Full opinion text
J. SKELLY WRIGHT, Chief Judge: In November 1978 the Occupational Safety and Health Administration (OSHA), exercising its authority and responsibility under Section 6 of the Occupational Safety and Health Act, 29 U.S.C. § 655 (1976), issued new rules designed to protect American workers from exposure to airborne lead in the workplace. In these consolidated appeals petitioners representing both labor union and industry interests challenge virtually every aspect of the new lead standard and the massive rulemaking from which it emerged. The unions claim that OSHA has failed to carry out its statutory duty to ensure that “no employee will suffer material impairment of health * *.” Id. § 655(b)(5). The industry, parties charge OSHA with almost every procedural sin of which an agency can be guilty in informal rulemaking, attack some of the most important substantive provisions of the standard as exceeding OSHA’s statutory authority, and assert that the agency has failed to present substantial evidence to support the factual bases of the standard. Though the numerous challenges to the standard and the size and complexity of the rulemaking require of us a lengthy analysis of the issues, we affirm most of the new occupational lead standard, remanding to the agency for reconsideration only the question of the feasibility of the standard for a number of the affected industries. I. BACKGROUND Lead exists naturally in the earth’s crust, the atmosphere, and the hydrosphere. For thousands of years human beings have found lead crucial to the manufacture of a vast number of essential products. For centuries we have recognized the health hazards of such use. We learned long ago that lead absorption through inhalation and ingestion could cause printers to lose movement in their fingers, and pottery and glass workers to suffer the “dry grippe.” For almost a century we have known that excessive lead absorption can injure the kidneys and the peripheral and central nervous systems of painters, plumbers, and industrial workers. 52952/3. We do not know to a scientific certainty that precise levels of air-lead exposure or blood-lead content at which different lead-induced diseases occur. That question, indeed, has been central to this rulemaking. We do know that in the United States today, where industry consumes annually over one million tons of lead, at least 800,000 workers, representing 120 occupations in over 40 industries, are exposed to airborne lead on the job and thereby face the dangers of lead poisoning. As scientific means for measuring lead exposure and lead absorption have improved over the last 50 years, scientists and the government have set lower and lower figures for the maximum tolerable level of airborne lead exposure, but have struggled in setting a precise permissible exposure limit (PEL). A PEL of 500 ug/m3 (500 micrograms of lead per cubic meter of air) was once the consensus figure, but in 1933 the United States Public Health Service recommended, and many industries at least theoretically adopted, a goal of 150 ug/m3. In 1957 the American Conference of Governmental Industrial Hygienists increased the recommended maximum to 200 ug/m3, but in 1971 lowered it once again to 150 ug/m3. Joint Appendix (JA) 1487-1491; 52952/3-52953/1. However, in that same year, 1971, the newly created Occupational Safety and Health Administration, acting without rulemaking under Section 6(a) of the OSH Act, 29 U.S.C. § 655(a) (1976), adopted the “national consensus standard” recommended by the American National Standards Institute, which set a PEL, measured as an eight-hour time-weighted average, of 200 ug/m3. Two years later the Director of the National Institute for Occupational Safety and Health (NIOSH) advised the Secretary of Labor to lower the PEL to 150 ug/m3 yet again, and two years after that, in August 1975, the NIOSH Director suggested that the Secretary lower the PEL still further. In response, on October 3, 1975 OSHA published notice of a proposed new standard for occupational lead exposure, which combined a PEL of 100 ug/m3 with detailed rules for environmental monitoring, employee medical surveillance and training, and other health and safety measures. 40 Fed.Reg. 45934 (1975). OSHA conducted public hearings in March, April, and May, and then again in November and December, 1977, and closed the record on August 8, 1978. It then issued the final standard, which differed from the proposed standard most noticeably in setting the final PEL at 50 ug/m3. Since most of the important provisions of the standard are on appeal, we will carefully explain these provisions and, where relevant, the parallel provisions in the proposed standard, as we address petitioners’ separate claims. However, we proceed now to summarize very briefly the scheme of the new lead standard. } The final standard restricts employee exposure to metallic lead, inorganic lead compounds, and organic lead soaps, 53007/2; § 1910.1025(b), and applies to almost all workplaces. The general scheme of the standard resembles that of earlier OSHA standards. It sets a PEL of 50 ug/m3 and an “action level” of 30 ug/m3. Sections 1910.1025(b), (c)(1). To determine whether exposure in any workplace exceeds the PEL or the action level, the employer must use environmental monitoring to measure airborne lead at least every six months or whenever changes in operations may alter lead exposures, and must warn employees whenever airborne lead exceeds the PEL. Section 1910.1025(d). All affected employers must meet the 50 ug/m3 PEL immediately through some combination of engineering controls, work practice or administrative controls, and supplemental respirators. However, the industries face deadlines, ranging from one to ten years, by which they must meet first an interim PEL of 100 ug/m3 and then the final PEL of 50 ug/m3 solely through engineering and work practice controls. The deadlines for each industry are determined by OSHA’s sense of that industry’s technological and economic capacity for change. Section 1910.1025(e)(1). The precise meaning and practical consequences of these rules on methods of compliance are among the most important issues in this appeal, and we consider them below when we review OSHA’s finding that the standard is feasible. Employers must also file written plans describing the means by which they intend to achieve the PEL without relying on respirators. Section 1910.1025(e)(3). Until these plans are carried out, and whenever engineering controls and work practice controls fail by themselves to achieve the PEL, employees must receive and wear respirators, §§ 1910.1025(e)(2), (f), use of which OSHA has carefully governed by strict rules on selecting, fitting, and testing, § 1910.1025(f). Moreover, where lead exposure exceeds the PEL, the employer must give the employees protective work clothing and equipment, § 1910.1025(g), and in all workplaces the employer must follow rigorous rules on housekeeping and hygiene, §§ 1910.1025(h), (i). Whenever exposure in a workplace exceeds the action level for more than 30 days in a year, the employer must supplement environmental monitoring with biological monitoring and medical surveillance. Under these rules the employer must measure employees’ blood-lead levels at periodic intervals determined by the magnitude of the employees’ initial or most recent measured level, § 1910.1025(j)(2), and must also give all employees medical examinations to determine whether the employees suffer or risk any bodily harm from lead exposure, § 1910.1025(j)(3). If an employee challenges the findings of a company physician’s medical examination, the employer must pay for a second, and possibly a third, medical examination to assess the accuracy of the first examination, § 1910.