There are concerns about the potential for excessive exposure of the operators of self-propelled agricultural vehicles to toxic agricultural chemicals when transporting or applying these materials, or both. A need exists for suitable procedures for determining the amount of toxic chemical contaminants in the vehicle operator environment when official testing is required.

The purpose of this practice is to provide a practical, reliable, and reproducible procedure for testing the performance of operator enclosure ventilating or air conditioning systems, or both, relative to the maintenance of safe environmental conditions with regard to toxic material contamination within the enclosure under static (laboratory) or dynamic (field) conditions, or both.