1. "Please wear your personal protective equipment (PPE) such as safety helmet, gloves and glasses before entering the workshop."

2. "It is compulsory to wear a safety helmet in the workshop for your own safety."

3. "To ensure your safety, all workers must wear a safety helmet while in the workshop."

4. "Safety first! Please wear a safety helmet to prevent any potential risks in the workshop."

5. "For your own protection, all personnel are required to wear a safety helmet when working in the workshop."