United States Environmental
Protection Agency
Office of Research and Development
Research Triangle Park, NC 27711
a EPA
EPA/600/N-98/003 Fall/Winter 1998
Inside I A Q
EPA's Indoor Air Quality Research Update
In This Issue
Evaluation of Low-VOC Latex Paints
A Compilation of Data on Emissions
from Indoor Sources
Page
Volatile Organic Emissions from Printed
Circuit Board Laminates 6
Factors Influencing IAQ, Immunity,
and Health 9
Modeling Emissions From Water-Based
Cleaning Supplies 10
Antimicrobial Agents Used in HVAC Systems 12
Summaries of Recent Publications 12
Glossary 15
Inside IAQ is distributed twice a year and
highlights indoor air quality (IAQ) research
conducted by EPA's National Risk Management
Research Laboratory's (NRMRL's) Indoor
Environment Management Branch (IEMB) and
other parts of EPA's Office of Research and
Development.
If you would like to be added to or removed from
the mailing list, please mail, fax, or e-mail your
name and address to;
Inside IAQ, Attn. Kelly Leovic
U.S. EPA -MD-54
Research Triangle Park, NC 27711
Fax: 919-541-2157
E-Mail: kleovic@engineer.aeerl.epa.gov
Also, check our home page on the Internet at:
http//www.epa.gov/docs/crb/iemb/iembhp.htm
EVALUATION OF LOW-VOC LATEX PAINTS
Low-volatile organic compound (VOC) latex paints are advertised as the
"perfect choice" for application in occupied buildings (e.g., hospitals,
nursing homes, schools, hotels, offices, and homes) during normal
business hours. IEMB recently evaluated four commercially available
low-VOC interior latex paints. Formaldehyde emissions were detected
in two of the paints, and detailed analyses were performed on the one
paint with the highest formaldehyde emissions. This paint is promoted
by its manufacturer as "no solvent" and "VOC free" based on EPA
Reference Method 24. The sales brochure claims "virtually no harmful
emissions into the air" and "no unfriendly or irritable odors."
A bulk analysis was performed by extracting the paint with methanol
and then analyzing the extract by gas chromatography/mass
spectrometry (GC/MS). While Method 24 measures only the total
volatile organic compound (TVOC) content, bulk analysis provides more
accurate and precise data for the content of individual VOCs. It was
found that most of the individual VOC concentrations in the paint were
below or near the quantification limit of the analytical techniques used.
The TVOC content (less than 0.1 wt.%) was well below that (about 5
wt.%) of an ordinary latex paint.
Small chambertests were also performed on the paint. The flow-through,
dynamic chambers have a volume of 53 liters and are constructed with
electropolished stainless steel interior surfaces to minimize adsorption of
VOCs. Small fans were used to enhance mixing and provide a velocity
near the test surface of 5-10 cm/s, which is typical of indoor
environments. Emissions testing was conducted by placing freshly
painted (2-3 minutes) gypsumboard (16.3 x 16.3 cm) in the chamber,
painted side up. The chamber was closed, and clean air (< 5(jg/m3
TVOCs) flow was started through the chamber. A flow rate of 0.44
L/min, equivalent to 0.5 air change per hour, was used. Testing was
conducted at 23 °C with an inlet relative humidity (RH) of 50%.
Small chambertests also showed very low VOC emissions for this paint;
however, the peak concentration of formaldehyde in the chamber air
reached as high as 2.0 mg/m3 about 30 minutes after painting. The
chamber air formaldehyde concentration decreased by about 85% in the
(Continued on Page 2)
Inside IAQ, Fall/Winter 1998
Page 1
-------
first 24 hours, and the concentration decrease slowed down
considerably in the second 24 hour period. After 120 hours,
the formaldehyde concentration was 0.16 mg/m3.
Formaldehyde is a primary upper respiratory tract irritant,
and its odor is characterized as "pungent." The lowest listed
odor detection threshold is 0.04 mg/m3. Symptoms of eye,
nose, and throat irritation, such as tearing, running nose, and
a burning sensation in these areas, are relatively common with
formaldehyde exposure. Formaldehyde is also classified as a
probable carcinogen based on sufficient evidence in animal
studies. The World Health Organization guideline for indoor
air formaldehyde concentrations is 0.1 mg/m3. The U.S.
Department of Housing and Urban Development recommends
that indoor formaldehyde concentrations from all sources not
exceed 0.5 mg/m3. The California Air Resources Board
recommends for homes an "action level" of 0.12 mg/m3 and
a "target level" of 0.06 mg/m3 or lower.
It was suspected and later confirmed that the biocide used in the
paint was a source of the formaldehyde (up to 50%). (Biocide is
used as an additive to prevent paint degradation by microbial
growth.) However, the source of the remainder of the
formaldehyde is not certain, though it is possible that it is from
the paint formulation, side reactions, or other additives.
The results illustrate that "no-VOC" does not necessarily
mean no-emissions. The common indoor air definition of
VOC only includes those organic compounds with boiling
points between 50 and 260°C. A number of hazardous air
pollutants (e.g., formaldehyde with a boiling point of -21°C)
are not accounted for by this definition. Also, the VOC
contained in the bulk paint may not be the VOC emitted since
VOCs can be formed as byproducts of chemical reactions
after the paint is applied.
The results also indicate that EPA Reference Method 24 is
probably not an adequate method for measuring the VOC
content of low-VOC latex paints. Since it is a gravimetric
method relying on the difference between weight loss upon
heating and water content of the sample paint, the analytical
precision is 1.5 and 4.7% for within- and between-laboratory
data, respectively. Current bulk analysis and emission test
results showed that the VOC contents of low-VOC latex
paints (e.g., less than 0.1%) are well within the uncertainty
range of Method 24, and the method is apparently not precise
enough to accurately define the VOC content of those paints.
IEMB has shared the results from this study with the paint
manufacturer who was willing to reformulate the paint. To
determine the extent of formaldehyde emissions from interior
paints on the market, a major effort involving the testing of a
number of interior paints would be needed. (EPA Contact:
John Chang, 919-541-3747, jchang@engineer.aeerl.epa.gov)
A COMPILATION OF DATA ON EMISSIONS FROM
INDOOR SOURCES
There is a growing amount of data in the scientific and technical
literature on pollutant emissions from indoor sources. Most of
the data have been reported by researchers interested in
developing testing methods, understanding mechanisms of mass
transfer from source to air, or studying a particular class of
indoor sources. IEMB has been compiling such data primarily to
support its in-house source characterization studies by seeing
where the data gaps are, and to develop descriptive statistics that
might be useful in designing new products, buildings, or
ventilation systems. This article summarizes the approach being
taken by IEMB and the current status of the compilation.
An Excel spreadsheet is used as the structure of the compilation.
Twenty fields (columns in the spreadsheet) have been
established; they are listed and described in Table 1. Note that
data are included only from references that report emission
factors (pollutant emission rate per unit of source), or
experimental data from which emission factors can be
calculated.
Table 2 summarizes the source categorization scheme used.
Source categories and examples of source "types" are shown.
IEMB is trying to use a nomenclature that is compatible with
industrial and commercial terminology, which can be variable.
While care is taken in selecting references, there are no detailed
acceptability criteria. Articles and reports from peer-reviewed
scientific and technical literature are preferred; these are labeled
"primary" references in the bibliography listed in Table 3.
References that may not have been through peer review but
appear to have been based on good measurement practices are
labeled "secondary" references in the bibliography. References
that summarize results from studies by other authors are used
very little in this database; those that have been are labeled
"tertiary" references in the bibliography.
The database currently has about 5000 records covering
about 60 source types, extracted from about 60 references.
Emphasis to date has been on development of the structure
and data entry guidelines. One round of quality assurance
(QA) has been completed, and a second QA review is
planned. Over the next year, the emphasis will shift to
additional data entry and analysis. IEMB has started to look
at the data with an eye toward developing representative
emission factors for product, building, and heating,
ventilating, and air-conditioning (HVAC) system design.
