Which type of license is required to handle substances that produce gas, vapors, and fumes?

To handle substances that produce gas, vapors, and fumes, a Restricted Pesticide License is required. This is because a Restricted Pesticide License specifically covers the handling of substances that produce gas, vapors, and fumes, whereas the other options do not have this specific designation. Option B, the Fumigant Handling License, may seem like a possible correct answer, but it is not as comprehensive as the Restricted Pesticide License. Option C, the General Pesticide Applicator License, and Option D, the Commercial Pesticide Certification, do not have the same restrictions and regulations as the Restricted Pesticide License. Thus, while these options may cover the use of pesticides, they do not necessarily apply to substances that produce gas, vapors, and fumes.