-1025(j)(3)(iii). Under one of the most important and controversial parts of the standard, and one relatively without precedent in earlier standards, whenever biological monitoring reveals a worker has an abnormally high blood-lead level or whenever medical surveillance reveals that a worker may suffer actual physical impairment from lead exposure, the employer must remove the employee from the workplace. Section 1910.-1025(k). Under this medical removal protection (MRP) provision, the employer may place the removed worker in another, low-exposure, workplace or, if no such workplace is available, may have to place the worker on leave. But whatever the employer’s choice, he must, during the period of removal, absolutely guarantee that the removed worker retain the earnings, benefits, and seniority rights of the job from which he was removed for at least 18 months, and the employer cannot return the employee to the original workplace until the lead-induced ailment disappears or the worker’s blood-lead level shows significant reduction. Sections 1910.1025(k)(l)(iii)-(v), 00(2). Finally, the standard requires employers to create safety and health training programs for their lead-exposed workers, § 1910.1025(7), to keep detailed records on environmental monitoring in the workplace and on the biological monitoring and medical surveillance of individual workers, and to make those records available to workers and certain of their representatives, as well as to the government. Section 1910.-1025(n). II. SCOPE OF REVIEW In our recent decision in the cotton dust case, AFL-CIO v. Marshall, 617 F.2d 636 (D.C.Cir.1979), we dealt at length with the criteria for judicial review appropriate to so-called “hybrid rulemaking” in general, and to cases under the OSH Act in particular. In the present case we feel no need to reinvent the wheel by recounting the relevant legislative and judicial history of the OSH Act and the general background of hybrid rulemaking. Rather, we incorporate our analysis in the cotton dust case as the established and proper interpretation of our scope of review for OSHA cases. However, we summarize that analysis very briefly here. Though the OSH Act adopts the “substantial evidence” test for judicial review, 29 U.S.C. § 655(f) (1976), rulemaking under that Act remains essentially informal. AFL-CIO v. Marshall, supra, 617 F.2d at 650: The tasks of this reviewing court are thus to ensure that the agency has (1) acted within the scope of its authority; (2) followed the procedures required by statute and by its own regulations; (3) explicated the bases for its decision; [and] (4) adduced substantial evidence in the record to support its determinations. (Footnotes omitted.) Of course, we must rigorously review the agency’s interpretations of the substantive provisions of its statutory mandate. Moreover, we must ensure that the agency has lived up to statutory and constitutional standards in its rule-making procedure — a subject we address in the next part of this opinion. These, however, are conventional problems of judicial review. The peculiar problem of reviewing the rules of agencies like OSHA lies in applying the substantial evidence test to regulations which are essentially legislative and rooted in inferences from complex scientific and factual data, and which often necessarily involve highly speculative projections of technological development in areas wholly lacking in scientific and'economic certainty. We noted in the cotton dust case that we do not pretend to have the competence or the jurisdiction to resolve technical controversies in the record, 617 F.2d at 650, 652, or, where the rule requires setting a numerical standard, to second-guess an agency decision that falls within a “zone of reasonableness,” id. at n.60, quoting Hercules, Inc. v. EPA, 598 F.2d 91, 107 (D.C.Cir.1978); see Industrial Union Dep’t, AFL-CIO v. American Petroleum Institute, 448 U.S. 607, 658, 100 S.Ct. 2844, 2872, 65 L.Ed.2d 1010 (1980) (plurality opinion); id., 448 U.S. at 662, 100 S.Ct. at 2874 (Burger, C. J., concurring). Rather, our task is to “ensure public accountability,” 617 F.2d at 651, by requiring the agency to identify relevant factual evidence, to explain the logic and the policies underlying any legislative choice, to state candidly any assumptions on which it relies, and to present its reasons for rejecting significant contrary evidence and argument. Generalization cannot usefully take us further. We will discuss other aspects of the proper scope of review as the need arises in our analysis of distinct issues in the case. III. PROCEDURAL CLAIMS OSHA was occasionally careless or inefficient in its procedures throughout this rulemaking, and we readily concede that procedural purists will never place the lead standard in the Pantheon of administrative proceedings. Moreover, we concede that most of LIA’s procedural claims raise difficult legal issues, and indeed force us to consider a number of important questions of informal rulemaking procedure that have not been fully resolved by this circuit in recent years. Nevertheless, we enter this area under two important restraints. First, as a legal matter, we generally have no power to impose extra-statutory procedural requirements on the agency unless it has violated the Constitution or flagrantly disregarded minimal principles of procedural fairness. Vermont Yankee Nuclear Power Corp. v. Natural Resources Defense Council, Inc., 435 U.S. 519, 98 S.Ct. 1197, 55 L.Ed.2d 460 (1978). Second, as both a legal and a practical matter, we must recognize the procedural flexibility inherent in informal rulemaking, as well as the difficulty an agency faces in managing hundreds of conn-ments and witnesses and developing a coherent standard out of tens of thousands of pages of record evidence. The OSH Act requires the agency to follow procedures more stringent than the minimal ones established in the Administrative Procedure Act, 5 U.S.C. § 553 (1976). Thus the agency must give interested parties the opportunity to request a public hearing on objections to a proposed rule, and must publish notice of the time and place for such hearing in the Federal Register. 29 U.S.C. § 655(b)(3) (1976). Moreover, the agency has added to these statutory procedures by rule. Thus OSHA itself requires a hearing examiner at oral hearings, who must provide an opportunity for cross-examination on important issues and offer interested persons verbatim transcripts of the hearing. 29 C.F.R. § 1911.