ASTM D6178-97(2008)
(Practice)Standard Practice for Estimation of Short-term Inhalation Exposure to Volatile Organic Chemicals Emitted from Bedding Sets
Standard Practice for Estimation of Short-term Inhalation Exposure to Volatile Organic Chemicals Emitted from Bedding Sets
SIGNIFICANCE AND USE
The objective of this practice is to provide procedures for estimation of human inhalation exposure to VOCs emitted from bedding sets. The estimated inhalation exposure can be used as an input to characterization of health risks from short-term VOC exposures.
The results of exposure estimation for specific raw materials and components, or processes used in manufacturing different bedding sets, can be used to compare their relative impacts on exposures.
SCOPE
1.1 This practice covers the procedures for estimation of short-term human inhalation exposure to volatile organic chemicals (VOCs) emitted from bedding sets when a new bedding set is first brought into a house.
1.2 The estimated exposure is based on an estimated emission profile of VOCs from bedding sets.
1.3 The VOC emission from bedding sets, as in the case of other household furnishings, usually are highest when the products are new. Procedures described in this practice also are applicable to used bedding sets.
1.4 Exposure to airborne VOC emissions in a residence is estimated for a household member, based on location and activity patterns.
1.5 The estimated exposure may be used for characterization of health risks that could result from short-term exposures to VOC emissions.
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to its use.
General Information
Relations
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D6178 − 97(Reapproved 2008)
Standard Practice for
Estimation of Short-term Inhalation Exposure to Volatile
Organic Chemicals Emitted from Bedding Sets
This standard is issued under the fixed designation D6178; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope D6177 Practice for Determining Emission Profiles of Vola-
tile Organic Chemicals Emitted from Bedding Sets
1.1 This practice covers the procedures for estimation of
short-term human inhalation exposure to volatile organic
3. Terminology
chemicals (VOCs) emitted from bedding sets when a new
3.1 Definitions—For definitions and terms used in this
bedding set is first brought into a house.
practice, refer to Terminology D1356.
1.2 The estimated exposure is based on an estimated emis-
3.2 Definitions of Terms Specific to This Standard:
sion profile of VOCs from bedding sets.
3.2.1 air change rate, n—the volume of outdoor air that
1.3 The VOC emission from bedding sets, as in the case of
enters the indoor environment in one hour, divided by the
other household furnishings, usually are highest when the
volume of the indoor space.
products are new. Procedures described in this practice also are
3.2.2 bedding set, n—an ensemble that includes a mattress
applicable to used bedding sets.
for sleeping and a supporting box spring.
1.4 Exposure to airborne VOC emissions in a residence is
3.2.3 emission profile, n—a time-series of emission rates of
estimated for a household member, based on location and
one or more compounds.
activity patterns.
3.2.4 exposure scenario, n—a description of how and where
1.5 The estimated exposure may be used for characteriza-
an estimated exposure occurs, including (1) the location and
tion of health risks that could result from short-term exposures
emission profile of the product or material that causes
to VOC emissions.
exposure, (2) the indoor environment where the individual is
1.6 This standard does not purport to address all of the
exposed to airborne emissions from the product or material,
safety concerns, if any, associated with its use. It is the
and (3) the location and activity patterns of the exposed
responsibility of the user of this standard to establish appro-
individual.
priate safety and health practices and determine the applica-
3.2.5 potential inhaled dose, n—the product of air concen-
bility of regulatory limitations prior to its use.
tration to which an individual is exposed times breathing rate
times duration of exposure.
2. Referenced Documents
3.2.5.1 Discussion—The potential inhaled dose is different
2.1 ASTM Standards:
from the dose actually absorbed by a target organ.
D1356 Terminology Relating to Sampling and Analysis of
3.2.6 short-term exposure, n—an exposure of one week or
Atmospheres
less in duration.
D5116 Guide for Small-Scale Environmental Chamber De-
terminations of Organic Emissions from Indoor Materials/ 3.2.7 volatile organic chemical, n—an organic compound
–2
Products with saturation vapor pressure greater than 10 kPa at 25°C.
D5157 GuideforStatisticalEvaluationofIndoorAirQuality
4. Summary of Practice
Models
4.1 This practice describes procedures for estimation of
inhalation exposure to VOCs emitted from new bedding sets
This practice is under the jurisdiction of ASTM Committee D22 on Air
(1) . The estimation of exposure is based on the emission
Qualityand is the direct responsibility of Subcommittee D22.05 on Indoor Air.
