ASTM D7034-18

Standard Guide for Deriving Acceptable Levels of Airborne Chemical Contaminants in Aircraft Cabins Based on Health and Comfort Considerations

SIGNIFICANCE AND USE
5.1 Although cabin air quality has been measured on numerous occasions and in many studies, there is very little guidance available for interpreting such data. Guidance for identifying contaminants and associated exposure levels that would cause concern in aircraft cabins is very limited. Federal Aviation Administration (FAA) Airworthiness Standards (14 CFR 25) provide regulatory guidance that explicitly applies to the aircraft cabin environment. The FAA standards, however, define acceptable exposure limits for a limited number of chemical contaminants (ozone, carbon dioxide, and carbon monoxide). Another limitation of the FAA standards is that these are design standards only and are not operational standards; thus, once an aircraft is put in service these standards are not strictly applicable.  
5.2 Measurements of aircraft cabin air quality often lead to a much larger list of volatile and semi-volatile organic chemicals of potential concern. Exposures to these chemicals, however, are largely unregulated outside of the industrial workplace.  
5.3 An important feature of the aircraft cabin environment is that both passengers (public) and flight attendants (worker population) occupy it simultaneously. Therefore, workplace exposure guidelines cannot simply be extended to address exposures in aircraft cabin environment. Also, the length of flights and work shifts can vary considerably for flight attendants.  
5.4 Contaminant levels of concern for the general public must account for the non-homogeneity of the population (for example, address sensitive individuals, the differences between passenger and crew activity levels, location, health status, personal microenvironment). Levels of concern associated with industrial workplace exposures typically consider a population of healthy adults exposed for 40 h per week (1).4 Consequently, exposure criteria developed to protect public health typically are more stringent than those for workers.  
5.4.1 Given that the aircra...
SCOPE
1.1 This guide provides methodology to assist in interpreting results of air quality measurements conducted in aircraft cabins. In particular, the guide describes methodology for deriving acceptable concentrations for airborne chemical contaminants, based on health and comfort considerations.  
1.2 The procedures for deriving acceptable concentrations are based on considerations of comfort and health effects, including odor and irritant effects, of individual chemical contaminants being evaluated. The guide does not provide specific benchmark or guidance values for individual chemicals to compare with results of air quality measurements.  
1.3 Chemical contaminant exposures under both routine and episodic conditions for passengers and crew are considered.  
1.4 This guide does not address airborne microbiological contaminants, which are also important in consideration of aircraft cabin air quality. This guide also does not address methodologies for investigations of air quality complaints.  
1.5 This guide assumes that a list of chemical contaminants of potential concern has been developed based on existing concentration, emission, or material composition data.  
1.6 The primary information resources for developing acceptable concentrations are databases and documents maintained or published by cognizant authorities or organizations concerned with health effects of exposure to contaminants.  
1.7 Acceptable concentrations developed through this guide may be used as a basis for selecting test methods with adequate reliability and sensitivity to assess the acceptability of aircraft cabin environments.  
1.8 Procedures described in this guide should be carried out in consultation with qualified toxicologists and health effects specialists to ensure that acceptable concentrations developed are consistent with the current scientific understanding and knowledge base.  
1.9 The values stated in SI units are to be regard...

General Information

• Status: Published
• Publication Date: 14-Apr-2018
• ICS: 49.095 - Passenger and cabin equipment
• Technical Committee: D22 - Air Quality
• Drafting Committee: D22.05 - Indoor Air

Relations

• Replaces: ASTM D7034-11 - Standard Guide for Deriving Acceptable Levels of Airborne Chemical Contaminants in Aircraft Cabins Based on Health and Comfort Considerations
• Effective Date: 15-Apr-2018
• Refers: ASTM D1356-20a - Standard Terminology Relating to Sampling and Analysis of Atmospheres
• Effective Date: 01-Sep-2020
• Refers: ASTM D1356-20 - Standard Terminology Relating to Sampling and Analysis of Atmospheres
• Effective Date: 15-Mar-2020
• Refers: ASTM D6399-18 - Standard Guide for Selecting Instruments and Methods for Measuring Air Quality in Aircraft Cabins
• Effective Date: 01-Mar-2018
• Refers: ASTM E609-16 - Standard Terminology Relating to Pesticides
• Effective Date: 15-Sep-2016
• Refers: ASTM D1356-15a - Standard Terminology Relating to Sampling and Analysis of Atmospheres
• Effective Date: 15-Oct-2015
• Refers: ASTM D1356-15 - Standard Terminology Relating to Sampling and Analysis of Atmospheres
• Effective Date: 01-Jul-2015
• Refers: ASTM E609-15a - Standard Terminology Relating to Pesticides
• Effective Date: 01-May-2015
• Refers: ASTM E609-15 - Standard Terminology Relating to Pesticides
• Effective Date: 01-Jan-2015
• Refers: ASTM D1356-14b - Standard Terminology Relating to Sampling and Analysis of Atmospheres
• Effective Date: 01-Dec-2014
• Refers: ASTM D1356-14a - Standard Terminology Relating to Sampling and Analysis of Atmospheres
• Effective Date: 01-May-2014
• Refers: ASTM D1356-14 - Standard Terminology Relating to Sampling and Analysis of Atmospheres
• Effective Date: 15-Jan-2014
• Refers: ASTM D1356-05(2010) - Standard Terminology Relating to Sampling and Analysis of Atmospheres
• Effective Date: 01-Apr-2010
• Refers: ASTM D6399-10 - Standard Guide for Selecting Instruments and Methods for Measuring Air Quality In Aircraft Cabins
• Effective Date: 01-Apr-2010
• Refers: ASTM E609-10 - Standard Terminology Relating to Pesticides
• Effective Date: 01-Mar-2010

