Glossary /Acronyms & Abbreviations A AADI - Adjusted Acceptable Daily Intake AChE - acetylcholinesterase ACGIH - American Conference of Governmental Industrial Hygienists ADI - Acceptable Daily Intake AHFS - American Hospital Formulary Service a.i. - active ingredient AIHA - American Industrial Health Association AMA - American Medical Association AOAC - Association of Official Analytical Chemists APA - American Pharmaceutical Association ASCII - American Standard Code for Information Exchange ASHP - American Society of Hospital Pharmacists AUR - Air Unit Risk Top of page B b:a lambda(a) - Blood-to-air partition coefficient of the chemical for the experimental animal species used in the HEC derivation of an RfC b:a lambda(h) - Blood-to-air partition coefficient of the chemical for the human used in the HEC derivation of an RfC BHP - biodegradation, hydrolysis, and photolysis BOD5 - biochemical oxygen demand as measured in the standard 5-day test BUN - blood urea nitrogen Bw - body weight BWa - Body weight (kg) for experimental animal species used in the HEC derivation of an RfC. BWh - Body weight (kg) for human used in the HEC derivation of an RfC. Top of page C CAG - Carcinogen Assessment Group, U.S. EPA CAS - Chemical Abstracts Service CBI - Confidential business information cc - cubic centimeters CC - closed cup CDC - Centers for Disease Control CERCLA - Comprehensive Environmental Response, Compensation, and Liability Act of 1980 CFR - Code of Federal Regulations CF - Conversion factor based on PBPK modeling used in the HEC derivation of an RfC for gases. Note: The CF is specific for the experimental animal species and the exposure regimen and concentration simulated. ChE - cholinesterase CHO - Chinese hamster ovary CIIT - Chemical Industry Institute of Toxicology CNS - central nervous system CPK - creatine phosphokinase CRAVE - Carcinogen Risk Assessment Verification Endeavor cu.m - cubic meter CWA - Clean Water Act Top of page D DASE - Dutch Association of Safety Experts DHEW - U.S. Department of Health, Education, and Welfare (now U.S. Department of Health and Human Services) DNA - deoxyribonucleic acid DOT - U.S. Department of Transportation DW - drinking water DWEL - Drinking Water Equivalent Level Top of page E E - exponent (e.g., 1.5E-6 = 1.5 x 10 to the power of -6) EED - estimated exposure dose EEG - electroencephalogram EKG - electrocardiogram ELISA - enzyme-linked immunosorbent assay EMTD - estimated maximum tolerated dose EP - Extraction Procedure ER - Extrarespiratory. Refers to effects peripheral to the respiratory system as the portal-of-entry, or systemic effects. ET - Extrathoracic region of the respiratory tract EPA - U.S. Environmental Protection Agency Top of page F FEL - frank-effect level FIFRA - Federal Insecticide, Fungicide, and Rodenticide Act FOI - Freedom of Information F1 - first filial generation (in experimental animals) FR - Federal Register FRC - functional reserve capacity FTS - Federal Telecommunications System FWS - U.S. Fish and Wildlife Service Top of page G g - grams GI - gastrointestinal GPT - glutamic-pyruvic transaminase Top of page H HA - Health Advisory HAPPS - Hazardous Air Pollution Prioritization System HAS - Health Assessment Summary HCT - hematocrit HDT - highest dose tested HEC - human equivalent concentration HEEP - Health and Environmental Effects Profile Hgb - hemoglobin HHS - U.S. Department of Health and Human Services HSDB - Hazardous Substance Database Top of page I IARC - International Agency for Research on Cancer ICR - Institute of Cancer Research ICRP - International Commission for Radiological Protection i.m. - intramuscular i.p. - intraperitoneal i.v. - intravenous IRIS - Integrated Risk Information System ITII - International Technical Information Institute Top of page K kg - kilogram Top of page L L - liter LCLO - Lethal Concentration Low; the lowest concentration at which death occurred LC50 - Lethal Concentration 50; concentration lethal to 50% of the animals LDLO LD50 - Lethal Dose 50; dose lethal to 50% of the animals LDH - lactic-acid dehydrogenase LDT - lowest dose tested LEL - lower explosive limit LEL - lowest-effect level