There are three types of commonly used poison cartridges and canisters: A/K/E. It turns out that the 3/4/7 filter cartridges in the 1995 standard.

1. According to GB2890-2009 "Self-priming Filter Gas Masks", the gas filter boxes are divided into various types such as A, B, K, E according to the protective gas. Among them, the following three categories are commonly used.

A: Protection against organic gases, such as acetone, benzene, chloropicrin, etc.

K: Ammonia, organic derivatives of ammonia and other alkaline gases.

E: Anti-chlorine, sulfur dioxide, hydrogen sulfide, nitrogen oxides and other acidic gases.

2. The selection of gas masks and gas filter boxes also depends on the concentration of harmful gases. The anti-virus levels of the poison filter box are divided into levels 1, 2, 3, and 4. Among them, level 4 is high and level 1 is low.

There are still many gas masks that still say they have been certified to the 1995 standard. At present, gas masks have implemented new standards.

The label is GB2890-2009