Overview

ASTM D7034-18, "Standard Guide for Deriving Acceptable Levels of Airborne Chemical Contaminants in Aircraft Cabins Based on Health and Comfort Considerations," provides a systematic approach to interpreting air quality measurements within aircraft cabins. Developed by ASTM International, this standard guides users in deriving acceptable concentrations for airborne chemical contaminants, focusing on both health and comfort for passengers and crew. Unlike regulatory standards that cover only a select few chemicals and apply primarily at the design stage, ASTM D7034-18 addresses a broad range of volatile and semi-volatile chemicals that may impact air quality during normal operation and episodic events.

The standard emphasizes the unique environment of aircraft cabins, where both the general public and occupational groups are present, and where exposure conditions differ from those in typical workplaces. It recognizes the need for more stringent exposure criteria to protect sensitive individuals and sets forth a framework for deriving values based on established scientific methods and authoritative sources.

Key Topics

• Interpretation Methodology: Step-by-step procedures to interpret air quality data and derive acceptable concentrations for chemicals in aircraft cabins.
• Exposure Assessment: Outlines the assessment of both acute (short-term) and chronic (long-term) exposures relevant to passengers and crew, considering varying duration and frequency of flights and work shifts.
• Health and Comfort Considerations: Incorporates health effects (including carcinogenic and non-carcinogenic endpoints) and comfort factors like odor and irritation.
• Population Sensitivity: Acknowledges non-homogeneity among occupants, including sensitive subgroups and activity level differences.
• Sources of Data: Utilizes information from recognized authorities, such as EPA’s IRIS, ATSDR’s Minimal Risk Levels, NIOSH, OSHA, and NASA SMACs, for selecting reference values.
• Uncertainty and Risk Assessment: Recommends use of uncertainty factors and decision-making at low risk levels, in consultation with toxicology and health effects specialists.
• Reporting Guidelines: Advises on compiling a comprehensive report that documents methodologies, assumptions, exposure scenarios, and key findings.

Applications

ASTM D7034-18 is highly relevant for:

• Aircraft manufacturers: Supporting design decisions related to materials and ventilation to manage cabin air quality.
• Airline operators: Assessing air quality during operations, responding to complaints, and implementing monitoring programs.
• Regulatory compliance and auditing: Benchmarking air quality data against derived acceptable concentrations rather than relying solely on limited regulatory design standards.
• Health and safety professionals: Evaluating occupational exposure for flight crew, assessing risk to passengers, and ensuring practices account for both chronic and acute health effects.
• Consultants and laboratories: Selecting valid measurement methods and interpreting results using scientifically sound exposure and risk assessment frameworks.

By providing a harmonized process focused on both health protection and comfort, this standard helps ensure safer and more pleasant air travel experiences for all aircraft occupants.

Related Standards

• ASTM D1356: Terminology Relating to Sampling and Analysis of Atmospheres
• ASTM D6399: Guide for Selecting Instruments and Methods for Measuring Air Quality in Aircraft Cabins
• OSHA 29 CFR 1910: Occupational Safety and Health Standards
• EPA 40 CFR 50: National Ambient Air Quality Standards (NAAQS)
• FAA 14 CFR 25: Airworthiness Standards
• NASA SMACs: Spacecraft Maximum Allowable Concentrations
• ACGIH TLVs: Threshold Limit Values for Chemical Substances and Physical Agents

These related standards and guidelines provide foundational concepts, recommended practices, and additional references for evaluating airborne chemical contaminants in highly controlled environments such as aircraft cabins.

