Ryan DeKeyser v. Thyssenkrupp Waupaca, Incorpor, 860 F.3d 918

Background

Waupaca operates six foundries (four in Wisconsin, two in IN/TN) where workers allege end-of-shift "foundry dust" contamination poses skin and inhalation risks.
Plaintiffs claim Waupaca required or effectively necessitated changing clothes and showering at work to reduce health risks but did not record or pay employees for that decontamination time (no regular or overtime pay).
District court conditionally certified an FLSA collective; hundreds of opt-ins joined; plaintiffs later limited state-law Rule 23 class certification to Wisconsin employees and sought decertification/transfer of IN/TN opt-ins.
This Court previously reversed summary judgment for defendant in DeKeyser I, holding decontamination might be compensable if integral/indispensable to work; case remanded for further proceedings.
On remand plaintiffs produced industrial-hygiene expert Thomas Armstrong, who testified that on-site changing and a dirty-side/clean-side shower system materially reduce contamination and associated health risk for foundry workers.
The district court certified a Wisconsin Rule 23 class and declined to keep a single multistate FLSA collective; Waupaca appealed the certification order under Rule 23(f).

Issues

Issue	Plaintiff's Argument	Defendant's Argument	Held
Class certification / commonality (Rule 23 and FLSA collective)	Common proof (Armstrong) shows all Wisconsin workers face contamination risk that is reduced by on-site decontamination, supporting classwide proof.	Individualized inquiries (varying exposures, medical histories) defeat commonality; need individual proof of benefit.	Affirmed certification for Wisconsin class: plaintiffs produced common evidence tending to prove the class claim.
Whether changing/showering is compensable "work" under FLSA (integral & indispensable)	Decontamination is necessitated by the nature of foundry work and is an integral and indispensable part of principal activities.	Such activities may not reduce risk for all workers; thus not uniformly "work" requiring compensation.	Court held question remains factual for trial; prior DeKeyser I reversed district court summary judgment; not decided here on the merits.
Sufficiency/admissibility of expert evidence supporting common proof	Armstrong's industrial-hygiene opinion shows substantial reduction in contamination from on-site decontamination across workers.	Company disputed only the weight, not admissibility, arguing variation among individuals undermines common proof.	Court found plaintiffs' expert evidence adequate to establish common questions and survive class-certification analysis; Daubert challenge not raised.
Severance/transfer of non-Wisconsin opt-ins	Plaintiffs limited Rule 23 class to Wisconsin; district court severed and ordered transfer of IN/TN opt-ins to their home districts.	Waupaca sought dismissal of non‑Wisconsin claims and contended sever/transfer improper.	Court: sever/transfer plan not reviewable on Rule 23(f) appeal; district court’s sever-and-transfer discretion under §1404(a) is acceptable; no reversible error on certification issue.

Key Cases Cited

DeKeyser v. Thyssenkrupp Waupaca, Inc., 735 F.3d 568 (7th Cir. 2013) (earlier reversal holding decontamination may be compensable and remanding summary judgment)
Steiner v. Mitchell, 350 U.S. 247 (1956) (activities that are "integral and indispensable" to principal work are compensable under FLSA)
Espenscheid v. Direct-Sat USA LLC, 705 F.3d 770 (7th Cir. 2013) (FLSA collective action/opt-in framework discussion)
Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993) (standard for admissibility of expert testimony)
Union Oil Co. of California v. John Brown E&C, 121 F.3d 305 (7th Cir. 1997) (scope of interlocutory appealability under §1292(b) and related procedural limits)
Alvarez v. City of Chicago, 605 F.3d 445 (7th Cir. 2010) (district courts' broad discretion to manage collective actions)