Full opinion text
COFFEY, Circuit Judge. Since 1982 Johnson Controls, Inc. (hereinafter “Johnson Controls” or “Johnson”) has maintained a fetal protection policy designed to prevent unborn children and their mothers from suffering the adverse effects of lead exposure. International Union, United Automobile, Aerospace and Agricultural Implement Workers of America, UAW (hereinafter “UAW”), several UAW local unions and a group of individual employees brought suit alleging that this policy violated Title VII, 42 U.S.C. § 2000e, et seq. The district court granted summary judgment in favor of Johnson Controls and the plaintiffs appealed. This case was originally argued before a panel of this court and the panel’s opinion was circulated among all the members of the court pursuant to Circuit Rule 40(f). Prior to publication of the panel opinion, a majority of the members voted to hear the case before an en banc court and, following rehearing en banc, a majority of the court voted to affirm the decision of the district court. I. The Battery Division of Johnson Controls, Inc., was created upon Johnson Controls’ 1978 purchase of Globe Union, Inc. (hereinafter “Globe” or “Globe Union”). Globe Union was formed through the consolidation of two battery companies and had been in the battery business for almost fifty years before Johnson’s purchase. Globe Union and Johnson Controls have maintained ongoing efforts to improve industrial safety through measures designed to minimize the risk lead poses to those directly involved in the manufacturing of batteries. The steps that Globe Union and Johnson Controls have taken to regulate lead exposure have not been focused merely on complying with governmental safety regulations, but originate from their longstanding corporate concern for the danger lead poses to the health and welfare of their employees, their employees’ families and the general public. During the period of the 1970’s when OSHA’s regulation of employee exposure to lead was virtually non-existent, Johnson Controls’ predecessor, Globe Union, initiated a large number of innovative programs in an attempt to control and regulate industrial lead exposure. For example, in 1969, Dr. Charles Fishburn, M.D., who later became one of the primary proponents of Johnson Controls’ fetal protection policy, instituted programs for monitoring employee blood lead levels. In an attempt to manage lead exposure, other safety programs were initiated at Globe and Johnson including a lead hygiene program, respirator program, biological monitoring program, medical surveillance program and a program regulating the type, use and disposal of employee work clothing and footwear to minimize lead exposure. Globe Union also transferred employees out of high lead environments whenever a physician's medical evaluation report established that the individual had a high blood lead level. In the case of such transfers, medical removal benefits were provided to the employee before OSHA required such compensation. Globe Union and Johnson Controls have continued to address their serious concern for industrial safety through efforts to design and regulate lead manufacturing areas to reduce employee lead exposure. For example, laminar flow pumps constantly supply a down draft of low velocity clean air to improve the environment of workstations where employees deal with lead. Central vacuum systems and powered floor scrubbers and sweepers are used to keep the manufacturing area as clear of lead dust as possible. Since Johnson Controls’ purchase of Globe Union in 1978, it has spent approximately $15 million on environmental engineering controls at its battery division plants. Globe Union, Johnson Controls’ predecessor, established its first policy regarding fetal protection from lead exposure in 1977 as part of its comprehensive efforts to protect its employees from exposure to lead. Globe Union’s announcement of the policy in a memorandum to battery plant and personnel managers stated: “This change [the announced policy] has come about slowly as more and more medical opinion and evidence is persuasive of the risk to the unborn, developing child. We have stopped short of excluding women capable of bearing children from lead exposure, but do feel strongly that those women who are working in lead exposure ... and those women who wish to be considered for employment be advised that there is risk, that we recommend not working in lead if they are considering a family, and further that we ask them to sign a statement that they have been advised of this risk.” (Emphasis in original). In its 1977 “Statement of Risks,” Globe also observed that at that time scientific and medical evidence had not as yet conclusively established the risk lead exposure posed to the unborn. However, after noting possible risks the 1977 policy statement read: “We would have to say that it is, medically speaking, just good sense not to run that risk [lead exposure] if you want children and do not wish to expose the unborn child to risk, however small, and so recommend that you counsel with your family doctor and advise us of your wishes to transfer.” Johnson adopted its current fetal protection program in 1982 following its determination, based upon scientific research, that it was medically necessary to bar women from working in high lead exposure positions in the battery manufacturing division. The fetal protection policy applies to work environments in which any current employee has recorded a blood lead level exceeding 30 /¿g/dl during the preceding year or in which the work site has yielded an air sample during the past year containing a lead level in excess of 30 ¡xg per cubic meter. The policy recites that women with childbearing capacity will neither be hired for nor allowed to transfer into those jobs in which lead levels are defined as excessive. A grandfather clause in Johnson’s fetal protection policy permits fertile women who were assigned to high lead exposure positions at the time of the adoption of the policy to remain in those job assignments if they are able to maintain blood lead levels below 30 jag/dl. Those employees who are removed from positions because of excessive lead levels are transferred to another job in Johnson’s employ without suffering either a loss of pay or benefits. The major reason Johnson adopted its current fetal protection policy was the inability of the previous voluntary policy to achieve the desired purpose: protecting pregnant women and their unborn children from dangerous blood lead levels. Between 1979 and 1983, at least six Johnson Controls employees in high lead exposure positions became pregnant while maintaining blood lead levels in excess of 30 micrograms. In addition, at least one of the babies born to this group of employees later recorded an elevated blood lead level. Moreover, Johnson Controls’ medical consultant, Dr. Fishburn, testified as follows concerning a specific lead-related incident: “Q: Now, let’s talk in terms of prior to 1983, at any of the other Globe plants, do you have any knowledge or do you have an opinion that in any instances the exposure of the mother — or the bloodlead level of the mother while she was pregnant had an effect on the fetus and, therefore, the child? A: [Dr. Fishburn] Well, I’m not aware of any specific instances other than the one, which was in the early 80s, about 1981. Q: And where was that? A: Pardon? Q: Where was that? What plant? A: The Globe plant? Q: