Is it a safety warning sign that non-staff members are not allowed to enter?

No entry for non-staff is a safety warning sign.

No entry sign for non-staff is a kind of safety warning sign, which is used to remind people to prohibit non-staff from entering an area. Such signs will be set at the entrance of the dangerous area to prevent unauthorized personnel from entering the dangerous area. The purpose of this sign is to protect personnel safety and avoid accidents. Non-staff entry signs are not set to maintain the safety order of the workplace and ensure that only trained and authorized personnel can enter the relevant areas. The use of this sign is a common safety management measure, which can effectively reduce potential safety hazards.