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Keywords: aircraft cabin air quality, airborne chemical contaminants, health considerations, comfort considerations, ASTM D7034-18, exposure assessment, risk management, air quality standards, cabin crew safety, passenger health.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D7034 − 18
Standard Guide for
Deriving Acceptable Levels of Airborne Chemical
Contaminants in Aircraft Cabins Based on Health and
Comfort Considerations
This standard is issued under the fixed designation D7034; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope specialists to ensure that acceptable concentrations developed
are consistent with the current scientific understanding and
1.1 This guide provides methodology to assist in interpret-
knowledge base.
ing results of air quality measurements conducted in aircraft
cabins. In particular, the guide describes methodology for
1.9 The values stated in SI units are to be regarded as
deriving acceptable concentrations for airborne chemical
standard. No other units of measurement are included in this
contaminants, based on health and comfort considerations.
standard.
1.2 The procedures for deriving acceptable concentrations
1.10 This standard does not purport to address all of the
are based on considerations of comfort and health effects,
safety concerns, if any, associated with its use. It is the
including odor and irritant effects, of individual chemical
responsibility of the user of this standard to establish appro-
contaminants being evaluated. The guide does not provide
priate safety, health, and environmental practices and deter-
specific benchmark or guidance values for individual chemi-
mine the applicability of regulatory limitations prior to use.
cals to compare with results of air quality measurements.
1.11 This international standard was developed in accor-
dance with internationally recognized principles on standard-
1.3 Chemicalcontaminantexposuresunderbothroutineand
ization established in the Decision on Principles for the
episodic conditions for passengers and crew are considered.
Development of International Standards, Guides and Recom-
1.4 This guide does not address airborne microbiological
mendations issued by the World Trade Organization Technical
contaminants, which are also important in consideration of
Barriers to Trade (TBT) Committee.
aircraft cabin air quality. This guide also does not address
methodologies for investigations of air quality complaints.
2. Referenced Documents
1.5 This guide assumes that a list of chemical contaminants
2.1 ASTM Standards:
of potential concern has been developed based on existing
D1356Terminology Relating to Sampling and Analysis of
concentration, emission, or material composition data.
Atmospheres
1.6 The primary information resources for developing ac- D6399Guide for Selecting Instruments and Methods for
ceptable concentrations are databases and documents main- Measuring Air Quality in Aircraft Cabins
tained or published by cognizant authorities or organizations E609Terminology Relating to Pesticides
concerned with health effects of exposure to contaminants.
E943Terminology Relating to Biological Effects and Envi-
ronmental Fate
1.7 Acceptableconcentrationsdevelopedthroughthisguide
2.2 Other Standards:
maybeusedasabasisforselectingtestmethodswithadequate
14 CFR 25Airworthiness Standards
reliability and sensitivity to assess the acceptability of aircraft
29 CFR 1910Occupational Safety and Health Standards
cabin environments.
40 CFR 50National Ambient Air Quality Standards
1.8 Procedures described in this guide should be carried out
in consultation with qualified toxicologists and health effects
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
This guide is under the jurisdiction of ASTM Committee D22 on Air Quality Standards volume information, refer to the standard’s Document Summary page on
and is the direct responsibility of Subcommittee D22.05 on Indoor Air. the ASTM website.
Current edition approved April 15, 2018. Published June 2018. Originally Available from U.S. Government Printing Office, Superintendent of
approved in 2004. Last previous edition approved in 2011 as D7034–11. DOI: Documents, 732 N. Capitol St., NW, Washington, DC 20401-0001, http://
10.1520/D7034-18. www.access.gpo.gov.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7034 − 18
3. Terminology cals of potential concern. Exposures to these chemicals,
however, are largely unregulated outside of the industrial
3.1 Definitions—For definitions of terms used in this guide,
workplace.
refer to Terminologies D1356, E609, and E943.
5.3 Animportantfeatureoftheaircraftcabinenvironmentis
4. Summary of Guide that both passengers (public) and flight attendants (worker
population) occupy it simultaneously. Therefore, workplace
4.1 Thepurposeofthisguideistoprovidemethodologyfor
exposure guidelines cannot simply be extended to address
interpretation of air quality data obtained by measurements
exposures in aircraft cabin environment. Also, the length of
conducted in aircraft cabins.Acceptable concentrations devel-
flights and work shifts can vary considerably for flight atten-
oped through this guide may also be used as a basis for
dants.
selecting test methods with adequate reliability and sensitivity
