Factors Affecting the Efficacy of Disinfectants

　　 1. Disinfectant concentration and contact time

　　Disinfection should be carried out according to the dilution concentration and contact time specified in the instruction manual approved by the Ministry of Agriculture. Do not increase the dilution ratio arbitrarily. Before disinfection, the surface of the disinfection object, such as the ground and walls, should be kept dry. If there is water on the ground, it will dilute the prepared disinfectant, failing to reach the required concentration. This should be paid more attention to when flushing the livestock house. It must be dried before disinfection. During disinfection, allow the disinfectant to completely wet the surface of the object. For disinfection of dry or high-temperature ground, due to rapid evaporation, the amount of disinfectant used needs to be increased, and the ground should be kept moist for the required disinfection time.

　　 2. Types and quantities of microorganisms

　　Different microorganisms have different resistance to disinfectants, and the number of microorganisms also affects the disinfection results. Therefore, the types and quantities of microbial contamination should be considered before disinfection. Generally, the resistance of microorganisms in the environment is ranked from strong to weak as follows: bacterial spores > fungal spores > mycobacteria > non-enveloped viruses > fungal vegetative cells > bacterial vegetative cells > enveloped viruses. When selecting disinfectants, appropriate disinfectants or combinations of disinfectants should be selected according to the microbial situation of the farm.

　　 3. Influence of environmental temperature on the effect of disinfectants

　　Generally speaking, the higher the temperature, the better the effect. In winter when the temperature is low, the temperature should be increased by 2℃～3℃ as much as possible to enhance the disinfection effect and reduce the stress on animals caused by disinfection.

　　The influence of temperature changes on disinfectants varies. Generally, when the temperature increases by 10℃, the bactericidal power can be increased by more than double. At the same time, it should be noted that temperature can change the solubility of the disinfectant itself, and has a certain influence on the stability and action time of the disinfectant. The temperature increase should not exceed the limit that the disinfectant itself can withstand, so as to avoid the evaporation or decomposition of the effective components of the disinfectant, affecting the disinfection effect. For example, iodine preparations and chlorine preparations have strong volatility, and increasing the temperature will accelerate the volatilization, which will reduce the bactericidal power.

　　 4. Influence of environmental humidity on the effect of disinfectants

　　Humidity has a great influence on fumigation disinfection. Too high or too low humidity will affect the disinfection effect. Do not fumigate immediately after flushing the livestock house with water. It needs to be aired for a while, and the fumigation should be carried out when there is no obvious standing water on the ground but it is still moist. Because only liquids can enter the microorganisms and achieve the desired disinfection effect, solids and gases cannot enter. Therefore, solid disinfectants must generally be dissolved in water, and gaseous disinfectants must be dissolved in the liquid layer around the bacteria to have a bactericidal effect. When using formaldehyde or peracetic acid gas for fumigation disinfection, the relative humidity should be 60%～80%. When using quick-acting disinfectant for fine mist droplet aerosol disinfection, if the environmental humidity is too low, the droplets themselves are only tens of micrometers, and they will evaporate quickly, affecting the action time of the disinfectant. In this case, it is necessary to spray water to increase humidity and dust removal before disinfection, or increase the amount of disinfectant per cubic meter.

　　 5. Influence of environmental pH and water hardness on disinfection effect

　　Changes in pH seriously affect the effect of disinfectants. For example, when the pH of hypochlorite solution increases from 3 to 8, the bactericidal effect is weakened. Under acidic conditions, the disinfection effect of chlorine disinfectants, iodine disinfectants, and aldehyde disinfectants is enhanced, while under alkaline conditions, the disinfection effect of cationic disinfectants such as benzalkonium chloride, and alkaline disinfectants such as caustic soda and quicklime is enhanced.

　　Since metal ions (such as Ca2+ and Mg2+) in water also affect the disinfection effect, this involves the hardness of the water used for diluting the disinfectant. For example, quaternary ammonium salt disinfectants do not have a good disinfection effect in hard water environments, and it is best to use distilled water for dilution.

　　 Quick-acting disinfectant can withstand various different water qualities, and the disinfection effect is not affected by hard water, soft water, or tap water.

　　 6. Influence of organic matter on the disinfection effect of disinfectants.

　　Common organic matter in livestock houses: urine, feces, feed residue, etc., have a mechanical blocking effect and protein protection effect on microorganisms. Therefore, mechanical removal (physical disinfection, which can remove more than 70% of microorganisms in the environment) must be carried out before disinfection, and after cleaning with water, it should be dried before disinfection, otherwise it will affect the disinfection effect.

　　 The main component of quick-acting disinfectant is organic acid, so the disinfection effect is not affected by other organic matter.

　　 Only by correctly using excellent disinfectants can daily disinfection work be done well.