-15(b) (1979). Nevertheless, Congress’ decision to impose the substantial evidence test on OSHA does not alter the essentially informal character of OSHA rulemaking. Industrial Union Dep’t, AFL-CIO v. Hodgson, 499 F.2d 467, 472-473 (D.C.Cir. 1974). Just recently, we emphasized that the presence of procedures beyond those mandated by Section 553 of the APA neither converts the essentially legislative process of informal rulemaking into something akin to adjudication, nor empowers courts to turn rule-making into courtroom trials. Ass’n of Nat’l Advertisers, Inc. v. FTC, 627 F.2d 1151 (D.C.Cir. 1979). Thus, as we examine the procedural claims in the lead proceeding, we must avoid imposing procedural constraints beyond those in APA Section 553, the OSH Act, and the Due Process Clause, and we remain bound by judicial construction of the demands of APA Section 553 as our source for the general principles of informal rulemaking. Acting under. these constraints, we ultimately find nothing illegal in OSHA’s procedural conduct. A. Bias of the Decisionmaker LIA urges us to vacate the entire lead standard because, in its view, the official who ultimately set the standard, Assistant Secretary of Labor Eula Bingham, had prejudged the essential issues in the rulemak-ing proceeding. For proof of this allegedly fatal bias, LIA points to a speech Bingham delivered on November 3, 1978 to a United Steelworkers of America conference on occupational exposure to lead. Bingham’s speech began innocuously, if dramatically (“Brothers and Sisters”), by noting her concern for workers and by recognizing how much OSHA depended on their unique perspective when it gathered information in setting safety standards. But after asserting that she and Secretary of Labor Marshall were “determined” to have a lead standard, Bingham proceeded to suggest her predisposition on important issues. As to the medical removal protection provision (MRP): I think that there may be some apprehension because Assistant Secretaries in the past have not always understood, or have ndt known how to spell the words medical removal protection, or rate retention * * *. Well, I learned to spell those words a long time ago on the Coke Oven Advisory Committee, and if you want to know how I feel about it, you need only to look up my comments during those Committee hearings. As far as I’m concerned, it is impossible to have a Lead Standard without it. * * ' * Appendix to Lodged Documents (ALD) 3. As to the dangers of lead: * * * I can tell you about a plant within 300 miles of the city where workers are told to go to the hospital from work and receive therapy that would drag out poison and precious metals. And then they’re sent back to be poisoned again. I bet I could go down to the hospitals of this city and find a worker that is undergoing kidney dialysis, and I’ll bet you a dinner that some of those workers have been in lead plants. Id. at 4. As to economic feasibility: I have told some people that I Have never aspired to be an economist, but I tell you I can smell a phony issue when I see one. And to say that safety and health regulations are inflationary is phony- * * * * * * * * * I don’t understand a society such as ours who is not willing to pay a dollar more for a battery to insure that workers do not have to pay for that battery with their lives. Id. at 5. The speech went on to urge workers “to control their own destiny” by educating themselves about the lead problem, and ended by calling for political support in the imminent congressional elections for candidates sympathetic to OSHA’s goals. Id. at 9. Were it our task to assess the wisdom and propriety of an administrator’s public conduct, we might well admonish Dr. Bingham for this speech. She served her agency poorly by making statements so susceptible to an inference of bias, especially statements to a group so passionately involved in the proceedings. But our task is rather to measure her conduct against the legal stan--dards for determining whether an official is so biased as to be incapable of finding facts and setting policy on the basjs_.of .the, ohjec-tive record before her. Moreover, we must bear in mind that this particular speech, though delivered five days before the Secretary of Labor signed the final standard and ten days before he released it, came 30 days after Bingham had effectively made her own decision on the standard and ten days after she had approved the final language. An administrative official is presumed to be objective and “capable of judging a particular controversy fairly on the basis of its own circumstances.” United States v. Morgan, 313 U.S. 409, 421, 61 S.Ct. 999, 1004, 85 L.Ed. 1429 (1941). Whether the official is engaged in adjudication or rulemaking, mere proof that she has taken a public position, or has expressed strong views, or holds an underlying philosophy with respect to an issue in dispute cannot overcome that presumption. Hortonvilie Joint School District No. 1 v. Hortonville Educ. Ass’n, 426 U.S. 482, 493, 96 S.Ct. 2308, 49 L.Ed.2d 1 (1976); United States v. Morgan, supra, 313 U.S. at 421, 61 S.Ct. at 1004. Nor is that presumption overcome when the official’s alleged predisposition derives from her participation in earlier proceedings on the same issue. FTC v. Cement Institute, 333 U.S. 683, 702-703, 68 S.Ct. 793, 804, 92 L.Ed. 1010 (1948). To disqualify administrators because of opinions they expressed or developed in earlier proceedings would mean that “experience acquired from their work * * * would be a handicap instead of an advantage.” Id. at 702, 68 S.Ct. at 804. When Congress creates an agency with an express mission — in OSHA’s case, to protect workers’ health and safety — the agency officials will almost inevitably form views on the best means of carrying out that mission. The subjective partiality of an official of such an agency does not invalidate a proceeding that the agency conducts in good faith. Lead Industries Ass’n, Inc. v. EPA, 647 F.2d 1130, 1178 (D.C.Cir. 1980); Carolina Environmental Study Group v. United States, 510 F.2d 796, 801 (D.C.Cir. 1975). This court has indeed required disqualification of an agency adjudicator when his public statements about pending cases revealed he “ ‘has in some measure adjudged the facts as well as the law of a particular ease in advance of hearing it.’ ” Cinderella Career & Finishing Schools, Inc. v. FTC, 425 F.2d 583, 591 (D.C.Cir. 1970), quoting Gilligan Will & Co. v. SEC, 267 F.2d 461, 469 (2d Cir.), cert. denied, 361 U.S. 896, 80 S.Ct. 200, 4 L.Ed.2d 152 (1959); see Texaco, Inc. v. FTC, 336 F.2d 754, 760 (D.C.Cir. 1964), vacated and remanded per curiam on other grounds, 381 U.S. 739, 85 S.Ct. 1798, 14 L.Ed.2d 714 (1965). And, although these cases involved adjudication, we could perhaps logically apply them to hybrid rule-making proceedings like the present one in which the factual predicates' of final rules are subject to review under the substantial evidence test. So applied, however, these cases would lead us to vacate the lead standard only if Dr. Bingham had demonstrably made up her mind about important and specific factual questions and was impervious to contrary evidence. This test would be hard enough for petitioners to meet. But in Ass’n of Nat’l Advertisers, Inc. v. FTC, supra, handed down after oral argument in the present case, we raised an even higher barrier to claims of bias in rulemaking proceedings. We stressed there the difference between the essentially “legislative” fact-finding of a rulemaker and the trial-type factfinding of an adjudicator, and thus held that the Cinderella test was inappropriate. We concluded that an agency official must be disqualified from rulemaking “only when there has been a clear and convincing showing that [she] has an unalterably closed mind on matters critical to the disposition of the proceeding.” 