Current edition approved April 1, 2008. Published July 2008. Originally
profiles for a bedding set, the environmental conditions in a
approved in 1997. Last previous edition approved in 2003 as D6178 - 97(2003).
residence where the bedding set is being used, and the location
DOI: 10.1520/D6178-97R08.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on The boldface numbers in parentheses refer to the list of references at the end of
the ASTM website. the standard.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D6178 − 97 (2008)
and activity patterns of an exposed individual. Emission the remainder of the house. Such calculations would result in
profiles are derived from environmental chamber emission less realistic yet useful estimates for screening purposes.
tests (2) (see Guide D5116 and Practice D6177).
6.2.4 Location and Activity Patterns—Specify the locations
of an exposed individual throughout a 24-h (or longer) period
4.2 Estimation of exposure involves development of expo-
in relation to the two or three indoor zones previously
sure scenarios, modeling of indoor-air concentrations, and
described 6.2.3.1. Also specify the time spent outside the
selection and calculation of exposure measures.
house, during which the individual is assumed not to be
5. Significance and Use
exposed to chemical emissions from the bedding set. See X1.2
5.1 The objective of this practice is to provide procedures for examples of location and activity patterns.
for estimation of human inhalation exposure to VOCs emitted
6.3 Modeling of Indoor-air Concentrations:
from bedding sets. The estimated inhalation exposure can be
6.3.1 The two major steps in modeling are selection of a
used as an input to characterization of health risks from
model and provision of model input parameters.
short-term VOC exposures.
6.3.2 Model Selection—Select a model that is capable of
5.2 The results of exposure estimation for specific raw
estimating indoor-air concentrations in multiple zones and
materials and components, or processes used in manufacturing
allows the user to specify various types of emission profiles in
different bedding sets, can be used to compare their relative
addition to the indoor zones, their volumes, their interzonal
impacts on exposures.
airflow rates, and zonal airflow rates to and from the outdoors.
6. Procedures for Exposure Estimation Three models that are known to meet these criteria are
CONTAM (4), EXPOSURE (5), and MCCEM (6). All three
6.1 The procedures for exposure estimation include devel-
models have been developed by or for U.S. government
opment of exposure scenarios, modeling of indoor-air
agencies, and are therefore in the public domain. Each model
concentrations,selectionandcalculationofexposuremeasures,
has advantages and disadvantages in terms of completeness,
and model evaluation.
simulation capabilities, the user interface, and how it addresses
6.2 Development of Exposure Scenarios:
exposure. For example, CONTAM has the capability of calcu-
6.2.1 An exposure scenario describes how and where expo-
lating airflows among zones whereas for EXPOSURE and
sure occurs. In specifying the exposure scenario(s), include a
MCCEM, the airflows need to be specified by the user;
description of (1) the emitting product or material, in terms of
MCCEM includes a library of airflow rates for selected
its age, emission profile, and location, (2) the indoor environ-
residences.
ment where exposure occurs, and (3) the location and activity
6.3.3 Model Inputs—In addition to emission profiles, indoor
patterns of an exposed individual.
zones, and location and activity patterns as previously
6.2.2 Emitting Product or Material—For this practice, the
described, specify (1) an air change rate for the residence, (2)
emitting product is a bedding set. Specify the assumed age,
airflow rates among the indoor zones, and (3) parameters
emission profile, indoor location, and size of the bedding set of
related to indoor sinks. Some models may also require or allow
interest.
the user to choose a time step.
6.2.2.1 Foraconservativeestimateofexposure,assumethat
6.3.3.1 Select a value for the air change rate for the
the bedding set has just been purchased and the wrapper is not
residence to be modeled. The air change rate for the residence
removed until it is placed in the residence.
–1
with the outdoors has units of inverse hours (h ).Ameasured
6.2.2.2 Estimate the emission profile using adjusted cham-
value for the residence representing the conditions to be
ber air concentrations (Practice D6177).
modeled, if available, should be used as a first choice. An
6.2.2.3 Theindoorlocationforthebeddingsetisassumedto
alternative is to select a value based on appropriate cases in the
be a bedroom.
literature. For example, a conservative value in the range from
6.2.2.4 Selectasizeofbeddingsetthatisappropriateforthe
–1
0.1 to 0.2 h and a central value in the range from 0.4 to 0.6
size of the bedroom.
–1
h were reported by Koontz and Rector (7) based on an
6.2.3 Indoor Environment:
analysis of measurements from several residential field studies.
6.2.3.1 Conceptualize the indoor environment as consisting
Representative values for the residential building stock are not
of the following three zones: (1) the immediate vicinity of the
available.
bedding set; (2) the remainder of the bedroom in which the
6.3.3.2 Multiply the air change rate by the zonal volume to
bedding set is located; and (3) the remainder of the house.
