opinion: EQUAL EMPLOYMENT OPPORTUNITY COMMISSION, Appellee, v. The COUNTY OF ALLEGHENY, Appellant, v. COMMONWEALTH OF PENNSYLVANIA and Richard Thornburgh, individually and in his capacity as Governor and Edward Biester, individually and in his capacity as Attorney General.
  No. 81-2530.
  United States Court of Appeals, Third Circuit.
  Argued March 1, 1982.
  Decided April 19, 1983.
  Thomas H.M. Hough (argued), Asst. County Sol., James H. McLean, County Sol., Pittsburgh, Pa., for appellant.
  W. Sherman Rogers (argued), Michael J. Connolly, Gen. Counsel, Philip B. Sklover, Acting Asst. Gen. Counsel, Vincent Black-wood, Asst. Gen. Counsel, E.E.O.C., Washington, D.C., for appellee, EEOC.
  Alton P. Arnold, Jr., Deputy Atty. Gen., Pittsburgh, Pa., for Commonwealth of Pennsylvania, Richard Thornburgh, Edward Biester.
  Before HUNTER, WEIS and HIGGIN-BOTHAM, Circuit Judges.
  OPINION OF THE COURT
  PER CURIAM:
  The Equal Employment Opportunity Commission (“EEOC”) filed a complaint against the County of Allegheny, Pennsylvania (“County”), alleging that the County maintained a discriminatory policy in its hiring of police officers in violation of the Age Discrimination in Employment Act of 1967, 29 U.S.C. §§ 621-634 (1976 & Supp. V 1981) (“ADEA”). On August 11, 1981, the United States District Court for the Western District of Pennsylvania granted partial summary judgment in favor of the EEOC. EEOC v. County of Allegheny, 519 F.Supp. 1328 (W.D.Pa.1981). The County appealed, and we have jurisdiction pursuant to 28 U.S.C. § 1292(a)(1) (1976).
  Although the case was argued on March 1, 1982, we decided to delay our decision pending the Supreme Court’s disposition of EEOC v. Wyoming, 514 F.Supp. 595 (D.Wyo.1981), prob. juris, noted, 454 U.S. 1140, 102 S.Ct. 996, 71 L.Ed.2d 291 (1982). That case presented the question of whether Congress violated the tenth amendment when it amended the ADEA in 1974 to include state and local governments within the coverage of the Act. Fair Labor Standards Amendments of 1974, Pub.L. No. 93-259, 88 Stat. 74 (codified at 29 U.S.C. § 630(b) (1976)). In EEOC v. Wyoming, -U.S.-, 103 S.Ct. 1054, 75 L.Ed.2d 18 (1983), the Supreme Court decided that question, holding that the amendment of the ADEA was constitutional. We will now address the issues presented on this appeal, and we will affirm the holding of the district court.
  I.
  The County has for years maintained a policy of refusing to allow individuals over the age of thirty-five to take its police examination. That examination is mandatory for individuals who want to become County police officers. The County adopted its hiring policy pursuant to a Pennsylvania statute applicable to Allegheny County. That statute provides in part:
  Each person desiring appointment to the police force ... shall apply to the commission for examination....
  No person shall be eligible to apply for examination unless he is more than eighteen years of age and, with respect to applicants for the police force not over thirty-five years of age at the date of application.
  16 P.S. § 4510 (Purdon Supp. 1982-83).
  The EEOC filed suit in the district court on behalf of three individuals who were not allowed to take the County’s police examination because they were over thirty-five years old. The EEOC claimed that the County’s hiring policy violated the ADEA. It sought an injunction against the continuation of the hiring policy, and it also sought immediate appointment of the three individuals with retroactive employment benefits and monetary damages.
  The district court concluded as a matter of law that the County’s hiring policy violated the ADEA. County of Allegheny, 519 F.Supp. at 1330. It found that the County’s refusal to allow individuals over thirty-five years old to take the police examination established a prima facie case of age discrimination in violation of section 4(a)(1) of the ADEA. 29 U.S.C. § 623(a)(1) (1976).
