The National Institute of Standards and Technology (NIST) Fire Department is tasked with the inspection and maintenance of portable fire extinguishers on the NIST Gaithersburg, MD Campus. Part of the ... The National Institute of Standards and Technology (NIST) Fire Department is tasked with the inspection and maintenance of portable fire extinguishers on the NIST Gaithersburg, MD Campus. Part of the maintenance of fire extinguishers is the hydrostatic test and refilling of the fire extinguisher. This is a required process per National Fire Protection Association (NFPA), Occupation Safety Health Administration (OSHA). The NFPA 10 code and OSHA 29 CFR 1910.157.