Lethal Dose Low - the lowest dose at which death occurred LOAEL - lowest-observed-adverse-effect level LOAEL(ADJ) - LOAEL adjusted to continuous exposure duration from an intermittent regimen by hour/day and days/7 days. LOAEL(HEC) - LOAEL adjusted for dosimetric differences across species to a human equivalent concentration. Top of page M m - meter MCL - maximum contaminant level MCLG - maximum contaminant level goal MED - minimum effective dose MEFV - maximum expiratory flow volume MF - modifying factor mg - milligram mg/kg - milligrams per kilogram mg/L - milligrams per liter mmHg - millimeters of mercury; a measure of pressure MMAD - mass median aerodynamic diameter MOE - margin of exposure MOS - margin of safety MTD - maximum tolerated dose MTL - median threshold limit MVa - Minute ventilatory volume for experimental animal species (composite value expressed in cu.m/day) used in the HEC derivation of an RfC. MVh - Minute ventilatory volume for human (composite value expressed in cu.m/day) used in the HEC derivation of an RfC. MVho - Minute ventilatory volume for human in an occupational environment, assuming 8 hour/day exposure (composite value expressed in cu.m/day), used in the HEC derivation of an RfC. Top of page N NAAQS - National Ambient Air Quality Standards NAS - National Academy of Sciences NESHAP - National Emission Standards for Hazardous Air Pollutants NFPA - National Fire Prevention Association ng - nanogram NIH - National Institutes of Health NIOSH - National Institute for Occupational Safety and Health NLM - National Library of Medicine NOAEL - no-observed-adverse-effect level NOAEL(ADJ) - NOAEL adjusted to continuous exposure duration from an intermittent regimen by hour/day and days/7 days. NOAEL(HEC) - NOAEL adjusted for dosimetric differences across species to a human equivalent concentration. NOEL - no-observed-effect level n.a. - not available n.o.s. - not otherwise specified NRC - National Research Council NSPS - New Source Performance Standards NTIS - National Technical Information Service NTP - National Toxicology Program Top of page O OAQPS - Office of Air Quality Planning and Standards, U.S. EPA OAR - Office of Air and Radiation, U.S. EPA OARM - Office of Administration and Resources Management, U.S. EPA OC - open cup OW - Office of Water, U.S. EPA OHEA - Office of Health and Environmental Assessment, U.S. EPA OHM/TADS - Oil and Hazardous Materials Technical Assistance Data Systems OPP - Office of Pesticide Programs, U.S. EPA OPPE - Office of Policy Planning and Evaluation, U.S. EPA OPTS - Office of Pesticides and Toxic Substances, U.S. EPA ORD - Office of Research and Development, U.S. EPA OSHA - U.S. Occupational Safety and Health Administration OST - Office of Science and Technology, U.S. EPA OSWER - Office of Solid Waste and Emergency Response, U.S. EPA OTS - Office of Toxic Substances, U.S. EPA OWRS - Office of Water Regulations and Standards, U.S. EPA Top of page P P - probit dose extrapolation model PBPK - physiologically based pharmacokinetic pCi - picocurie PD - Position Document PEL - permissible exposure limit PHS - U.S. Public Health Service p.o. - per os (by mouth) ppb - parts per billion ppm - parts per million PU - pulmonary region of the respiratory tract Top of page R RA - risk assessment RBC - red blood cell(s) RCRA - Resource Conservation and Recovery Act RDDR - Regional deposited dose ratio used in derivation of an HEC for particles. RDDR(ER) - Regional deposited dose ratio used in the HEC derivation of an RfC for an observed extrarespiratory effect of particles. RDDR(ET) - Regional deposited dose ratio used in the HEC derivation of an RfC for an observed effect of particles in the extrathoracic region of the respiratory tract. RDDR(PU) - Regional deposited dose ratio used in the HEC derivation of an RfC for an observed effect of particles in the pulmonary region of the respiratory tract. RDDR(TB) - Regional deposited dose ratio used in the HEC derivation of an RfC for an observed effect of particles in the tracheobronchial region of the respiratory tract. RDDR(TH) - Regional deposited dose ratio used in the HEC derivation of an RfC for an observed