Developers of other emission data bases will also be contacted
to compare compilation and analysis approaches. Comments
are welcome, as are recommendations for additional
references. (EPA Contact: W. Gene Tucker, 919-541-2746,
tucker.gene@epa.gov)
Inside IAQ, Fall/Winter 1998
Page 2
-------
Table 1. Names of fields in indoor emissions database
Name of Field
Record
Number
Description Data Entry Guidelines
Number assigned to first field of each record.
Records (rows) generally represent emissions data
for a single pollutant or pollutant class from a single
sample, or set of samples, of a source type.
Occasionally, a record will represent two or more
pollutants.
Source Information
Category
Type
NAICS
Source category of the sample that was tested. (See
Table 2 for listing of source categories.)
Source type of the sample that was tested. (See
Table 2 for listing of some source types.) Use
judgement creating new source types; consider
author's descriptions.
North American Industrial Classification System
code number. (NAICS replaced the Standard
Industrial Classification, or SIC, system in 1997.)
Enter the code of the source category-or, if
possible-the source type. See
http://www.theodora.com/sic_index.html or
www.census.gov/epcd/naicscod.txt for listing of
NAICS codes and titles, and www/naics4.html.
Emission Testing Information
Reference
Specific
Identification
Age of Tested
Sample
Code for the reference from which the emissions
data were obtained. Use first three letters of first
author's last name followed by the last two digits of
year the data were published. If same author (or
more than one author with the same three first letters
of last name) published more than once during same
year, add lower-case a, b, etc. to distinguish them.
Specific information about the source sample that
expands on the "source type" entry (such as
composition data, condition or history of the product
from which the sample was taken). If the author's
description differs from the description used in the
Category and Type fields, enter it here.
Time that elapsed between when the source sample
was first put into use and when emission sampling
occurred. If sample was purchased at a store, that
should be noted in the "specific identification" field.
If the reference presents both an empirical model
and tabulated emission factors, enter the tabulated
values and describe the model in the "comment"
field. If an empirical emission model is presented
and measured emission factors are not clearly
tabulated, records should be created for the
following preselected ages, limited to the time period
for -which the model is applicable'. 1 hour, 24 h, 168
h (1 week), 730 h (1 month), and 8760 h (1 year). In
these cases, note that a specific age has been
selected: e.g., enter "24 h (modeled age)."
Pollution Information
Name
CASN
Test Methods/
Conditions
Analytical
Method
Chemical name of the pollutant (or other name, if is
not a single chemical substance).
Chemical Abstract Service (CAS) Number for the
pollutant. For a listing of CAS numbers, see
http://webbook.nist.gov/chemistry/name-ser.htm.
Enter information such as chamber size, material of
construction, air change rate or flow, temperature
and relative humidity during testing, and air
sampling rate or volume.
Enter the method(s) used to chemically or physically
characterize the pollutant in the air sample.
Name of Field
Description Data Entry Guidelines
Emission Factors
Units
Number of
Measure-
ments, N
Minimum
Median
Mean (SD)
Maximum
Emission factors should be reported in units of
emission rate per unit of source. (Units for emission
rate are general by mass per time', units of source are
area for surface materials, or a single product for
sources like machines or pieces of furniture).
Emission factors for physical or chemical pollutants
should therefore be entered in units of fig/h per m2
for surface materials, or /ug/h per unit of product for
other source types. If other units are used in the
reference, convert to the units and note in the
"comments" field that the conversion has been made.
Units for biological pollutants such as fungi should
be entered as reported; colony-forming units (CPUs)
are often used instead of mass.
The number of measurements that were made to
establish the values entered into the next four fields.
Where N= 1 , the emission factor value should be
entered into the "mean" field. When it is not clear
from the reference how many measurements were
made, enter "?."
Minimum value, where multiple emission
measurements of a single same sample, or set of
similar samples) are reported in the reference.
Median value, where multiple emission
measurements (of a single same sample, or set of
similar samples) are reported in the reference.
Mean and standard deviation values, where reported.
If a single measurement is reported in the reference,
enter it in this field.
Maximum value, where multiple measurements (of a
single sample, or set of similar samples) are reported
in the reference.
Emissions Modeling
Yes/No
Half-Time
Enter Y or N, depending on whether the reference
includes a mathematical model that represents
measurements taken. Note that references dealing
only with purely theoretical models or discussion of
emission models (i.e., references that do not report
new data) are not to be covered in this data base.
Time, in hours, for the emission factor to go from its
maximum value to half the maximum, as estimated
by the model. Also enter standard deviation for the
half-time, if reported.
Comments
Use this field to note special information on the
reference that might be useful to users of the data
base. If emissions modeling was reported, enter the
mathematical form of the model and values for
coefficients; also note range of applicability (e.g., for
time or temperature). Note any adjustments made to
reported data (e.g., change of emission factor units
or conversion of chamber concentration data to
emission factors). If the value entered in the
emission factor field was calculated from the model,
note that in this field. When emission factor data
were not obtained directly from the reference, but
through contact with an author, note by a statement
such as "The value for this emission factor, which is
difficult to estimate from Figure x of the reference,
was obtained directly from the author."
Inside IAQ, Fall/Winter 1998
Page 3
-------
Table 2. Source categories and types
Category
Adhesive s
Cabinetry
Caulks &
Seals
Cleaning Agents
(see also pesticides)
Floor Materials
Furnishings
HVAC Systems and
Components
(see also space heating and
cooking equipment)
Insulation
Products
Machines
Type (Examples)
Carpet adhesive
Flooring adhesive
General adhesive
Kitchen cabinets
Caulk, general
Sealant, general
Detergent
Disinfectant
Misc. cleaning agents
Solvent-based cleaner
Carpet-synthetic fiber
Carpet-wool fiber
Carpet cushion
Carpet system
Cork flooring
Linoleum
Sheet vinyl flooring
Tile vinyl flooring
Wood flooring
Other flooring
Drapery
Drapery lining
Office furniture-metal
Office furniture-upholstered
Office furniture-wood
Residential furniture-metal
Residential furniture-upholstered
Residential furniture-wood
Other furnishings
Air cleaning device
Air moving equipment
Cooling coils
Ductwork
Heating coils
Humidification equipment
Fibrous insulation
Foam insulation
Air cleaner, in-room
Air conditioner, room
Electronic circuit board
Humidifier, in-room
Photocopier, dry-process
Photocopier, wet-process
Printer, laser
Spirit duplicator
Digital duplicator
Vacuum cleaner (see also
occupant activities)
Other machines
Category
Miscellaneous
Materials
Occupants and
Occupant Activities
Paints and Coatings
Personal Care Items
Pesticides
(see also cleaning agents)
Space Heating and Cooking
(See also HVAC systems and
components)
Wall and Ceiling Materials
(other than paints and
coatings)
Wood Products
Type (Examples)
Brick
Ceramic tile
Clothing
Concrete
Glass
Metal
Microbial culture
Misc. stored material
Mortar
Paper-based material
Stone
Animals (pets)
Cleaning
Cooking
Human occupants- bioeffluents
Smoking
Human occupants- other activities
Oil-based finish
Solvent-based paint
Stain
Varnish
Water-based finish
Water-based paint
Wax
Hair spray
Other PCIs
Moth repellent
Other pesticides
Electric
Gas fueled
Oil fueled
Solid fuel
Ceiling tile
Gypsum board
Plaster
Wall paneling
Wallpaper/wall covering
Other wall and ceiling materials
Fiber panel material (e.g.,
insulation board, hardboard)
Particleboard
Plywood
Solid natural wood product
Veneer
Waferboard/chipboard
Other wood products
Inside IAQ, Fall/Winter 1998
Page 4
-------
Table 3. References cited to date
ALE96 Alevantis, L. E. (1996). Califor-
nia Department of Health Ser-
vices, Berkeley, California. (3 °)
ALL78 Allen, Wadden, and Ross (1978).
Am. Ind. Hyg. Assoc. Jour.
39(6):466-471. (1°)
ANT97 Anttonen et al. (1997).