for measuring cabin air quality.
5.4 Contaminant levels of concern for the general public
must account for the non-homogeneity of the population (for
4.2 To provide a background for assessment of cabin air
example,addresssensitiveindividuals,thedifferencesbetween
quality, the guide summarizes information on the concepts of
passenger and crew activity levels, location, health status,
exposure,dose,andrelatedhealtheffects,andmakesadistinc-
personal microenvironment). Levels of concern associated
tion between chronic (long-term) and acute (short-term) ef-
withindustrialworkplaceexposurestypicallyconsiderapopu-
fects.
lation of healthy adults exposed for 40 h per week (1).
4.3 This guide describes data sources and procedures for
Consequently, exposure criteria developed to protect public
derivingacceptableconcentrationsinaircraftpassengercabins.
health typically are more stringent than those for workers.
The acceptable concentrations are based on characterization of
5.4.1 Given that the aircraft cabin environment must meet
risk of chronic and acute inhalation exposure. Risk character-
the needs of passengers as well as crew, a more stringent
izationalsoincludesanassessmentofpotentialodorproblems.
concentration level based upon the general population would
4.4 An eight-step procedure is described for deriving an
protect both.
acceptable level for an airborne contaminant in aircraft cabins
5.4.2 Aircraft cabin air quality must be addressed both
that considers both chronic and acute effects. The steps are:
during flight and on the ground because the conditions during
4.4.1 Select population to be considered;
flight are much different than when the aircraft is on the
4.4.2 Choose effects to be considered;
ground.
4.4.3 Develop a summary of standards/guidelines and
health effects data;
6. Exposure and Effects
4.4.4 Develop scenarios for exposure;
6.1 Concepts of Exposure and Dose:
4.4.5 Select risk levels of concern;
6.1.1 Exposureisdefinedashumancontactwithachemical
4.4.6 Calculate level of concern for each selected effect;
or physical agent (see Terminology E943). Exposure via the
4.4.7 Determine an acceptable concentration for aircraft
inhalation route, of interest in this guide, can be expressed as
cabins; and
the product of airborne concentration times the duration of
4.4.8 Compareacceptableconcentrationwithexistinginfor-
exposure, provided that the concentration remains constant
mation.
duringthetimeperiodofinterest.Iftheairborneconcentration
4.5 Guidance also is provided on development of a report
variesovertime,thenexposureisdefinedastheareaunderthe
thatsummarizesthemethodologyandunderlyingassumptions,
curve (integral of all the finite or momentary concentrations)
and describes implications of results, including limitations.
obtained when concentration values are plotted against time.
Exposureisexpressedasconcentrationmultipliedbytimewith
5. Significance and Use
resultant units such as ppm-h or mg/m -h. The relevant
5.1 Although cabin air quality has been measured on nu-
exposure measure depends on the type of biological effect.
merous occasions and in many studies, there is very little
Some effects, for example, allergic sensitization, may depend
guidance available for interpreting such data. Guidance for
more on frequency of peak exposure above a certain limit than
identifying contaminants and associated exposure levels that
on the exposure measures described here.
would cause concern in aircraft cabins is very limited. Federal
6.1.2 Doseisthequantityofchemicalorphysicalagentthat
Aviation Administration (FAA) Airworthiness Standards (14
enters an organism or target organ (see Terminology E609),
CFR 25) provide regulatory guidance that explicitly applies to
with units such as mg. Dose also can be expressed as a rate,
the aircraft cabin environment. The FAA standards, however,
with mass/time units such as mg/day. The dose rate can be
define acceptable exposure limits for a limited number of
normalized in relation to body mass, with units such as
chemical contaminants (ozone, carbon dioxide, and carbon
mg/kg-day.Aspecific term that often is used in risk character-
monoxide). Another limitation of the FAA standards is that
ization is potential inhaled dose—the product of average
these are design standards only and are not operational
concentration in an environment (mg/m ) times the duration in
standards; thus, once an aircraft is put in service these
standards are not strictly applicable.
5.2 Measurements of aircraft cabin air quality often lead to
Theboldfacenumbersinparenthesesrefertothelistofreferencesattheendof
a much larger list of volatile and semi-volatile organic chemi- this standard.
D7034 − 18
the environment (h) times the average breathing rate while in 8-hworkperiod (7).TheAmericanConferenceofGovernmen-
the environment (m /h), commonly expressed in mass units tal Industrial Hygienists (ACGIH) has defined threshold limit
such as mg. values (TLVs) for 8-h work periods as well as STELs for
6.1.3 Chronic exposure generally refers to a long-term 15-min work periods (8). Guidelines or data on irritation
perspective such as repeated exposures or the cumulative effects are not available in a single database and need to be
exposure for more than 3 months. gleaned from multiple databases (2-5).
6.1.4 Acute exposure refers to a short-term exposure to a