Yes. A: It was in Owosso. Q: Where’s the Owosso plant? A: In Owosso, Michigan. Q: In just simple terms, what was the nature of the problem? A: The nature of the problem was hyperactivity and control of the child. And the child had elevated blood-leads and protoporphyrinis. Q: In your medical judgment was the problem of the child affected in any way by the exposure of the mother during pregnancy? A: In my opinion the history of the hyperactivity and the difficulty she was having with him could very well and probably was due to the lead that he had.” In announcing its new, more defined policy, Johnson Controls emphasized its continuing interest in the protection of employees and their families from occupational health hazards and was responding to the increased understanding of the risk of lead exposure that had developed in the five years since it established its former voluntary policy: “We have over the years developed policies to protect the health of our employees whenever the nature of their duties may expose them to a health hazard and to prevent members of their families from being exposed to a health hazard because of their employment with Globe Battery Division. Medical research has shown that a woman’s exposure to lead can cause ill effects on the health of her unborn child because the lead absorbed in the mother’s blood as the result of this exposure can cross the placenta and mix with the child’s blood. This has been acknowledged by the Occupational Safety and Health Administration. Medical research also shows that a risk to the unborn child’s health is present at a much lower blood-lead level than an adult. The ill effects to the unborn child can occur during the early stage of pregnancy, before the mother is aware that she is pregnant, and can continue throughout the pregnancy. Because of this, it is the Division’s policy that women who are pregnant or who are capable of bearing children will not be placed into jobs involving lead exposure or which could expose them to lead through the exercise of >job bidding, bumping, transfer or promotion rights. This policy is intended to reduce or eliminate the possible unhealthy effects of lead on the unborn children of pregnant employees and applicants. It does not apply to those women who have medical confirmation that they cannot bear children. However, the policy is in no way intended to support or encourage women of childbearing capability to seek to change this status. Employees are strongly advised against any such action.” Prior to adopting its updated fetal protection policy, Johnson seriously considered alternatives to the exclusion of women with childbearing capacity from high lead exposure positions, but after research and consultation with medical and scientific experts found itself unable to structure and implement any alternatives which would adequately protect the unborn child from the risks associated with excessive lead exposure. Johnson’s experience demonstrated that the voluntary exclusion program was ineffective. To date neither Johnson nor any other battery manufacturer has been able to produce a lead free battery, or to utilize engineering research and technology to implement a system or procedure capable of reducing the lead exposure of its employees to acceptable levels for fertile women. Limitation of the fetal protection policy to women actually pregnant was found ineffective because there is the very definite possibility that lead exposure will occur between conception and the time the woman discovers her pregnancy. Such a limitation is further inadequate because reduction of blood lead levels following removal from a lead exposure area requires a significant length of time that frequently extends well into the pregnancy term. Limitation of the policy to women planning pregnancy also was not found to be a suitable alternative because of one of the exigencies of life, the frequency of unplanned or undetected pregnancies. Permitting fertile female employees to attempt to maintain a blood lead level below 30 /tg/dl or utilizing the mean or median blood lead levels of current workers as a measure of whether a woman should be permitted in a position would also not effectively protect the unborn child. The reason these actions would be inadequate is that an employee’s risk of high lead levels is usually greatest immediately after commencement of work in a high lead environment. Dr. Fishburn, Johnson Controls’ medical consultant, noted that Johnson and other corporations manufacturing batteries accept and routinely follow these medical policies: “Q: Now, you testified as to what other industries had done in the past with respect to women working — women capable of bearing children working in high lead areas. Are you familiar with other companies as to their practices? A: [Dr. Fishburn] Yes. Q: And which companies? A: Well, I’m familiar with a good many companies that I’ve worked with here in the area in foundry industry. I’m familiar with General Motors, Dow Chemical, Ford Motor Company, Owens-Corning. There’s a large number of large and small companies that I’m familiar with, and where there are occupational standard programs within those companies I’ve exchanged the information with them. Q: And what problems do they have in regard to this problem? A: In regard to lead even the doctors — as I said Dr. Kehoe or Dr. Bellmap here — any doctor that has worked with lead, either in the mines as I did with Bellmap, or smelters, primary smelter we did not, and — and I was never taught to place a reproductive female in the average work exposure of lead. And furthermore, before the 60s, to my knowledge, no women were working in lead exposures. It was Kehoe’s opinion at the time that any doctor that would allow this to happen was committing malpractice. Q: Now this was — now my question was: Are you familiar with what other companies are doing now? A: Yes. Q: What are they doing? A: They are restricting women from lead exposure who can have children.” In altering its fetal protection policy to more effectively protect the unborn child and its mother, Johnson responded to the most recent medical evidence which established that lead exposure in útero presents a substantial health risk to the unborn child, as well as its female employees, and believed that Title VII would allow it to address this risk. II. Proper analysis of the Title VII issues this case presents requires a thorough understanding of the following fundamental question: Does lead pose a health risk to the offspring of Johnson’s female employees? In considering the evidence in the record on this subject it is important to note that both the UAW and Johnson Controls agree on appeal that a substantial health hazard to the unborn child in the womb has been established. The UAW admits in its brief that “it is clear that ... substantial risk of harm to the fetus ... has been established.” UAW Brief at 33. Similarly, Johnson Controls states that “[t]he evidence in the record on [substantial risk of harm to the fetus] is overwhelming.” Johnson Controls Brief at 22. The record very clearly establishes that once lead is deposited in a mother’s blood, it crosses the placenta and affects her unborn child. Because the fetus’ blood system is nourished by the mother, the unborn child possesses approximately the same blood lead level as the mother. It is similarly undisputed that the unborn child “is medically judged to be at least as