United States
Environmental Protection
Agency
Office of Monitoring Systems and
Quality Assurance
Washington DC 20460
Research and Development
EPA-600/S4-83-046 Jan. 1984
Project Summary
Guidelines for Monitoring
Indoor Air Quality
Niren L Nagda, Harry E. Rector, and Lance A. Wallace
This document provides guidelines
for designing programs to measure
indoor air quality. Brief summaries of
past and current research and descrip-
tions of indoor contaminants provide a
background for developing the moni-
toring design. Factors that influence
indoor air quality are discussed with the
aid of mass balance models. An exten-
sive review of measurement systems,
including a listing of numerous instru-
ments with their performance specifi-
cations, is presented.
Design considerations are discussed
for two types of studies—applied
research in indoor air quality and
investigations of building-associated
problems. A systematic approach for
developing the design is also described.
In addition, the document presents a
format for data reporting and sugges-
tions on quality assurance and quality
control.
This Project Summary was developed
by EPA's Office of Monitoring Systems
and Quality Assurance, Washington,
DC, to announce key findings of the
research project that is fully documented
in a separate report of the same title (see
Project Report ordering information at
back).
Introduction
The problem of indoor air pollution is
receiving increased attention as buildings
are constructed more tightly to conserve
energy and as new methods are developed
to detect a wider variety of pollutants at
lower concentrations. The U.S. Environ-
mental Protection Agency (EPA) is
concerned with indoor air pollution
because it contributes to human exposure
to pollutants.
Measuring indoor pollutants sometimes
requires different techniques than mea-
suring outdoor pollutants. For example,
high-volume pumps cannot be used
because they could affect the flow pattern
in an enclosed space. In fact, many of the
bulky or noisy instruments currently used
in outdoor measurements must be
redesigned or totally replaced to be
adequate for indoor use. Other require-
ments, such as measuring air exchange
rates, are unique to the indoor environ-
ment, and have no counterpart in outdoor
monitoring.
The present project was conceived to
develop guidelines for the design and
operation of indoor monitoring programs.
An attempt was made to collect in one
volume self-contained descriptions of the
major measurement methods, equipment,
design considerations, and data require-
ments needed by anyone contemplating
an indoor monitoring program. The
results should be useful for air pollution
engineers; building engineers; building
energy conservation experts; heating,
ventilation, and air conditioning (HVAC)
engineers; and students of environmental
or building-related fields.
Organization of Report
Section 1—Introduction
Section 2—Indoor Air Quality
Research
An historical perspective will familiarize
the reader with research conducted in the
field of indoor air quality. Ongoing
research projects are also listed (Table 1).
Section 3—Pollutants and
Other Factors Affecting Indoor
Air Quality
Thirteen pollutants or pollutant groups
and their indoor sources are summarized
(Table 2). A generalized mass balance
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Table 1. A Partial Summary of Ongoing Research Related to Indoor Air Quality
Area/brief title Pollutants Study frame
Characterization and
Modeling
Office buildings, homes
for elderly, and
schools
Air transport within
buildings
Monitoring and
modeling of energy
use. infiltration, and
indoor air quality
Pollutants in
residential air
Residential and
commercial indoor air
quality
Effects of residential
woodburning appliances
on indoor air quality
Assessment of natural
Rn and Rn progeny in
U.S. single-family
houses
Measurement of annual
indoor and outdoor
22*Rn and its
relationship to
environmental variables
Studies of Rn in
buildings
Residential ventilation
influence of building
design and other factors
on indoor air quality
Emissions
Emission from unvented
combustion sources; from
tobacco combustion; and
occupancy and tobacco
odor
Emission factors for
several indoor sources
Characterization of
emissions from unvented
gas stoves, wood stoves.
and kerosene heaters
Building materials
Characterization of
emissions from unvented
Organics
Rn progeny
CO. NO* IP.
Rn and Rn progeny.
HCHO
CO. NOi. HCHO.
particulates.
volatile vapors
Rn. NO* HCHO.
RSP, CO
CO, COz NO*
particulates
Rn and Rn
progeny
Rn
Rn
Rn, HCHO, CO.