627 F.2d at 1195. The relevant statute in Ass’n of Nat’l Advertisers, Inc. v. FTC, supra, Section 18 of the Federal Trade Commission Act, 15 U.S.C. § 57a (1976), like the OSH Act, creates procedures more formal than the minimal ones required for informal rulemaking by 5 U.S.C. § 553 (1976). We held, however, that even in such hybrid rulemaking the findings of fact so intertwine with the policies that emerge from them that we could not, as we could in Cinderella^”cleave law from fact” in deciding whether the official had prejudged factual issues. 627 F.2d at 1168. Dr. Bingham’s general expression of solidarity with the Steelworkers was legally harmless. Her call for support for congressional candidates sympathetic to her agency’s mission did not bear on any specific issues in the case, and is probably the sort of political activity we simply must accept from a political appointee. Thus her bias, if any, shows up in her remarks about MRP, the dangers of lead poisoning, and the inflationary effect of the lead standard. Had she made these remarks before the rulemaking began or while OSHA was receiving public comments, we might still have had to strain precedent to find grounds for disqualification. Her remarks on MRP do not bear on any specific factual issues, but rather reveal a general predisposition on a matter of policy, of the sort held legally harmless in FTC v. Cement Institute, supra, and Ass’n of Nat’l Advertisers, Inc. v. FTC, supra. Her remarks about endangered workers do bear on a factual question, but only very generally; they reveal no prejudgment on the precise and complex factual issues in the case, such as the exact blood-lead level at which disease develops. Finally, although the speech does allude specifically to the cost of the standard to the battery industry, Dr. Bingham’s expression of disbelief in the inflationary effect of the standard is really part of a general rhetorical flourish about the danger of undervaluing worker health. In any event, the fact remains that Dr. Bingham delivered the speech after she had decided on the standard and after the record had been closed. We can thus infer bias only if we construe her remarks retroactively. There may be cases warranting such judicial mindreading, but they would have to involve far more explicit and detailed statements by the allegedly biased person. The only language of predisposition in Bingham’s speech that we can plausibly read retroactively is that on MRP, and her statement on that subject falls within the category of views derived from administrative experience to which the Supreme Court referred in FTC v. Cement Institute, supra, 333 U.S. at 702, 68 S.Ct. at 804. Thus, Bingham’s speech simply does not reveal prejudgment with sufficient specificity to prove bias under the Cinderella standard, and, all the more so, does not constitute the “clear and convincing” evidence demanded by Ass’n of Nat’l Advertisers, Inc. v. FTC, supra. Judicial review of rulemaking, unlike the ABA Canon of Ethics, does not attack the mere appearance of impropriety. Bingham’s speech, however unfortunate, does not prove the proceedings unfair. B. Improper Staff Role and Separation of Functions LIA aims its next procedural attack at OSHA staff attorneys who, LIA argues, acted essentially as advocates for a stringent lead standard by consulting with and persuading the Assistant Secretary as she drew her conclusions from the record. LIA would have us conclude that the agency decisionmaker engaged in ex parte, off-the-record contacts with one of the adverse sides in the rulemaking, thereby rendering the proceedings unfair. Grounding its contention somewhat equivocally on due process, the procedural principles inherent in hybrid rulemaking, and OSHA’s own regulations providing for cross-examination, LIA asks us to invalidate the entire proceeding. The key agency employee in question was Richard Gross, a lawyer in the Office of the Solicitor at OSHA, who served as a so-called “standard’s attorney” throughout the rulemaking. His precise role is as ambiguous as it is important. LIA portrays him as a sort of guardian ad litem for a stringent lead standard who “horse-shed” expert witnesses to contrive a record that would support such a standard, LIA brief at 30, and then impermissibly advocated before the Assistant Secretary to make certain she construed the record as he intended. OSHA portrays him rather as a neutral party with no particular cause other than developing the fullest and soundest scientific and economic record possible, and with no bias other than the general orientation toward worker health inevitable in any OSHA employee. The standard’s attorney was at the center of activity throughout the rulemaking. He worked with the regular OSHA staff in reviewing preliminary research and drafting the proposed standard, all the while offering informal legal advice. He helped organize the public hearings and, having immersed himself in the scientific literature and in the submitted public comments, he communicated regularly with the prospective expert witnesses. In these communications he briefed the witnesses on the issues they were to address in their testimony, explained the positions of the agency, the industry, and the unions on key questions, discussed the likely criticism of the experts’ testimony, and asked the experts for any new information that supported or contradicted the OSHA proposal. During the hearing itself he conducted all initial questioning of OSHA witnesses and cross-examined all other witnesses. After the hearings he assisted the Assistant Secretary by reviewing the evidence in the record, preparing summaries, analyses, and recommendations, and helping draft the Preamble to the final standard. In a proceeding to create a general rule it makes little sense to speak of an agency employee advocating for one “side” over another. However contentious the proceeding, the concept of advocacy does not apply easily where the agency is not determining the specific rights of a specific party, and where the proposed rule undergoes detailed change in its journey toward a final rule. Indeed, as OSHA notes, the true adversaries here may well have been the industry and the unions, since the final standard, while in no sense a mathematical compromise, did fall between the old standard, to which the industry had resigned itself, and the extremely stringent one the unions urged, see Part VIII infra. Thus, the standard’s attorney may have been an advocate for some new lead standard, and probably even a stringent one, but not necessarily for one specific standard supported by one specific party. Nevertheless, the adversary tone and format of the proceedings are obvious. At the very least, the standard’s attorney was committed to the general principles of the proposed standard, and so inevitably represented those principles “against” the industry parties so obviously adverse to them. Moreover, by conducting the “direct examination” of OSHA witnesses and the cross-examination of all others, the standard’s attorney certainly created the public impression of conventional legal advocacy. Thus OSHA’s portrayal of his role, while logical, is a bit disingenuous. The Assistant Secretary might well have been able to assess the record more objectively — if less efficiently — had the standard’s attorney not been constantly at her side. Therefore, although we have some doubt about calling the standard’s attorney an “advocate” in the context of such rulemaking, we will assume he played that role so we can measure his conduct against the legal constraints on the agency. We note at the outset that nothing in the Administrative Procedure Act bars a staff advocate from advising the decisionmaker in setting a final rule. The APA deals with ex parte contacts in two provisions. 