What are the commonly used gas fumigants
There are more than 20 kinds of commonly used gas fumigants, such as bromethane (Ernbafurne), calcium disulfide (Carbon disulphide), propylene oxide, hydrocyanic acid (Zyklon), aluminum phosphide (phostoxin), hydrocyanic acid (Zyklon), Calcium Hydroxide (Cyanogas), Carbon Tetrachloride (Carbontetrchloride), Chloropicrin (Chloropicrin), Dichloroethane (Chlorasol), Dibromoethane (EDB), Trichloroacetonitrile (Tritox), p-dichlorobenzene (PDB ), phosphine, bromoformaldehyde, dichlorvos (DDVP), etc.Fumigants
are a class of pesticides that use the vapor generated during volatilization to kill harmful organisms. The gaseous molecules enter the body of harmful organisms and play a poisonous role, which is different from gasified liquid, solid or compressed gas. The dosage is calculated according to the space volume of the fumigation place (unit is g/m³), and the concentration is determined according to the fumigation time, the airtightness of the fumigation place, the amount of fumigant, and the adsorption capacity of fumigant vapor. It should be applied in closed or nearly closed conditions such as warehouses, tents, houses, carriages, and ship cabins. It can effectively eliminate hidden pests or germs when a large number of fumigated objects are concentrated.
What does fumigant
The fumigant vapor generally enters the respiratory system directly through the pest's epidermis or stomata, thereby penetrating into the blood to poison the pest to death. Its insecticidal effect is generally believed to lie in the chemical action on enzymes. For example, methyl bromide can combine with sulfhydryl to cause gradual and irreversible inhibition of various enzymes in the pest body. Phosphine inhibits the central nervous system of animals, stimulates the lungs and causes edema, resulting in cardiac swelling syndrome. The mechanism of action of phosphine on insects is mainly to inhibit the activity of cytochrome C oxidase and catalase in insects, block the respiratory chain of insects and cause death by suffocation and accumulation of cytotoxins such as peroxides in insects. Fumigants
such as trichloroethane, dibromoethane, and carbon tetrachloride are mainly anesthetics, while carbon dioxide is mainly used for asphyxiation.
Harm of pesticide fumigant to human body
Scientists used animal experiments a long time ago to infer the degree of its impact on the human body from the animal's response to the fumigant. At present, the toxicity of fumigation to the human body can be roughly divided into three types: acute poisoning, subacute poisoning and slow poisoning.
The so-called acute poisoning refers to some fumigants that are more toxic and produce relatively quickly, such as methyl bromide or chloropicrin. After these fumigants are ingested into the human body by mistake or through the skin, obvious poisoning symptoms will appear immediately, such as dizziness, Nausea, vomiting, dyspnea, incontinence, etc. Poisoning by these fumigants often causes disability or even death.
The manifestation time of subacute poisoning is later than that of acute poisoning. It usually takes a period of time from touching the poison to the manifestation, and it is the same as acute poisoning after the manifestation. The occurrence of subacute poisoning is mostly due to the long-term contact with a small amount of fumigants by the staff, which will appear after accumulation to a certain extent.
Slow poisoning refers to the fact that the fumigant
itself is not highly toxic but has a strong cumulative effect. The judgment of slow poisoning is mainly carcinogenic, teratogenic, and mutagenic. In clinical practice, it is necessary to investigate the genetic variation, multi-generational reproduction status, and frequency of occurrence of freaks, etc. to do detailed research on the effects of individual traditional Chinese medicines that have survived for 2-6 months or even several generations in white mice.
Personnel engaged in fumigation work must have a clear understanding of the protective measures of the chemicals used in fumigation. Technicians with skilled fumigation skills and clear thinking are responsible for the fumigation work; skilled workers are responsible for the actual operation. If there are no skilled workers, you must organize complete and thorough training before you can start working. People with heart disease, lung disease, liver disease, skin disease, skin damage, pregnant, lactating, menstruating women and minors under the age of 18 are prohibited from fumigation. During the fumigation process, it is necessary to wear a full-face gas mask and select a suitable canister according to the characteristics of the fumigant. If the agent is corrosive to the skin, it is necessary to wear an airtight fully enclosed chemical protective suit and an air respirator. The 800 filter gas mask is equipped with Type B No. 1 canister or Type A No. 3 canister, which can resist the damage of most fumigants to the respiratory tract. For fumigants that are corrosive to the skin, fully enclosed three-level chemical protective clothing should be used, and air respirators should be deployed to achieve all-round protection for the human body.
In the work of fumigants, if the powder or liquid accidentally infects the skin, it should be rinsed with plenty of water immediately. Whenever any kind of work is carried out in a toxic environment, there should be at least two people present. When someone is poisoned, it is necessary to take emergency first aid measures and be sent to the hospital for treatment.