MR. CHIEF JUSTICE WARREN delivered the opinion of the Court.This case raises an issue of coverage under the Fair Labor Standards Act, as amended by the Portal-to-Portal Act of 1947 with respect to work performed before or after the direct or productive labor for which the worker is primarily paid.The precise question is whether workers in a battery plant must be paid as a part of their "principal" activities for the time incident to changing clothes at the beginning of the shift and showering at the end, where they must make extensive use of dangerously caustic and toxic materials, and are compelled by circumstances, including vital considerations of health had hygiene, to change clothes and to shower in facilities which state law requires their employer to provide, or whether these activities are "preliminary" or "postliminary" within the meaning of the Portal-to-Portal Act, and therefore not to be included in measuring the work time for which compensation is required under the Fair Labor Standards Act.The Secretary of Labor, contending that these activities are so covered, brought this action in the United States District Court for the Middle District of Tennessee to enjoin petitioners from violating the overtime and recordkeeping requirements of Sections 7 and 11(c) of the Fair Labor Standards Act of 1938, as amended, in the employment of production workers, and from violating Section 15(a)(1) of the Act by making interstate shipments of the goods produced by such workers.The District Court gave judgment for the plaintiff, and the Court of Appeals for the Sixth Circuit affirmed.  215 F.2d 171, 172.  Because of the importance of the interpretation of the portal-to-portal provisions in the administration of the Fair Labor Standards Act, and because of a conflict between the circuits on the subject, Mitchell v. Page 350 U. S. 249 King Packing Co., 216 F.2d 618, we granted certiorari in both cases, 349 U.S. 914.There is no question of backpay involved here, because the Court limited its judgment to prospective relief.  Nor is the question of changing clothes and showering under normal conditions involved, because the Government concedes that these activities ordinarily constitute "preliminary" or "postliminary" activities excluded from compensable work time as contemplated in the Act.  It contends, however, that such activities in the circumstances of this case are an integral and indispensable part of the production of batteries, the "principal activity" in which these employees were engaged, and are therefore compensable under the relevant provisions of the Act.The petitioners own and operate a plant where they are engaged in manufacturing automotive-type wet storage batteries which they sell in interstate commerce.  All of the production employees, such as those with whom we are here concerned, customarily work with or near the various chemicals used in the plant.  These include lead metal, lead oxide, lead sulphate, lead peroxide, and sulphuric acid.  Some of these are in liquid form. some are in powder form, and some are solid.  In the manufacturing process, some of the materials go through various changes and give off dangerous fumes.  Some are spilled or dropped, and thus become a part of the dust in the air.  In general, the chemicals permeate the entire plant and everything and everyone in it.  Lead and its compounds are toxic to human beings.  Regular exposure to atmosphere containing 1.5 milligrams or more of lead per 10 cubic meters is regarded by the medical profession as hazardous and involving the possibility of lead intoxication or lead poisoning.  In battery plants, such as this one, it is "almost impossible," it was testified, to keep lead concentration in the air "within absolutely safe limits," and, in petitioners' plant, "lead oxide was on the floor Page 350 U. S. 250 and in the air and on the plates which employees handled."  Abnormal concentrations of lead were discovered in the bodies of some of petitioners' employees, and petitioners' insurance doctor recommended that such employees be segregated from their customary duties.  The primary ways in which lead poisoning is contracted are by inhalation and ingestion, e.g., by taking in particles through the nose or mouth, an open cut or sore, or any other body cavity.  The risk is "very great," and even exists outside the plant, because the lead dust and lead fumes which are prevalent in the plant attach themselves to the skin, clothing, and hair of the employees.  Even the families of battery workers may be placed in some danger if lead particles are brought home in the workers' clothing or shoes.  Sulphuric acid in the plant is also a hazard.  It is irritating to the skin, and can cause severe burns.  When the acid contacts clothing, it causes disintegration or rapid deterioration.  