effect of particles in the thoracic region of the respiratory tract. RDDR(TOTAL) - Regional deposited dose ratio used the HEC derivation of an RfC for an observed effect of particles in the total respiratory tract. RGDR - Regional gas dose ratio used in derivation of an HEC for gases. RGDR(ET) - Regional gas dose ratio used in the HEC derivation of an RfC for an observed effect of a gas in the extrathoracic region of the respiratory tract. RGDR(PU) - Regional gas dose ratio used in the HEC derivation of an RfC for an observed effect of a gas in the pulmonary region of the respiratory tract. RGDR(TB) - Regional gas dose ratio used in the HEC derivation of an RfC for an observed effect of a gas in the tracheobronchial region of the respiratory tract. RGDR(TH) - Regional gas dose ratio used in the HEC derivation of an RfC for an observed effect of a gas in the thoracic region of the respiratory tract. RGDR(TOTAL) - Regional gas dose ratio used in the HEC derivation of an RfC for an observed effect of a gas in the total respiratory tract. RfD - Oral Reference Dose RfC - Inhalation Reference Concentration RgD - Regulatory Dose RM - risk management RPAR - rebuttable presumption against registration RQ - Reportable Quantity RTECS - Registry of Toxic Effects of Chemical Substances RV - residual volume Top of page S Sa - Surface area (in sq.cm) for respiratory tract region for experimental animal species used in the HEC derivation of an RfC. Sa(ET) - Surface area (in sq.cm) of extrathoracic region for experimental animal species used in the HEC derivation of an RfC. Sa(TB) - Surface area (in sq.cm) of tracheobronchial region for experimental animal species used in the HEC derivation of an RfC. Sa(TH) - Surface area (in sq.cm) of thoracic region for experimental animal species used in the HEC derivation of an RfC. Sa(PU) - Surface area (in sq.cm) of pulmonary region for experimental animal species used in the HEC derivation of an RfC. Sa(TOTAL) - Surface area (in sq.cm) of total respiratory system for experimental animal species used in the HEC derivation of an RfC. SAB - Science Advisory Board SANSS - Structure and Nomenclature Search System SAP - serum alkaline phosphatase SARA - Superfund Amendments and Reauthorization Act of 1986 s.c. subcutaneous SCE - sister-chromatid exchange SDWA - Safe Drinking Water Act SF - safety factor SGOT - serum glutamic-oxaloacetic transaminase SGPT - serum glutamic-pyruvic transaminase Sh - Surface area (in sq.cm) of respiratory tract for human used in the HEC derivation of an RfC. Sh(ET) - Surface area (in sq.cm) of extrathoracic region for human used in the HEC derivation of an RfC. Sh(TB) - Surface area (in sq.cm) of tracheobronchial region for human used in the HEC derivation of an RfC. Sh(TH) - Surface area (in sq.cm) of thoracic region for human used in the HEC derivation of an RfC. Sh(PU) - Surface area (in sq.cm) of pulmonary region for human used in the HEC derivation of an RfC. Sh(TOTAL) - Surface area (in sq.cm) of total respiratory system for human used in the HEC derivation of an RfC. sigma g - geometric standard deviation SMCL - secondary maximum contaminant level SMR - standard mortality ratio sq.cm. - square centimeters SRI - Stanford Research Institute STEL - short-term exposure limit Top of page T TB - tracheobronchial region of the respiratory tract TCC - Tagliabue closed cup, a standard method of determining flash points TDB - Toxicology Database TH - thoracic (TB + PU) region of the respiratory tract TLV - Threshold Limit Value TOC - Tagliabue open cup, a standard method of determining flash points TOTAL - total respiratory tract TSCA - Toxic Substances Control Act TWA - time-weighted averageý Top of page U UCL - upper confidence limit UEL - upper explosive limit UF - uncertainty factor µg - microgram umol - micromoles Top of page V VAa - Alveolar ventilation rate (cu.m/day) for experimental animal species used in HEC derivation of an RfC. VAh - Alveolar ventilation rate (cu.m/day) for human used in HEC derivation of an RfC. VOC - volatile organic compound v/v - volume for volume Top of page W WBC - white blood cell(s) WQC - Water Quality Criteria Top of page