5 U.S.C. § 554(d) (1976), which applies solely to adjudications, prohibits any off-the-record communication between an agency decisionmaker and any other person about a fact in issue, and in particular bars any prosecuting or investigating employee of the agency from participating in final decisions. Since an OSHA proceeding to set a safety and health standard is obviously rulemaking, and not adjudication, Industrial Union Dep’t, AFL-CIO v. Hodgson, supra, 499 F.2d at 472-473; see 5 U.S.C. § 551(4) (1976), that provision cannot apply here. See Ass’n of Nat’l Advertisers, Inc. v. FTC, supra; Hercules, Inc. v. EPA, supra, 598 F.2d at 125 (citing legislative history of APA). 5 U.S.C. § 557(d) (1976), which applies to formal rulemaking as well as adjudication, prohibits ex parte communications relevant to the merits of a proceeding between the agency and interested parties outside the agency. Even were we to ignore our own determination and Congress’ that the OSH Act creates essentially informal rulemaking, Industrial Union Dep’t, AFL-CIO v. Hodgson, supra, 499 F.2d at 472-473; Legislative History of the Occupational Safety and Health Act of 1970, 92d Cong., 1st Sess. 1187, 1201 (Committee Print) (June 1971) (hereinafter Legislative History), this provision cannot apply to ex parte contacts wholly among agency employees. Hercules, Inc. v. EPA, supra, 598 F.2d at 125 n.60 (citing legislative history of § 557(d)). Moreover, in establishing the special hybrid procedures in the OSH Act, Congress never intended to impose the separation-of-functions requirement it imposes in adjudications. The legislative history shows that Congress consistently turned back efforts to impose such formal procedures on OSHA standard-setting. Adding to informal rulemaking the special requirement of a substantial evidence test does not change the essential character of the rule-making, Ass’n of Nat’l Advertisers, Inc. v. FTC, supra, 627 F.2d at 1161, especially under a statute like the OSH Act which does not even require a hearing before the agency sets a standard, see 29 U.S.C. § 655(b)(3) (1976). Thus we can discern no statutory basis in either the APA or the OSH Act for a separation-of-functions requirement in OSHA rulemaking. And under the Supreme Court’s decision in Vermont Yankee Nuclear Power Corp. v. Natural Resources Defense Council, Inc., supra, that is virtually the end of the inquiry. Unless we find that the standard’s attorney here violated the due process rights of the petitioners, 435 U.S. at 543, 98 S.Ct. at 1211, or that this is one of those “extremely compelling circumstances” in which courts remain free to impose nonconstitutional extra-statutory procedures on agencies, id., we must reject LIA’s challenge here. In recent cases we have in fact gone beyond the strict terms of the APA and the substantive agency statute to impose a ban on ex parte contacts. In Home Box Office, Inc. v. FCC, 567 F.2d 9, 51-59 (D.C. Cir.) (per curiam), cert. denied, 434 U.S. 829, 98 S.Ct. 111, 54 L.Ed.2d 89 (1977), we held that off-the-record communications between members of the agency and interested outside parties violated the due process rights of parties not privy to the communications. In United States Lines, Inc. v. FMC, 584 F.2d 519, 536-543 (D.C.Cir.1978), decided after Vermont Yankee, we reaffirmed the principle of Home Box Office, finding the ban on ex parte contacts there inherent in the statutory requirements of a hearing and judicial review under the arbitrary and capricious standard. See Nat’l Small Shipments Traffic Conference, Inc. v. ICC, 590 F.2d 345, 351 (D.C. Cir. 1978). But neither of these cases involved improper influence of staff on agency decisionmakers, nor does the reasoning of either case lead us to apply the ban on ex parte contacts to agency staff. In Home Box Office, of course, we expressed our general concern that whenever the record fails to disclose important communications that mav have influenced .the agency decisionmaker, the court cannot fully exercise its power of review. Home Box Office, Inc. v. FCC, supra, 567 F.2d at 54. But we spoke there in the context of massive evidence that industry parties financially interested in the rulemaking secretly lobbied with FCC staff and commissioners. We stated: [T]he evidence is certainly consistent with often-voiced claims of undue industry influence over Commission proceedings, and we are particularly concerned that the final shaping of the rules we are reviewing here may have been by compromise among the contending industry forces, rather than by exercise of the independent discretion in the public interest the Communications Act vests in individual commissioners. * * * Id. at 53. Influence from within an agency poses no such threat. Moreover, in summarizing our guidance for the agencies in Home Box Office we identified the type of communication we were restricting specifically as that between the agency and “any interested private party, or an attorney or agent for any party[.]” Id. at 57. In United States Lines, where the agency abruptly reversed its decision on the antitrust exemption of a shipping agreement after it heard ex parte legal arguments from private parties, we stated that “adversarial comment is particularly critical where, as here, ex parte communications are made by a party interested in securing the Commission approval necessary for the legality of its contracts[.]” United States Lines, Inc. v. FMC, supra, 584 F.2d at 542. Neither the constitutional nor the implicit statutory principles that decided these cases apply with any force to the type of staff influence LIA challenges here. Moreover, an OSHA rulemaking proceeding is of a character wholly distinct from that of a proceeding which resolves “conflicting private claims to a valuable privilege,” Sanga-mon Valley Television Corp. v. United States, 269 F.2d 221, 224 (D.C. Cir. 1959), quoted in Home Box Office, Inc. v. FCC, supra, 567 F.2d at 55, and from a “quasi-adjudicatory” proceeding in which we found the potential for bias as great as that in a case of competing claims, United States Lines, Inc. v. FMC, supra, 584 F.2d at 539, 542. In only one recent case have we actually addressed the propriety of ex parte contacts between agency decisionmakers and agency staff, but even there our discussion of the issue was only dictum, and indeed essentially supports OSHA here. In Hercules, Inc. v. EPA, supra, we dealt with a claim that the chief judicial officer of the Environmental Protection Agency, who assisted the Administrator in setting final regulations on two toxic substances, consulted after the record was closed with staff experts, including two staff lawyers who had represented the staff position at the administrative hearing. 598 F.2d at 121-122. We noted that the problem was one “of great sensitivity,” id. at 126, which caused us some “uneasiness,” id. at 127, and on which we suggested we might rule when a more concrete case than the one there presented itself, id. at 126. To be sure, most of the special factors we cited in avoiding ruling on the issue in Hercules, Inc. are absent here. Nevertheless, LIA’s reading of Hercules, Inc. ignores the almost unmistakable conclusion we drew there: that the issue was one for Congress or the agencies to resolve. Recognizing, however euphemistically, that Vermont Yankee “counsels restraint” in imposing nonstatutory procedural requirements on agencies, id. at 126, we reviewed the legislative history of the APA on the staff contacts issue. We discovered there a clear congressional intent not to impose any separation-of-functions requirement unless agencies begin to abuse the practice, in which case “[ajmendatory or supplementary legislation can supply any deficiency.” 