sensitive, and, indeed, is probably even more sensitive to lead than the young child.” Affidavit of J. Julian Chisholm, M.D. (hereinafter Dr. Chisholm Aff.) at 116. See Affidavit of Dr. Anthony R. Scialli, M.D. (hereinafter Dr. Scialli Aff.) at ¶ 5 (“[BJecause of the extremely rapid development of the central nervous system during gestation, the fetus may be even more sensitive to toxic effects of lead than the young child”); Affidavit of M. Donald Whorton, M.D. (hereinafter Dr. Whorton Aff.), at ¶ 8 (“[Recent medical studies] suggest that even relatively low levels of lead exposure to the fetus can cause damage to the higher brain function resulting in decreased neuro-behavioral development in the child”); Deposition of Marvin S. Le-gator, Ph.D. (hereinafter Dr. Legator Dep.) at 49 (UAW witness) (“There is no question about the sensitivity of the fetus.... I don’t think one could argue about the fact that lead affects the fetus”); Deposition of Ellen Silbergeld, Ph.D. (hereinafter Dr. Silbergeld Dep.) at 21-23 (UAW witness) (Noting that in the area of central nervous system impairment a young child is probably more sensitive than an adult and that the consequences for the young child and the fetus are similar). The Centers for Disease Control summarized these basic facts in a document questioning the efficacy of current OSHA standards in protecting the unborn child and implying that an unborn child is adversely affected by lead levels lower than the 30 jug/dl reflected in Johnson Controls’ fetal protection policy: “In a pregnant woman, lead crosses the placenta and lead concentrations in umbilical cord blood are nearly equal to those in maternal blood. Since the growing brain of the fetus is likely to be at least as sensitive to the neurologic balance of lead as the brain of a young child, umbilical cord blood levels should be at least below 25 gg/dl. Therefore, the OSHA standard is probably not sufficiently strict to protect the fetus. Further study is needed to define acceptable lead levels among women of childbearing age. “Ideally, engineering features should prevent workers from being exposed to lead dust and vapors. When workers are exposed, compliance with Occupational Safety and Health Administration (OSHA) regulations appears to be effective in preventing them from transporting lead home to children_ The prevention of lead exposure to the fetus needs special emphasis. Women of childbearing age should be excluded from working at jobs where significant lead exposure occurs.” The chief reason why an unborn child’s lead exposure is of such great concern is that it has been medically established that lead attacks the fetus’ central nervous system and retards cognitive development. See Dr. Chisholm Aff. at ¶ 6 (“[HJarm [to the fetus] includes ... retarded cognitive development which may result in learning deficiencies and behavioral disorders”); Dr. Scialli Aff. at f 7 (“The potential damage to the central nervous system of the fetus from lead exposure includes intellectual and motor retardation, behavioral abnormalities and deficiencies in learning abilities. It is my medical opinion that such damage may be permanent”); Dr. Whorton Aff. at f 8 (“[Recent medical studies] suggest that even relatively low levels of lead exposure to the fetus can cause damage to the higher brain function resulting in decreased neurobehavioral development in the child”); Affidavit of Dr. Paul B. Hammond, Ph.D., Professor, Environmental Health, University of Cincinnati (hereinafter Dr. Hammond Aff.) at f 3 (“[As] the director of a study that is currently being conducted in Cincinnati on the health effects of lead exposure on children ... [we] analyze[] the subsequent mental development of children who have been exposed to lead both in útero and postnatally. The initial results of this ongoing study ... establish that exposure of the fetus to maternal blood lead levels in excess of 12 micrograms per deciliter of whole blood creates a significant risk of low birth weight and a clear decrement in the subsequent mental development of the infant”); Dr. Silbergeld Dep. at 64 (Describing studies of child exposure to lead, in which she participated, which are “highly consistent with reports of hyperactivity, decreased attention span, learning problems which have been described in [lead exposed] children”), and at 49-50 (Reporting that studies of prenatal lead exposure in which she participated found similar effects to post-natal lead exposure. These effects are “substantial irreversible cellular and functional damage to the brain”). Unlike physical birth defects, such as those associated with thalidomide, lead’s sometimes subtle damaging effects may not fully manifest themselves until the child is diagnosed as having learning problems in a school setting some five to six years after birth: “What we are worried about are very subtle things, the ability to really affect learning ability. And so far as impairing the child’s progress, they really aren’t evident until he gets into school. He discovers that he can’t remember, that his brain cannot pay attention, what our psychologists here called deficits in auditory processing, which is a fancy way of saying they can’t understand what they hear, can’t process it, and use it effectively. And those things will impair a child perhaps toward the end of the first grade, particularly in the second grade.” Deposition of Dr. J. Julian Chisholm, Jr., M.D., Director, Lead Program, John F. Kennedy Institute and Associate Professor of Pediatrics, Johns Hopkins School of Medicine (hereinafter Chisholm Dep.), at 27. Probably the worst aspect of lead’s influence upon an unborn child’s future intellectual development is that its effects have frequently been found to be irreversible. Further, the most recent research suggests that the unborn child may be affected at lead levels previously believed safe. See J.M. Davis & D. Svendsgaard, Lead and Child Development, 329 Nature 297 (1987) (Collecting results of recent studies in this area). Lead exposure can also pose other physical threats to the unborn child such as reduction of the infant’s birth weight, premature delivery, and stillbirth. See Dr. Chisholm Aff. ¶ 6. Lead may also affect the other vital fetal organs including, but not limited to, the liver and kidneys. The danger resulting from lead exposure cannot simply be avoided through removing a pregnant woman from lead exposure promptly after the discovery of pregnancy. Dr. Chisholm, a recognized expert in the research field of treatment and prevention of lead poisoning in young children, observed that “excluding only woman who are actually pregnant from work areas where there are elevated blood lead levels would not sufficiently protect the health and safety of the unborn child.” Dr. Chisholm Aff. at ¶ 10. This is true because lead continues to exert an effect upon the mother and her unborn child for a significant period of time after she has been removed from lead exposure. Dr. Chisholm’s uncontroverted affidavit explained: “[Substantial medical evidence ... establishes that lead remains in the body for a significant period of time after removal from a high lead environment. Lead builds up not only in the blood and soft tissues, but is also stored in the bones. Following removal from the high lead environment, as the lead built up in the blood and soft tissues leaves the body, the lead in the bone begins to turnover, thus maintaining high blood lead levels even