Environmental Terms Glossary
I-K
IA
Insecticide Act (1910)
IATA
International Air Transport Association
IC
Ion chromatography
ICAO
International Civil Aviation Organization
ICP
Inductively coupled (argon) plasma. Used with reference to both the analytical method and the apparatus.
Identification Number for EPA
The individual number assigned to each generator, transporter, and treatment, storage, or disposal facility by state or federal regulatory agencies.
IDLH
Immediately Dangerous to Life or Health. An environmental condition which would immediately place a worker in jeopardy. Usually used to describe a condition existing where self-contained breathing apparatus must be used.
IG
Inspector General
Ignitable
A liquid with a flashpoint less than 140 degrees F.
Ignition Temperature (Auto-Ignition)
The minimum temperature required to initiate or cause self sustained combustion in a substance. The temperature that the vapors of a product must be heated to for ignition to occur.
Illicit Connection
Any unauthorized, unknown, unpermitted or illegal drainage connection through which non-storm discharges could drain to a storm water conveyance.
IMDG
International Maritime Dangerous Goods
IMDGC
International Maritime Dangerous Goods Codes
Immediately Dangerous to Life or Health (IDLH)
Any atmosphere that poses an immediate hazard to life or produces immediate irreversible effects on health that will be debilitating.
IMO
International Maritime Organization (formerly IMCO)
Inactive Facility
The EPA designation for a treatment, storage, or disposal facility that has not accepted hazardous waste since November 19, 1980.
Incident
The release or potential release of a hazardous substance into the environment.
Incident Action Plan
The strategy goals, tactical objectives, and support requirements for the incident. All incidents require an action plan. For simple incidents the action plan is usually not in written form. Large or complex incidents will require that the action plan be documented in writing.
Incident Command Post (ICP)
That location at which primary command functions are executed and usually co-located with the incident base.
Incident Command System (ICS)
The combination of facilities, equipment, personnel, procedures, and communications operating within a common organizational structure with responsibility for the management of assigned resources to effectively accomplish stated objectives pertaining to an incident.
Incident Commander
The individual responsible for the management of all incident operations.
Incineration
An engineered process using controlled flame combustion to thermally degrade waste materials.
Incompatible
Incapable of being combined without a dangerous effect, e.g., descriptive of two or more substances that produce an unfavorable chemical reaction if they come in contact.
Infiltration
The flow of fluid into a substance through pores or small openings.
Information
Knowledge required concerning the conditions or circumstances particular to an incident. Information gathered in a response should be disseminated.
Ingestion
The swallowing of certain chemicals can obviously be harmful. Sometimes chemicals are harmful in such small quantities that special precautions must be taken to ensure that they do not inadvertently get into the mouth and are then swallowed.
Inhalation
The breathing of airborne contaminants in the form of vapors, gases, mists, or particulates may produce harmful effects.
Inhibitor
A compound that retards or stops a chemical chain reaction such as corrosion, oxidation, or polymerization. These are used quite often to make products with unstable characteristics become stable for use and transportation.
Injection
The introduction of chemicals into the body through puncture.
Injection Well
A well into which fluids are injected.
Inlet
An entrance into a ditch, storm sewer, or other waterway.
Inorganic Compounds
Chemical compounds that do not contain the element carbon.
Inorganic Matter
Chemical substances of mineral origin, not containing carbon to carbon bonding. Generally structured through ionic bonding.
Insecticide
A chemical product used to kill and control nuisance insect species.
Instability
The characteristic of a compound, mixture, or solution which would allow it to change its form or chemical structure.
Interim Authorization
The conditional permission from EPA that enables a state to operate its own hazardous waste management program.
Interim Status
A period of time, which began November 19, 1980, when hazardous waste storage and treatment facilities and hazardous waste transporters could continue to operate under a special set of regulations until the appropriate permit or license application is or was approved by EPA.
