| P-A TEST | Presence-absence Test | - | Computer Acronyms(common) |
| P-T-T-D | Pressure-temperature-time-deformation Path (for Metamorphic Rocks) | - | Computer Acronyms(common) |
| PA | Photoinduced Absorption | - | Computer Acronyms(common) |
| PA | Preliminary Assessment | - | Computer Acronyms(common) |
| PA-FTIR | Photoacoustic Fourier Transform Infrared Spectroscopy | - | Computer Acronyms(common) |
| PA/SI | Preliminary Assessment/Site Inspection | - | Computer Acronyms(common) |
| PAA | Photon Activation Analysis | - | Computer Acronyms(common) |
| PAA | Poly (acrylic Acid) | - | Computer Acronyms(common) |
| PAAP | Platelet Aggregation-associated Protein | - | Computer Acronyms(common) |
| PAB | Pollutant Assessment Branch (US EPA) | - | Computer Acronyms(common) |
| PAB | Particle Associated Bacteria | - | Computer Acronyms(common) |
| PAB | Passenger-side Air Bag | - | Computer Acronyms(common) |
| PABA | P-aminobenzoic Acid | - | Computer Acronyms(common) |
| PAC | P1-derived Artificial Chromosome | - | Computer Acronyms(common) |
| PAC | Polycyclic Aromatic Compound | - | Computer Acronyms(common) |
| PAC | Perturbed Angular Correlation | - | Computer Acronyms(common) |
| PAC | Photoacoustic Calorimetry | - | Computer Acronyms(common) |
| PAC | Polyaluminum Chloride | - | Computer Acronyms(common) |
| PAC | Powdered Activated Carbon | - | Computer Acronyms(common) |
| PACAP | Pituitary Adenylate Cyclase-activating Polypeptide | - | Computer Acronyms(common) |
| PACE | Pacific Atmospheric Chemistry Experiment | - | Computer Acronyms(common) |
| PACE | Plasma Assisted Chemical Etching | - | Computer Acronyms(common) |
| PACIMS | Passive Chem. Ionization Mass Spectrometry | - | Computer Acronyms(common) |
| PACS | Physics And Astronomy Classification Scheme | - | Computer Acronyms(common) |
| PACT | Powdered Activated Carbon Treatment | - | Computer Acronyms(common) |
| PACT | Process Automation Configuration Tool [EPRI Software] | - | Computer Acronyms(common) |
| PACVD | Plasma-assisted Chemical Vapor Deposition | - | Computer Acronyms(common) |
| PAD | Pulsed Amperometric Detection | - | Computer Acronyms(common) |
| PADMR | Photoinduced Absorption Detected Magnetic Resonance | - | Computer Acronyms(common) |
| PADRE | Particle Analysis And Data Reduction Program | - | Computer Acronyms(common) |
| PADS | Photoacoustic Deflection Spectroscopy | - | Computer Acronyms(common) |
| PAE | Postantibiotic Effect | - | Computer Acronyms(common) |
| PAECE | Protective Action Evaluator For Chemical Emergencies | - | Computer Acronyms(common) |
| PAEP | Photovoltaic Array Environmental Protection Program | - | Computer Acronyms(common) |
| PAES | Positron-induced Auger Electron Spectroscopy | - | Computer Acronyms(common) |
| PAF | Platelet Activating Factor | - | Computer Acronyms(common) |
| PAFC | Phosphoric Acid Fuel Cells | - | Computer Acronyms(common) |
| PAFP | Photochemical Aerosol Forming Potential | - | Computer Acronyms(common) |
| PAFT | Program For Alternative Fluorocarbon Toxicology Testing | - | Computer Acronyms(common) |
| PAG | Periaqueductal Gray | - | Computer Acronyms(common) |
| PAG | Photoacid Generator | - | Computer Acronyms(common) |
| PAGE | Polyacrylamide Gel Electrophoresis | - | Computer Acronyms(common) |
| PAGE | Policy Analysis Of The Greenhouse Effect | - | Computer Acronyms(common) |
| PAGIF | Polyacrylamide Gel Isoelectric Focusing | - | Computer Acronyms(common) |
| PAGIRS | Pesticide Assessment Guidelines Information Retrieval System | - | Computer Acronyms(common) |
| PAH | Polycyclic Aromatic Hydrocarbon | - | Computer Acronyms(common) |
| PAHO | Pan American Health Organization | - | Computer Acronyms(common) |
| PAI | Pesticide Active Ingredient | - | Computer Acronyms(common) |
| PAI | Plasminogen Activator Inhibitor | - | Computer Acronyms(common) |
| PAI-1 | Plasminogen Activator Inhibitor 1 | - | Computer Acronyms(common) |
