SN/T 5294-2021 in English

Interpretation of the core content of the standard

This standard innovatively establishes a fire protection classification system for customs laboratories, which divides flammable liquids into six levels (IA-IIIB) according to flash point and boiling point, and divides them into four fire hazard levels (AD) according to the usage/storage volume. Among them, IA-level liquids (flash point <22.8℃ and boiling point <37.8℃) have the highest fire risk.

Key data comparison

Technical Points Analysis

1. Ventilation System Design

The standard requires that the wind speed of the fume hood surface must ensure that the gas is completely discharged, and the placement should avoid the exit channel. It is specially stipulated that when the exhaust duct passes through different fire protection zones, its fire resistance limit must match the highest level of the zone.

2. Special requirements for fire extinguishing systems

It is clearly prohibited to use a water sprinkler fire extinguishing system. It is recommended to use a special dangerous goods fire extinguishing system (in accordance with GB 50151) and a waterless automatic fire extinguishing system (in accordance with GB 50370). For Class A laboratories storing Class IA liquids, a dual alarm system must be installed.

Implementation recommendations

1. Graded control: It is recommended that laboratories establish a liquid classification ledger and use color labels to distinguish different hazard levels (such as red for Class IA)
2. Ventilation optimization: Test the wind speed of the fume hood every quarter, and the maintenance record should include key parameters such as average wind speed and inspection time
3. Emergency drills: Develop special drill plans for different levels of fire scenarios, and Class A laboratories should conduct drills at least twice a year
4. Equipment management: Temperature control equipment must be equipped with double protection, such as electric heating devices must be equipped with over-temperature cut-off switches