Warning signs.
As you no doubt know the safety rules in the Occupational Safety Health Act (OSHA) usually apply only in the work place. Namely, between employer and employee. OSHA makes the employer responsible only for worker safety. But as in life, there are exceptions.
OSHA section 29 CFR 1910.145 says warning signs safety rule applies to workers and the general public. Yup, you read that correctly. OSHA safety warning signs applies to the general public as well. Not just between employer and employee.
The purpose of warning signs is to alert the worker AND general public of hazards which may not be readily apparent. You have seen warning signs on electrical boxes warning of the hazard of electrocution. You have also no doubt seen signs in public swimming pools about shallow water, no diving.
Warning signs are simple and easy to implement to safe guard all (workers and the general public) from hazards. Use warning signs to keep everyone safe.