92 Cong.Rec. 2159 (1946) (remarks of Senator McCarran), quoted in Hercules, Inc. v. EPA, supra, 598 (F.2d at 127. We ended our discussion of the issue by asserting: Now might be a particularly propitious time for Congress or the agencies to limit or provide disclosure of post-hearing contacts between staff advocates and deci-sionmakers. * * * Id. at 127-128. The invitation to Congress and the agencies may remain, but so do the limits of the judicial task. Rulemaking is essentially an institutional, not an individual, process, and it is not vulnerable to communication within an agency in the same sense as it is to communication from without. In an enormously complex proceeding like an OSHA standard setting, it may simply be unrealistic to expect an official facing a massive, almost inchoate, record to isolate herself from the people with whom she worked in generating the record. See Braniff Airways, Inc. v. CAB, 379 F.2d 453, 461 (D.C.Cir.1967). In any event, we rest our decision not on our own theory of agency management, but on the state of the law. C. Improper Use of Consultants LIA makes two attacks on OSHA’s reliance on out-of-house consultants in developing the lead standard. The first attack goes to the general use of consultants and the effect thereof on the Assistant Secretary’s exercise of her duty to determine the final standard. LIA contends that the Assistant Secretary hired so many consultants and relied on them so heavily for so many tasks that she essentially abdicated her responsibility for setting the lead standard to outsiders. OSHA itself admits it lacked sufficient staff expertise to deal with all the important issues without outside help, thus perhaps earning LIA’s ironic observation that the agency requests deference to its expertise while pleading it does not have enough of that commodity. But the question is whether the use of consultants here violated the law. The record shows that OSHA did make rather broad requests for help from the consultants. As we discuss below, OSHA relied heavily on David Burton Associates (DBA) and Nicholas Ashford and his Center for Policy Alternatives (CPA) in examining the data on feasibility and developing a “technology-forcing” rationale for the standard. The agency hired a number of other expert consultants, giving them fairly broad mandates to summarize and evaluate data in the record, prepare record data for computer processing, and help draft portions of the Preamble and the final standard. E.g., ALD 39-40, 51-60, 65. LIA argues that such reliance on outsiders invites abuse, even if one assumes the honesty of the ones in this case, since hired hands have a financial incentive to tell the agency what it wants to hear, and have no civil service protection against retaliation for telling uncomfortable truths. LIA asserts that no case has considered and upheld the legality of such reliance. But neither can LIA locate a case or statute forbidding such a practice, and once again we are restrained by Vermont Yankee Nuclear Power Corp. v. Natural Resources Defense Council, Inc., supra, in imposing procedural rules on the agencies. If anything, the law generally bearing on the issue supports OSHA here. The OSH Act empowers the agency to employ expert consultants, 29 U.S.C. § 656(c) (1976), and OSHA might have possessed that power even without express statutory authority, see Tabor v. Joint Board for Enrollment of Actuaries, 566 F.2d 705, 708 n.5 (D.C.Cir.1977). Moreover, we have even treated the use of consultants as proof that the agency has taken its responsibilities seriously. Weyerhauser Co. v. Costle, 590 F.2d 1011, 1026 (D.C.Cir. 1978). LIA’s position thus comes down to the challenge that OSHA has violated the principle of Morgan v. United States, 298 U.S. 468, 480-481, 56 S.Ct. 906, 80 L.Ed. 1288 (1936) (Morgan I): “The one who decides must hear,” and an agency denies the parties a true hearing if the official who acts for the agency has not personally confronted the evidence and the arguments. See Braniff Airways, Inc. v. CAB, supra, 379 F.2d at 461. Though Morgan I expressly allowed agency officials to rely on their subordinates in reviewing the record, 298 U.S. at 481, 56 S.Ct. at 911, it did not, of course, address the question of outside consultants. Nevertheless, applying the general principle of Morgan I, we see that LIA cannot buttress its general allegation of excessive reliance with any specific proof that the Assistant Secretary failed to confront personally the essential evidence and arguments in setting the final standard. Without at this point addressing the substantive validity of the lead standard, we note that in the lengthy Preamble and Attachments to the final standard the deci-sionmaker reviewed the evidence and explained the evidentiary bases for each part of the standard. Moreover, the Assistant Secretary demonstrated her independence from the consultants by strongly criticizing some of their conclusions on the key issue of feasibility. E.g., 52984/1. To inquire further would be to probe impermissibly into the mental processes by which the Assistant Secretary made her decision. See United States v. Morgan, supra, 313 U.S. at 422, 61 S.Ct. at 1004; Washington Research Project, Inc. v. Dep’t of HEW, 504 F.2d 238, 248 (D.C.Cir. 1974), cert. denied, 421 U.S. 963, 95 S.Ct. 1951, 44 L.Ed.2d 450 (1975). The unsupported allegation that hired consultants might have an incentive to act dishonestly cannot overcome the presumption that agency officials and those who assist them have acted properly. See Willapoint Oysters, Inc. v. Ewing, 174 F.2d 676, 696 (9th Cir. 1949). Thus we generally see no reason to force agencies to hire enormous regular staffs versed in all conceivable technological issues, rather than use their appropriations to hire specific consultants for specific problems. LIA’s second attack goes to specific uses of consultants, and alleges damage to the state of the rulemaking record, rather than to the Assistant Secretary’s fulfillment of her personal responsibility. After closing the record, OSHA sought help from outside consultants in reviewing the record and preparing the Preamble. Two consultants were primary. The agency asked David Burton and DBA to help review the record to determine the feasibility of a permissible air-lead standard of 50 ug/m3, as opposed to the 100 ug/m3 standard the agency had proposed in the original notice of rulemaking, and on which most of the public commentary had focused. And OSHA asked Nicholas Ashford and CPA to analyze, in light of the record, the possibility of marking a correlation between air-lead levels and blood-lead levels. Both these consultants had previously aided OSHA by supplying on-the-record reports and testifying as expert witnesses at the public hearings. Both fulfilled the new requests by submitting written reports, of 117 and 192 pages respectively, neither of which the agency has released or placed in the rulemaking record. LIA contends that the reports are illegal ex parte communications which, like the communications with the staff advocates described earlier, constitute “secret