects commerce;
(e) Commerce means trade, traffic, commerce, transportation, or communication among the several States, or between a State and any place outside thereof, or within the District of Columbia, or a possession of the United States (other than the Trust Territory of the Pacific Islands), or between points in the same State but through a point outside thereof;
(f) Standard means a standard which requires conditions, or the adoption or use of one or more practices, means, methods, operations, or processes, reasonably necessary or appropriate to provide safe or healthful employment and places of employment;
(g) National consensus standard means any standard or modification thereof which
(1) has been adopted and promulgated by a nationally recognized standards-producing organization under procedures whereby it can be determined by the Secretary of Labor or by the Assistant Secretary of Labor that persons interested and affected by the scope or provisions of the standard have reached substantial agreement on its adoption,
(2) was formulated in a manner which afforded an opportunity for diverse views to be considered, and
(3) has been designated as such a standard by the Secretary or the Assistant Secretary, after consultation with other appropriate Federal agencies; and
(h) Established Federal standard means any operative standard established by any agency of the United States and in effect on April 28, 1971, or contained in any Act of Congress in force on the date of enactment of the Williams-Steiger Occupational Safety and Health Act.