6.4 Odor Thresholds:
substanceoccurringfromasingleincidentoroveraperiodless
6.4.1 Data relating to odor thresholds are available for the
than 24 h. In the case of occupational exposures, exposure
general population (9) or for workers (10).
limitshavebeendefinedforcertainchemicalsfor8-hworkday
6.5 Consideration of Uncertainty Factors:
periods and short-term, 15-min periods.
6.5.1 To account for the known and unknown variations in
6.2 Chronic Effects:
thetoxicologicalresponseoforganisms,includingthevariabil-
6.2.1 The risk of cancer, due to lifetime exposure to a
ity across species and among individuals within the same
contaminant, typically is calculated using the slope for the
species, uncertainty factors are used. Such factors are applied
low-dose linear portion of the dose-response curve for the
by adjusting a value derived from experimental data by a
contaminant.Forcancer,athresholdfordose-responsemaynot
multiplier or divisor that reflects the degree of uncertainty.
be known or, if one does exist, it may be very low and cannot
6.5.2 The National Research Council, NRC (11, 12), pro-
be reliably identified. If the slope for the low-dose linear
vides guidance on uncertainty factors. For example, an uncer-
portion of the dose-response curve for the contaminant is
tainty factor of 10 is applied to NOAEL values derived from
unknown or uncharacterized, methodologies are available in
animal testing if the most sensitive species is not used in
the peer-reviewed literature to approximate the dose-response
toxicologicalstudies,ifthemechanismormodeofphysiologic
curve (2).
or metabolic response is unknown, or if the data are inad-
6.2.2 For chronic toxic effects other than cancer, one gen-
equate. An uncertainty factor of 3 applies if the most appro-
erally accepted procedure used for evaluating health effects
priatespeciesisusedinlaboratorystudies,orifthemechanism
involves identifying the highest exposure among all experi-
or mode of action does not differ between humans and the
mental studies at which no toxic effect has been observed, that
species studied in the laboratory. An uncertainty factor of 1
is,the“noobservedadverseeffectlevel”orNOAEL.TheU.S.
may be applied when there is a high degree of confidence that
Environmental Protection Agency (USEPA) has developed
the animal model tested is a sensitive surrogate for humans or
chronic and non-chronic inhalation reference concentrations
more sensitive than humans. The magnitude of uncertainty
(RfCs)forsomecontaminantsforcomparisonwiththeaverage
factors can also depend on the type of effect under consider-
concentration to which an individual has been exposed over a
ation. For example, the uncertainty factor could range from 3
relatively long period; the sub-chronic RfCs pertain to expo-
for local tissue irritation to 10 or more for serious systemic
sures of less than 7 years (3). Minimum risk levels (MRLs)
effects.
have been derived by the Agency for Toxic Substances and
6.5.3 Inadditiontotheuncertaintyfactorsmentionedabove,
DiseaseRegistry(ATSDR)forchronicexposureperiodsof365
additional modifying factors may be used to account for
days and longer (4).
uncertainties or for known differences in toxicity among
6.3 Acute Effects:
structurally similar chemicals. For further extrapolation from
6.3.1 Specific guidelines available for considering acute thereportedexposuredurationandchemicalconcentrationofa
effects of exposure to contaminants in air are quite limited.
toxic endpoint to an equivalent concentration for a specified
Minimum risk levels (MRLs) have been derived for acute period such as one hour, a time-scaling method has been used
exposures of one day to 14 days (4). Other guidelines such as
by the AEGL committee (11) and by California Office of
Acute Exposure Guidelines Levels (AEGLs) developed by the
Environmental Health Hazard Assessment (13).
NationalAdvisory CommitteeAcute Exposure Guideline Lev-
6.6 Effects of Mixture of Chemicals:
els for Hazardous Substances (NAC/AEGL Committee) are
6.6.1 There generally is a paucity of information on effects
applicable only for one-time, short-term hazardous exposures
of mixtures, except for selected types of mixtures such as jet
during chemical emergency situations (5). For occupational
engine oil (14). Whenever health-effects data on mixtures are
settings, the National Institute for Occupational Safety and
available, such data should be considered in conjunction with
Health (NIOSH) develops and recommends criteria for pre-
the toxicity of individual chemicals.
venting disease or hazardous conditions. NIOSH recom-
6.6.2 In the absence of health-effects information on
mended exposure limits (NIOSH RELs) are expressed as a
mixtures, the effects of chemicals affecting the same target
time-weighted average for up to 10 h/day during a 40-h
organ should be considered additive. For example, the follow-
workweek. The NIOSH RELs are also expressed as a short-
ingexpressionisusedforderivingacombinedTLVfromTLVs
termexposurelimit(STEL)thatshouldneverbeexceededover
for individual compounds (8).
aspecifiedtime—usually15minorasceilinglimitthatshould
TLVofmixture 51/$C /TLV 1C /TLV 1…1C /TLV % (1)
never be exceeded even instantaneously (6). In conjunction
1 1 2 2 n n
with recommendations from NIOSH, the Occupational Safety
