EPA Indoor Air Quality Glossary of Terms, Oct 1997

NYC 9/11 Public Portal Document indoor Air Quality (lAQ) - Glossary of Terms Page 5 of 8

pressure in the crawlspace relative to air pressure in the living spaces, by use of a fan.

MICROBIOLOGICALS: See "Biological Contaminants."

MODEL BUILDING CODES: The building codes published by the 4 Model Code Organizations and commonly adopted by state or other jurisdictions to control local construction activity.

MODEL CODE ORGANIZATIONS: Includes the following agencies and the model building codes they promulgate:

• Building Officials and Code Administrators International, Inc. (BOCA National Building Code/1993 and BOCA National Mechanical Code/1993); • International Conference of Building Officials (Uniform Building Code/1991 and Uniform Mechanical Code/1991); • Southern Building Code Congress, International, Inc. (Standard Building Code/1991 and Standard Mechanical Code/1991); • Council of American Building Officials (CABO One- and Two-Family Dwelling Code/1992 and CABO Model Energy Code/1993).

MULTIPLE CHEMICAL SENSmviTY (MCS): A condition in which a person reports sensitivity or intolerance (as distinct from "allergic") to a number of chemicals and other irritants at very low concentrations. There are different views among medical professionals about the existence, causes, diagnosis, and treatment of this condition.

NEGATIVE PRESSURE: Condition that exists when less air is supplied to a space than is exhausted from the space, so the air pressure within that space is less than that in surrounding areas. Under this condition, if an opening exists, air will flow from surrounding areas into the negatively pressurized space.

ORGANIC COMPOUNDS: Chemicals that contain carbon. Volatilejorganic compounds vaporize at room temperature and pressure. They are found in many indoor sources, including many common household products and building materials.

OUTDOOR AIR SUPPLY: Air brought into a building from the outdoors (often through the ventilation system) that has not been previously circulated through the system. Also known as "Make-Up Air."

pels: Permissible Exposure Limits (standards set by the Occupational, Safety and Health Administration - OSHA).

PICOCURIE (pCi): A unit for measuring radioactivity, often expressed as picocuries per liter (pCi/L) of air.

PLENUAA: Air compartment connected to a duct or ducts.

PM: Preventive Maintenance.

POLLUTANT PATHWAYS: Avenues for distribution of pollutants In a building. HVAC systems are the primary pathways in most buildings; however all building components interact to affect how air movement distributes pollutants. Also - a term used in the lAQ Tools for Schools: lAQ Coordinator’s Guide.

POSITIVE PRESSURE: Condition that exists when more air is supplied to a space than is exhausted, so the air pressure within that space is greater than that in surrounding areas. Under this condition, if an opening exists, air will flow from the nnehh/Ah/ ©no/'o infz\ eiirr’ZMinrlinn oroo©

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