| N-BOD | Nitrogenous Biochemical Oxygen Demand | - | Computer Acronyms(common) |
| NAA | Nonattainment Area | - | Computer Acronyms(common) |
| NAA | Neutron Activation Analysis | - | Computer Acronyms(common) |
| NAAQS | National Ambient Air Quality Standards | - | Computer Acronyms(common) |
| NABSA | Nucleic Acid Based Sequence Amplification | - | Computer Acronyms(common) |
| NACA | National Agricultural Chemicals Association | - | Computer Acronyms(common) |
| NACCA | North American Council Of Chemical Associations | - | Computer Acronyms(common) |
| NACCHO | National Association Of County And City Health Officials | - | Computer Acronyms(common) |
| NACE | National Association Of Corrosion Engineers | - | Computer Acronyms(common) |
| NACE | Nonaq. Capillary Electrophoresis | - | Computer Acronyms(common) |
| NACEPT | National Advisory Council For Environmental Policy And Technology | - | Computer Acronyms(common) |
| NACLA | The National Cooperation For Laboratory Accreditation | - | Computer Acronyms(common) |
| NACSN | North American Commission On Stratigraphic Nomenclature | - | Computer Acronyms(common) |
| NAD | Nicotinamide Adenine Dinucleotide | - | Computer Acronyms(common) |
| NADA | New Animal Drug Application | - | Computer Acronyms(common) |
| NADAP | National Atmospheric Deposition Assessment Program | - | Computer Acronyms(common) |
| NADB | National Air Data Branch (US EPA) | - | Computer Acronyms(common) |
| NADC | National Animal Disease Center | - | Computer Acronyms(common) |
| NADC | Sodium Deoxycholate | - | Computer Acronyms(common) |
| NADH | Reduced Nicotinamide Adenine Dinucleotide | - | Computer Acronyms(common) |
| NADP | National Atmospheric Deposition Program | - | Computer Acronyms(common) |
| NADP | Nicotinamide Adenine Dinucleotide Phosphate | - | Computer Acronyms(common) |
| NADW | North Atlantic Deep Water | - | Computer Acronyms(common) |
| NAEG | Nevada Applied Ecology Group (of US Department Of Energy) | - | Computer Acronyms(common) |
| NAEP | National Association Of Environmental Professionals | - | Computer Acronyms(common) |
| NAERG | North American Emergency Response Guidebook | - | Computer Acronyms(common) |
| NAFTA | North American Free Trade Agreement | - | Computer Acronyms(common) |
| NAI | Neutral Atom Imaging (astronomical Plasmas) | - | Computer Acronyms(common) |
| NAICS | North American Industrial Classification System | - | Computer Acronyms(common) |
| NAIM | Nucleotide Analog Interference Mapping | - | Computer Acronyms(common) |
| NAIMA | North American Insulation Manufacturers Association | - | Computer Acronyms(common) |
| NAIP | Non-Apatite Inorganic Phosphorus | - | Computer Acronyms(common) |
| NAIP | Neuronal Apoptosis Inhibitory Protein | - | Computer Acronyms(common) |
| NAL | No Action Level | - | Computer Acronyms(common) |
| NAMA | National Air Monitoring Audits | - | Computer Acronyms(common) |
| NAMAS | National Measurement Accreditation Service (UK) | - | Computer Acronyms(common) |
| NAME | Nuclear Accident Modeling Exercise [a Model] | - | Computer Acronyms(common) |
| NAMF | Non-asbestos Mineral Fibers | - | Computer Acronyms(common) |
| NAMICS | North American Chapter Of The International Chemometrics Society | - | Computer Acronyms(common) |
| NAMS | National Air Monitoring Station | - | Computer Acronyms(common) |
| NAMS | Neutron Activation Mass Spectrometry | - | Computer Acronyms(common) |
| NAMT | National Advanced Manufacturing Testbed | - | Computer Acronyms(common) |
| NAO | Natural Atomic Orbital | - | Computer Acronyms(common) |
| NAPAP | National Acid Precipitation Assessment Program | - | Computer Acronyms(common) |
| NAPBN | National Air Pollution Background Network | - | Computer Acronyms(common) |
| NAPCA | National Air Pollution Control Administration | - | Computer Acronyms(common) |
| NAPIAP | National Agricultural Pesticide Impact Assessment Program | - | Computer Acronyms(common) |
| NAPIM | National Association Of Printing Ink Manufacturers (US) | - | Computer Acronyms(common) |
| NAPIS | National Agricultural Pest Information System | - | Computer Acronyms(common) |
