United States Court of Appeals
                       For the First Circuit


No. 17-1537

                 A.C. CASTLE CONSTRUCTION CO., INC.

                            Petitioner,

                                 v.

              R. ALEXANDER ACOSTA, Secretary of Labor;
                      U.S. DEPARTMENT OF LABOR,

                            Respondents.


               PETITION FOR REVIEW OF AN ORDER OF
      THE OCCUPATIONAL SAFETY AND HEALTH REVIEW COMMISSION


                               Before

                   Torruella, Lipez, and Kayatta,
                           Circuit Judges.


     James F. Laboe, with whom Orr & Reno, P.A. was on brief, for
petitioner.
     Amy S. Tryon, Senior Attorney, U.S. Department of Labor, with
whom Nicholas C. Geale, Acting Solicitor of Labor, Ann S.
Rosenthal, Associate Solicitor for Occupational Safety and Health,
and Charles F. James, Counsel for Appellate Litigation, were on
brief, for respondents.


                          February 7, 2018
            KAYATTA, Circuit Judge.               General contractor A.C. Castle

Construction Co., Inc. appeals fines imposed by the Occupational

Safety and Health Administration ("OSHA") for violations related

to   an   accident      at    a   construction        worksite      in     Massachusetts.

A.C. Castle argues, among other things, that OSHA wrongly held it

responsible for the acts and omissions of a subcontractor.                             For

the reasons below, we affirm.

                                           I.

            Two roofers fell over twenty feet and sustained serious

injuries     at    a     residential        construction            site     in     Wenham,

Massachusetts on October 2, 2014, when a spruce board used for

scaffolding       snapped         in    half.         OSHA     inspectors         promptly

investigated      the        worksite    and    the     two    employers          involved:

A.C. Castle,      the        general     contractor,          and    Provencher        Home

Improvements ("PHI"), the sole proprietorship of Daryl Provencher

and the only subcontractor on the job.                   The Secretary of Labor,

charged with enforcing the Occupational Safety and Health Act

of 1970, 29 U.S.C. §§ 651-678 (the "OSH Act"), subsequently cited

both   A.C. Castle       and      PHI   under   the    OSH    Act.         The    Secretary

proffered two alternative theories for citing both companies,

rather than just the roofing subcontractor PHI: first, that under

Occupational Safety and Health Review Commission ("Commission")

precedent, the two companies constituted a single employer; and,

second, that under the common law agency test set forth by the


                                          - 2 -
United States Supreme Court in Darden, Daryl Provencher was a

supervisory employee of A.C. Castle.          See Nationwide Mut. Ins. Co.

v. Darden, 

(1992).              Under either legal test, the

constructive or actual knowledge that Provencher possessed of the

worksite violations would be imputed to A.C. Castle. See Empire

Roofing Co. Se., 25 BNA OSHC 2221, 2222 (No. 13-1034, 2016); Cent.

Soya de P.R., Inc. v. Sec'y of Labor, 

, 40 (1st Cir.

1981).

             A.C. Castle and Provencher challenged the citations.

Following a three-day testimonial hearing, the Administrative Law

Judge ("ALJ") determined that Provencher and A.C. Castle "acted as

a single employer in the worksite" and that Provencher "was a

supervisory employee working for A.C. Castle."             In so ruling, the

ALJ did not rest on her finding that Provencher was an employee of

A.C. Castle as an independent and sufficient basis upon which to

justify the citation of A.C. Castle.           Instead, she relied on that

finding to provide support for the conclusion that A.C. Castle and

PHI could be treated as a single employer.           The ALJ also rejec