N.H. Rev. Stat. Ann. § 125-S:1

The general court finds that emissions of air contaminants from motor vehicles represent a potential serious health problem to the citizens of New Hampshire and a threat to the air quality of the state. The purpose of this chapter is to establish a fund to be used for costs incurred by the department of environmental services in the prevention and abatement of emissions of air contaminants from motor vehicles registered for on-road use in the state of New Hampshire.