It is unnecessary that we decide the constitutionality of the Occupational Safety and Health Act of 1970 and its enforcement procedures established by sections 5, 6, 8, 9, 10, 11, 12, and 17, which matter is also pending and under submission before another panel of this Court in Atlas Roofing Company, Inc. v. Secretary of Labor, No. 73 — 2249. We are in agreement with the well-reasoned dissent of Chairman Moran of the Occupational Safety and Health Review Commission in this matter, and especially with that portion pertaining to the general rule that a contractor is not responsible for the acts of his subcontractors or their employees; accordingly, that the tractor driver was not an employee of respondent. Therefore, respondent was not using the motor vehicle involved in this case at the time of the accident within the meaning of 29 C.F.R. § 1926.-601(b)(4), and the majority ruling of the Commission is erroneous.

Reversed.