  The court then concluded that the County had failed to produce evidence to satisfy either of the statutory defenses provided in section 4(f)(1) of the ADEA. 29 U.S.C. § 623(f)(1) (1976). That section permits an employer to avoid liability if it can show either 1) that “age is a bona fide occupational qualification [“bfoq”] reasonably necessary to the normal operation of the particular business,” or 2) that “the differentiation is based on reasonable factors other than age.” Id.
  The district court rejected the bfoq defense, relying on the two-pronged test set out in Usery v. Tamiami Trail Tours, Inc., 531 F.2d 224 (5th Cir.1976). It found that the record was barren of any evidence that the refusal to hire individuals over thirty-five was reasonably necessary to the operation of the police force. It further found that there was no evidence that the County could not deal with applicants over thirty-five on an individualized basis. The district court thus held that there was a total absence of any record evidence to support the bfoq defense. County of Allegheny, 519 F.Supp. at 1333-34.
  The court next addressed the second statutory defense. The County argued that its refusal to hire individuals over thirty-five was “based on reasonable factors other than age,” namely, the mandate of a state statute. The court held that reliance on a state statute which conflicts with federal law cannot insulate an employer from liability for employment discrimination. Id. at 1335 n. 19. The court explained that an employer may invoke the “reasonable factor” defense only if it produces evidence that it did not in fact differentiate on the basis of age, but rather on the basis of some legitimate factor other than age. Id. at 1334. The court noted that, although the existence of the state statute in this case may explain the County’s motives for its hiring policy, the County had nonetheless relied on age as a determinative factor in its hiring decisions. Id. at 1335. The court thus rejected the County’s attempt to invoke the second statutory defense.
  The district court granted partial summary judgment against the County. It enjoined the County from continuing to use its hiring policy which violates the ADEA and also enjoined the Commonwealth of Pennsylvania from enforcing the provisions of its code which mandate that policy. The court ordered the County to accept the applications of the three plaintiffs and of all other individuals within the age group protected by the ADEA. It ordered the County to allow those individuals, if otherwise qualified, to take the police examination. App. at 153-54. The court decided that further development of the facts was required before deciding whether the individual plaintiffs were entitled to appointment, retroactive benefits, and monetary damages. County of Allegheny, 519 F.Supp. at 1337.
  II.
  On appeal the County does not contest the district court’s conclusion that its hiring policy constitutes a prima facie violation of section 4(a)(1) of the ADEA. 29 U.S.C. § 623(a)(1) (1976). Furthermore, it does not contest the district court’s conclusion that it has failed to produce any evidence to support the defense that age is a bona fide occupational qualification for serving as a County police officer. The County does argue that it should not be foreclosed from adopting a hiring policy in the future which may include an age limitation, if it can show that such an age limitation is a permissible bfoq under the ADEA. We do not read the district court’s opinion to hold, nor do we hold, that the County can never establish an age limitation for its police officers without violating the ADEA. Until the County proves that age is a bona fide occupational qualification for serving as a County police officer, however, it cannot lawfully establish such an age limitation.
  The County also argues that the district court erred in rejecting its attempt to invoke the second statutory defense. It renews its argument that age discrimination in reliance on a state statute constitutes differentiation “based on reasonable factors other than age.” 29 U.S.C. § 623(f)(1) (1976). That argument need not detain us. The district court correctly concluded that the plain language of section 4(f)(1) precludes such an argument. Furthermore, it is well-settled that under the Supremacy Clause a state statute which conflicts with a federal statute cannot stand, Jones v. Rath Packing Co., 430 U.S. 519, 525-26, 97 S.Ct. 1305, 1309-10, 51 L.Ed.2d 604 (1977), and that reliance on such an unconstitutional statute cannot justify employment discrimination. See Kober v. Westinghouse Electric Corp., 480 F.2d 240, 245-46 (3d Cir.1973); Rosenfeld v. Southern Pacific Co., 444 F.2d 1219, 1225-27 (9th Cir.1971).
  III.
  We, therefore, will affirm the district court’s grant of partial summary judgment against the County.
  . The statute is part of the Second Class County Code, 16 P.S. §§ 3101-6302 (Purdon 1956 & Supp. 1982-83), which is applicable to counties with a population between 800,000 and 1,800,-000. 16 P.S. § 3210(2) (Purdon Supp. 1982-83).
  . The district court permitted the County to add as defendants the Commonwealth of Pennsylvania, its governor, and its attorney general because part of the injunctive relief requested was directed at those parties.