Moreover, the effects of sulphuric acid make the employee more susceptible than he would otherwise be to contamination by particles of lead and lead compounds.Petitioners, like other manufacturers, try to minimize these hazards by plant ventilation, but industrial and medical experts are in agreement that ventilation alone is not sufficient to avoid the dangers of lead poisoning.  Safe operation also requires the removal of clothing and showering at the end of the work period.  This has become a recognized part of industrial hygiene programs in the industry, and the state law of Tennessee requires facilities for this purpose.  Tenn.Code Ann. (Williams 1934), 1952 Supp., Section 5788.15.  In addition, the Tennessee Workmen's Compensation Act, Tenn.Code Ann. (Williams 1934), 1952 Supp., Sections 6851-6901, which covers petitioners, makes lead poisoning a compensable occupational disease, Section 6852(d).  In order to comply with this statute, petitioners carry insurance, under Section 6895, to protect against liability, and Page 350 U. S. 251 the insurance carrier would not accept the insurance risk if defendants refused to have showering and clothes-changing facilities for their employees.Accordingly, in order to make their plant as safe a place as is possible under the circumstances and thereby increase the efficiency of its operation, petitioners have equipped it with shower facilities and a locker room with separate lockers for work and street clothing.  Also, they furnish without charge old but clean work clothes which the employees wear.  The cost of providing their own work clothing would be prohibitive for the employees, since the acid causes such rapid deterioration that the clothes sometimes last only a few days.  Employees regularly change into work clothes before the beginning of the productive work period, and shower and change back at the end of that period. [Footnote 1]Petitioners issued no written instructions to employees on this subject, but the employees testified and the foreman declared in a signed statement that,"In the afternoon, the men are required by the company to take a bath because lead oxide might be absorbed into the blood stream.  It protects the company and the employee both."Petitioners do not record or pay for the time which their employees spend in these activities, which was found to amount to thirty minutes a day, ten minutes in the morning and twenty minutes in the afternoon, for each employees.  They do not challenge the concurrent findings of the courts below that the clothes-changing and showering activities of the employees are indispensable to the performance of their productive work, and integrally related thereto.  They do contend that these activities fall without the concept of "principal activity," and that, Page 350 U. S. 252 being performed off the production line and before or after regular shift hours, they are beyond the protection of the Fair Labor Standards Act.The trial court held that these activities "are made necessary by the nature of the work performed"; that they fulfill "mutual obligations" between petitioners and their employees; that they "directly benefit" petitioners in the operation of their business, and that they"are so closely related to other duties performed by [petitioners'] employees as to be an integral part thereof, and are therefore included among the principal activities of said employees."It concluded that the time thereby consumed is not excluded from coverage by Section 4 of the Portal-to-Portal Act, but constitutes time worked within the meaning of the Fair Labor Standards Act.  The Court of Appeals affirmed, likewise holding that the term "principal activity of activities" in Section 4 [Footnote 2] embraces all Page 350 U. S. 253 activities which are "an integral and indispensable part of the principal activities," and that the activities in question fall within this category.With this conclusion, we agree.The Portal-to-Portal Act was designed primarily to meet an "existing emergency" resulting from claims which, if allowed in accordance with Anderson v. Mt. Clemens Pottery Co., 328 U. S. 680, would have created "wholly unexpected liabilities, immense in amount and retroactive in operation." [Footnote 3]  This purpose was fulfilled by the enactment of Section 2. [Footnote 4]  The trial court specifically Page 350 U. S. 254 limited the effect of this judgment to services rendered after the judgment becomes final.  We are not therefore concerned with the provisions of Section 2, which is inapplicable to actions relating to activities of employees performed after May 14, 1947.The language of Section 4 is not free from ambiguity, and the legislative history of the Portal-to-Portal Act becomes of importance.  