briefs” and off-the-record evidence which LIA was deprived of a chance to rebut and the court a chance to review. We note first that, as in the case of the staff-influence charge discussed earlier, LIA has not identified any hard data or new legal arguments which are contained only in the allegedly improper ex parte communications and on which OSHA demonstrably relied in setting the standard. See Seacoast Anti-Pollution League v. Costle, 572 F.2d 872, 881 (1st Cir. 1978), cert. denied, 439 U.S. 824, 99 S.Ct. 94, 58 L.Ed.2d 117 (1979). Thus LIA has not shown that OSHA has materially prejudiced parties who were not privy to the communications. See id.; compare Doe v. Hampton, 566 F.2d 265, 276-278 (D.C.Cir.1977) (ex parte introduction of substantive medical evidence that went beyond merely assisting decision-maker in evaluating record might violate statute and agency rules, but harmless error where evidence merely cumulative). Rather, LIA asks us to infer that there must have been such ex parte evidence or legal argument, its request essentially relying on three factors: (1) The consultants were not agency employees; (2) they had previously testified as expert witnesses and prepared on-the-record reports; and (3) the documents we have before us, which describe the agreements and expectations between OSHA and the consultants and the content of the undisclosed reports, imply that actual new evidence was requested and supplied. We find the first two factors legally irrelevant, or at least insufficient to prove impropriety. As for the third, as we demonstrate below, we simply reject LIA’s construction of the documents. Were we to construe these factors otherwise, we might face the difficult task of resolving the scope of the ex parte contacts doctrine as generated by Home Box Office, Inc. v. FCC, supra, and developed by United States Lines, Inc. v. FMC, supra: Does the doctrine apply to a rulemaking proceeding leading to a truly general regulation, as opposed to a proceeding resolving “conflicting private claims to a valuable privilege” like that in Home Box Office or quasi-adjudication like United States Lines l But we need not address that question here, because the documents show that the communications between the agency and the consultants were simply part of the deliberative process of drawing conclusions from the public record. The consultants acted after the record was closed as the functional equivalent of agency staff, so the question of the legal propriety of OSHA’s reliance on DBA and CPA is foreclosed by our earlier conclusion that neither the APA nor the Home Box Office doctrine imposes a separation-of-functions requirement on the agencies. Thus, even though we readily assume that OSHA used the consultants’ reports — and even incorporated parts of them verbatim in the Preamble— LIA has suffered no legal prejudice from such use. Despite some suspicious phrases singled out by LIA, a few examples from the documents reveal that the consultants’ task was to help in the deliberative process. The contract between OSHA and DBA happens to include the remark: “It is understood by OSHA and DBA that the information necessary to provide satisfactory ‘answers’ may not be found in the hearing record.” ALD 23. But the immediately preceding line states that “[ajnswers to these suggestions must be derived exclusively from the hearing record,” and the agreement clearly describes DBA’s task as one of analyzing, not providing, evidence. ALD 22-23. The language underscored by LIA is nothing more than a realistic warning that there are no absolutely clear answers to some of the speculative questions about the lead standard. Similarly, the remark in a Task Order to DBA that “[references supplied that are not in the record are for your own information only and should not be used as documentation for any conclusions,” ALD 101, read carefully, actually supports OSHA here — all the more so in context. Finally, in a released segment of its actual post-hearing report DBA states unmistakably, “Where sufficient information is not available in the record from which to draw conclusions, no analysis is presented.” ALD 108. The OSHA contract with CPA and Ash-ford may seem to give the consultant a broad mandate — “to conduct additional research and prepare material supplementary to the above testimony regarding medical removal protection [and a] post-hearing comment in response to a number of animal studies cited during the hearings to support a view contrary to OSHA’s application of the Bernard model to predict blood lead levels.” ALD ll. At other points the contract asks CPA to “address the criticisms and defense” of the theoretical models on which OSHA sought to rely for its air-lead standards. ALD 12. Again, these requests to CPA must be read in the context of its assignment to summarize record evidence, to evaluate studies to probe them for flaws in method, and generally to marshal and interpret the data. ALD 147-152 (Vaughn index to CPA report). The phrases “additional research” and “material supplementary” add nothing to the clear instructions to CPA to offer opinions about and analyses of record evidence. That CPA was to respond off-the-record to on-the-record criticism of its own earlier report and testimony means nothing more than that its own earlier on-the-record testimony and comment were part of the larger rulemak-ing record it was now to review. When performed by agency staff, this sort of sophisticated review of evidence has always been recognized as legitimate participation in the deliberative process. Morgan I, supra, 298 U.S. at 481-482, 56 S.Ct. at 911, 912; Montrose Chemical Corp. v. Train, 491 F.2d 63, 69-71 (D.C. Cir. 1974); Braniff Airways, Inc. v. CAB, supra, 379 F.2d at 461. And the circuit courts, in applying the intra-agency exemption to the Freedom of Information Act, 5 U.S.C. § 552(b)(5) (1976), have recognized that where outside consultants so engage in the deliberative process there is no functional difference between staff and consultants, and so there should be no legal difference. Thus, in Soucie v. David, 448 F.2d 1067, 1078 n.44 (D.C. Cir. 1971), we asserted that hired consultants, just like regular staff, need assured confidentiality so they can advise agency officials frankly. The Soucie holding was adopted in Wu v. Nat’l Endowment for Humanities, 460 F.2d 1030, 1032-1033 (5th Cir. 1972), cert. denied, 410 U.S. 926, 93 S.Ct. 1352, 35 L.Ed.2d 586 (1973), where the court also noted, as we do here, that the agency had been specifically empowered by statute to hire consultants. Recognizing that the principle of Exemption 5 of the FOIA bears generally on the question of post-hearing contacts with consultants, we find ourselves fortunate in having before us Judge Friendly’s recent opinion holding that Exemption 5 applies directly to the very reports at issue in this case. After petitioning for review of this rulemaking, LIA went to federal court in New York to seek disclosure of various consultants’ reports under the FOIA. In Lead Industries Ass’n, Inc. v. OSHA, 610 F.2d 70 (2d Cir. 1979), Judge Friendly examined the same affidavits, agreements, and indices that we have examined, and concluded that both the DBA report and the CPA report contributed to the process by which the Assistant Secretary made her final decision. He conceded that the reports might contain some factual matter, but asserted that in a vast rulemaking like this one such information was