Continental Tire Americas LLC (CTA) builds tires in downstate Mount Vernon. The Mount Vernon plant has a health-services department that provides medical treatment to sick or injured employees. In April 2010, Jeff Phillips visited the department to report that his fingers went numb at work and to start a workers’ compensation claim. CTA required drug-testing in certain situations: 1) Pre-employment testing; 2) random testing for the initial 12 months of employment; 3) for-cause testing; 4) OSHA recordable …