Does the storage cabinet need ventilation?

Do storage cabinets need ventilation from a safety risk perspective? The following explanations are given in several commonly used standards.

Based on the purpose of the storage cabinet -4 (to achieve a fire resistance rating of at least 10 minutes in the event of a fire, allowing personnel to evacuate or use firefighting facilities), NFPA 30 stipulates that storage cabinets cannot be ventilated, but at the same time, it states that if ventilation is required inside (such as by regulatory authorities), it should be discharged to a safe outdoor location or led to a VOC treatment system, but it should not affect the fire performance of the storage cabinet.

EN14470-1 specifies that storage cabinets should be equipped with air inlet and outlet ports, which can lead to the exhaust treatment system, and also requires the ventilation system to meet a minimum of 10 air changes per hour. At the same time, it is required that the air inlet and outlet of the storage cabinet can automatically close when the temperature reaches 70 ± 10 ℃.

Although FM6050 does not specify ventilation requirements, it requires testing of storage cabinets in accordance with EN14470-1 (including ventilation systems).

UL1275 only stipulates that storage cabinets need to be equipped with ventilation interfaces.

According to the Australian standard AS/NZS 2243.10, ventilation is generally not required unless it is necessary for risk control measures. If ventilation is used for risk control measures (such as for volatile substances, highly toxic substances, or corrosive substances), it needs to be discharged to a safe outdoor location. The air duct needs to have the same fire resistance rating as the storage cabinet. In addition, each storage cabinet needs to be individually ventilated to prevent interlocking and the spread of fire.

In summary, the European standard EN14470-1 and the Australian standard AS/NZS 2243.10 clearly stipulate (or under certain conditions) the need for a ventilation system to control the risk of chemical leakage in storage cabinets. NFPA 30 stipulates from a fire prevention perspective that ventilation is not allowed. One major reason for such differences is cost. If both ventilation and fire protection requirements are met, such fireproof cabinets are usually expensive. If we look at it from a risk control perspective, the first accident case shows that if the storage cabinet has an effective ventilation system, it can prevent flammable liquid storage cabinets from catching fire and exploding. Therefore, I personally believe that the need for ventilation should be based on risk assessment, such as equipping effective ventilation systems for flammable liquids and highly volatile toxic/corrosive substances, and managing them as important control measures. 

Common problems during the use of storage cabinets. Due to the current requirement in China for storage cabinets to be connected to exhaust gas treatment systems, many companies' laboratory storage cabinets have their ventilation systems connected to devices such as activated carbon adsorption or spray towers for VOCs treatment. But at the same time, it also brings the following typical risks.

·Several storage cabinet air ducts are connected to the main pipe and enter the exhaust gas treatment system, but the risk of backfire and interconnection has not been considered.

·Most of the air ducts are made of non-metallic materials (such as PP pipes), which results in insufficient fire resistance and poses a risk of static electricity.

·Although there is a ventilation system, the effectiveness of the ventilation system is poor, and there is still a strong smell when opened. The ventilation system design and calculation have not been well done.

·Storage is not standardized, and the incompatibility between chemicals has not been considered.

Summarize

1. A systematic strategy is required for the management of chemical storage cabinets, taking into account both exhaust gas treatment and the new safety risks that may arise.

2. Storage cabinets storing flammable liquids should be grounded to static electricity as much as possible, while other types of storage cabinets may not consider static electricity grounding from a risk perspective.

3. For highly volatile toxic and corrosive substances, it is recommended to use a ventilation system as a risk control measure to prevent the formation of explosive environments and personnel exposure risks after leakage.

4. It is recommended to carry out corresponding systematic design for the ventilation system, including fan selection and air volume calculation.

5. After adding a ventilation system to the storage cabinet, a systematic risk assessment is required to identify relevant hazards and control any new risks that may arise