necessarily incident to and not severable from the process of summary and analysis. Id. at 83. He suggested, moreover, that to the extent the reports drew inferences from and weighed the evidence they were more truly “deliberative” and thus better candidates for exemption than mere summaries of the record. Id. Finally, responding to LIA’s argument that CPA’s off-the-record response to criticisms of its earlier report and testimony was improper, Judge Friendly found that the response contained no new evidentiary material, and that “the answers are of the same sort that could have been made by a knowledgeable member of OSHA’s staff defending his expert witness’ credibility before the decisionmaker.” Id. at 84. Thus, the earlier participation of these consultants as expert witnesses in no way disqualifies them as aides in the final decision. Indeed, their participation is even less suspect than that of the staff advocates we discussed earlier, since any predisposition they held was a result of their factual research and not, as in the case of staff, an incident of serving as legal advocates for an institutional position. Once again, we sense no serious danger “that the final shaping of the rules we are reviewing here may have been by compromise among the contending industry forces, rather than by exercise of the independent discretion in the public interest” of agency officials. Home Box Office, Inc. v. FCC, supra, 567 F.2d at 53. We note finally that, at least with respect to DBA’s post-hearing report on feasibility, OSHA’s reliance on consultants at the deliberative stage of the rulemaking did cause problems in the record. Thus we share LIA’s concern that the post-hearing contract with DBA was OSHA’s first attempt to obtain expert advice directly addressing the feasibility of the 50 ug/m3 standard. However, since the consulting contract only requested analysis of established record evidence, we prefer to consider any resulting deficiencies in the record as part of our review for substantial evidence to support OSHA’s findings on feasibility, rather than under the ex parte contacts doctrine. D. Notice of Rulemaking The industry’s most serious procedural attack on the lead standard goes to the sufficiency of the original notice of proposed rulemaking. The notice issue illustrates as well as any other that the rule-making to set the lead standard was something less than a masterpiece of administrative procedure. Our task, however, is only to see whether the agency has complied with the law, and though the notice of rulemaking could well have been clearer and more specific, it meets the demands of that ubiquitous term of art in administrative law — “adequacy.” The OSH Act itself simply requires the Secretary to publish a proposed rule in the Federal Register, 29 U.S.C. § 655(b)(2) (1976), but implicitly incorporates the general requirement for informal rulemaking in 5 U.S.C. § 553(b)(3) (1976): notice of “the terms or substance of the proposed rule or a description of the subjects and issues involved.” The agency must “fairly apprise interested persons” of the nature of the rulemaking, American Iron & Steel Institute v. EPA, 568 F.2d 284, 293 (3d Cir. 1977), but a final rule may properly differ from a proposed rule — and indeed must so differ — when the record evidence warrants the change. “A contrary rule would lead to the absurdity that in rule-making under the APA the agency can learn from the comments on its proposals only at the peril of starting a new procedural round of commentary.” International Harvester Co. v. Ruckelshaus, 478 F.2d 615, 632 n.51 (D.C. Cir. 1973). Where the change between proposed and final rule is important, the question for the court is whether the final rule is a “logical outgrowth” of the rulemaking proceeding. South Terminal Corp. v. EPA, 504 F.2d 646, 659 (1st Cir. 1974). The courts have described the notice requirement with other verbal formulas, but general principles only take us so far. We must proceed to compare carefully the specific language of the proposal with that of the final rule, in light of the evidence adduced at the hearings. LIA and other industry parties stress two serious — and related — differences between the proposed and final lead standard: (1) The proposal set a PEL of 100 ug/m3 while the final standard’s PEL is 50 ug/m3. (2) The proposal apparently allowed industry to meet the PEL by relying on respirators whenever engineering and work practice controls proved infeasible, while the final standard strictly requires industry, after interim phase-in periods, to meet the PEL without relying on respirators at all. 1. Notice of the PEL. The difference between a PEL of 100 ug/m3 and one of 50 ug/m3 is obviously substantial. Though OSHA finds the latter PEL feasible, it cannot deny that the change in the final rule greatly increases the number of employees affected by the standard, as well as the standard’s economic and technological demands on industry. Nevertheless, the published explanation accompanying the proposed rule does in fact give notice that OSHA might set a PEL lower than 100 ug/m3. OSHA first listed the major issues raised by the rulemaking, including: 1. Whether the proposed permissible exposure limit to lead should be 100 ug/m3: and whether this level incorporates an appropriate margin of safety; 2. Whether subclinical effects of exposure should be considered in establishing a standard for occupational exposure to * * * lead; * * * * * # 8. To what extent are there groups with increased susceptibility to lead in the working population, such as women of childbearing age; and should such increased susceptibility, if it exists, be considered in establishing a standard for occupational exposure to * * * lead[.] 40 Fed.Reg. 45934/1-2 (1975). The question of “appropriate margin of safety” raised the possibility that OSHA might find the 100 ug/m3 PEL not safe enough. The issue of subclinical effects, in the context of the published proposal as a whole, also portended a lower PEL. There is scientific consensus that people rarely suffer actual clinical symptoms of lead intoxication at blood-lead levels below 80 micrograms of lead per 100 grams of whole blood (80 ug/100g), id. at 45935/2, which would probably correlate with air-lead levels over 100 ug/m3. Nevertheless, OSHA noted that there were studies showing such subclinical effects of lead as inhibition of the important enzyme ALA at a blood level of 40 ug/100g, id. at 45936/1, which might correlate with an air level as low as 50 ug/m3. The proposal noted, in fact, that “it is not known with certainty at what level this enzyme inhibition becomes clinically important,” id. at 45935/1, and, most important, clearly stated: In any event, the question of both clinical and subclinical effects should be fully discussed in comments submitted as well as at the hearing, if one is held, and might necessitate a different permissible exposure limit in the final standard than that proposed. Id. (emphasis added). Finally, notice of the issue of the special susceptibility of women of child-bearing age also should have alerted the parties that OSHA might lower the proposed PEL. The proposal noted there was evidence that fetuses and children, as well as people already suffering such conditions as anemia or renal insufficiency, needed their blood-lead levels kept as low as 30 ug/100g, and plainly stated that OSHA believed its statutory mandate required it to protect these groups