What are the signs that a pesticide has gone bad? Here's how to store it properly

Pesticides are a type of chemical agent commonly used in our pesticide production process to control pest and disease infestation, and the state has very strict requirements for their use. In actual production, some farmers buy pesticides and leave them for a long time, by which point they have actually deteriorated or lost their efficacy. So what are the signs that a pesticide has gone bad? How should it be stored?

1. What are the signs that a pesticide has gone bad?

1. Hot-water dissolution method: Put the emulsifiable concentrate pesticide with sediment, bottle and all, into warm water at 50°C. After 1 hour, if the sediment slowly dissolves, it means the pesticide has not yet lost its efficacy. If the sediment is very difficult to dissolve or does not dissolve, then the pesticide has already deteriorated and lost its efficacy.

2. Shaking method: When an emulsifiable concentrate pesticide shows oil-water separation, shake it forcefully, shake the bottle, and let it stand for 1 hour. If a separated layer still appears, it means the pesticide has already lost its efficacy.

3. Floating method: Take 1 gram of wettable powder pesticide and sprinkle it evenly on the surface of 200 milliliters of clean water. If it becomes wet and sinks into the water within 1 minute, it is a pesticide that has not lost its efficacy; otherwise, it is a pesticide that has lost its efficacy.

4. Dilution method: Take 100 grams of emulsifiable concentrate pesticide and put it into a glass bottle with 300 grams of water. Shake forcefully, and after letting it stand for half an hour, if the concentration of the pesticide liquid is uneven, with emulsifiable oil appearing on top and sediment at the bottom, it means the pesticide has already lost its efficacy. The more emulsifiable oil there is, the worse the efficacy.

5. Suspension method: Take 50 grams of wettable powder pesticide and put it into a glass container, add water and stir evenly. After letting it stand for 10 minutes, if the pesticide has poor solubility and the suspended powder particles are coarse, it is a pesticide that has lost its efficacy.

2. How should pesticides be stored?

1. Prevent exposure to sunlight. Pesticides contained in brown bottles generally need to be stored away from light. If pesticides that need to be stored away from light are exposed to light for a long time, it will cause the pesticides to decompose, deteriorate and lose efficacy. For example, after emulsifiable concentrate pesticides are exposed to sunlight, their emulsifying performance becomes worse and their efficacy decreases. Therefore, when storing them, exposure to light and sunlight must be avoided; if microbial active preparations are exposed to strong light, the active bacteria will lose their activity.

2. The temperature of the place where pesticides are stored should not exceed 25°C, and even more attention should be paid to keeping them away from fire sources to prevent the agents from decomposing efficiently; the storage of microbial-source pesticides requires special attention. At low temperatures, attention should be paid to preventing freezing, and the temperature should be kept above 1°C; a common way to prevent freezing is to use broken firewood and grass, chaff husks or unused cotton quilts as covering for insulation.

3. Pesticides with strong volatility should be sealed to prevent volatilization from reducing efficacy, polluting the environment and harming human health. A small amount of pesticide that has lost efficacy or is left over must not be poured out casually in fields or at field edges, and even more so must not be poured into ponds, streams, rivers or wells; nor should it be used after arbitrarily increasing the concentration. It should be deeply buried to avoid polluting the environment.

4. Pesticides should be stored together in one place and marked clearly. If a bottled pesticide breaks, it should be repackaged properly and labeled to prevent misuse.

5. Pesticides must not be stored in the same room as grain, oil, beans, seeds, vegetables, food or animal feed, and special attention should be paid to not placing them where children can reach them.

6. Powder pesticides should be placed in a dry place to prevent them from absorbing moisture, caking and losing efficacy.

7. Store by category. According to acidity and alkalinity, pesticides can be divided into three major categories: acidic, alkaline and neutral. These three types of pesticides should be stored separately, not too close to each other, to prevent the pesticides from deteriorating; they also must not be stored together with alkaline substances, ammonium bicarbonate, ammonium nitrate, etc.

8. Do not store pesticides together with flammable and explosive items, such as fumigants, gasoline, etc., to prevent causing fire.