| PAIR | Patent Application Information Retrieval System | - | Computer Acronyms(common) |
| PAIR | Preliminary Assessment Information Rule | - | Computer Acronyms(common) |
| PAIRS | Program For The Analysis Of Infrared Spectra | - | Computer Acronyms(common) |
| PAIS | Public Affairs Information Service | - | Computer Acronyms(common) |
| PAK | P21-Activated Kinase | - | Computer Acronyms(common) |
| PAL | Positron Annihilation Lifetime | - | Computer Acronyms(common) |
| PALMS | Particle Analysis By Laser Mass Spectrometry | - | Computer Acronyms(common) |
| PALS | Positron Annihilation Lifetime Spectroscopy | - | Computer Acronyms(common) |
| PAM | Photolabile Attachment Molecules | - | Computer Acronyms(common) |
| PAM | Peptidylglycine Alpha-amidating Monooxygenase | - | Computer Acronyms(common) |
| PAM | Performance Assessment Methodology | - | Computer Acronyms(common) |
| PAM | Periodic Anderson Model | - | Computer Acronyms(common) |
| PAMBE | Plasma-assisted Molecular Beam Epitaxy | - | Computer Acronyms(common) |
| PAMPA | Parallel Artificial Membrane Permeation Assay | - | Computer Acronyms(common) |
| PAMS | Photochem. Assessment Monitoring Stations | - | Computer Acronyms(common) |
| PAMSA | PCR Amplification Of Multiple Specific Alleles | - | Computer Acronyms(common) |
| PAN | Peroxyacetyl Nitrate | - | Computer Acronyms(common) |
| PANAK | Peroxyacetyl Nitrate Aldehyde Ketones | - | Computer Acronyms(common) |
| PANH | Polycyclic Aromatic Nitrogen Heterocycle | - | Computer Acronyms(common) |
| PANNA | Pesticide Action Network North America | - | Computer Acronyms(common) |
| PAO | Polarized Atomic Orbital | - | Computer Acronyms(common) |
| PAO | Polyphosphate Accumulating Organism | - | Computer Acronyms(common) |
| PAO | Pseudo-atomic Orbital | - | Computer Acronyms(common) |
| PAOD | Peripheral Arterial Occlusive Disease | - | Computer Acronyms(common) |
| PAP | Pancreatitis-associated Protein | - | Computer Acronyms(common) |
| PAP | Prostatic Acid Phosphatase | - | Computer Acronyms(common) |
| PAPP-A | Pregnancy-associated Plasma Protein A | - | Computer Acronyms(common) |
| PAPS | Phase-alternated Pulse Sequence | - | Computer Acronyms(common) |
| PAPVD | Plasma-assisted Physical Vapor Deposition | - | Computer Acronyms(common) |
| PAR | Population At Risk | - | Computer Acronyms(common) |
| PAR | Photosynthetically Active Radiation | - | Computer Acronyms(common) |
| PAR | Proteinase-activated Receptor | - | Computer Acronyms(common) |
| PARAFAC | Parallel Factor Analysis | - | Computer Acronyms(common) |
| PARC | Polycyclic Aromatic Ring Cleavage | - | Computer Acronyms(common) |
| PARISS | Prism And Reflector Imaging Spectroscopy System | - | Computer Acronyms(common) |
| PARP | Poly ADP-ribose Polymerase | - | Computer Acronyms(common) |
| PARS | Photoacoustic Raman Spectroscopy | - | Computer Acronyms(common) |
| PAS | Periodic Acid Schiff | - | Computer Acronyms(common) |
| PAS | Photoacoustic Spectroscopy | - | Computer Acronyms(common) |
| PAS | Positron Annihilation Spectrometry | - | Computer Acronyms(common) |
| PASA | PCR Amplification Of Specific Alleles | - | Computer Acronyms(common) |
| PASADENA | Para-hydrogen And Synthesis Allow Dramatically Enhanced Nuclear Alignment | - | Computer Acronyms(common) |
| PASH | Polycyclic Aromatic Sulfur-containing Hydrocarbons | - | Computer Acronyms(common) |
| PASPE | Photochemically Accumulated Stimulated Photon Echo | - | Computer Acronyms(common) |
| PASTM | Photon Assisted Scanning Tunnel Microscopy | - | Computer Acronyms(common) |
| PAT | Proficiency Analytical Testing (NIOSH) | - | Computer Acronyms(common) |
| PAT | Process Analytical Technology | - | Computer Acronyms(common) |
| PATOLIS | Patent Online Information System | - | Computer Acronyms(common) |
| PATRAM | Packaging And Transportation Of Radioactive Material | - | Computer Acronyms(common) |
| PAUR | Photochemical Activity And Solar Ultraviolet Radiation [project] | - | Computer Acronyms(common) |
