If an employee is exposed to chlorine or some other substance at work and oxygen is administered as a purely precautionary measure, is the case recordable?

From the National Association of Manufacturers (NAM) legal challenge to OSHA’s Recording and Reporting regulations:

“If oxygen is administered as a purely precautionary measure to an employee who does not exhibit any symptoms of an injury or illness, the case is not recordable. If an employee exposed to a substance at work exhibits symptoms of an injury or illness, the administration of oxygen makes the case recordable.”