Intermunicipal Agency
An agency established by two or more municipalities with responsibility for planning or administration of solid waste.
Ionic Bond
A chemical bond in which electrons are transferred from one element to another, creating a cation and an anion which are held together by an electrostatic charge. Metals and non-metals bond together in this fashion, creating salts.
Ionizing Radiation
High-energy radiation that causes irradiated substances to form ions, which are electrically charged particles.
IPM
Integrated Pest Management
IPY
Inches per year
Irritant
Any material, liquid or solid substance, that upon contact with fire or when exposed to air gives off dangerous or intensely irritating fumes, such as tear gas, but not including Poison Class A or B material. Materials names as irritants are presented in Title 49 CFR 173.38.
ISO
International Organization for Standardization
ITR
Innovative Technology Requirement
K
Kilogram (Kg)
The fundamental unit of mass in the International System, about 2.2046 pounds.
L
Label (DOT)
Diamond, square, or rectangular-shaped attachment to a package that identifies the hazardous nature of a material.
LAER
Lowest Achievable Emission Rate
Land Treatment Facility
A facility or part of a facility where hazardous waste is applied or incorporated into the soil surface; such facilities are disposal facilities if the waste will remain after closure.
Latent Period
The time which elapses between exposure and the first manifestation of damage.
LC50
Lethal Concentration 50% died of test animals. The concentration of a material which on the basis of laboratory tests is expected to kill 50 percent of a group of test animals when administered as a single exposure.
LCLo
Lethal Concentration Low. The lowest concentration of a substance in air, other then LC50, which as been reported to have caused death in human or animals. The reported concentrations may be entered for periods of exposure that are less than 24 hours (acute) or greater than 24 hours (subacute and chronic).
LD50
Lethal Dose 50% died of test animals. The dose which is required to produce death in 50 percent of the exposed species. Death is usually reckoned as occurring within the first 30 days.
LDLo
Lethal Dose Low. The lowest dose of a substance introduced by any route, other than inhalation, over any given period of time in one or more divided portions and reported to have caused death in humans or animals.
LEL
Lower Explosive Limit. The lowest concentration of the material in air that can be detonated by spark, shock, fire, etc.
LEPC
Local Emergency Planning Committee
LFL
Lower Flammable Level. The lowest concentration of the material in air that will support combustion from a spark or flame.
List of Lists
Consolidated list of chemicals subject to reporting under The Emergency Planning and Community Right To Know Act.
LLRWPA
Low-Level Radioactive Waste Policy Act
LUST
Leaking Underground Storage Tank
M
Macroencapsulation
The isolation of a waste by embedding it in, or surrounding it with, a material that acts as a barrier to water or air.
Malaise
Vague feeling of bodily discomfort.
Manifest
The shipping document used for identifying the quantity, composition, origin, routing, and destination of hazardous waste during its transportation from the point of generation to the point of treatment, storage, or disposal.
Manometer
An instrument for measuring pressure that usually consists of a U-shaped tube containing a liquid, the surface of which in one end of the tube moves proportionally with pressure changes on the liquid in the other end. Also, a tube type of differential pressure gauge.
MAQ
Manager Air Quality
Marking
Applying the required descriptive name, instructions, cautions, weight, or specifications or combinations thereof on containers of HM/HW (see Title 49 CFR 171.8).
Material Safety Data Sheet (MSDS)
Product specific information system which furnishes comprehensive information on a specific chemical. MSDS is one of the best sources of information, however, they also have limitations. Primarily, trade secrets do not have to be revealed on a MSDS.
Material Storage Area
Onsite location or area where raw materials, products, intermediate products, final products, by-products, or waste materials are stored.
MCL
Maximum Contaminant Level. The maximum permissible level of a contaminant in water which is delivered to any user of a public system, except in the case of turbidity where the maximum permissible level is measured at the point of entry to the distribution system.