| NAPL | Nonaqueous Phase Liquid | - | Computer Acronyms(common) |
| NAPPA | Nucleic Acid Programmable Protein Array | - | Computer Acronyms(common) |
| NAPRI | North American Pollutant Release Inventory | - | Computer Acronyms(common) |
| NARA | United States National Archives And Records Administration | - | Computer Acronyms(common) |
| NARE | North Atlantic Regional Experiment | - | Computer Acronyms(common) |
| NAREL | National Air And Radiation Environmental Laboratory | - | Computer Acronyms(common) |
| NARL | National Air And Radiation Laboratory | - | Computer Acronyms(common) |
| NARS | National Asbestos Registry System | - | Computer Acronyms(common) |
| NARSTO | North American Research Strategy For Tropospheric Ozone | - | Computer Acronyms(common) |
| NARSTO-NE-OP | North American Research Strategy For Tropospheric Ozone-Northeast Oxidant And Particle Study | - | Computer Acronyms(common) |
| NAS | National Academy Of Science | - | Computer Acronyms(common) |
| NAS | Naval Air Station | - | Computer Acronyms(common) |
| NASA | National Aeronautics And Space Administration | - | Computer Acronyms(common) |
| NASBA | Nucleic Acid Sequence-based Amplification | - | Computer Acronyms(common) |
| NASC | North American Shale Composite | - | Computer Acronyms(common) |
| NASD | National Ag Safety Database | - | Computer Acronyms(common) |
| NASDA | National Space Development Agency Of Japan | - | Computer Acronyms(common) |
| NASICON | Na Super-ionic Conductor | - | Computer Acronyms(common) |
| NASN | National Air Sampling Network | - | Computer Acronyms(common) |
| NASO | Nasmyth Adaptive Optics System | - | Computer Acronyms(common) |
| NASP | National Aerospace Plane | - | Computer Acronyms(common) |
| NASQAN | National Stream Quality Accounting Network | - | Computer Acronyms(common) |
| NASQUAN | National Stream Water Quality Accounting Network | - | Computer Acronyms(common) |
| NAT | Nitric Acid Trihydrate (polar Stratosphere Cloud Aerosol) | - | Computer Acronyms(common) |
| NATA | National Air Toxics Assessment | - | Computer Acronyms(common) |
| NATAS | North American Thermal Analysis Society | - | Computer Acronyms(common) |
| NATICH | National Air Toxics Information Clearinghouse | - | Computer Acronyms(common) |
| NATO | North Atlantic Treaty Organization | - | Computer Acronyms(common) |
| NAVORDSTA | Naval Ordnance Station (US) | - | Computer Acronyms(common) |
| NAWDEX | National Water Data Exchange | - | Computer Acronyms(common) |
| NAWQA | National Water Quality Assessment (US Geological Survey) | - | Computer Acronyms(common) |
| NBACC | National Biodefense Analysis And Countermeasures Centerpa | - | Computer Acronyms(common) |
| NBC | Nuclear, Biological And Chemical | - | Computer Acronyms(common) |
| NBD | Nucleotide Binding Domain | - | Computer Acronyms(common) |
| NBFAC | National Bioforensic Analysis Center Par | - | Computer Acronyms(common) |
| NBI | Neutral Beam Injection | - | Computer Acronyms(common) |
| NBII | National Biological Information And Infrastructure | - | Computer Acronyms(common) |
| NBMO | Nonbonded Molecular Orbital | - | Computer Acronyms(common) |
| NBO | Natural Bond Order | - | Computer Acronyms(common) |
| NBOD | Nitrogenous Biochemical Oxygen Demand | - | Computer Acronyms(common) |
| NBR | Nitrile-butadiene Rubber | - | Computer Acronyms(common) |
| NBRF | National Biomedical Research Foundation | - | Computer Acronyms(common) |
| NBS | National Bureau Of Standards | - | Computer Acronyms(common) |
| NBS | Nijmegen Breakage Syndrome | - | Computer Acronyms(common) |
| NBS | Nuclear Backscattering Spectroscopy | - | Computer Acronyms(common) |
| NBS | Nucleotide-binding Site | - | Computer Acronyms(common) |
| NBSB | National Biomonitoring Specimen Bank | - | Computer Acronyms(common) |
| NBSR | Neutron Beam Split-core Reactor | - | Computer Acronyms(common) |
| NC-IUBMB | Nomenclature Committee Of The International Union Of Biochemistry And Molecular Biology | - | Computer Acronyms(common) |
| NCAC | Nitrogen-containing Aromatic Compound | - | Computer Acronyms(common) |
| NCAM | Neural Cell Adhesion Molecule | - | Computer Acronyms(common) |