3 –1
obtain the airflow rate to and from the outdoors, in m h .The
Specify a volume for the entire residence and for each of the
simplifying assumption can be made that each zone has a
zones. For a typical volume of the total residence, use the
balanced inflow and outflow with respect to outdoors. While
average value (369 m ) listed in the Exposure Factors Hand-
this is generally not the case in a real building, one must have
book (3). For a conservative value of the residential volume,
3 3
measured interzonal airflow rates or rates that were calculated
use one of the 10th percentile values (147 m or 167 m ) listed
with a multi-zone airflow model (such as CONTAM) to avoid
in the Exposure Factors Handbook. See X1.1 for example
using this assumption.
calculations to determine the volumes for the bedroom and the
vicinity of the bedding set. 6.3.3.3 Use measured values, if available, for interzonal
6.2.3.2 Tosimplifycalculations,theindoorenvironmentcan airflow rates between the bedroom and the remainder of the
be considered as consisting of just two zones, the bedroom and house. Alternatively, interzonal flows can be estimated using
D6178 − 97 (2008)
the CONTAM model (or some other multizone airflow model) time-integrated concentration will be compared. In determin-
or an equation such as the following: ing this maximum concentration, it is necessary to track the
exposed individual’s location within the indoor environment,
Q 5 V 0.07810.31N (1)
~ !
integrating across contiguous time periods in each zone as
previously described for the potential inhaled dose.
where:
6.5 Model Evaluation—Ideally, the models that predict
3 –1
Q = interzonal flow rate, m h
indoor air concentrations for the purposes of exposure estima-
V = volume of the house, m , and
tion should be evaluated with concentration measurements
–1
N = air change rate of the house, h .
from actual residences. Use tools described in Guide D5157 to
Theaboveempiricalequationisbasedonananalysisofflow
judge the comparability of predicted and measured concentra-
rates from several hundred nonrandomly selected residences
tions.
(7).
7. Report
6.3.3.4 If three zones are elected for calculations, the
bedroom area in the vicinity of the bedding set is assumed to
7.1 The report on estimation of inhalation exposure should
exchange air only with the rest of the bedroom. See X1.3 for
contain the sections listed as follows:
example calculations to determine the airflow rate between the
7.2 Bedding Set Samples—Give description of the bedding
vicinity of the bedroom set and the remainder of the bedroom.
sets (for example, size, style), sample selection process (for
6.3.3.5 For a conservative approach, assume no indoor
example, random), and brand name (if appropriate).
sinks. If indoor sinks are present, they are likely to be
7.3 Emission Profiles—List the time-varying emissions, or
reversible. Both CONTAM and EXPOSURE are capable of
provide an equation describing the time-varying emissions, for
handling reversible sinks.The MCCEM allows only a one-way
–1
each chemical emitted from a bedding set. Describe the
sink, expressed as a first-order rate constant in units of h .
chamber conditions and the technique used for estimating
6.3.3.6 If the model requires or allows user input for the
emissions from the chamber data.
time step, then specify a time step of no longer than 15 min,
7.4 Exposure Scenarios—Describe all assumptions used in
and preferably as short as 5 min or 1 min. A shorter time step
estimating exposures, including the age and indoor location of
will result in longer execution time but will increase the
the bedding set, the emission profile, the volume and partition-
resolution of the results.
ing of the indoor environment, the air change rate, interzonal
6.4 Selection and Calculation of Exposure Measures:
airflows, and human location and activity patterns, and asso-
6.4.1 Two commonly used measures of exposure are the
ciated breathing rates.
potential inhaled dose and the maximum indoor concentration
7.5 Modeling of Indoor-Concentrations—Describe model
to which an individual is exposed.
selection. List all inputs including the number of zones, air
6.4.2 Potential Inhaled Dose—The potential inhaled dose is
change rates, interzonal airflow rates, zonal volumes, and the
the product of indoor-air concentration times breathing rate
time step used in modeling. Include the comparison of pre-
times duration of exposure. This dose needs to be calculated
dicted and measured concentrations, if available.
separately for each contiguous period of time when the
exposed individual is in a different zone of the indoor envi-
7.6 Exposure Estimates—Describe the exposure measures
ronment; the resultant estimates are then summed to determine
selected, the manner in which each exposure measure was
the total inhaled dose. The time period over which the total
calculated, and the resultant exposure estimates.
inhaled dose is determined could be 1 h, 8 h, or 24 h, or longer,
8. Keywords
depending on the health end point of potential concern.
6.4.3 Maximum Indoor Concentration—The maximum in- 8.1 activity pattern ; air change rate; bedding set; emission
door concentration to which an individual is exposed typically profile; emissions; environmental chamber; exposure assess-
is integrated over a relatively short time period such as1hor ment;
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.