  . Section 4(a)(1) provides in pertinent part:
  (a) It shall be unlawful for an employer—
  (1) to fail or refuse to hire or to discharge any individual ... because of such individual’s age.
  29 U.S.C. § 623(a)(1) (1976).
  . The ADEA protects individuals between the ages of 40 and 70. 29 U.S.C. § 631(a) (Supp. II 1978). The County argues on appeal that the district court erred in ordering the County to administer the police examination to the three individual plaintiffs because there was no record evidence that each was within the age group protected by the ADEA. Because of the lapse of time in this case, however, it is clear that each plaintiff now is at least 40 years old.
  . The Commonwealth of Pennsylvania and the individual state defendants have not appealed from the district court’s order.
  . Of course we express no opinion as to whether the County can in fact establish a bfoq defense. • See Orzel v. City of Wauwatosa Fire Dep't, 697 F.2d 743 (7th Cir.1983); Tuohy v. Ford Motor Co., 675 F.2d 842 (6th Cir.1982); Stewart v. Smith, 673 F.2d 485, 491 n. 26 (D.C. Cir.1982); EEOC v. County of Santa Barbara, 666 F.2d 373 (9th Cir.1982); Arritt v. Grisell, 567 F.2d 1267, 1271 (4th Cir.1977); Usery v. Tamiami Trail Tours, Inc., 531 F.2d 224, 233-38 (5th Cir.1976).
instruction: What follows is an opinion from a United States Court of Appeals.
  Intervenors who participated as parties at the courts of appeals should be counted as either appellants or respondents when it can be determined whose position they supported. For example, if there were two plaintiffs who lost in district court, appealed, and were joined by four intervenors who also asked the court of appeals to reverse the district court, the number of appellants should be coded as six.
  In some cases there is some confusion over who should be listed as the appellant and who as the respondent. This confusion is primarily the result of the presence of multiple docket numbers consolidated into a single appeal that is disposed of by a single opinion. Most frequently, this occurs when there are cross appeals and/or when one litigant sued (or was sued by) multiple litigants that were originally filed in district court as separate actions. The coding rule followed in such cases should be to go strictly by the designation provided in the title of the case. The first person listed in the title as the appellant should be coded as the appellant even if they subsequently appeared in a second docket number as the respondent and regardless of who was characterized as the appellant in the opinion.
  To clarify the coding conventions, consider the following hypothetical case in which the US Justice Department sues a labor union to strike down a racially discriminatory seniority system and the corporation (siding with the position of its union) simultaneously sues the government to get an injunction to block enforcement of the relevant civil rights law. From a district court decision that consolidated the two suits and declared the seniority system illegal but refused to impose financial penalties on the union, the corporation appeals and the government and union file cross appeals from the decision in the suit brought by the government. Assume the case was listed in the Federal Reporter as follows:
  United States of America,
  Plaintiff, Appellant
  v
  International Brotherhood of Widget Workers,AFL-CIO
  Defendant, Appellee.
  International Brotherhood of Widget Workers,AFL-CIO
  Defendants, Cross-appellants
  v
  United States of America.
  Widgets, Inc. & Susan Kuersten Sheehan, President & Chairman
  of the Board
  Plaintiff, Appellants,
  v
  United States of America,
  Defendant, Appellee.
  This case should be coded as follows:Appellant = United States, Respondents = International Brotherhood of Widget Workers Widgets, Inc., Total number of appellants = 1, Number of appellants that fall into the category "the federal government, its agencies, and officials" = 1, Total number of respondents = 3, Number of respondents that fall into the category "private business and its executives" = 2, Number of respondents that fall into the category "groups and associations" = 1.
  Your task is to identify the state of the first listed state or local government agency that is an appellant.
choices: not Alabama Alaska Arizona Arkansas California Colorado Connecticut Delaware Florida Georgia Hawaii Idaho Illinois Indiana Iowa Kansas Kentucky Louisiana Maine Maryland Massachussets Michigan Minnesota Mississippi Missouri Montana Nebraska Nevada New New New New North North Ohio Oklahoma Oregon Pennsylvania Rhode South South Tennessee Texas Utah Vermont Virginia Washington West Wisconsin Wyoming Virgin Puerto District Guam not Panama