Proceedings of IAQ'97, Healthy
Buildings (ASHRAE). 3:
575-579. (2°)
BAT91 Batterman, Bartoletta, and Burge
(1991). Presented at 84th Annual
Meeting of AWMA. (2°)
BAY90 Bayer and Papanicolopoulos
(1990). Proceedings of Indoor Air
'90, 3:725-730. (2°)
BER97 Bernheim and Levin (1997). Proc.
of IAQ '97, Healthy Buildings
(ASHRAE). 3:599-604. (2°)
BL A91 Black, Pearson, and Work (1991).
Proc. of IAQ'91, Healthy
Buildings (ASHRAE). 267-272.
(2°)
BRO97 Brockmann et al. (1997).
Engineering Solutions to IAQ
Problems, pp. 403-420 (1 °)
CHA92 Chang and Guo (1992). Indoor
Air. 2:146-153. (1°)
CHA94 Chang and Guo (1994). Indoor
Air. 4:35-39. (1°)
CHA97 Chang et al. (1997). Indoor Air.
7:241-247. (1°)
COL93 Colombo, De Bortoli, and
Tichenor (1993). Proceedings of
Indoor Air '93, 2:573-578. (2°)
DAV91 Davidson et al. (1991).
Proceedings of IAQ'91, Healthy
Buildings (ASHRAE). 299-303.
(2°)
FIS95 Classification of Indoor Climate,
Construction, and Finishing
Materials. FiSIAQ Publication
5E. Finnish Society of Indoor Air
Quality and Climate, Espoo,
Finland, 1995. (2°)
FOR97 Fortmann et al. (1997).
Engineering Solutions to IAQ
Problems, pp. 117-127. (1°)
FUN97 Punch, Winther, and Larsen
(1997). Proc. IAQ'97, Healthy
Buildings (ASHRAE). 3:617-622.
(2°)
HAN86 Hansen and Anderson (1986).
Am. Ind. Hyg. Assoc. Jour.
47(10):659-665. (1°)
HAW92 Hawkins et al. (1992). American
Industrial Hygiene Association
Journal. 53(5):275-282. (1°)
HET95 Hetes, Moore, and Northeim
(1995). EPA/600/R-95-045. (3°)
HOD93 Hodgson, Wooley, and Daisy
(1993). Jour, of Air and Waste
Manag. Assoc. 43:316-324. (1°)
HOR97 Horn, Ullrich, and Seifert (1997).
Proc. of IAQ'97, Healthy
Buildings (ASHRAE). 3:
533-538. (2°)
HOW97 Howard, McCrillis, and Krebs
(1997). Engineering Solutions to
IAQ Problems, pp 3-15. (2°)
KER90 Kerr and Sauer (1990).
Proceedings of Indoor Air '90,
3:759-763. (2°)
LAR97 Larsen and Punch (1997).
Proceedings of IAQ'97, Healthy
Buildings (ASHRAE).
3:611-616. (2°)
LEO96 Leovic et al. (1996). Jour, of Air
and Waste Management
Association. 46:821-829. (1°)
LEO97 Leovic etal. (1997). Proceedings
of IAQ'97, Healthy Buildings
(ASHRAE). 3:623-628. (2°)
LUN97 Lundgren, Jonsson, and
Ek-Olausson (1997). IAQ'97,
Healthy Bldgs (ASHRAE).
1:287-292. (2°)
MAY96 Mayo, Figley, and Robinson
(1996). Presented at Clean Air'96,
Orlando, Florida. (3°)
MOR96 Morrison and Hodgson (1996).
Proceedings of Indoor Air '96,
3:585-590. (2°)
MUL94 Muller and Black (1994).
Presented at the American
Industrial Hygiene Conf, May
1994. (2°)
NAG95 Nagda, Koontz, and Kennedy
(1995). Indoor Air. 5:189-195.
(1°)
NEL87 Nelms, Mason, and Tichenor
(1987). EPA/600/D-87/165. (1°)
NIU97 Niu et al. (1997). Engineering
Solutions to IAQ Problems, pp.
547-554. (2°)
NOR97 Northeim et al. (1997).
Engineering Solutions to IAQ
Problems, pp 71-81. (2°)
ROA96 Roache et al. (1996). Proceedings
of Indoor Air'96,2:657-662. (2°)
SAA92 Saarela (1992). Proceedings of
IAQ <92, Environments for People
(ASHRAE). 349-354. (2°)
SAA97 Saarela, Tirkkonen, and
Suomi-Lmdberg (1997). IAQ'97,
Hlthy Bldgs (ASHRAE).
3:545-550. (2°)
SEL80 Selway, Allen, and Wadden
(1980). Am. Ind. Hyg. Assoc.
Journal. 41:455-459. (1°)
SMI90 Smith, Donovan, and Ensor
(1990). Proceedings of Indoor Air
'90,3:647-652. (2°)
STR91 Strobndge and Black (1991).
Proceedings of IAQ <91, Healthy
Buildings (ASHRAE). 292-298.
(2°)
TEP95 Tepper et al. (1995). American
Industrial Hygiene Association
Journal. 56:158-170. (1°)
TIC86 Tichenor and Mason (1986).
EPA/600/D-86/088. (1°)
TIC88a Tichenor et al. (1988).
EPA/600/D-88/086. (2°)
TIC88b Tichenor, Sparks, and Jackson
(1988). EPA/600/2-88/061. (1°)
TIC88c Tichenor and Mason (1988).
Jour.APCA. 38(3):264-268. (1°)
TIC89 Tichenor (1989). Environment
International. 15:389-396. (1°)
TIC91 Tichenor and Guo (1991).
EPA/600/D-91/155. (1°)
TUC88 Tucker (1988). Proceedings of
Healthy Buildings <88,1:149-157.
(3°)
VAN90 Van der Wai, Steenlage, and
Hoogeveen (1990). Proc. Indoor
Air <90, 3:611-616. (2°)
VAN97 Van der Wai, Hoogeveen, and
Wouda (1997). Indoor Air.
7:215-221. (1°)
WAL87 Wallace (1987). Atmospheric
Environment. 21(2):385-393.
0°)
WOL93 Wolkoff et al. (1993). Indoor Air.
3:113-123. (1°)
WOL96 Wolkoff and Nielsen (1995).
Atmospheric Environment.
30: (15): 2679-2689. (1°)
WOR94 Worthan (1994). Presented at
National Coalition on IAQ
conference, Tampa. (2°)
ZHA97 Zhang etal. (1997). Proceedings of
IAQ'97, Healthy Buildings
(ASHRAE). 3:521-526. (2°)
1 ° = primary
2° = secondary
3 ° = tertiary
Inside IAQ, Fall/Winter 1998
Page 5
-------
VOLATILE ORGANIC EMISSIONS FROM PRINTED
CIRCUIT BOARD LAMINATES
The printed circuit board is a vital operating component in
many electronic products; e.g., personal computers (PCs),
telephones, fax machines, and photocopiers. Offgassing from
printed circuit boards is most prominent during the initial use
period when electrical heating occurs in the product. This is
especially true in the case of PC monitors, where internal
operating temperatures can range from 60 to 70°C.
In this evaluation, IEMB worked cooperatively with Research
Triangle Institute (RTI) to measure emissions from printed
circuit board laminates (without circuitry) to determine if an
alternative laminate would be less emitting than conventional
laminates. The complete study can be found in the EPA
Report, Personal Computer Monitors: A Screening
Evaluation of Volatile Organic Emissions from Existing
Printed Circuit Board Laminates and Potential Pollution
Prevention Alternatives, April 1998 (EPA-600/R-98-034,
NTISPB98-137102).
Methodology
Because laminates used in PC monitors are subjected to high
operating temperatures, they were selected as test laminates
for this project. As shown in the test matrix in Table 4, eight
samples of the following types of base/resin printed circuit
board laminates were evaluated: Glass/lignin-containing
epoxy (G/L), Glass/epoxy (G/E), Paper/phenol (P/P), and
Paper/ reformulated phenolic (P/RP).
The screening evaluation was conducted to determine if the
glass/lignin-containing epoxy resin and the reformulated phenolic
laminates would be less emitting than conventional laminates
which are made primarily from paper/phenol. Glass/epoxy
laminates were included in the evaluation because they exist
primarily in central processing units (CPUs).
The glass/lignin-containing epoxy and glass/epoxy laminates
were acquired from U.S. manufacturers. The paper/phenol
laminate was acquired from an overseas manufacturer because
almost all phenol-based laminates are produced overseas.