where:
&HealthAdministration(OSHA)haspromulgatedpermissible
C and TLV = concentration and TLV of compound 1,
1 1
exposure limits (PELs) for certain chemicals that relate to an
D7034 − 18
exposures to the routine or typical cabin environment and (2)
C and TLV = concentration and TLV of compound 2, and
2 2
infrequent exposures to episodic conditions in the cabin. The
C and TLV = concentration and TLV of compound n.
n n
first type can contribute to long-term exposure, whereas the
6.7 No Health Effects Data:
second can result in elevated short-term exposure.
6.7.1 If some chemical has no health guideline values or
7.2.2 The types of effects to be considered include (1)
toxicitydataavailable,thenguidelinevaluesforcompoundsof
cancerandotherchronicendpointsforlong-termexposure(see
similar type and structure should be considered. However,
6.2) and (2) acute effects, including exceedance of irritation/
given the uncertainty in extrapolating from other substances,
odor thresholds (see 6.3 and 6.4), for short-term exposure.
steps should be considered to reduce the concentration of that
While all possible effects should at least be considered, the
compound to as low a level as possible.
final choice may be dictated in part by availability of appro-
6.8 Effects of Altitude:
priate data.
6.8.1 It should be recognized that most toxicity data for
7.3 Develop a Summary of Standards/Guidelines and
chemicals are for ground-based environments and the cabin
Health Effects Data:
pressure regulation (14 CFR 25) is not to be less than pressure
7.3.1 The first step in developing a summary involves
at 2438 m. Two types of effects need to be considered with
compiling standards, guidelines, and health-effects data that
respecttocabinpressures:(1)thereducedpressurewouldtend
pertain to the contaminant under consideration, based on the
to increase the inhalation rate in persons that are not acclima-
type of effect(s) considered (see 7.2). Table 1 presents an
tized to such pressures; and (2) the lower pressure could cause
example format for summarizing human regulatory standards
adverse effects or could exacerbate effect(s) of chemicals.
or guidelines for chronic and sub-chronic effects. Table 2
These effects of pressure should be considered for chemicals
presents a similar format for information on acute effects,
for which such data are available.
including acute inhalation MRLs and immediately dangerous
6.8.2 There is a possibility that the flow rate of sampling
to life or health (IDLH) concentrations (15). The “Notes”
pumps under reduced pressures may vary from a value pre-set
column in the table can be used to record information on data
and calibrated under different pressure conditions (for
sources or references or for details such as the duration of
example, at sea-level). The manufacturer should be consulted
exposure on which the value is based.
to determine whether a specific pump type is affected, or
7.3.2 In addition to the chronic, sub-chronic and acute
preferably,thepumpsshouldbecalibratedundertheconditions
guidelines, it is useful to develop a summary of the data
of use. Certain types of flow meters (for example, rotometers)
reported for laboratory animals or humans on NOAELs or
are strongly affected by pressure differences, and should either
LOAELs (see Table 3).
notbeused,orshouldbecalibratedundertheconditionsofuse.
7.3.3 Leading examples of information resources that com-
(Itmayalsobepossibletocalculatethemagnitudeoftheeffect
pile and summarize such data appear in Appendix X1.
for a specific pressure and apply a correction to the reading.)
7.4 Develop Scenarios for Exposure:
Rotometers provided with certain types of pumps are for flow
7.4.1 Development of a realistic and reasonable scenario is
indication purposes only and cannot be used for accurate
necessary for an accurate estimation of exposure. Short-term
measurement of flow rate.
exposure scenarios often are straightforward, requiring only
specification of an exposure duration (for example, 30 min or
7. Procedure
1 h). Long-term exposure scenarios commonly require a
7.1 Select Population to be Considered:
number of assumptions, as described below.
7.1.1 A first step in deriving an acceptable level for an
7.4.2 Long-term exposure scenarios involve time periods
airborne contaminant in aircraft cabins is to select the popula-
thatspanalifetimeorasubstantialportionthereof.Abounding
tion to which such levels will apply. Two major population
estimate for passengers and crew on commercial flights can be
groupsinaircraftcabinsarethecabincrewandthepassengers.
based on the assumption that such an individual might log an
If the selected population were the cabin crew, then occupa-
tional guidelines would be influential in determining the
acceptable level. However, occupational guidelines need to
TABLE 1 Example Format for Summarizing Standards/Guidelines
for Chronic and Subchronic Health Effects Data
take into account the atmosphere at cruise conditions rather
than ground-level environments. On the other hand, if only the
Chemical Name: CASRN:
A
passenger population is of interest, then public health guide-
Parameter Value Notes
lineswillhavestrongerinfluenceindeterminingtheacceptable
EPA IRIS Chronic Inhalation RfC
EPA HEAST Chronic RfC
level. Further, if a highly sensitive subset of passengers (for