MCLG
Maximum Contaminant Level Goal
MCM
Manager Compliance Measurement
MEFO
Manager Environmental Field Operations
Melting Point
The temperature at which a material changes from a solid to a liquid.
MEP
Maximum Extent Practicable
MESR
Manager Environmental Site Remediation
MeV
Million electron-volts
MFP&ST
Manager Fire Protection & Storage Tanks
mg
Milligram. A metric unit of weight. There are 1,000 milligrams in one gram (g) or a substance.
mg/kg
Milligrams per Kilogram
MHE
Material Handling Equipment
Microorganism
A living organism discretely invisible to the unaided eye.
Miscellaneous Materials
Materials which do not fit into the classes listed above but because of the characteristics require special handling during transportation.
Mitigation
Actions taken to prevent or reduce the severity of harm from a chemical release.
Mixture
A substance which is made up of different elements, but cannot be represented by a chemical formula. Its components can usually be separated by mechanical means. Example: Air, Gasoline, Plastics, Sea Water.
ml
Milliliter. A metric unit of volume, equal in volume to one cubic centimeter (cc), or about 1/16 of a cubic inch. There are 1,000 milliliters in one liter (l).
MLA
Mineral Leasing Act (Amended) (1973)
mm
Millimeters
mm Hg
Millimeters of Mercury
MMPA
Marine Mammal Protection Act (1972)
Monitoring
The process of measuring certain environmental parameters on a real-time basis for spatial and time variations. For example, air monitoring may be conducted with direct-reading instruments to indicate relative changes in air contaminant concentrations at various times.
MPRSA
Marine Protection, Research, and Sanctuaries Act of 1972
MSDS
Material Safety Data Sheet. Contains descriptive information on hazardous chemicals, health, physical hazards, exposure limits, and precautions.
MSHA
Mine Safety and Health Administration (approve respirator)
MSW
Municipal Solid Waste
MSWLF
Municipal Solid Waste Landfill Facility
MTB
Materials Transportation Bureau. (formerly of DOT); now the Research and Special Programs Administration (RSPA) of DOT.
MTR
Minimum Technology Requirements
MUC
Maximum Concentration for Use
Municipal Separate Storm Sewer (MS4)
A separate storm water conveyance system operated by a municipality or other public agency.
Mutagen
A substance capable of causing genetic change.
N
NAAQS
National Ambient Air Quality Standard
NAFED
National Association of Fire Equipment Distributors
Narcosis
Stupor or unconsciousness produced by chemical substances.
NBAR
Nonbinding Preliminary Allocation of Responsibility
NCA
Noise Control Act (1972)
NCP
National Contingency Plan
NCRP
National Council on Radiation Protection and Measurements
Necrosis
Destruction of body tissue.
NEPA
National Environmental Policy Act of 1969
NESHAP
National Emission Standards for Hazardous Air Polluntants. Federal emissions standards for air toxics regulated under Clean Air Act.
Neutralization
The process by which acid or alkaline properties of a solution are altered by addition of certain reagents to bring the hydrogen and hydroxide concentrations to an equal value.
Neutralize
To make harmless anything contaminated with a chemical agent.
NFPA
National Fire Protection Association
NIOSH
National Institute for Occupational Safety and Health (approve respirator)
NOAA
National Oceanic and Atmospheric Administration
NOI
Notice of Intent. A formal, written declaration of intent to be covered by a general permit and thereby abide by the terms and conditions of such permits. NOIs are submitted either to EPA or a state permitting agency.
Non-Contact Wastewater
Any water resulting from industrial activities which does not come into direct with any raw material, intermediate product, finished product, by-product, waste product, or wastewater.
Non-salt
The compound formed when a non-metal and another non-metal chemically bond together using a covalent bond.
Non-Storm Water Discharges
Non-storm water does not have its immediate origin in storm water runoff and generally includes equipment or vehicle wash waters, interior floor drain waters, tank waste waters or wash waters, slop waters, equipment or vehicle flush waters, anti-freeze, oils and non-water liquids, vegetation care, etc.
