The full case caption appears at the end of this opinion.
The Road Sprinkler Fitters Union, Local 669 represents all sprinkler fitters and their apprentices employed by Grinnell Fire Protection Systems Company. The Union went on strike against Grinnell in 1994 when their collective bargaining agreement expired, and Grinnell continued its operations with nonstriking Union employees and non-Union replacement workers. After Grinnell provided payroll information but refused to provide names and home addresses of employees in the Union’s bargaining unit, the Union filed unfair labor practice charges asserting Grinnell failed to provide relevant bargaining information. Following a hearing, an administrative law judge (ALJ) held Grinnell engaged in an unfair labor practice by failing to bargain in good faith when Grinnell refused to provide the Union with the names and home addresses of bargaining unit employees, including strike replacements. The ALJ held the information was presumptively relevant, and found Grinnell failed to show the information was either irrelevant or requested in bad faith. The National Labor Relations Board affirmed the ALJ’s decision and ordered Grinnell to provide the requested information. Grinnell Fire Protection Sys. Co. & Road Sprinkler Fitters, Local Union No. 669, 332 N.L.R.B. 120 (2000). Grinnell petitions for review, and the Board cross-applies for enforcement. We review the Board’s factual findings for substantial evidence on the record as a whole, and review its legal conclusions for rationality and consistence with the National Labor Relations Act. Chicago Tribune Co. v. NLRB, 79 F.3d 604, 607 (7 th Cir. 1996) (holding employer did not commit unfair labor practice in refusing to disclose replacement employees’ home addresses).