Which of the following is a disadvantage of high concentration active ingredients in pesticides?

High concentration active ingredients in pesticides can indeed be corrosive. This attribute poses a significant concern for safety during handling, application, and storage. Corrosive substances can damage skin, eyes, or respiratory systems if proper protective measures are not taken. In addition, they can cause corrosion to application equipment, leading to potential leaks, malfunctions, or the need for more frequent equipment replacements, which can become costly.

By contrast, reduced effectiveness or the need for bulk purchases, while they may present logistical challenges, do not fundamentally characterize the nature of high concentration active ingredients. Similarly, high concentration pesticides can often be mixed with other pesticides, provided proper guidelines and compatibility are observed. Therefore, corrosiveness is a genuine disadvantage that highlights the necessity for careful management and protective strategies in the use of high concentration active ingredients.