Final answer:
Secondary labels for chemical containers should include the full name and concentration of the chemical, which is essential for proper identification and risk assessment in accordance with OSHA guidelines.
Step-by-step explanation:
When working with potentially hazardous materials in a laboratory, proper labeling is crucial for safety. According to OSHA's guidelines, a secondary label for a chemical container should at least include certain information for safety compliance. The correct answer to the student's question regarding what information is required on a secondary label is C. Full name and concentration of chemical. This ensures proper identification and risk assessment when handling the chemical. It's important to note that while other details such as the name of manufacturer, Permissible Exposure Limits (PEL), and emergency phone number are critical, they are generally found on the primary label or safety data sheets (SDS) that accompany the chemical container.