N.H. Rev. Stat. Ann. § 228:10

No member of the department shall act as agent or representative, or engage in private consulting work for, or involving, any contractor, architect, engineer, firm or individual engaged, or interested in the performance of state contracts or whose business includes the manufacture or furnishing of equipment, materials or supplies to the state. No member of the department shall, acting as a private individual, solicit or engage in consulting or other engineering work for political subdivisions of the state. Violation of this section shall be cause for dismissal or other disciplinary action, subject to such appeal as may be provided by law.