long after removal. As a general rule of thumb, it takes approximately two or three times as long for the blood leads to decrease as it did for such blood levels to increase. Therefore, if a woman is exposed to blood lead levels in excess of 25 or 30 micrograms for any length of time, such levels will not decrease sufficiently to avoid damage to the fetus, even if she is removed when the pregnancy is discovered.” Dr. Chisholm Aff. at ¶ 10. See also Whor-ton, supra note 16, at 8 (“Since lead is an accumulative toxicant which is stored in the bone, with a half-life in the body of 5 to 7 years, a woman with a significant blood lead burden would pose a potential hazard to any conceptas for many years after exposure”)-, Dr. Silbergeld Dep. at 27-28 (“For all purposes there is continuing exposure to lead even after removal from sources of lead.... If it were possible to take a person into a lead-free environment after an episode of exposure, the turnover of lead is probably on the order of 100 days. So within a year or so there would be a reduction of lead. There is also, of course, a rapid removal of lead from the blood into the bones [and] soft tissue that is no longer available for circulation. But considering that most people are not removed to lead-free environments, even if they go from areas of relatively high exposure to lower exposures, there is continuing cyclic ... exposure to lead”) (emphasis added). Furthermore, because lead is stored in the mother’s bones, and “because the bones may decalcify during pregnancy in order to provide the fetus with calcium, there may be an additional danger of transfer of stored lead to the fetus.” Dr. Chisholm Aff. at If 10. See also Whorton, supra note 16, at 7-8 (“[Dr. W.] Mantón [in a 1985 edition of the British Journal of Industrial Medicine] reported on a longitudinal study of blood lead levels in a woman before, during and after pregnancy. He reported a doubling of prepregnancy blood levels during pregnancy and suggested] mobilization of lead from bone during pregnancy as the mechanism”) (footnote omitted). These conclusions are consistent with research that OSHA relied upon and quoted in establishing its 1978 lead standard: “The placenta also has considerable storage capacity, and during the first few months of pregnancy, it grows tremendously in size while the fetus remains relatively small. Calcium along with other substances is stored in the placenta to be used in the later months of pregnancy for growth by the fetus. It could be expected that lead would be similarly stored.” Occupational Health and Safety Administration, U.S. Department of Labor, Final Standard for Occupational Exposure to Lead: Attachments to Preamble, 43 Fed. Reg. 54,395 (1978) (quoting study of Dr. Vilma Hunt, Associate Professor of Environmental Health, Pennsylvania University, contained in OSHA’s record). The overwhelming evidence in this record establishes that an unborn child’s exposure to lead creates a substantial health risk involving a danger of permanent harm. This evidence clearly approaches a “general consensus within the scientific community,” and certainly “suffices to show that within that community there is [a] considerable body of opinion that significant risk exists to the unborn child from exposure to lead.” Wright v. Olin Corp., 697 F.2d 1172, 1191 (4th Cir.1982). Next we consider the proper legal standards to be applied when employees bring a Title VII sex discrimination action challenging an employer’s response to this serious health risk. III. Having considered both the nature of the risk of harm that lead exposure presents to the unborn child and the mother and the policies Johnson implemented in response to this problem, we now turn to the question of the proper legal analysis to be applied to Johnson’s fetal protection program under Title VII. The question presented is should we follow the lead of the Fourth Circuit, the Eleventh Circuit and the EEOC in determining that these policies can be justified with a “business necessity” defense or must we conclude that these policies may only be justified with a bona fide occupational qualification defense. In approaching this issue we are cognizant of the mandates the United States Supreme Court has recited on two occasions concerning the necessity of avoiding rigid application of proof patterns to particular factual situations. The Court’s concern was first set forth in Furnco Construction Corp. v. Waters, 438 U.S. 567, 576, 98 S.Ct. 2943, 2849, 57 L.Ed.2d 957 (1978), where the Court noted that the formula it had devised for demonstrating a prima facie case of disparate treatment in McDonnell Douglas Corp. v. Green, 411 U.S. 792, 802, 93 S.Ct. 1817, 1824, 36 L.Ed.2d 668 (1973) “was not intended to be an inflexible rule.” The Court expanded on this same subject in International Brotherhood of Teamsters v. United States, 431 U.S. 324, 358, 97 S.Ct. 1843, 1866, 52 L.Ed.2d 396 (1977), when it observed: “Our decision in [McDonnell Douglas ] did not purport to create an inflexible formulation. We expressly noted that ‘[t]he facts necessarily will vary in Title VII cases, and the specification ... of the prima facie proof required from [a plaintiff] is not necessarily applicable in every respect to differing factual situations.’ [.McDonnell Douglas, 411 U.S. at 802 n. 13, 93 S.Ct. at 1824 n. 13].” (Footnote omitted). The thrust of these repeated Supreme Court pronouncements is that courts are required to avoid inflexible application of judicially devised proof patterns in cases that present factual circumstances different from those encountered previously. See also Wright v. Olin Corp., 697 F.2d 1172, 1184 (4th Cir.1982). Any proof scheme a federal court applies is useful only if it assists the court in properly identifying the employment practices Congress intended to prohibit under Title VII. These concerns are particularly important in a case of this nature where the interest in financial reward is balanced against a medically established risk of the birth of a medically or physically deprived baby and where the challenged distinction is based upon the reality that only the female of the human species is capable of childbearing. Two other federal courts of appeals and the Equal Employment Opportunity Commission have addressed the question of the defenses available to an employer under Title VII in a case challenging a fetal protection program. The first court of appeals to address this question was the Fourth Circuit in Wright v. Olin Corp., 697 F.2d 1172 (4th Cir.1982). That case involved a fetal protection program very similar to the one Johnson instituted, in that it forbade any fertile woman from working in a job which “ ‘may require contact with and exposure to known or suspected abortifa-cient or teratogenic agents.’ ” Olin, 697 F.2d at 1182. In considering which of several possible theories of claim and defense should apply in a Title VII analysis of a fetal protection policy, the Fourth Circuit observed: “We must start by conceding that the fact situation [the fetal protection policy] presents does not fit with absolute precision into any of the developed theories. It differs in some respects — either in its claim or defense elements — from each of the paradigmatic fact situations with which the different theories have been centrally concerned. This of course accounts for the conflict on the point between the parties. “That there would be such fact situations in Title VII litigation has always been recognized by the Supreme Court as it has developed and applied the different theories. The Court has continually admonished, and indeed demonstrated in its own decisions, that these theories were not expected nor intended to operate with rigid precision with respect to the infinite variety of factual patterns that would emerge in Title VII litigation. So has this court.” 