N.H. Rev. Stat. Ann. § 143:13

In case any establishment, or any part thereof, licensed hereunder shall be deemed by the commissioner of the department of health and human services to be conducted in an insanitary manner, or there shall be any practice deemed in violation of any law, or of any legally adopted rule or regulation of the commissioner, it shall be the duty of the commissioner to notify the licensee or registrant concerned, and in case the required changes in conditions, methods, composition or branding are not effected within a reasonable time, to close such establishment or part thereof, or to suspend, revoke or cancel the license or registration accordingly as the commissioner may deem expedient.