EPA HEAST Sub-Chronic RfC
example, those with a pre-existing condition that may make
Intermediate Inhalation MRL
themmoresensitivetochemicalexposures)isconsidered,then
Chronic Inhalation MRL
Chronic REL (California)
the selected level will be need to address the higher level of
NIOSH REL
protection that may need to be provided for such individuals.
SMAC 180 days
ACGIH TLV
7.2 Choose Effects to be Considered:
OSHA PEL
7.2.1 One of the primary considerations in choosing the
Inhalation unit risk
typeofeffect(s)isthefrequency/durationofexposure.Thetwo A
Include units when completing this portion of the table.
major types of exposures to be considered are (1) repeated
D7034 − 18
TABLE 2 Example Format for Summarizing Standards/Guidelines
LifetimeCancerRiskofConcern5 (2)
for Acute Health Effects and Odor Thresholds
LADD 3SlopeofDose 2 ResponseCurve
Chemical Name: CASRN:
Parameter Value Notes
where:
Acute Inhalation MRL
Odor Threshold LADD mg ⁄ kg2day 5 (3)
~ !
Detection
Recognition 3 3
Concentration~mg ⁄ m ! 3ExposureDuration~h! 3InhalationRate~m ⁄h!
Acute REL (California)
BodyWeight kg 3Lifespan days
~ ! ~ !
NIOSH STEL/Ceiling Limit
SMAC 1-h
The concentration equated to the lifetime excess risk can be
OSHA STEL
NIOSH IDLH
determined from Eq 2 and 3 as:
LifetimeExcessRisk
Concentration 5 (4)
SlopeofDoseResponseCurve
TABLE 3 Example Format for Summarizing LOAELs and NOAELs
for Humans and Laboratory Animals
BodyWeight 3Lifespan
Chemical Name: CASRN: 3
DurationofExposure 3InhalationRate
Data Reported for Laboratory Animals
Parameter Value Notes
7.6.1.1 Discussion—As an example of applying Eq 2-4,
No-adverse-effect level (NOAEL)
consider a contaminant with a slope of 0.01 mg/kg–day. For a
Low-adverse-effect level (LOAEL)
Data Reported for Humans lifetime risk of concern of 1 in 100000, an average body
Parameter Value Notes
weight of 70 kg, a life span of 25550 days (70 years), an
NOAEL
exposure duration of 7800 h, and an inhalation rate of 0.5
LOAEL
m /h(appropriate for a seated population such as airline
passengers), the calculated concentration is 0.66 mg/m . This
value can be considered an acceptable concentration for the
contaminant in the cabin environment, from the standpoint of
average of 40 h per month, or 480 h per year
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D7034 − 11 D7034 − 18
Standard Guide for
Deriving Acceptable Levels of Airborne Chemical
Contaminants in Aircraft Cabins Based on Health and
Comfort Considerations
This standard is issued under the fixed designation D7034; 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
1.1 This guide provides methodology to assist in interpreting results of air quality measurements conducted in aircraft cabins.
In particular, the guide describes methodology for deriving acceptable concentrations for airborne chemical contaminants, based
on health and comfort considerations.
1.2 The procedures for deriving acceptable concentrations are based on considerations of comfort and health effects, including
odor and irritant effects, of individual chemical contaminants being evaluated. The guide does not provide specific benchmark or
guidance values for individual chemicals to compare with results of air quality measurements.
1.3 Chemical contaminant exposures under both routine and episodic conditions for passengers and crew are considered.
1.4 This guide does not address airborne microbiological contaminants, which are also important in consideration of aircraft
cabin air quality. This guide also does not address methodologies for investigations of air quality complaints.
1.5 This guide assumes that a list of chemical contaminants of potential concern has been developed based on existing
concentration, emission, or material composition data.
1.6 The primary information resources for developing acceptable concentrations are databases and documents maintained or
published by cognizant authorities or organizations concerned with health effects of exposure to contaminants.
1.7 Acceptable concentrations developed through this guide may be used as a basis for selecting test methods with adequate
reliability and sensitivity to assess the acceptability of aircraft cabin environments.
1.8 Procedures described in this guide should be carried out in consultation with qualified toxicologists and health effects
specialists to ensure that acceptable concentrations developed are consistent with the current scientific understanding and
knowledge base.
1.9 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.10 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory requirementslimitations prior to use.
1.11 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
D1356 Terminology Relating to Sampling and Analysis of Atmospheres
D6399 Guide for Selecting Instruments and Methods for Measuring Air Quality in Aircraft Cabins
E609 Terminology Relating to Pesticides
E943 Terminology Relating to Biological Effects and Environmental Fate
This guide is under the jurisdiction of ASTM Committee D22 on Air Quality and is the direct responsibility of Subcommittee D22.05 on Indoor Air.
Current edition approved March 1, 2011April 15, 2018. Published March 2011June 2018. Originally approved in 2004. Last previous edition approved in 20052011 as