The reformulated phenolic laminate is also produced overseas
and has been in use in Europe within the past 5 years.
Participating manufacturers were sent "sampling kits" with
sampling instructions and steel cans. A designated person at
each manufacturing facility was responsible for:
1) Collecting a laminate sample from the production line;
2) Cutting the laminate sample size to 0.15 by 0.25 m; and
3) Immediately sealing the laminate in a labeled, precleaned,
air-tight, 7.85-L steel can provided.
Each can was shipped overnight to RTI, inspected upon arrival,
and then stored at -10 °C for about 4 months. Immediately prior
to testing, the sealed storage cans containing the laminates were
removed from the freezer, and the laminate samples were
transferred to individual clean steel cans for testing. The cans
were the same type as those used for storage. Inside the can, each
laminate sample was placed on its edge, leaning against the side
of the can, in order to maximize the exposed area. The lid of
each test can was fitted with Teflon inlet and outlet tubes which
were attached to the supply air manifold and sampling ports.
This allowed continuous regulated air flow through the chambers
during testing.
The test cans were then placed in a temperature-controlled
oven maintained at 65±3 ° C. Oven temperature and RH of the
supply air (50±5% RH at 23 °C) were continuously
monitored. As the air was warmed to 65 ° C, the RH in the test
cans dropped to approximately 6%.
Total air flow to the system was controlled, monitored, and
recorded using mass flow controllers. Just prior to placing the
test cans containing the laminate samples in the oven, each can
was purged with clean air to flush the cans of laboratory air.
Collection of air samples from the test cans began within 10
minutes of placing the test samples in the cans. Flows were
measured and adjusted immediately after the test cans were
placed in the oven, during the middle, and again at the end of
testing.The flow rate was 131 mL/minute (approximately 1.02
Table 4. Test matrix for circuit board laminate evaluation
Air Samples
Laminate
Air sample type;
vocc
VOC duplicate
Aldehyde/ketone
Number of
sampling intervals
Number of air
samples taken
Background
1
1
1
3
G/L-lAa
1
1
1
9
27
G/L- IB
1
1
1
9
27
G/L-2
1
1
1
9
27
G/E-1
1
1
1
9
27
G/E-2
1
1
1
9
27
P/P
1
1
1
9
27
P/RP-A
1
1
1
9
27
P/RP-B
1
1
1
9
27
Laminates supplied -without circuitry; copper coated on one side. Sample G/L-2 -was copper coated on both sides.
A background air sample -was taken from two separate test cans prior to the start of the test.
c Includes phenol and cresols.
Inside IAQ, Fall/Winter 1998
Page 6
-------
air changes per hour). Air samples were analyzed for VOCs
(including phenol and cresols) and adehydes/ketones. A list
of target compounds were identified from an initial set of air
samples taken for each laminate sample. Quantitative analysis
of these target compounds was then conducted for all
subsequent air samples taken for each laminate sample.
Results
The data presented in Figures 1 and 2 summarize the results
of the aldehydes/ ketones and VOCs emitted from each of the
eight printed circuit board laminates, respectively. The data
are expressed in terms of concentration (yWg/m3) and illustrate
the sum of measured concentrations for all identified
compounds emitted from each printed circuit board laminate
at t = 0 or 5 hours and t = 336 hours (14 days). Emission
factors over time are presented in the report referenced on
page 6.
Figure 1 shows that, at time t = 0 hours, the sum of measured
aldehydes/ketones emitted from the paper/reformulated
phenolic and the paper/phenol laminates ranged from 3,900 to
6,400 Aig/m3. For the same time point, the sum of measured
aldehydes/ketones emitted from the glass/lignin laminates
ranged from 200 to 270 jWg/m3, and emissions from the
glass/epoxy laminates ranged from 33 to 200 yWg/m3. After
336 hours, the sum of measured aldehydes/ketones emitted
from the paper/reformulated phenolic and the paper/phenol
laminates ranged from 650 to 870 jWg/m3. The sum of
measured aldehydes/ketones emitted from the glass/lignin
laminates after 336 hours ranged from 42 to 53 Aig/m3, and
concentrations from the glass/epoxy laminates ranged from
17 to 25 Aig/m3. Other observations from the data in Figure 1
are:
1) In the first hours of simulated on-time operation at 65 ° C,
the paper/phenolic resin-based laminates emit more
aldehydes/ketones than the glass/lignin or glass/epoxy
laminates. It appears that offgassing of volatile
compounds would continue beyond the 336 hours of this
screening evaluation.
2) Concentrations for the glass/epoxy sample 2 laminate are
greater than those for the glass/epoxy sample 1. This
difference could be due to the fact that the glass/epoxy
sample 2 laminate is manufactured by a different
company than the glass/epoxy sample 1 laminate.
3) All three glass/lignin laminate samples and the two
glass/epoxy laminates show average concentrations 95%
lower than the paper/reformulated phenolic resin-based
laminates.
Figure 2 shows that, at time t = 0 or 5 hours, the sum of
measured VOC concentrations (excluding aldehydes/ketones)
from the paper/reformulated phenolic and the paper/phenol
laminates ranged from 9,600to 23,000 Aig/m3. Concentrations
from the glass/lignin laminates ranged from less than 1,3 00 to
1,700 jWg/m3, and concentrations from the glass/epoxy
laminates ranged from less than 1 to 15 jWg/m3. After 336
hours, VOC concentrations from the paper/reformulated
phenolic and the paper/phenol laminates ranged from 3,900 to
6,200 Aig/m3. For the same time interval, VOC
concentrations for the glass/lignin and glass/epoxy laminates
ranged from nearly 0 to 100 j
Other observations from the data in Figure 2 are:
1) As was the case for the aldehydes and ketones, all three
glass/lignin laminate samples and the two glass/epoxy
laminates show an average sum of measured
concentrations of VOCs to be 95% lower than the
paper/reformulated phenolic resin-based laminates.
2) VOC concentrations from both glass/epoxy laminates are
virtually negligible. This is a good indication, on a
screening basis only, that VOC concentrations from
glass/epoxy laminates would probably not contribute
significantly to indoor air emissions.
3) VOC concentrations at t =5 hours from the paper/
reformulated phenolic laminates are lower than for the
paper/phenol, whereas aldehyde/ketone concentrations
from the paper/reformulated phenolic laminates (Figure
1) were higher than for the paper/phenol. However, at t
= 336 hours, VOC concentrations from the paper/
reformulated phenolic laminates are higher than for the
paper/phenol.
Conclusions
Conclusions from this screening evaluation are:
• Glass/lignin laminates result in lower concentrations of
volatile compounds than paper/phenolic resin-based
laminates. Although this test was conducted on only
eight laminate samples of four different laminate types,
the results show that, for the samples tested, glass/lignin-
containing epoxy resin laminates emit lower
concentrations of volatile compounds than the
paper/phenolic resin-based laminates during simulated PC
monitor on-time operation at 65 °C. The data also
suggest that, if these laminates were used as pollution
prevention alternatives for paper/phenol circuit board
laminates in PC monitors, reductions in VOC emissions
from PC monitors could be achieved. Alternatively, an
initial exposure period at an elevated temperature would
be a possible control option to reduce volatile emissions
prior to operation in an indoor environment.
Volatile emissions from glass/epoxy laminates are
relatively low compared to glass/lignin and
paper/phenol laminates. Although glass/epoxy laminates
appear to be good substitutes for paper/phenol laminates,
they are not predominantly used in PC monitors. This is
because glass/epoxy laminates are designed for high-
speed applications and data processing, whereas PC
monitors do not perform the same operating functions or
experience the same operating conditions as CPUs.
In general, concentrations decay over time. The results
show that a majority of the compounds decayed to low
levels (-50 jWg/h-m2) after 336 hours at 65 °C. However,
the data clearly show that some of the compounds would
likely have continued to emit from the laminates beyond
the 336 hours of the test. (EPA Contact: Kelly Leovic,
919-541-7717, kleovic@ engineer.aeerl.epa.gov)
Inside IAQ, Fall/Winter 1998
Page 7
-------
7,000
6,000
5,000
4,000
"ro
~ 3,000
-------
FACTORS INFLUENCING IAQ, IMMUNITY, AND
HEALTH
In June 1995, a conference on IAQ, Immunity, and Health
was held at North Carolina State University in Raleigh, NC.