697 F.2d at 1184 (emphasis added, footnotes omitted). The court applied the disparate impact/business necessity theory of claim and defense that normally is applied only in cases in which an employer’s policy is “facially neutral.” Even though the court recognized that the facial neutrality of a fetal protection policy "might be subject to logical dispute, the dispute would involve mere semantic quibbling having no relevance to the underlying principle that gave rise to this theory.” 697 F.2d at 1186. Because a fetal protection policy involves motivations and consequences most closely resembling a disparate impact case, the Fourth Circuit felt it should be analyzed under the disparate impact/business necessity theory. See id. The Fourth Circuit defined the business necessity defense in the context of a fetal protection policy as requiring a demonstration that “significant risks of harm to the unborn children of women workers from their exposure during pregnancy to toxic hazards in the workplace make necessary, for the safety of the unborn children, that fertile women workers, though not men workers, be appropriately restricted from exposure to those hazards.... ” 697 F.2d at 1190 (footnote omitted). However, the Fourth Circuit permitted this evidentia-ry demonstration to be rebutted with proof that “there are ‘acceptable alternative policies or practices which would better accomplish the business purpose ... [or protect against the risk of harm], or accomplish it equally well with a lesser differential ... impact [between women and men workers].’ ”- The Eleventh Circuit utilized a similar analysis in Hayes v. Shelby Memorial Hospital, 726 F.2d 1543 (11th Cir.1984) (Tuttle, J.). In Hayes a hospital terminated a pregnant woman’s employment upon discovering her pregnancy. In Hayes the Court utilized the elements of the business necessity defense found in Olin to establish that the involved policy was not “facially discriminatory.” The Eleventh Circuit stated: “In other words, the employer must show (1) that there is a substantial risk of harm to the fetus or potential offspring of women employees from the women’s exposure, either during pregnancy or while fertile, to toxic hazards in the workplace and (2) that the hazard applies to fertile or pregnant women, but not to men.” 726 F.2d at 1548 (footnote omitted). The theory underlying the facial neutrality analysis utilized in Hayes is that a policy meeting the above criteria “is neutral in the sense that it effectively and equally protects the offspring of all employees.” 726 F.2d at 1548. If facial neutrality is established, the court proceeds to a disparate impact/business necessity analysis. 726 F.2d at 1552. Under the Eleventh Circuit’s analysis, if facial neutrality is hot established, the employer must present a bona fide occupational qualification defense to justify its fetal protection policy. The Eleventh Circuit went on to set out the disparate impact/business necessity analysis it would apply in cases where facial neutrality was established. The court recognized that a fetal protection policy, even if “facially neutral,” “clearly has a disproportionate impact on women since only they are affected by it.” Id. However “the employer’s business necessity defense applies automatically, just as the employee’s prima facie case of disparate impact applies automatically. That is because to reach the disparate impact stage of analysis in a fetal protection case, the employer has already proved — to overcome the presumption of facial discrimination— that its policy is justified on a scientific basis and addresses a harm that does not affect men.” Id. at 1553. As in Olin, “the employer’s business necessity defense may be rebutted by proof that there are acceptable alternative policies that would better accomplish the purposes of promoting fetal health, or that would accomplish the purpose with less adverse impact on one sex.” Id. Although Olin and Hayes present somewhat different analyses, both cases, in essence, determine that a business necessity defense in a fetal protection policy case requires (1) a demonstration of the existence of a substantial health risk to the unborn child, and (2) establishment that transmission of the hazard to the unborn child occurs only through women. Both cases also allow the employee to present evidence of less discriminatory alternatives equally capable of preventing the health hazard to the unborn. On October 3, 1988, the Equal Employment Opportunity Commission, the agency responsible for the administration of Title VII, issued a Policy Statement on Reproductive and Fetal Hazards Under Title VII that, in substance, endorsed the approaches that the Fourth and Eleventh Circuits have taken to fetal protection cases. Equal Employment Opportunity Commission, Policy Statement on Reproductive and Fetal Hazards Under Title VII (October 3, 1988) (found in Fair Empl. Prac. Manual (BNA) 401:6013). As the Supreme Court has recognized, while such EEOC pronouncements “do not have the force of law, ... still they ‘ “constitute a body of experienced and informed judgment to which courts and litigants may resort for guidance.” ’ ” Local No. 93, International Association of Fire Fighters v. City of Cleveland, 478 U.S. 501, 518, 106 S.Ct. 3063, 3073, 92 L.Ed.2d 405 (1988) (quoting General Electric Co. v. Gilbert, 429 U.S. 125, 142, 97 S.Ct. 401, 411, 50 L.Ed.2d 343 (1976) which quoted, in turn, Skidmore v. Swift & Co., 323 U.S. 134,140, 65 S.Ct. 161, 164, 89 L.Ed. 124 (1944)). A fair reading of the EEOC’s Policy Statement reflects that the EEOC thoroughly considered the various interests under Title VII and followed earlier judicial decisions only after concluding that these decisions properly implemented Title VII policies. The EEOC noted that fetal protection “cases do not fit neatly into the traditional Title VII analytical framework and, therefore, must be regarded as a class unto themselves.” Policy Statement (found in Fair Empl. Prac. Manual (BNA) 401:6013, 6015 n. 11) (emphasis added). The EEOC then candidly recognized that fetal protection policies that “exclude only women constitute per se violations of the Act.” Id. at 401:6014 (footnote omitted). However, the EEOC went on to observe that “[although the BFOQ defense is normally the only one available in cases of overt discrimination, the Commission follows the lead of every court of appeals to have addressed the question [in determining] that the business necessity defense applies to these cases. While business necessity has traditionally been limited to disparate impact cases, there is an argument that in this narrow class of cases the defense should be flexibly applied.” Id. at 401:6014-15 (emphasis added, footnote omitted). The EEOC concluded that: “The issues [in a fetal protection policy case to which the business necessity defense is applicable] are (1) whether there exists a substantial risk of harm to employees’ offspring through the exposure of employees to a reproductive hazard in the workplace; (2) whether the harm to employees’ offspring takes place through the exposure of employees of one sex but not employees of the opposite sex; and (3) whether the employer’s policy effectively eliminates the risk of fetal or reproductive harm. Even if these elements are proved, the policy will not withstand scrutiny [if] it is shown that there exists a reasonable alternative policy that will protect employees’ offspring from fetal or reproductive harm and that has a less discriminatory impact on employees of the restricted sex. Thus, an employer’s reproductive or fetal protection policy must be neutrally designed to protect all employees’ offspring from hazards existing in the workplace. Where substantial evidence exists that the risk of harm to employees’ offspring takes place only through the exposure of one sex to a hazard existing in the workplace, an employer may exclude from the workplace employees of that sex, but only to the extent necessary to protect employees’ offspring from reproductive or fetal hazards.” Id. at 401:6015-16 (footnotes omitted). We agree with the Fourth Circuit, the Eleventh Circuit and the EEOC in their conclusion that a business necessity defense may be utilized in a fetal protection policy case. It is interesting to note that neither the text of Title VII nor Supreme Court pronouncements mandate a holding that all forms of facial discrimination are justifiable only with a bona fide occupational qualification defense. See Olin, 697 F.2d at 1186 n. 21 (“While the loose equation — overt discrimination/only B.F.O.Q. defense — is ... properly descriptive of a paradigmatic litigation pattern, it is not an accurate statement of any inherent constraints in Title VII doctrine”). See also Scherr v. Woodland School Community Consolidated District, No. 50, 867 F.2d 974, 977-81 (7th Cir.1988) (Permitting business necessity defense to be utilized under Pregnancy Discrimination Act). We are convinced that the components of the business necessity defense the courts of appeals and the EEOC have utilized in fetal protection cases balance the interests of the employer, the employee and the unborn child in a manner consistent with Title VIL The requirement of a substantial health risk to the unborn child effectively distinguishes between the legitimate risk of harm to health and safety which Title VII permits employers to consider and the “[m]yths or purely habitual assumptions” that employers sometimes attempt to impermissibly utilize to support the exclusion of women from employment opportunities. Likewise, the requirement that the risk of harm to offspring be substantially confined to female employees means that a fetal protection policy applying only to women recognizes the basic physical fact of human reproduction, that only women are capable of bearing children. Finally, the employee’s option of presenting less discriminatory alternatives to a fetal protection policy assures that these policies are only as restrictive as necessary to prevent the serious risk of harm to the unborn child. Accordingly, we agree with the Fourth Circuit, Eleventh Circuit and EEOC that the business necessity defense can be appropriately applied to fetal protection policy cases under Title VII. We now proceed to determine whether this defense can be utilized to sustain Johnson Controls’ fetal protection policy. IV. In Wards Cove Packing Co. v. Atonio, — U.S.-, 109 S.Ct. 2115, 2125-26, 104 L.Ed.2d 733 (1989), the Supreme Court recently described the general policies underlying the business necessity defense that we utilize in considering Johnson Controls’ fetal protection policy: “Though we have phrased the query differently in different cases, it is generally well-established that at the justification stage of ... a disparate impact case, the dispositive issue is whether a challenged practice serves, in a significant way, the legitimate employment goals of the employer. The touchstone of this inquiry is a reasoned review of the employer’s justification for his use of the challenged practice. A mere insubstantial justification in this regard will not suffice, because such a low standard of review would permit discrimination to be practiced through the use of spurious, seemingly neutral employment practices. At the same time, though, there is no requirement that the challenged practice be ‘essential’ or ‘indispensable’ to the employer’s business for it to pass muster: this degree of scrutiny would be almost impossible for most employers to meet, and would result in a host of evils....” (Citations omitted). In Wards Cove the Court also clarified the proof burdens to be applied in addressing an employer’s business necessity defense: “[T]he employer carries the burden of producing evidence of a business justification for his employment practice. The burden of persuasion, however, remains with the disparate-impact plaintiff. To the extent that the Ninth Circuit held otherwise in its en banc decision in this case, or in the panel’s decision on remand — suggesting that the persuasion burden should shift to the [defendants] once the [plaintiffs] establish a prima facie case of disparate impact — its decisions were erroneous. ‘[T]he ultimate burden of proving that discrimination against a protected group has been caused by a specific employment practice remains with the plaintiff at all times.’ Watson [v. Fort Worth Bank & Trust Co., — U.S.-, 108 S.Ct. 2777, 2790, 101 L.Ed.2d 827 (1988)] (O’Connor, J.) (emphasis added). This rule conforms with the usual method for allocating persuasion and production burdens in the federal courts, and more specifically, it conforms to the rule in disparate treatment cases that the plaintiff bears the burden of disproving an employer’s assertion that the adverse employment action or practice was based solely on a legitimate neutral consideration. We acknowledge that some of our earlier decisions can be read as suggesting otherwise. But to the extent that those cases speak of an employers’ (sic) ‘burden of proof’ with respect to a legitimate business justification defense, they should have been understood to mean an employer’s production — but not persuasion —burden. The persuasion burden here must remain with the plaintiff, for it is he who must prove that it was ‘because of such individual’s race, color,’ etc., that he was denied a desired employment opportunity. See 42 U.S.C. § 2000e-2(a).” Wards Cove, 109 S.Ct. at 2126 (citations omitted, emphasis added). The allocation of the burden of proof under substantive Title VII law outlined in Wards Cove plays a significant role in summary judgment proceedings of this nature. We have previously recognized that: “Summary judgment is properly entered in favor of a party when the opposing party is unable to make a showing sufficient to prove an essential element of a case on which the opposing party bears the burden of proof.” Common v. Williams, 859 F.2d 467, 469 (7th Cir.1988). The Supreme Court explained the reasons for this rule in Celotex Corp. v. Catrett, 477 U.S. 317, 322-23, 106 S.Ct. 2548, 2552-53, 91 L.Ed.2d 265 (1986): “In our view, the plain language of Rule 56(c) mandates the entry of summary judgment, after adequate time for discovery and upon motion, against a party who fails to make a showing sufficient to establish the existence of an element essential to that party’s case, and on which the party will bear the burden the proof at trial. In such a situation, there can be ‘no genuine issue as to any material fact,’ since a complete failure of proof concerning an essential element of the nonmoving party’s case necessarily renders all other facts immaterial. The moving party is ‘entitled to judgment as a matter of law’ because the nonmoving party has failed to make a sufficient showing on an essential element of her case with respect to which she has the burden of proof.” “Where the record taken as a whole could not lead a rational trier of fact to find for the non-moving party, there is no ‘genuine issue for trial.’ ” Matsushita Electric Industrial Co. v. Zenith Radio Corp., 475 U.S. 574, 587, 106 S.Ct. 1348, 1356, 89 L.Ed.2d 538 (1986) (quoting First National Bank of Arizona v. Cities Service Co., 391 U.S. 253, 288-89, 88 S.Ct. 1575, 1592-93, 20 L.Ed.2d 569 (1968)). Thus, the question we must address is whether the UAW, which bears the burden of persuasion, has presented evidence sufficient to permit the district court to conclude that Johnson Controls’ business necessity defense cannot be factually supported. Our inquiry must be based on the underlying premise that the creation of a record adequate to meet legal challenges is the responsibility of the parties litigating the case. We may neither add nor subtract from the record; we must accept it as it is. Thus, “[wjhen confronted with a motion for summary judgment, a party who bears the burden of proof on a particular issue, may not rest on its pleadings, but must affirmatively demonstrate by specific factual allegations, that there is a genuine issue of material fact which requires trial.” Beard v. Whitley County, REMC, 840 F.2d 405, 410 (7th Cir.1988) (emphasis in original). As we have also noted: “A district court need not scour the record to make the ease of a party who does nothing.... [Cjourts will not discover that the movants slighted contrary information if opposing lawyers sit on their haunches; judges may let the adversary system take its course.” Herman v. City of Chicago, 870 F.2d 400, 404 (7th Cir.1989). We now turn to whether the UAW has established a genuine issue of material fact concerning any of the elements of the business necessity defense upon which it bears the burden of persuasion. A. Substantial Risk of Harm to the Unborn Child Both the UAW and Johnson Controls agree on appeal that the significant evidence of risks to the health of the fetus contained in the record establishes a substantial health risk to the unborn child. The UAW in its brief admits that “it is clear that ... substantia] risk of harm to the fetus ... has been established.” UAW Brief at 33. Similarly, Johnson states that “[t]he evidence in the record on [substantial risk of harm to the fetus] is overwhelming.” Johnson Controls Brief at 22. In light of the parties’ agreement on the question of substantial risk of harm to the unborn child, this issue is not before this court on appeal. Although the parties do not contest this question on appeal, the evidence in the record that we recounted in Section II, supra, conclusively supports the accepted medical and scientific finding that lead creates a substantial risk of harm to unborn children. In order to present the risk of harm necessary to sustain a fetal protection policy “it is not necessary to prove the existence of a general consensus on the [question of risk of harm to the unborn child] within the qualified scientific community. It suffices to show that within that community there is so considerable a body of opinion that significant risk exists ... that an informed employer could not responsibly fail to act on the assumption that this opinion might be the accurate one.” Olin, 697 F.2d at 1191. The overwhelming medical and scientific research data demonstrating a substantial risk to the unborn child from lead exposure, found in the record and set forth in Section II, supra, approaches a “general consensus within the qualified scientific community,” and certainly “suffices to show that within that community there is [a] considerable body of opinion that significant risk exists.” Accordingly, we are convinced that there is no genuine issue of material fact with respect to this component of Johnson Controls’ business necessity defense. B. Exposure Through a Single Sex The UAW’s efforts in this case have primarily been devoted toward negating the second element of Johnson’s business necessity defense, that the risk of transmission of potentially harmful lead exposure to unborn children is substantially confined to fertile female employees. On this issue, as with the question of substantial risk of harm to the unborn child, “it is not necessary to prove the existence of a general consensus on the [issue] within the qualified scientific community.” Olin, 697 F.2d at 1191. In this case Johnson Controls’ experts, without exception, testified that a male worker’s exposure to lead at levels within the 50 fig/dl maximum set forth in OSHA’s current (1978) lead exposure guidelines did not pose a substantial risk of genetically transmitted harm from the male to the unborn child. Moreover, Johnson’s experts took the position that because this data dealt exclusively with animals, the results of these studies were not scientifically established as being applicable to humans. In contrast, the UAW witnesses posited that animal studies had demonstrated that there was a possible risk of genetic damage to human offspring as a result of male lead exposure. The UAW witnesses attempt to bridge the wide chasm between the results of animal studies and a conclusion of genetic harm allegedly transmitted through the male human being with human studies merely establishing a correlation between male lead exposure and changes in sperm shape. It is interesting to note that the UAW has not presented any medical evidence in the record of any human study scientifically documenting genetic defects in human beings resulting from male lead exposure. It is this lack of convincing scientific data that the plaintiffs attempt to gloss over and cast aside in ignoring the differences between the effect of lead on the human and animal reproductive systems. As noted previously, when the Title VII disparate impact/business necessity proof scheme is applied at the summary judgment phase of litigation, the UAW is required to present facts sufficient for the trier of fact to conclude that transmission of the significant risk of harm lead presents to the unborn child is not substantially confined to female employees. Unlike the recorded evidence of a substantial risk of harm resulting to an unborn child from exposure to lead through the mother’s blood stream and placenta, the evidence of risk to the unborn child resulting from exposure of the father to the lead levels currently present in Johnson Controls’ battery manufacturing factories is, at best, speculative and unconvincing. The UAW’s animal research evidence does not present the type of solid scientific data necessary for a reasonable factfinder to reach a non-speculative conclusion that a father’s exposure to lead presents the same danger to the unborn child as that resulting from a female employee’s exposure to lead. The facts the UAW posits do not negate the conclusion that the harm lead exposure causes to the unborn child is “substantially confined to female employees.” Accordingly, we are convinced that the UAW has failed to present facts sufficient to carry its burden of demonstrating the absence of the second element of Johnson Controls’ business necessity defense, application of the risk of transmitting lead exposure to unborn children only through females. This recognition of the physical differences between the human sexes creates a distinction between men and women that accords with our previous recognition that Title VII permits distinctions based upon the real sex-based differences between men and women, especially those related to child birth. As we observed in Torres v. Wisconsin Dept. of Health and Human Social Services, 859 F.2d 1523, 1527-28 (7th Cir.1988) (en banc): “ ‘Myths and purely habitual assumptions about a woman’s [or a man's] inability to perform certain kinds of work are no longer acceptable reasons for refusing to employ qualified individuals, or for paying them less.’ City of Los Angeles Department of Water and Power v. Manhart, 435 U.S. 702, 707 [98 S.Ct. 1370, 1374, 55 L.Ed.2d 657] (1978). On the other hand, there are real as well as fictional differences between men and women. Id. For instance, the Supreme Court has never hesitated to recognize sex-based differences, particularly in cases involving physiology, marriage, childbirth, or sexuality. See Michael M. v. Superior Court of Sonoma County, 450 U.S. 464, 469 [101 S.Ct. 1200, 1204, 67 L.Ed.2d 437] (1981) (‘[TJhis Court has consistently upheld statutes where the gender classification is not invidious, but rather realistically reflects the fact that the sexes are not similarly situated in certain circumstances.’); id. at 481 [101 S.Ct. at 1210] (Blaekmun, J., concurring) (‘The Constitution surely does not require a State to pretend that demonstrable differences between men and women do not really exist.’) See generally Parham v. Hughes, 441 U.S. 347, 354 [99 S.Ct. 1742, 1747, 60 L.Ed.2d 269] (1979) (opinion of Stewart, J.) (‘In cases where men and women are not similarly situated, however, and a statutory classification is realistically based upon the differences in their situations, this Court has upheld its validity.’); Schlesinger v. Ballard, 419 U.S. 498, 508 [95 S.Ct. 572, 577, 42 L.Ed.2d 610] (1975) (‘The different treatment of men and women ... reflects, not archaic and overbroad generalizations, but, instead, the demonstrable fact that male and female line officers in the Navy are not similarly situated with respect to opportunities for professional service.’ (emphasis in original)). This same principle has been recognized in the Title VII area. See, e.g., Backus v. Baptist Medical Center, 510 F.Supp. 1191, 1195 (E.D. Ark.1981), vacated because of mootness, 671 F.2d 1100 (8th Cir.1982) (recognizing the need to have female registered nurses care for obstetrical patients); see also I A. Larson & L. Larson, Employment Discrimination — Sex § 14.30 (1987) (‘[G]iving respect to deep-seated feelings of personal privacy involving one’s own genital area is quite a different matter from catering to the desire of some male airline passengers to have ... an attractive stewardess.’)” Because scientific data available as of this date reflects that the risk of transmission of harm to unborn children is confined to fertile female employees, the sex-based distinction present in Johnson Controls’ fetal protection policy is based upon real physical differences between men and women relating to childbearing capacity and is consistent with Title VII. C. Adequate But Less Discriminatory Alternatives We are cognizant of the fact that Johnson’s fetal protection policy might very well not have been sustainable had the UAW presented facts and reasoning sufficient for the trier of fact to conclude that “there are ‘acceptable alternative policies or practices which would better accomplish the business purpose ... [of protecting against the risk of harm], or accomplish equally well with a lesser differential ... impact [between women and men workers].’ ” Olin, 697 F.2d at 1191 (quoting Robinson v. Lorillard Corp., 444 F.2d 791, 798 (4th Cir.), cert. dismissed, 404 U.S. 1006, 92 S.Ct. 573, 30 L.Ed.2d 655 (1971)). As an initial matter, we must determine whether the UAW has preserved this issue for appeal. The UAW’s brief explicitly admits that “the plaintiffs did not respond to the defendant’s allegations that it had considered a number of alternatives [to its fetal protection policy],” UAW Brief at 37 n. 14, and fails to present any of its own alternatives. Federal Rule of Appellate Procedure 28(a)(4) provides, in relevant part, that: “The brief of the appellant shall contain under appropriate headings and in the order here indicated: ... (4) an argument. ... The argument shall contain the contentions of the appellant with respect to the issues presented, and the reasons therefor, with citations to the authorities, statutes and parts of the record relied on.” In Zelazny v. Lyng, 853 F.2d 540, 542 n. 1 (7th Cir.1988), we observed that: “We have said that an appellant is required by Rule 28(a)(4) of the Federal Rules of Appellate Procedure to present in his brief to the appellate court the issues that he desires to litigate and to support his arguments on those issues with appropriate judicial authority. See Beard v. Whitley County REMC, 840 F.2d 405, 408 (7th Cir.1988). ‘ “It is not the obligation of this court to research and construct the legal arguments open to parties especially when they are represented by counsel.” ’ Id. at 408-09 (quoting Sanchez v. Miller, 792 F.2d 694, 703 (7th Cir.1986), cert. denied, 479 U.S. 1056, 107 S.Ct. 933, 93 L.Ed.2d 984 (1987)). Mr. Zelazny’s conclusory remarks about his lack of diligence without any further argument on the issue and without any attempt to offer a justification for his delay do not comply with the strictures of Rule 28(a)(4). Therefore, even if Mr. Zelazny disputes the district court’s determination of inexcusable delay, he has waived any argument on that issue.” The UAW’s failure to specifically articulate a less discriminatory alternative argument in the manner required in Federal Rule of Appellate Procedure 28(a)(4) means that it has failed to adequately present this issue to this court. Even were we to conclude that the UAW had preserved this issue for appeal, we would be constrained to hold that the UAW failed to present facts sufficient for a trier of fact to conclude that less discriminatory alternatives would equally effectively achieve an employer’s legitimate purpose of protecting unborn children from the substantial risk of harm lead exposure creates. In Wards Cove Packing Co. v. Atonio, — U.S. -, 109 S.Ct. 2115, 2126-27, 104 L.Ed.2d 733 (1989), the Supreme Court recently explained the burden a Title. VII plaintiff must carry in order to establish that an employer’s policy is invalid on the basis of the availability of less discriminatory alternatives: “[I]f ... [plaintiffs] cannot persuade the trier of fact on the question of [the employer’s] business necessity defense, [plaintiffs] may still be able to prevail. To do so, [plaintiffs] will have to persuade the factfinder that ‘other tests or selection devices, without a similarly undesirable racial effect, would also serve the employer’s legitimate [hiring] interest^];’ by so demonstrating, [plaintiffs] would prove that ‘[the employers were] using [their] test merely as a “pretext” for discrimination.’ Albemarle Paper Co. [v. Moody], 422 U.S. 405, 425, 95 S.Ct. 2362, 2375, 45 L.Ed.2d 280 [ (1975) ]; see also Watson, 487 U.S. at-[108 S.Ct. at 2780] (O’Connor, J.); Id., at-[108 S.Ct. at 2781] (Blackmun, J.). If [plaintiffs], having established a prima facie case,