Which of the following is NOT a common characteristic of fumigants?

Fumigants are typically gases at room temperature, which allows them to penetrate various materials and effectively reach pests that might be hiding in cracks, crevices, and other inaccessible areas. Their gaseous state is crucial because it enables them to disperse throughout the infested space, allowing for better coverage and effectiveness.

One of the key attributes of fumigants is that they are effective against a wide range of pests, not limited to surface exposure. They are designed to work through a process where the gas is absorbed by pathogens and pests, which leads to their eradication. This type of treatment does not rely solely on surface contact, making it much more versatile in pest management.

Additionally, while inhalation of fumigants can be harmful, this characteristic reinforces the need for proper safety protocols during use. Therefore, "effective against surface pests only" does not accurately reflect the capabilities of fumigants, as they are designed to control pests that are not only on surfaces but also those that may be hidden within materials or in the air.