It was cosponsored by the Cornell University Institute for
Comparative and Environmental Toxicology, the Cornell
Center for the Environment, and North Carolina State
University and provided an opportunity to examine a
significant societal inhalation toxicology issue. The program,
which brought together leading national scientists as well as
policy formulators, also included important policy
perspectives for discussion of scientific data application. This
article provides an overview of the proceedings by the
organizing committee.
Discussions focused on how indoor air pollutants, including
both industrially and naturally derived volatile chemicals and
allergens, as well as cofactors (e.g., levels of outside air
pollutants such as ozone), might affect upper respiratory tract
symptoms and immune response. The need to consider the
entire range of outdoor pollution factors (e.g., particulates,
pollen, ozone, NO2) as well as indoor chemical emissions and
the entire range of allergens (e.g., dust mites, mold spores,
rodent and insect allergens) was stressed by several
presenters. In the case of VOC emissions, the relevance of
evaluation methodologies to actual exposure conditions was
emphasized. This was required to avoid potential erroneous
interpretations of results as they relate to actual risk. For
example, carpet emissions were reported to become
significant only at temperatures exceeding 62°C; however,
this was not usually the case under conditions that actually
occur in typical indoor environments.
Exposure scenarios to measure inhalation responses were
discussed by several presenters. In particular, issues
concerned the exposure methodologies (e.g., whole body,
head, nose and mouth, nose only, intratracheal), dose
response, and the type of endpoints that would be important
for determining health implications. Endpoints that were
discussed included sensory irritation, sensitivity to infection,
allergic challenge responses (including asthmatic-type
responses), cellular and biochemical changes in nasal lavage,
hypersensitivity pneumonitis, and pulmonary function
endpoints.
An overall consideration of immune effector functions in the
context of inhalation exposure was presented, and several
presenters described the chemical mediators and/or
biomarkers associated with inflammatory reactions. In
particular, the codependent relationship of the neurological
and immunological systems in controlling inflammatory
reactions was detailed.
Additional sympathetic nervous system neurotransmitters
such as norepinephrine were discussed as regulators of
immune cell activity. This was extended beyond model
neuroimmune interactions for a consideration of the
integrative topics of stress, psychology, and altered immune
capacity. Within this discussion, it was shown that specific
stressors can exert targeted effects over certain portions of the
immune system.
Potential individual genetic (allelic) variation in response to
indoor air was considered and was particularly relevant given
the possible existence of hypersusceptible subpopulations of
humans for certain stimuli-induced symptomologies. In this
case, the investigators reported on a rodent model for
hypersensitive pneumonitis.
The symptomology of multiple chemical sensitivity (MCS)
was delineated, as well as the approaches to enhanced health
of the patients. The unclear etiology of both MCS and sick
building syndrome was discussed, as well as the data and
hypotheses that might link these conditions to immune and/or
inflammatory processes. The potential for psychoneurogenic
associations with MCS was considered, and additional
presentations described the physiological linkages involving
the nervous and other (e.g., immune) systems, and the
opportunity to investigate possible underlying biochemical
involvement in MCS symptomology was enhanced. Therefore,
the determination of cause-effect relationships in MCS
symptomology should be more readily approachable in the
future.
The role of specific biomarkers for detection of differential
sensitization was discussed. Significant progress has been
made in the areas of inflammation and immunomodulation.
This occurred with the development of both functional assays
and biomarkers for the detection of respiratory versus contact
sensitizing potential of environmental factors. Similar
progress has been made relative to nonspecific inflammatory
processes. This research progress pertains not only to the
direct capacity of indoor air factors to serve as potential
sensitizers but also to the possibility that such factors could
alter the host relative to sensitizing potential and/or the
challenge response to allergens. The biomarkers described
here offer a potentially sensitive and economical method for
screening emissions from indoor products for their sensitizing
and/or host-allergy response potential.
The combined presentations pointto a research and evaluation
direction for indoor air and immunity issues in which cross-
disciplinary expertise should contribute to the effective
resolution of these issues. Two presentations crossed the
science-policy boundary to provide specific examples of the
opportunities for effective outreach to the general public. In
these presentations, the benefits of a consolidated effort for
the translation of specific indoor air and health findings into
cost-effective remedial action within communities were also
discussed. (EPA Contact: Mary Jane Selgrade, 919-541-
2657, selgrade.maryjane@epa.gov)
Inside IAQ, Fall/Winter 1998
Page 9
-------
MODELING EMISSIONS FROM WATER-BASED
CLEANING SUPPLIES
Executive Order 12873, issued Oct.20,1993, requires federal
agencies to purchase "environmentally preferable" products.
As a pilot project under this executive order, EPA and the
General Services Administration worked together to develop
guidance for federal agencies to select environmentally
preferable cleaning supplies. These cleaners are biodegradable
degreasers. They are generally diluted with water before use,
and are frequently applied using a hand-held pump spray.
Three types of chemical compounds are of primary concern
in these cleaners: terpenes, butyl cellusolve (2-butoxyethanol),
and ethoxylatednonylphenol surfactants. The largest potential
exposure is to the cleaning staff, but there is also exposure to
building occupants.
EPA encountered difficulty evaluating the risk associated with
indoor air exposures because the method used to compare
risks relied on overly simplified indoor air models. The goal
of this research is to improve upon EPA's indoor emission
models for water-based cleaners. The first phase of work
focuses on improving models for evaporative emissions from
films or pools, and validating them in the laboratory.
Emissions from the aerosol will be examined later.
Products Tested
Two different water-based cleaners have been selected forthis
work. The first (Cleaner A) is a 2-butoxyethanol-based
product with an ethoxylated nonylphenol surfactant. The
second (Cleaner B) is a terpene-based cleaner. Both cleaners
will be analyzed by gas chromatography/mass spectrometry
(GC/MS) to identify and quantify VOCs that may be emitted
during and after use.
Headspace Measurements
Headspace measurements are being made over various cleaner
dilutions to determine partition coefficients, and hence
Henry's Law constants. Headspace measurements will also
be made over various dilutions of a laboratory formulated
cleaner surrogate, containing only 2-butoxyethanol (at the
same concentration as Cleaner A) and water. The data will be
used to:
• Provide input for modeling;
• Compare to Henry's Law predictions made by a
structure/activity relationship program (HENRYWIN
v3.00, SRC-HENRY for Microsoft Windows, 1994-
1997); and
• Compare the partition coefficients of the diluted
cleaner to those of the VOCs and water to see whether
the surfactants and minor constituents have any effect
on partitioning. If there is a large effect, it may be
necessary to do additional work before emissions can
be successfully modeled and predicted.
Models
In the past, IEMB has developed and verified mass-transfer-
based models to predict the evaporative emissions from
solvent-based indoor coating materials based on Raoul's Law.
However, the emissions from aqueous solutions behave in a
diufferent manner which conforms to Henry's Law.
The proposed models have the potential to predict the
emissions based on the product formulation. A series of
chamber tests will be conducted to evaluate these candidate
models. For the purposes of modeling the evaporative
emissions, the surfactant (ethoxylated nonylphenols) is
considered to be non-volatile.
The Pool Evaporation Models-Two mass transfer source
models, called PI and P2, are proposed for estimation of the
VOC emissions from a liquid pool (or bucket). Model P1 was
found in the literature (Little, J.C., 1992, "Applying the two-
resistance theory to contaminant volatilization in showers,"
Environ. Sci. Technol, 26, 1341-1349). Both models are
based on Henry's Law and the following expression for mass
transfer for evaporative emissions:
E = kr (C - C)
where E = emission factor, mg/m2/h;
kT = the overall gas-phase mass transfer coefficient, m/h;
Cs = VOC concentration at air/liquid interface,
calculated based on Henry's Law, mg/m3; and
C = VOC concentration in the bulk air, mg/m3.