NOs
CO, NOSr SOZe
Oa RSP. HCHO
NO* CO. SO,,
COz. O2
depletion;
particulates.
odor, CO, trace
elements, organics;
occupancy odor
NO* CO, SO*
COz, 02
depletion
CO. A/Oz,
S02
Organics
All
Phase 1: 1 building
each
Phase II: 2 buildings
each
3-compartment
chamber
2 identical
houses
4O homes
40 homes for
passive monitor-
ing of pollutants;
2 homes subset for
real-time
Test homes
40 representative
homes
Indoor/outdoor;
detailed, long-term
correlation for a
small number of
homes
140 homes
3 pairs of homes, to
assess heat exchanger.
weatherization, and
occupancy
4 homes
Chamber
Chamber
Research house
Chamber
Chamber
Sponsoring
organization
EPA
DOE
EPRI
CPSC
Niagara
Mohawk/
NYERDA
TVA/BPA
DOE
DOE
DOE
Pacific Power
& Light/
Battelle
Northwest
NSF
NIEHS
NIEHS
DOE and
CPSC
DOE
GRI
Principal
investigator*
Phase 1:
E. Pellizzari, RTI
Phase II: not
selected
D. Grimsrud,
A. Nero, LBL
N.L. Nagda,
GEOMET
T.G. Matthews,
Oak Ridge National
Laboratory
R. O'Neil, Niagara
Mohawk
J. Harper. TVA
J. Rundo,
Argonne National
Laboratory
N. Harley. New
York University
B. Cohen.
University of
Pittsburgh
D. Zerba; Pacific
Power & Light
C. Davidson.
Carnegie Mel/on
J.A.J. Stolwijk.
B.P. Leaderer.
W.S. Cain;
John B. Pierce
Foundation/ Yale
University
J.A.J. Stolwijk,
B.P. Leaderer;
John B. Pierce
Foundation/ Yale
University
D. Grimsrud,
A. Nero, LBL
D. Grimsrud,
A. Nero. LBL
D. Moschandreas,
IITRI
gas appliances, wood-
* Addresses of principal investigators appear at the end of Table 1.
2
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Table 1. (concluded)
Area/brief title
Pollutants
Study frame
Sponsoring
organization
Principal
investigator*
burning devices,
kerosene heaters,
cooking, and cigarette
smoking
Emissions from kerosene
heaters
Formaldehyde content in
various preserved wood
products supplied by
manufacturers
Controls (Including
Ventilation)
Pollutant-specific
removal techniques
Behavior of heat
exchangers
Instrumentation,
Development and field
evaluation of passive
samplers
Assessment of radioactive
and chemically active air
contaminants
CO, CO,, NO*
SOZ
HCHO
Rn, Rn progeny,
particulates
None
HCHO, CO,
particulates
Rn, Rn progeny
Chamber
Chemical analysis
of wood products
3-compartment
chamber
Chamber
Laboratory
Develop calibration
facility, instrumenta-
tion, and methods for
residential and
public building
sampling
CPSC
CPSC
DOE
DOE
EPA. BPA
DOE
DOE
W. Porter, CPSC
T.G. Matthews,
Oak Ridge National
Laboratory
D. Grimsrud,
A. Nero. LBL
D. Grimsrud.
A. Nero. LBL
D. Grimsrud,
A. Nero, LBL
£. Knutson, DOE
Exposure Studies
24-hour exposure of
residents of Washington
D.C., and Denver
24-hour exposure of
residents of chemical-
industrial cities
Total exposure to
emissions of unvented
gas appliances
Characterization of
24-hour exposure of
three population
subgroups
Assessing exposures and
adverse health effects
associated with alterna-
tive heat sources in
residences
Pollutants, aero-
allergens, and respir-
atory diseases
Data Evaluation
Evaluation of indoor
air quality data for
making risk assessments
Evaluation of risk of
exposure to Rn for
design of epidemio-
logjcal studies
CO
18 volatile
organics
CO. NO*
CO
NOt, CO, CO*
SO* HCHO.
Oi depletion
TSP, RSP. Oa,
CO, NOi. pollen
bacilli, fungi,
algae
All
Rn and Rn
progeny
1,000 person-
days in each
location
500 person-days
in two major
industrial areas
Large multi-
pollutant field
study
200 person-days
Field study
200 homes in
4 geographic
clusters
Data from past
studies
Data from past
studies
EPA T. Hartwell. RTI;
T. Wey, PEDCo
EPA E. Pellizzari,
RTI
GRI J. Spengler,
Harvard
EPRI N.L. Nagda. GEOMET
NIEHS/CPSC J.A.J. Stolwijk.
B.P. Leaderer;
John B. Pierce
Foundation/Yale
University
EPA M.D. Lebowitz.