Nonexempt Nonstorm Water
All nonstorm water which is not exempt nonstorm water.
Nonpoint Sources
Ill-defined runoff that enters waterways.
NOS
Not otherwise specified.
NOT
Notice of Termination. A formal, written declaration that a facility is withdrawing its coverage under a general permit after once being covered by a general permit. NOIs are submitted either to EPA or a state permitting agency; justification of the withdrawal must be provided.
NOV
Notice of Violation
NPDES
National Pollutant Discharge Elimination System. See the definition of "National Pollutant Discharge Elimination System: in 40 CFR 122.2 for further discussion. Federal permitting system established by the CWA and administered by EPA to regulate point source discharges of wastewater, process wastewater, non-contact wastewaters, stormwater, and similar discharges to waters of the United States.
NPDWS
National Primary Drinking Water Standards
NPL
National Priorities List. Official list of hazardous waste sites to be addressed by CERCLA.
NPTN
National Pesticide Telecommunications Network
NQT
Nonquenched and tempered
NRC
National Response Center
NRT
National Response Team
NSPS
New Source Performance Standards
NTP
National Toxicology Program
NWPA
Nuclear Waste Policy Act of 1982
O
OBA
Oxygen Breathing Apparatus
OCSLA
Outer Continental Shelf Lands Act (1953)
OECM
Office of Enforcement and Compliance Monitoring
OERR
Office of Emergency and Remedial Response
Off-Site
Presence outside of the chemical contamination. Area where air is below the OSHA PEL.
OH-
Hydroxide Ion
OHMR
Office of Hazardous Materials Regulation
OHMT
Office of Hazardous Materials Transportation
Oil-Water Separator
A device installed, usually at the entrance to a drain, which removes oil and grease from water flows entering the drain.
Oil Pollution Act
Regulates the transportation and storage of petroleum products to prevent water pollution.
Oil/Water Separator
A device installed, usually at the entrance to a drain, which removes oil and grease from water flows entering the drain.
On-Site
Presence within the boundaries of the chemical contamination. Area above the OSHA PEL.
Opacity
The quality or state of a body that makes it impervious to the rays of light. Used to determine quality of emission from locomotives.
Oral Toxicity
Adverse effects resulting from taking substance into the body through the mouth.
Organic Peroxide
Any organic compound containing the bivalent O-O structure and that may be considered a derivative of hydrogen peroxide where one or more of the hydrogen atoms have been replaced by organic radicals.
Organic Pollutants
Substances containing carbon which may cause pollution problems in receiving streams.
Organic Solvents
Liquid organic compounds capable of dissolving solids, gases, or liquids.
ORM
Other Regulated Materials
OSC
Onscene Coordinator. In emergency response actions.
OSHA
Occupational Safety and Health Act of 1970. Oversees and regulates work place health and safety.
OSW
Office of Solid Waste
OSWER
Office of Solid Waste and Emergency Response
OTA
Office of Technology Assessment
OTS
Office of Toxic Substances
Outfall
The point of exit of waters from a conveyance system; at industrial facilities, the exit point for storm water conveyance systems is usually the point where storm waters leave the facility boundary.
Outside Packaging
A packaging plus its contents (see Title 49 CFR 171.8).
OVA
Organic Vapor Analyzer
Overpack
Except when referenced to a packaging specified in Title 49 CFR Part 178, means an enclosure used by a single consignor to provide protection or convenience in handling of a package or to consolidate two or more packages.
Oxidation Ability
The ability of a material to release oxygen. Materials with a high oxidation ability are known as oxidizing materials. They spontaneously evolve oxygen at or just above room temperature. These materials should be stored away from organics because when they come in contact with these materials, a violent reaction may occur.
Oxidizers
Products which yield oxygen readily to stimulate the combustion of organics.