When the VOC concentration at the interface is considered
constant, there is an explicit solution for the indoor
concentration (model PI). All the parameters can be
estimated from the properties of the source and the
environment, and the model is simple enough to be used in a
spreadsheet. Chamber testing will reveal whether models
using this simplification predict emissions sufficiently well for
water-based cleaners.
However, when the volume of the cleaner liquid is limited, the
pollutant concentration in the liquid may not hold constant.
For instance, water evaporation may concentrate the solute.
On the other hand, fast emission of the solute (with large
Henry's Law constant) may result in decreased concentration
in the liquid. These factors could be important for small or
shallow pools, such as those used in small chamber testing.
Therefore, model P2 modifies PI to include the effects of
changes in liquid concentration. Model P2 should be
especially useful in interpreting data from small chamber
tests, where the solvent pool is often small and the VOC
concentration in the liquid may change significantly during the
test period. P2 consists of three differential equations, which
can be solved numerically.
Film Evaporation Models-TEMB is evaluating three new
source models for predicting the VOC emissions from water-
based cleaners applied to hard surfaces (i.e., emissions from
the thin film). For the convenience of discussion, the models
will be called Fl, F2, and F3, where F stands for "film."
Inside IAQ, Fall/Winter 1998
Page 10
-------
Model Fl is a comprehensive mass transfer model that takes
into consideration VOC emissions from both the wet and dry
films. The term "dry film" here means the thin film of organic
liquid left on the surface due to water evaporation. Models F2
and F3 are derived from Fl with different degrees of
simplification. Model F3 does not require the Henry's Law
constant and is simple enough to be implemented in a
spreadsheet.
Model Fl takes into consideration three mass transfer
processes:
• The rate of VOC emissions from the wet film, described
by Henry's Law and gas-phase molecular diffusion;
• The rate of VOC emissions from the "dry" film,
described by the simplified vapor barrier (VB) model
(Guo, Z, et al, 1997 "Predicting the Emissions of
Individual VOCs from Petroleum-Based Indoor
Coatings," Atmospheric Environment, Vol. 32, No. 2,
pp. 231-237); and
• The rate of dry film formation due to water evaporation,
described by a model similar to the VB model. This mass
transfer process affects the VOC emission rates from
both the wet and dry films.
Model F2 is a simplified version of model Fl. Since the first-
order decay rate constant, k, is inversely proportional to the
film thickness (Clausen, P. A., 1993, "Emission of volatile
and semivolatile organic compounds from water-borne paints
- the effect of the film thickness," Indoor Air 3, 269-275) and
the dry film is very thin, k is usually very large. The
simplifying assumption is, therefore, that the VOC emission
from the dry film is an instantaneous process.
Model F3 is derived from model F2 by assuming that:
The wet emission is insignificant compared to the dry
emission; and
• Water evaporation roughly follows the first-order decay
pattern.
Information about the product and the environment required
by each of the three models is given in Table 5. All the
parameters are easy to come by, except the Henry's Law
constant. There are three ways to find the Henry's Law
constant:
• Compiled Henry's Law constants in the literature;
Experimental determination; and
• Theoretical calculation based on the molecular structure.
Chamber Testing
Three "bucket" tests will be run. In these tests, an open
cylindrical container of diluted cleaner will be placed in a
small chamber, and emissions measured for about a day. The
purposes of these tests are to:
Table 5. Summary of all parameters included in the three
film models
Category
Environ-
ment
Pollutant
Test
Product
Parameter
Room volume
Air flow rate
Relative Humidity
Air velocity '
Molecular formula
of VOC
Henry's Law
constant
Vapor pressure 2
Diffusivity in air 3
VOC content in
liquid
Source area
Amount applied
Model
Ff
X
X
X
X
X
X
X
X
X
X
X
Model
F2
X
X
X
X
X
X
X
X
X
Model
F3
X
X
X
X
X
X
1 used to estimate gas-phase mass transfer coefficients for VOC
and water.
2 used to estimate the decay rate constant for dry emissions (k).
3 used to estimate gas-phase mass transfer coefficient for VOC
• Determine the overall mass transfer coefficient using
Cleaner A;
• Verify whether the PI and P2 models work for
butoxyethanol in Cleaner A; and
Verify the model for other compounds/products, using
Cleaner B.
Chamber testing will also be conducted to provide data to
compare to the performance of the film evaporation models.
RH proved difficult to control in initial tests in the small
chamber, because the control systems and geometry of the
small chamber produced an unrealistically high RH. Because
the compounds of interest are somewhat polar and
hydrophillic, humidity may affect the emission behavior.
Therefore, this work will be performed in a large chamber.
(EPA Contact: Betsy Howard, 919-541-7915,
bhoward@engineer.aeerl. epa.gov)
Inside IAQ, Fall/Winter 1998
Page 11
-------
ANTIMICROBIAL AGENTSUSED INHVACSYSTEMS
Biocides or antimicrobial agents can be used to manage
biological contamination in HVAC systems as an alternative
to HVAC component replacement. All commercial biocides
and antimicrobial products are regulated and must be
registered in compliance with the Federal Insecticide,
Fungicide, and Rodenticide Act (FIFRA). IEMB has begun a
study of biocides and antimicrobial agents used in HVAC
systems. The study, which will take place within the next
year, includes:
1) Determining the efficacy of biocides and antimicrobial
agents used in HVAC systems. This will be
accomplished by surveying commercial biocides and
antimicrobial products used in HVAC systems; surveying
the industry to determine product use and preferences;
and conducting tests on 10 biocides and antimicrobial
agents using cultured samples of fungi, mold, and
bacteria.
2) Investigating the application effectiveness of biocides
and antimicrobial agents used in HVAC systems. This
will be accomplished by testing various concentrations
(manufacturers' recommended concentration and 50%
recommended) of 10 products for 30 and 60 days using
dynamic chambers and evaluating the effectiveness on
fungi, mold, and bacteria and by testing the impact of
organic load to act as a barrier to chemical reaction.
3) Determining the relationship between RHand microbial
growth. The effectiveness of biocides and antimicrobial
agents will be tested at RH levels of 60, 85, and 100% of
saturation.
4) Determining the impact of biocides and antimicrobial
agents on IAQ. Microbial emissions will be measured from
inoculated and treated surfaces. (EPA Contact: Marc
Menetrez, 919-541-7981, mmenetrez@engineer.aeerl.
epa.gov
SUMMARIES OF RECENT PUBLICA TIONS
This section provides summaries of recent
publications on EPA' s indoor air research.
The source of the publication is listed after
each summary.
Cost Analysis of Activated Carbon vs.
Photocatalytic Oxidation for Remov-
ing Organic Compounds from Indoor
Air-A cost comparison has been
conducted of 1 m3/s indoor air cleaners
using granular activated carbon (GAC)
vs. photocatalytic oxidation (PCO) for
treating a steady-state inlet VOC
concentration of 0.27 mg/m3. The
commercial GAC unit was costed
assuming that the inlet VOCs had a
reasonable carbon sorption affinity,
representative of compounds having
four or more atoms (exclusive of
hydrogen). A representative model PCO
unit for indoor air application was
designed and costed, using VOC
oxidation rate data reported in the
literature for the low inlet concentration
assumed here, and using a typical
illumination intensity. The analysis
shows that, for the assumptions used
here, the PCO unit would have an
installed cost more than 10 times
greater, and an annual cost almost 7
times greater, than the GAC unit. It
also suggests that PCO costs cannot
likely be reduced by a factor greater
than 2 to 4, solely by improvements in
the PCO system configuration and
reductions in unit component costs.
