How should entry into a B28 mechanical room be controlled?

• A. Access unrestricted to all staff
• B. Access restricted to supervisors only
• C. Access restricted to trained personnel; use signage, door interlocks, and LOTO when necessary
• D. Access allowed only during maintenance windows

Answer: (C)

Access to a B28 mechanical room that contains flammable-refrigerant equipment must be limited to people who are trained to work with these hazards, and safety controls should be in place to prevent exposure or ignition. The best approach is to restrict entry to trained personnel and use practical safeguards such as proper signage to communicate the hazards and access requirements, door interlocks to prevent unauthorized or accidental entry, and lockout/tagout procedures when maintenance could energize equipment or release energy. This combination ensures that anyone entering understands the risks, is protected from unexpected equipment energization, and cannot start or release energy during servicing.

Unrestricted access would expose untrained individuals to ignition sources, refrigerant release risks, and other hazards. Limiting entry to supervisors only is too narrow because many trained technicians or operators may perform necessary tasks. Allowing entry only during maintenance windows ignores the need for routine inspections, urgent maintenance, or emergency access, which could be required outside those windows.