1805.2.3.4 Pyrophoric Liquids and Class 3 Water-Reactive Liquids
Pyrophoric liquids and Class 3 water-reactive liquids in containers greater than 0.5-gallon (2 L) but not exceeding 5.3-gallon (20 L) capacity shall be allowed at workstations when located inside cabinets and the following conditions are met:
1. Maximum amount per cabinet: The maximum amount per cabinet shall be limited to 5.3 gallons (20 L).
2. Cabinet construction: Cabinets shall be constructed in accordance with the following:
2.1. Cabinets shall be constructed of not less than 0.097-inch (2.5 mm) (12 gage) steel.
2.2. Cabinets shall be permitted to have self-closing limited access ports or noncombustible windows that provide access to equipment controls.
2.3. Cabinets shall be provided with self- or manual-closing doors. Manual-closing doors shall be equipped with a door switch that will initiate local audible and visual alarms when the door is in the open position.
3.1. The system shall be designed to operate at a negative pressure in relation to the surrounding area.
3.2. The system shall be equipped with a pressure monitor and a flow switch alarm monitored at the on-site emergency control station.
4. Cabinet spill containment: Spill containment shall be provided in each cabinet, with the spill containment capable of holding the contents of the aggregate amount of liquids in containers in each cabinet.
5. Valves: Valves in supply piping between the product containers in the cabinet and the workstation served by the containers shall fail in the closed position upon power failure, loss of exhaust ventilation and upon actuation of the fire control system.
6. Fire detection system: Each cabinet shall be equipped with an automatic fire detection system complying with the following conditions:
6.1. Automatic detection system: UV/IR, high- sensitivity smoke detection (HSSD) or other approved detection systems shall be provided inside each cabinet.
6.2. Automatic shutoff: Activation of the detection system shall automatically close the shutoff valves at the source on the liquid supply.
6.3. Alarms and signals: Activation of the detection system shall initiate a local alarm within the fabrication area and transmit a signal to the emergency control station. The alarms and signals shall be both visual and audible.