University of Arizona
EPRI J. Yocom, TRC;
J. Spengler,
Harvard
DOE A. Nero,
D. Grimsrud,
LBL
* Addresses and phone numbers:
Argonne National Laboratory, Argonne, IL 60439, 1312)972-4168.
Carnegie MellonJJniversity, Pittsburgh, PA 15213, (412)578-2951.
GEOMET Technologies, "inc.. 1801 Research Boulevard. Rockville. MD 20850. (301) 424-9133.
Harvard School of Public Health. 665 Huntingdon Avenue. Boston. MA O2115. (617) 732-1255.
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IIT Research Institute, 10 West 35th Street. Chicago. IL 6O616, (312) 567-4310.
Lawrence Berkeley Laboratories, University of California. Berkeley, CA 94720, (415) 486-4023.
Niagara Mohawk. 300 Erie Boulevard West. Syracuse, NY 13202, (315) 474-1511.
Oak Ridge National Laboratory, Oak Ridge, TN 3783O, (615)574-6248.
Pacific Power & Light, Portland, OR 97204, (503) 243-4876.
Pierce, John B., Foundation, Yale University, 290 Congress Street, New Haven, CT 06519, (203)562-9901.
PEDCo Environmental, Inc., 11499 Chester Road, Cincinnati, OH 45246, (513) 782-47OO.
Research Triangle Institute, Research Triangle Park. NC 277O9, (919) 541-6OOO.
Tennessee Valley Authority. Chattanooga. TN 37401, (615)751-0011.
TRC Environmental Consultants, Inc., 800 Connecticut Boulevard, East Hartford, CT 06108, (203) 289-8631.
University of Arizona, University Health Sciences Center, College of Medicine, Tucson, AZ 65724, (602) 626-6379.
U.S. Department of Energy, Environmental Measurements Laboratory, 376 Hudson Street. New York. NY 10014. (212) 620-3570.
model relates various factors affecting
indoor concentrations; an example
illustrates the use of the model. Publica-
tions describing different aspects of
indoor air quality research are highlighted.
Section 4—Measurement
Systems
This section discusses measurement
and instrumentation characteristics,
operating principles, and sources of
information. Instrumentation and meth-
ods for measuring pollutant concentra-
tions and air exchange rates are summa-
rized (Table 3).
Section 5—Design
Considerations
A discussion of various design consid-
erations, including selection of parameters,
determination of sample size, and selec-
tion of a measurement system, will help
the user systematically develop a moni-
toring program. Helpful hints on such
specifics as probe placement are given,
and feedback and iterative procedures for
developing a design are emphasized.
Approaches for addressing building-
associated indoor quality problems are
discussed.
Section 6—Data Reporting
Guidelines for data reporting will
enable users and study investigators to
understand the descriptors required to
make useful data sets accessible to other
users. Formats for reporting the scope
and content of data are included.
Section 7—Quality Assurance
and Quality Control
Quality assurance (QA) and quality
control (QC) considerations, with refer-
ences, are discussed.
Appendix A
This appendix categorizes and reviews
commercial instruments suitable for
measuring indoor air quality.
Table 2.
Sources and Exposure Guidelines of Indoor Air Contaminants
Pollutant/sources Guidelines
Asbestos and Other Fibrous Aerosols
Friable asbestos: fireproofing.
thermal and acoustic insulation, decoration.
Hard asbestos: vinyl floor and cement
products, automatic brake linings (0).-\
Biological Aerosols
Human and animal metabolic activity
products, infectious agents, allergens, fungi,
bacteria in humidifiers, bacteria in cooling
devices.
Carbon Monoxide
Kerosene heaters, gas stoves, gas space
heaters, wood stoves, fireplaces, smoking,
and automobiles (0).
Formaldehyde
Particleboard, paneling, plywood, ceiling
tile, urea-formaldehyde foam insulation,
other construct/on materials.
Inhalable Particulates
Smoking, vacuuming, combustion sources 55 to 110 ug/m3 annual. #150 to 350 ug/m3 for
(0), industrial sources, fugitive dust (0), and 24 hour.ti
other organic paniculate constituents.
Metals and Other Inorganic Paniculate Contaminants
0.2 fibers/ml for fibers longer than
5 urn (based on ASHRAE* guidelines of 1/10 of
U.S. 8-hour occupational standard).
None available.
9 ppm for 8 hours (NAAQS§); 35 ppm for 1 hour
(NAAQS).