Rather, an improved catalyst having a
higher quantum efficiency would be
needed, increasing reaction rates and
reducing illumination requirements
relative to the catalysts reported in the
literature. GAC costs would increase
significantly if the VOCs to be removed
were lighter and more poorly sorbed
than assumed in this analysis. Source:
Accepted for publication in J. of the Air
& Waste Management Assoc. (EPA
Contact: D. Bruce Henschel, 919-541-
4112, bhenschel@engineer.aeerl.
epa.gov)
Enhanced Allergic Responses to
House Dust Mite by Oral Exposure to
Carbaryl in J?ate-Epidemiological
studies have demonstrated an
association between use of carbamate
insecticides, including carbaryl, and
increased incidence of allergic asthma
in farmers. In this study, the effect of
oral carbaryl exposure on the
development of allergic responses to
house dust mites (HDMs) was
examined in female Brown Norway
rats. Rats were gavaged for two weeks
with 0, 2, 10, or 50 mg/kg/day of
carbaryl. They were sensitized with a
subcutaneous injection of HDM in
aluminum hydroxide adjuvant 3 days
afterthe beginning of carbaryl exposure
and challenged with antigen via the
trachea one day after the final carbaryl
ingestion. In 2 days, antigen specific
cell proliferation in pulmonary lymph
nodes was significantly higher in the 50
mg/kg group than in controls, while
antigen specific splenocyte proliferation
was decreased in groups dosed with 2,
10, and 50 mg/kg carbaryl. Total
protein and lymphocyte numbers in
bronchoalveolar lavage (BAL) fluid
were also increased in the 50 mg/kg
group. In 7 days, immune-mediated
pulmonary inflammation (eosinophils),
antigen specific immunoglobulin (Ig) E
level in serum, and antigen specific IgE
and IgA levels in BAL fluid were
significantly elevated in the 50 mg/kg
group. No apparent change was
observed for lactate dehydrogenase and
eosinophil peroxidase in BAL fluid,
while the number of BAL macrophages
were decreased in groups dosed with 10
and 50 mg/kg carbaryl. This suggests
that carbaryl may cause systemic
immune suppression, while enhancing
pulmonary allergic responses to HDM
antigen. Source: Toxicological
Sciences; In Press, ToxicolSci. March,
1998 (EPA Contact: Wumin Dong,
919-541-7808, dong.wumin@epa.gov)
Inside IAQ, Fall/Winter 1998
Page 12
-------
Entrainment by Ligament-Controlled
Effervescent Atomizer-Produced
Sprays-An innovative spray nozzle for
use with precharged aerosol containers
was developed and evaluated. The new
design allows for the reformulation of
selected aerosol consumer products
using water and air in place of VOC
solvents and hydrocarbon propellents.
This article discusses the entrainmentof
ambient air into sprays produced by
this effervescent atomizer. Entrainment
data were analyzed using a model
together with measured momentum rate
data that were collected as part of this
study. The analysis shows that entrain-
ment by sprays produced using this
type of atomizer is predicted to within
about 35%. Source: International
Journal of Multiphase Flow, vol. 23,
no. 5, pp. 865-884, 1997 (EPA
Contact, Kelly W. Leovic, 919-541-
7717, kleovic@ engineer.aeerl.epa.gov)
Evaluation of a Test Method for
Measuring Indoor Air Emissions
from Dry-Process Photocopiers-A.
four-laboratory evaluation of a large
chamber test method for measuring
emissions from office equipment was
conducted. A single dry-process
photocopier was shipped to each of the
four laboratories along with supplies
(i.e., toner and paper). Results
demonstrate that the test method was
used successfully in the different
chambers to measure emissions from
the copier. Differences in chamber
design and construction appeared to
have had minimal effect on the results
for the VOCs. Percent relative standard
deviation (%RSD) was used to provide
a simplistic view of interlaboratory
precision. Excluding problems with
suspected analytical bias observed from
one of the laboratories, the precision
was excellent for the VOCs with RSDs
of less than 10% in most cases. Less
precision was observed among the
laboratories for aldehydes/ketones
(RSD of 23.2% for formaldehyde). The
precision for ozone emission rates
among three of the laboratories was
excellent (RSD of 7.9%). Source:
Accepted for Publication by the J. Air
& Waste Management Association,
May 1998 (EPA Contact: Kelly W.
Leovic, 919-541-7717, kleovic@
engineer, aeerl.epa.gov)
Evaluation of Low-Emitting Products
for Use in the Indoor Environ-
ment-lEMB recently completed
cooperative research on the application
of pollution prevention techniques to
reduce indoor air emissions from
aerosol consumer products, engineered
wood products, and office equipment.
For aerosol consumer products, one
project focused on developing
measurement methods and models that
can be used by manufacturers to better
understand aerosol behavior so that
more efficacious and less toxic products
can be developed. A second project
resulted in the development and
evaluation of an innovative spray
nozzle for use with pressurized aerosol
containers. The new design will allow
manufacturers to reformulate selected
aerosol consumer products using water
and air in place of VOC solvents and
hydrocarbon propellants. To evaluate
emissions from engineered wood
products, emissions were screened from
four common types of finished
engineered wood used indoors. Acid-
catalyzed alkyd-urea coatings and
particleboard were subsequently
identified as the primary emission
sources. Laboratory testing identified
three types of fiber panels as low-
emitting alternative materials: fiber
panels made with medium density
fiberboard and methylene diisocyanate
resin, wheat straw and methylene diiso-
cynate resin, and corrugated cardboard.
Three types of lower-emitting coatings
were identified: a two component water-
borne polyurethane, an aliphatic urethane
acrylate, and a water-based acrylic. All
three fiber panels and coatings are
commercially available. A fourth project
resulted in the development of a test
guidance method to measure office
equipment emissions. The method was
evaluated by testing four dry-process
photocopiers in one chamber and then
conducting a round-robin evaluation of
one copier. Another component of this
project evaluated emissions from printed
circuit board laminates. Source:
Proceedings of the Annual Air & Waste
Management Association Meeting, San
Diego, June 1998 (EPA Contact: Kelly
W. Leovic, 919-541-7717, kleovic®
engineer.aeerl.epa.gov)
Evaluation of Sink Effects on VOCs
from a Latex Paint-The sink strength
of two common indoor materials, carpet
and gypsum board, was evaluated by
environmental chamber tests with four
VOCs: propylene glycol, ethylene
glycol, 2-(2-butoxyethoxy)ethanol, and
Texanol. These oxygenated compounds
represent the major VOCs emitted from
a latex paint. Each chamber test
included two phases. Phase 1 was the
dosing/ sorption period during which
sink materials (pieces of carpet and
gypsum board samples) were exposed
to the four VOCs. The sink strength of
each material tested was characterized
by the amount of the VOCs adsorbed or
absorbed. Phase 2 was the purging/
desorption period during which the
chambers with the dosed sink materials
were flushed with purified air. The
remission rates of the adsorbed VOCs
from the sinks were reflected by the
amount of the VOCs being flushed.
Phase 1 results indicated that the sink
strength for the four target compounds
is more than 1 order-of-magnitude
higher than that for other VOCs
previously tested by EPA. The high
sink strength reflected the unusually
high sorption capacity of common
indoor materials for the four VOCs.
Phase 2 results showed that remission
was an extremely slow process. If all
the VOCs adsorbed were remittable, it
would take more than a year to
completely flush out the VOCs from the
sink materials tested. The long
remission process can result in chronic
and low level exposure to the VOCs
after painting the interior walls and
surfaces. Source: Accepted for
Publication in the J. of the Air & Waste
Management Association (EPA
Contact: John C. S. Chang, 919-541-
3747, jchang@engineer.aeerl.epa.gov)
Inside IAQ, Fall/Winter 1998
Page 13
-------
Increased Immune and Inflammatory
Responses to Dust Mite Antigen in
Rats Exposed to 5 ppm AY^-Immune
hypersensitivity to RDM is a frequent
cause of respiratory allergy. The
objective of this study was to determine
whether exposure to NO2, a common
indoor air pollutant, modulates immune
responses to HDM and influences
immune-mediated lung disease. Brown
Norway rats were immunized ip with
100 (jg semipurified antigen and
Bordetella pertussis adjuvant and
challenged 2 weeks later with an
intratracheal injection of 50 (jg of a
crude antigen preparation. Exposure to
5 ppm NO2 for 3 hours after both
immunization and challenge procedures
resulted in significantly higher levels of
antigen-specific serum IgE, local IgA,
IgG, and IgE antibody than air controls,
and increased numbers of inflammatory
cells in the lungs. Lymphocyte respons-
iveness to antigen in the spleen and
MLN was also significantly higher in
NO2-exposed animals. These data show
that exposure to a common air pollutant
can upregulate specific immune
responses and subsequent immune-
mediated pulmonary inflammation.
