Making sure a building has a code-compliant emergency door lock system in place is very important for the functioning of a business and is required by law. The Occupational Safety and Health Administration (OSHA) and the National Fire Protection Association (NFPA) both set specific standards for how and when emergency doors should be locked. This is for the safety of the employees and the general population.
Emergency exit door locks serve two primary purposes. They prevent unauthorized access to a building and expedite an emergency exit from the building. They are required worldwide in compliance with local codes and fire safety procedures.
Designing an Emergency Locking System
The task of designing a locking system requires that the right considerations be made for locking the door when needed while making sure it will be unlocked in the direction of egress in case of emergency. Whether you are assessing existing locking arrangements to determine compliance or designing a new system to put in place, it is essential to follow OSHA and NFPA guidelines.
OSHA establishes standards regarding emergency exit procedures, and locking arrangements are part of these requirements. Any door that is an exit door must be unlocked from the inside, and individuals must be able to open it at any time with no special knowledge or tools. The only situation where a door can be locked from the inside is in correctional, penal, or mental facilities and under close supervision.
The locking requirements of the NFPA 101, also known as the Life Safety Code, requires that locking arrangements be made so that the door can only be unlocked with the right key or credential from the outside, and unlocked automatically and without the use of a key from the inside. This ensures only the right people have access to the building or specific areas.
Additionally, the mechanism that unlocks and unlatches the door from the inside should not require any prior or specialized knowledge. It should be easy to use for anyone, properly lit, and marked as an emergency exit. There are three main locking systems highlighted in the NFPA 101: Delayed-egress, access-controlled egress, and electrically controlled egress locking systems.
1. Delayed-Egress Locking Systems
Doors fitted with a delayed-egress locking system do not open when the exit bar is engaged for a set amount of time, usually 15 to 30 seconds. In that time, an alarm will sound, notifying the appropriate parties of an attempted unauthorized exit. Often, businesses choose this locking system when trying to protect their product.
Delayed-egress locking systems are allowed in buildings that are entirely protected for fire, including having a sprinkler and fire detection system. The door must also automatically unlock if either of those two systems is activated or if the power goes out.
2. Access-Control Locking Systems
Access-Control locking systems use of a sensor on the egress side of the door. This sensor detects when an occupant is walking toward the door and unlocks automatically. As a failsafe, a clearly labeled redundant manual release must be placed by the door, which, if engaged, unlocks the door for at least 30 seconds.
While the door for these systems must also automatically unlock in case of fire, sprinkler protection is not mandatory. However, if the building does have a sprinkler system, the door must also unlock if it’s activated. The door must also automatically unlock in the case of power loss to either the locking system or the motion sensor.
3. Electrically Controlled Egress Locking Systems
An electrically controlled door is not considered a special locking arrangement. The door features hardware that unlocks the door when activated. The built-in switch disrupts the power to the locking mechanism temporarily.
This is best for situations where the door egress works in one direction. The exit is easily opened from the inside, but the door cannot be opened from the outside by unauthorized personnel who can unlock the door using an RFID or key card. The door also unlocks when power to the locking mechanism is lost.
It is essential to understand the difference between locking systems when choosing a door lock, designing an egress system, or assessing new locking arrangements. OSHA and NFPA guidelines are established to protect employees and patrons in case of an emergency, and most other regulations follow these recommendations.