0.1 ppm (based on Dutch and West German
guidelines as reported in ASHRAE Guidelines,
1981, and National Research Council report,
1981).
Lead: old paint, automobile exhaust (0).
Mercury: old paint, fossil fuel combustion
(0).
Cadmium: smoking, use of fungicides (O).
Arsenic: smoking, pesticides, rodent
poisons.
Nitrates: Outdoor air.
Sulfates: Outdoor air.
Nitrogen Dioxide
Gas stoves, gas space heaters, kerosene
space heaters, combustion sources (0),
automobile exhaust (0).
Ozone
Photocopying machines, electrostatic air
cleaners, outdoor air.
Pesticides and Other Semivolatile Organics
Sprays and strips, drift from area
applications (0).
*ASHRAE—American Society of Heating. Refrigerating and Air-Conditioning Engineers.
\(0) refers to outdoor sources.
§NAAQS—U.S. National Ambient Air Quality Standards.
HThese numbers indicate the probable range for the new NAAQS for particulates of Wumorlessin
size. Based on "Recommendations for the National Ambient Air Quality Standards for
Particulates—Revised Draft Paper," Strategies and Air Standard Division, Office of Air Programs.
EPA, October 1981.
**National Research Council. 1982. "An Assessment of Health Risk of Seven Pesticides Used for
Termite Control." National Academy Press, Washington, D.C.
1.5 fig/m3 for 3 months (NAAQS).
2 ng/rrfl for 24 hours (ASHRAE).
2 ug/m3 for 24 hours (ASHRAE).
None available.
None available.
4 ug/m3 annual. 12 ug/m3 for 24 hours
(ASHRAE).
0.05 ppm annual (NAAQS).
Not exceeding 0.12 ppm once a year (NAAQS).
5 ug/m3 for chlordane (NRC). **
-------
Table 2, (concluded!
Pollutant/sources
Guidelines
Polyaromatic Hydrocarbons and Other
Organic Paniculate Constituents
Woodburning, smoking, cooking, coal
combustion, and coke ovens (0).
Radon and Radon Progeny
Diffusion through floors and basement
walls from soil in contact with a residence,
construction materials containing radium,
untreated groundwater containing
dissolved radon, combustion of natural gas
used in cooking and unvented heating.
Radon from local soil emanation (0).
Sulfur Dioxide
Kerosene space heaters, coal and oil fuel
combustion sources (0).
Volatile Organics
Cooking, smoking, room deodorizers,
cleaning sprays, paints, varnishes, solvents
and other organic products used in homes
and offices, furnishings such as carpets
and draperies, clothing, furniture,
emissions from waste dumps (0).
None available.
O.O1 working level (ASHRAE guidelines).
Appendix B
Standard or accepted methods can be
used for certain measurements when no
off-the-shelf, commercial instrumenta-
tion is available. In some cases, these
methods can serve as alternatives to the
instrumentation summarized in Appendix
A. Appendix B summarizes these methods.
80 fjg/m3 annual;
315 ug/m3 for 24 hours (NAAQSI.
None available.
Table 3. Summary of Selected Pollutant Concentration Measurement Systems
Pollutant
Operating principle
Personal,
portable,
or stationary
Active
or
passive
Analyzer
or
collector
Appendix
cross-reference *
Asbestos and
ither fibrous
aerosols
Biologic aerosols
Carbon monoxide
Induced Oscillation/Optical Scattering— Portable Active Analyzer A1-1
Sample air passes through an oscillating
electric field. Fibers are detected by
detecting right-angle scattering pulses
from larger illumination aligned with the
fiber axis.
Filtration—A laboratory analyzes the filters. Personal Active Collector B
Impaction—Sample air passes through a Stationary Active Collector A2-1,A2-2
series of selective stages (petri dish
containing agar); inertial effects cause
particles in size ranges of interest to collide
with collector surface. Microbial colonies
are incubated for 24 hours and counted
manually.
Nondispersive Infrared (NDIR)—Infrared Stationary Active Analyzer
radiation passes through parallel optical
cells, one containing sample air, the other
containing reference CO-free air. The
difference in absorbance relates to CO
concentration.
Gas Filter Correlation fGFCJ—Infrared Stationary Active Analyzer
radiation passes through a spinning fitter
wheel that contains a sealed CO reference
cell and a nitrogen reference cell. The IR
beam then passes through a chamber
containing sample air and is detected. The
signal difference observed between the
nitrogen cell and the CO cell relates to CO
concentration.