Source: Fundam. Appl. Toxicol. 31. 65-
70 (EPA Contact: Mary Jane E.
Selgrade, 919-541-2657, selgrade.
maryjane@epa.gov)
Indoor Air Emissions from Office
Equipment: Test Method Development
and Pollution Prevention Oppor-
tunities-EPA and RTI conducted
cooperative research to identify pollution
prevention approaches for reducing
emissions from office equipment. The
project included: 1) forming a group of
technical advisors; 2) preparing a
literature review on the operation of, and
emissions from, office equipment as well
as pollution prevention opportunities;
3) developing and evaluating an
Emissions Testing Guidance Document
for Dry-Process Photocopy Machines;
and 4) identifying and evaluating poll-
ution prevention options. Because no
standard test method exists to measure
emissions from office equipment (e.g.,
ozone, VOCs, aldehydes/ ketones,
inorganic gases, and particles), it is
difficult to compare data from different
studies. Thus, the focus of this project
was the development and evaluation of a
large chamber test method for measuring
emissions from dry-process photocopiers.
The goal is to apply the method to better
understand emissions from office
equipment and to develop lower emitting
machines. The test method was evaluated
in two phases. Phase I was a single
laboratory evaluation of the method at
RTI using four mid-range dry-process
photocopiers. Phase I results indicated
that the test method provided acceptable
performance for characterizing emissions,
adequately identified differences in
emissions between machines both in
compounds emitted and their emission
rates, and was capable of measuring both
intra- and inter-machine variability in
emissions. Phase II was a four-labor-
atory round-robin evaluation of the
method. A single dry-process photocopier
was shipped to each of the four
laboratories along with supplies (i.e.,
toner and paper). Phase II results
demonstrate that the method was used
successfully in the different chambers to
measure emissions and that differences in
chamber design and construction
appeared to have had minimal effect.
Source: EPA Report, "Indoor Air Emis-
sions from Office Equipment: Test
Method Development and Pollution
Prevention Opportunities," EPA-600/R-
98-080 (EPA Contact: Kelly W. Leovic,
919-541-7717, kleovic@engineer.aeerl.
epa.gov)
Indoor Emissions from Conversion
Varnishes-Conversion varnishes are
two-component, acid-catalyzed
varnishes that are commonly used to
finish cabinets. They are valued for
their water- and stain-resistance, as
well as their appearance. They have
been found, however, to contribute to
indoor emissions of organic
compounds. For this project, three
commercially available conversion
varnish systems were selected. An EPA
Method 24 analysis was performed to
determine total volatile content, and a
sodium sulfite titration method was
used to determine uncombined (free)
formaldehyde content of the varnish
components. The resin component was
also analyzed by GC/MS (EPA Method
311 with an MS detector) to identify
individual organic compounds.
Dynamic small chamber tests were then
performed to identify and quantify
emissions following application to
coupons of typical kitchen cabinet
wood substrates, during both curing
and ageing. Because conversion
varnishes cure by chemical reaction, the
compounds emitted during curing and
ageing are not necessarily the same as
those in the formulation. Results of
small chamber tests showed that the
amount of formaldehyde emitted from
these coatings was 2.3 to 8.1 times the
amount of free formaldehyde applied in
the coatings. A long-term test showed a
formaldehyde emission rate of 0.17
mg/m2/h after 115 days. Source:
Accepted for Publication in the J. of the
Air & Waste Management Association
(EPA Contact: Elizabeth M. Howard,
919-541-7915, bhoward@engineer.
aeerl.epa.gov)
Inside IAQ, Fall/Winter 1998
Page 14
-------
Ligament-Controlled Effervescent
Atomization-The operating principles
and performance of a new type of spray
nozzle are presented. This nozzle,
termed a "ligament-controlled
effervescent atomizer," was developed
to allow consumer product
manufacturers to replace VOC solvents
with water and hydrocarbon propellants
with air, while meeting the following
criteria: that the spray mean drop size
remain below 70 (jm, that the atomizing
air consumption be less than 0.009, and
that atomizer performance be
uncompromised by the increase in
surface tension or by changes in
viscosity. The current atomizer differs
from previous effervescent designs
through inclusion of a porous disc
located immediately upstream of the
nozzle exit orifice. The purpose of this
disc is to control the diameter of
ligaments formed at the injector exit
place. Atomizer performance is
reported in terms of the spray Sauter
mean diameter, with drop size data
analyzed using a model developed from
first principles. The model describes the
spray formation process as the breakup
of individual cylindrical ligaments
subject to a gas stream. Ligament
diameter is estimated from
manufacturer supplied pore size data
for the porous disc. The model correctly
predicts the experimentally observed
relationship between Sauter mean
diameter and air-to-liquid ratio by
mass, liquid surface tension, and liquid
viscosity. Source: Atomization and
Sprays, vol. 7, pp. 383-406, 1997
(EPA Contact: Kelly W. Leovic, 919-
541-7717, kleovic@ engineer.aeerl.
epa.gov)
Transfer of Allergic Airway
Responses with Serum and
Lymphocytes from Rats Sensitized to
Dust Mite-HDM antigen is one of the
most common allegens associated with
extrinsic asthma. In a model of allergic
lung disease, Brown Norway rats were
sensitized to RDM with alum and
Bordetella pertusis adjuvants to
produce high levels of IgE antibody and
experience bronchoconstriction,
increased airway hyperresponsiveness
(AHR) to acetylcholine , and
pulmonary inflammation after antigen
challenge. The purpose of this study
was to determine whether these
asthmatic symptoms could be
transferred from sensitized animals to
naive recipients via humoral or cellular
factors. Syngenetic recipient rats were
injected with either HDM or bovine
serum albumin from lymph nodes of
sensitized or control rats, respectively.
Other groups received a tail-vein
injection of serum from either HDM-
sensitized or control rats. Antigen
challenge in rats injected with sensitized
cells caused increases in pulmonary
inflammation and in AHR, but no
changes in immediate broncho-
constriction as compared with control
recipients. Antigen challenge in serum
recipients resulted in immediate
bronchoconstriction but had no effect
on AHR or on pulmonary inflam-
mation. These data show that immune-
mediated lung inflammation and AHR
are promoted by antigen-specific
lymphocytes, whereas immediate
allergic responses are caused by serum
factors. Source: Respir. Crit. Care
Med. 1998; 157:000-000. (EPA
Contact: Daniel L. Costa, 919-541-
2532, costa.daniel@ epa.gov)
GLOSSARY
AHR - Airway Hyperresponsiveness
BAL - Bronchoalveolar Lavage
CAS - Chemical Abstract Service
CPU - Central Processing Unit
FIFRA - Federal Insecticide, Fungicide,
and Rodenticide Act
GAC - Granular Activated Carbon
GC/MS - Gas Chromatography/Mass
Spectrometry
G/E - Glass/epoxy
G/L - Glass/lignin
HDM - House Dust Mite
HVAC - Heating, Ventilating, and Air-
Conditioning
IAQ - Indoor Air Quality
IEMB - Indoor Environment Manage-
ment Branch
MCS - Multiple Chemical Sensitivity
NAICS - North American Industrial
Classification System
NRMRL - National Risk Management
Research Laboratory
PC - Personal Computer
PCO - Photocatalytic Oxidation
P/P - Paper/Phenol
P/RP - Paper/Reformulated Phenolic
QA - Quality Assurance
RH- Relative Humidity
RSD - Relative Standard Deviation
RTI - Research Triangle Institute
TVOC - Total Volatile Organic Com-
pound
VB - Vapor Barrier
VOC - Volatile Organic Compound
Inside IAQ, Fall/Winter 1998
Page 15
-------
United States
Environmental Protection Agency
National Risk Management Research Laboratory
MD-54
Research Triangle Park, NC 27711
Official Business
Penalty for Private Use
$300
EPA/600/N-98/003, Fall/Winter 1998
FIRST CLASS MAIL
POSTAGE AND FEES PAID
EPA
PERMIT No. G-35
An Equal Opportunity Employer
Inside IAQ, Fall/Winter 1998
Page 16
------- |