Fumigant is a fumigant that we often talk about, which specifically refers to a chemical agent that can produce a gas concentration that is lethal to harmful organisms at the required temperature and pressure. This molecular state gas can penetrate into the substance being fumigated. After fumigation treatment, it can be diffused after being ventilated. Fumigation technology is widely used in plant quarantine to eliminate various pests and diseases. With the development of international trade and globalization, due to the need to control pests and avoid the destruction of biological chains, people have expanded the fumigant The scope and amount of use, but also brought about some fumigant residues to pollute agricultural products and food, posing a threat to human health, becoming a common problem worldwide and the cause of some international trade disputes. In addition, in order to obtain the ideal insecticidal and sterilizing effect, it is necessary to fully understand and master the performance and use technology of fumigants.
I. Fumigant types
1. There are more than 20 kinds of fumigants commonly used, such as methyl bromide (Ernbafurne), calcium disulphide (Carbon disulphide), propylene oxide, hydrocyanic acid (Zyklon), aluminum phosphide (phostoxin), hydrocyanic acid (Zyklon) , Cyanogas, Carbontetrchloride, Chloropicrin, Chlororasol, EDB, Tritox, P-dichlorobenzene (PDB), phosphane, bromoformaldehyde, dichlorvos (DDVP), etc.
按物理性质分： 2. According to physical properties:
Solid state, such as aluminum phosphide; Liquid state (liquid at normal temperature), such as carbon tetrachloride, chlorinated bitter, etc .; Gaseous state (gaseous at normal temperature), such as sulfuryl fluoride, bromomethane, etc., are compressed and liquefied and stored under pressure Inside the cylinder.
According to chemical substances: halogenated hydrocarbons, such as methyl bromide, carbon tetrachloride, etc .; cyanides, such as acrylonitrile, etc .; nitro compounds, such as bitter chloride, nitroethane, etc .; sulfur compounds, such as carbon disulfide, etc. ;
Phosphorous compounds, such as aluminum phosphide and calcium hydride.
Generally, the most halogenated hydrocarbon derivatives. From the application point of view, it can be divided into: low molecular weight high vapor pressure, such as methyl bromide; high molecular weight, low vapor pressure, such as bitter chloride, dichloroethane, dibromoethane and so on.
一般认为理想的熏蒸剂具有以下特点： 3. Generally believed that the ideal fumigant has the following characteristics:
① Good insecticidal effect;
； ② Lowest toxicity to animals and plants ;
； ③ Easy to produce and cheap ;
； ④ Human sensory organs are easy to detect ;
⑤ Harmless to food;
； ⑥ Non-corrosive to metal, no damage to fibers and buildings ;
； ⑦ Does not explode or burn ;
； ⑧Insoluble in water ;
； ⑨ does not deteriorate ;
； 强 Strong ability of effective penetration and diffusion ;
⑪Does not easily condense into lumps or liquids.