Electrochemical Oxidation—Sample air Personal Active Analyzer A3-3
passes into an electrochemical cell Personal Passive Analyzer A3-2, A3-5
where oxidation of CO to COz Portable Active Analyzer A3-1, A3-4
produces a signal related to the CO
concentration.
EPA Reference Method,
Appendix A
EPA Equivalent Method,
Appendix A
1 or B denotes the appendix where system is discussed; the numbers following A show instrument summary number.
-------
Table 3 (continued)
Pollutant
Operating principle
Personal,
portable.
or stationary
Active
or
passive
Analyzer
or
collector
Appendix
cross-reference*
Formaldehyde
Inhalable
paniculate matter
Metals and other
inorganic
paniculate
constituents
Nitrogen dioxide
Ozone
Wet Chemical—HCHO is scrubbed from the Portable Active Analyzer
sample airstream by a standard reagent
solution. Addition of a second reagent
forms a distinctive color whose intensity
is related to HCHO concentration.
Sorption/Spectrophotometry—HCHO is Personal Passive Collector
adsorbed onto treated substrate and
subsequently desorbed and quantitated in
the laboratory.
Optical Scattering—Sample air passes Persona/ Passive Analyzer
through a size-selective inlet prior to Portable Active Analyzer
entering an optical cell. Forward light
scattering from controlled light source
relates to IP concentration.
Filtration—Sample air passes through a Stationary Active Co/lector
size-selective inlet. Particles in size range(s)
of interest are retained on filter(s) for mass
determination in laboratory.
Impaction—Sample air passes through a Personal Active Collector
series of selective stages; inertial effects
cause particles in size range of interest to
collide with collector surface.
Piezoelectric Resonance—Sample air Portable Active Analyzer
passes through a size-selective inlet. Stationary Active Analyzer
Particles within the size range of interest are
electrostatically precipitated onto a quartz
crystal. Alterations in oscillation frequency
relate to collected mass.
Filter Collection/Laboratory Analysis— Personal Active Collector
Inorganic constituents are collected by Portable Active Collector
passing sample air through a suitable filter. Stationary Active Collector
Metals may be quantitated by atomic
absorption spectroscopy, neutron
activation analysis, proton-induced X-ray
fluorescence. Nitrates and sulfates can be
determined spectrophotometrica/fy.
Gas-Phase Chemiluminescence—Photon Stationary Active Analyzer
emission that accompanies reaction of NO
with Os is monitored to simultaneously Portable Active Analyzer
quantify NO and NO*. NO, is quantified
by first reducing all oxides of nitrogen to
nitric oxide, NO. NOz is the algebraic
difference between A/O, and NO.
Triethanol Amine (TEA) Adsorption—NOz Personal Passive Collector
is quantitatively sorbed onto treated
substrate for subsequent quantisation in
the laboratory.
Wet Chemical—NOz reacts with
a reagent system and is quantified
color/metrically.
Gas-Phase Chemiluminescence—Photo-
metric detection of the Chemiluminescence
resulting from the gas-phase reaction
between ethylene and O*
Gas-Solid Phase Chemiluminescence—
Photometric detection of the
Chemiluminescence resulting from
the reaction between Os and rhodamine-B.
Ultraviolet Absorption—Measurement of Stationary Active Analyzer
the difference in ultraviolet intensity
between sample air and reference.
A4-4 and B
A4-1.A4-2.A4-3,
B
A5-1
A5-2
A5-3, A5-4. B
A5-5
A5-6
A5-6
EPA Reference Method,
Appendix A
A6-1
A6-3, A6-5
Portable
Personal
Stationary
Portable
Stationary
Active
Passive
Active
Active
Active
Analyzer
Collector
Analyzer
Analyzer
Analyzer
A6-4
A6-2
EPAr
Appei
A7-1
EPAE
EPA Reference Method,
EPA Equivalent Method.
Appendix A
EPA Equivalent Method,
Appendix A
*A or B denotes the appendix where system is discussed; the numbers following A show instrument summary number.
6
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Table 3. (continued)
Pollutant
Pesticides and other
semivolatile
organics
Polyaromatic
hydrocarbons and
other organic
particulate
constituents
Radon/radon
progeny
Sulfur dioxide
Personal, Active
portable. or
Operating principle or stationary passive
Sorbent Collection/Laboratory Analysis—
Semivolatile organics are collected by
passing sample air through polyurethane
foam. In the laboratory, compounds are
extracted for chromatographic quantitation.
