In dry and cold climates, sometimes powder-like substances may appear on the surface of anti-rust films. Why is this so? Are these substances harmful to the human body?

In dry and cold climatic conditions, the appearance of powder-like substances on the surface of VCI anti-rust films is due to the physical changes of the vapor phase anti-rust agent (VCI particles) in the anti-rust films under low-temperature or dry conditions. VCI rust inhibitors are usually embedded in the film material in the form of particles or tiny crystals. These rust prevention particles form a protective atmosphere by volatilizing into the interior of the packaging. When the temperature is too low or the humidity is too low, the evaporation and release of rust inhibitors are restricted, and some rust inhibitors may precipitate from the surface of the film, forming white or powder-like substances. This phenomenon is particularly common in winter when the ambient temperature is low and the air humidity is low, or in dry areas. As for whether these powdered substances are harmful to the human body, generally speaking, VCI rust inhibitors are non-toxic or have low toxicity, and most VCI products have passed safety certifications. However, long-term exposure to high concentrations of VCI gas or powder may irritate the respiratory tract. Therefore, it is best to avoid direct inhalation of the powder when in contact and operate in a well-ventilated environment. Generally speaking, these powdered substances usually do not cause significant harm to the human body, but excessive contact should still be avoided, especially when used in a closed space. It is recommended to take appropriate safety precautions, such as wearing masks or gloves.