That Act originated in a House bill, which had no provision comparable to Section 4, but rather gave similar treatment to retroactive and prospective claims, i.e., excluding coverage except by contract or custom in the industry.  H.R.Rep. No. 326, 80th Cong., 1st Sess. 12.  The Conference Report stated that the language of Section 4 follows the Senate bill.  S.Rep. No. 48, 80th Cong., 1st Sess. 48.  In the Senate, the colloquy between several Senators and Senator Cooper, a sponsor of the bill and a member of the three-man subcommittee that held hearings for the Committee on the Judiciary which reported it, demonstrates that the Senate intended the activities of changing clothes and showering to be within the protection of the Act if they are an integral part of and are essential to the principal activities of the employees. [Footnote 5]There is some conflicting history in the House, [Footnote 6] but the Senate discussion is more clear-cut and, because the Section originated in that body is more persuasive.In 1949, Section 3(o) was added to the Act. [Footnote 7]  Both sides apparently take comfort from it, but the position Page 350 U. S. 255 of the Government is strengthened by it, since its clear implication is that clothes changing and washing, which are otherwise a part of the principal activity, may be expressly excluded from coverage by agreement.  The congressional understanding of the scope of Section 4 is further marked by the fact that the Congress also enacted Section 16(c) [Footnote 8] at the same time, after hearing from the Administrator his outstanding interpretation of the coverage of certain preparatory activities closely related to the principal activity and indispensable to its performance. [Footnote 9]On the whole ,it is clear, we think, that, while Congress intended to outlaw claims prior to 1947 for wages based on all employee activities unless provided for by contract or custom of the industry, including, of course, activities performed before or after regular hours of work, it did not intend to deprive employees of the benefits of the Fair Labor Standards Act where they are an integral part of and indispensable to their principal activities.  Had Congress intended the result urged by petitioner, the Page 350 U. S. 256 very different provisions of Sections 2 and 4 would have been unnecessary; Section 2 could have been given prospective, as well as retroactive, effect.We therefore conclude that activities performed either before or after the regular work shift, on or off the production line, are compensable under the portal-to-portal provisions of the Fair Labor Standards Act if those activities are an integral and indispensable part of the principal activities for which covered workmen are employed and are not specifically excluded by Section 4(a)(1).We find no difficulty in fitting the facts of this case to that conclusion, because it would be difficult to conjure up an instance where changing clothes and showering are more clearly an integral and indispensable part of the principal activity of the employment than in the case of these employees.The judgment isAffirmed
U.S. Supreme CourtSteiner v. Mitchell, 350 U.S. 247 (1956)Steiner v. MitchellNo. 22Argued November 16, 1955Decided January 30, 1956350 U.S. 247SyllabusWorkers in a plant manufacturing wet storage batteries, in which extensive use is made of dangerously caustic and toxic materials, are compelled by vital considerations of health and hygiene and by other considerations to change clothes before and after work and to shower after work in facilities which state law requires their employer to provide.Held:  changing clothes and showering are parts of their "principal," rather than their "preliminary" or "postliminary," activities, within the meaning of § 4(a)(2) of the Portal-to-Portal Act, and the time spent in these activities must be counted in measuring the worktime for which compensation is required by the Fair Labor Standards Act.  Pp.  350 U. S. 248-256.(a) Activities performed either before or after the regular work shift, on or off the production line, are compensable under the portal-to-portal provisions of the Fair Labor Standards Act if those activities are an integral and indispensable part of the principal activities for which covered workmen are employed, and are not specifically excluded by § 4(a)(1).  P.  350 U. S. 256.(b) The conclusion here reached is supported by the legislative history of the Portal-to-Portal Act and by other provisions of the Act and amendments thereto.  Pp.  350 U. S. 253-256.(c) On the facts of this case, changing clothes and showering by these employees clearly are integral and indispensable parts of the principal activity of their employment.  Pp.  350 U. S. 249-252,  350 U. S. 256.215 F.2d 171 affirmed. Page 350 U. S. 248