Filter Collection/Laboratory Analysis —
Organic constituents are collected by
passing sample air through a suitable
filter. Organic constituent may be
quantified through a number of
chromatographic techniques.
Filtration/Gross Alpha Counting— Rn
progeny collect onto a filter; consequent
alpha activity relates to working level.
Electrostatic Collection/Thermolumine-
scent Dosimetry—Rn passes into a special
chamber where subsequent progeny (ions)
are electrostatically focuseV onto a thermo-
luminescent dosimeter (TLD) chip.
Subsequent alpha disintegrations create
metastable defects in the TLD, which is
deactivated and quantified in the laboratory.
Grab Sample/Alpha Scintillation — Rn
progeny collect in a filter; Rn is collected
in a scintillation flask. Subsequent alpha
activity relates to working level (filter
sample) and to Rn concentration
(scintillation flask).
Filtration/Alpha Spectroscopy Coupled
to Electrostatic Collection/Alpha
Spectroscopy— Rn progeny (ions) are
collected on a filter; subsequent alpha
decay relates to working level. Rn passes
into a special chamber where subsequent
decay ions are electrostatically focused
onto a detector; subsequent alpha decay
relates to Rn concentration.
Filtration/Alpha and Beta Spectroscopy —
Rn progeny are collected on a filter;
subsequent alpha and beta activity relate
to working level.
TRACK ETCH™— Alpha-sensitive film
registers damage tracks when chemically
etched; average Rn concentration is
related to the number of damage tracks
per unit area.
Sorption/ Gamma Activity— Rn is absorbed
onto activated charcoal; subsequent
gamma activity is related to average Rn
concentration.
Flame Photometric Detection (FPD)—
Measurement of sulfur-specific emissions
from hydrogen-rich air flame.
Pulsed Fluorescence— Measurement of
the intensity of the ultraviolet fluorescence
of SOi excited by a high-intensity light
source.
Wet Chemical— SOz reacts with a reagent
system and is quantified conducto-
metrically or colorimetrically.
Electrochemical Oxidation— Sample air
passes into an electrochemical cell where
Personal
Portable
Stationary
Personal
Portable
Stationary
Stationary
Stationary
Portable
Stationary
Stationary
Stationary
Stationary
Stationary
Stationary
Stationary
Portable
Personal
Personal
Active
Active
Active
Active
Active
Active
Active
Passive
Active
Active
Active
Passive
Active
Active
Active
Active
Active
Active
Passive
Analyzer
or
collector
Collector
Collector
Collector
Collector
Collector
Collector
Collector
Collector
Analyzer
Analyzer
Analyzer
Collector
Collector
Analyzer
Analyzer
Analyzer
Analyzer
Analyzer
Analyzer
Appendix
cross-reference*
B
B
A8-2
A3- J, A8-6
A8-3
A8-4
A8-5. A8-7
A8-8
B
EPA Equivalent Method
EPA Equivalent Method
EPA Equivalent Method
A9-3
A9-1
A9-2
and B denotes appendix where system is discussed; the numbers following A show instrument summary number.
-------
Table 3 (concluded)
Pollutant
Operating principle
Personal,
portable,
or stationary
Active
or
passive
Analyzer
or
collector
Appendix
cross-reference *
Volatile organics
oxidation of SOz produces a signal
proportioned to concentration.
Sorbent Collection/Laboratory Analysis-
Volatile organics are collected by
passing sample air through a suitable
absorbent column. In the laboratory,
compounds of interest are desorbed for
chromatographic Quantisation.
Personal-
Portable
Stationary
Active
Active
Active
Collector
Collector
Collector
"A or B denotes the appendix where system is discussed; the numbers following A show instrument summary number.
Niren L Nagda and Harry E. Rector are with Geomet Technologies, Inc., Rockville,
MD.
Lance A. Wallace is the EPA Project Officer (see below).
The complete report, entitled "Guidelines for Monitoring Indoor Air Quality," (Order
No. PB 83-264 465; Cost: $22.00, subject to change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield. VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Office of Monitoring Systems and Quality Assurance
U.S. Environmental Protection Agency (RD-680)
401 M Street, S.W.
Washington, DC 20460
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
Official Business
Penalty for Private Use $300
5 5 .-• ? " 5
CHICAGO IL 6060M
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