D7034 – 05.D7034 – 11. DOI: 10.1520/D7034-11.10.1520/D7034-18.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7034 − 18
2.2 Other Standards:
14 CFR 25 Airworthiness Standards
29 CFR 1910 Occupational Safety Andand Health Standards
40 CFR 50 National Ambient Air Quality Standards
3. Terminology
3.1 Definitions—For definitions of terms used in this guide, refer to Terminologies D1356, E609, and E943.
4. Summary of Guide
4.1 The purpose of this guide is to provide methodology for interpretation of air quality data obtained by measurements
conducted in aircraft cabins. Acceptable concentrations developed through this guide may also be used as a basis for selecting test
methods with adequate reliability and sensitivity for measuring cabin air quality.
4.2 To provide a background for assessment of cabin air quality, the guide summarizes information on the concepts of exposure,
dose, and related health effects, and makes a distinction between chronic (long-term) and acute (short-term) effects.
4.3 This guide describes data sources and procedures for deriving acceptable concentrations in aircraft passenger cabins. The
acceptable concentrations are based on characterization of risk of chronic and acute inhalation exposure. Risk characterization also
includes an assessment of potential odor problems.
4.4 An eight-step procedure is described for deriving an acceptable level for an airborne contaminant in aircraft cabins that
considers both chronic and acute effects. The steps are:
4.4.1 Select population to be considered;
4.4.2 Choose effects to be considered;
4.4.3 Develop a summary of standards/guidelines and health effects data;
4.4.4 Develop scenarios for exposure;
4.4.5 Select risk levels of concern;
4.4.6 Calculate level of concern for each selected effect;
4.4.7 Determine an acceptable concentration for aircraft cabins; and
4.4.8 Compare acceptable concentration with existing information.
4.5 Guidance also is provided on development of a report that summarizes the methodology and underlying assumptions, and
describes implications of results, including limitations.
5. Significance and Use
5.1 Although cabin air quality has been measured on numerous occasions and in many studies, there is very little guidance
available for interpreting such data. Guidance for identifying contaminants and associated exposure levels that would cause
concern in aircraft cabins is very limited. FAA Federal Aviation Administration (FAA) Airworthiness Standards (14 CFR 25)
constitute the only source of provide regulatory guidance that explicitly applies to the aircraft cabin environment. The FAA
standards, however, define acceptable exposure limits for a limited number of chemical contaminants (ozone, carbon dioxide, and
carbon monoxide). Another limitation of the FAA standards is that these are design standards only and are not operational
standards; thus, once an aircraft is put in service these standards are not strictly applicable.
5.2 Measurements of aircraft cabin air quality often lead to a much larger list of volatile and semi-volatile organic chemicals
of potential concern. Exposures to these chemicals, however, are largely unregulated outside of the industrial workplace.
5.3 An important feature of the aircraft cabin environment is that both passengers (public) and flight attendants (worker
population) occupy it simultaneously. Therefore, workplace exposure guidelines cannot simply be extended to address exposures
in aircraft cabin environment. Also, the length of flights and work shifts can vary considerably for flight attendants.
5.4 Contaminant levels of concern for the general public must account for the non-homogeneity of the population (for example,
address sensitive individuals, the differences between passenger and crew activity levels, location, health status, personal
microenvironment). Levels of concern associated with industrial workplace exposures typically consider a population of healthy
adults exposed for 40 h per week (1). Consequently, exposure criteria developed to protect public health typically are more
stringent than those for workers.
5.4.1 Given that the aircraft cabin environment must meet the needs of passengers as well as crew, a more stringent
concentration level based upon the general population would protect both.
5.4.2 Aircraft cabin air quality must be addressed both during flight and on the ground because the conditions during flight are
much different than when the aircraft is on the ground.
Available from U.S. Government Printing Office, Superintendent of Documents, 732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401.20401-0001,
http://www.access.gpo.gov.
The boldface numbers in parentheses refer to the list of references at the end of this standard.
D7034 − 18
6. Exposure and Effects
6.1 Concepts of Exposure and Dose:
6.1.1 Exposure is defined as human contact with a chemical or physical agent (see Terminology E943). Exposure via the
inhalation route, of interest in this guide, can be expressed as the product of airborne concentration times the duration of exposure,
provided that the concentration remains constant during the time period of interest. If the airborne concentration varies over time,
then exposure is defined as the area under the curve (integral of all the finite or momentary concentrations) obtained when
concentration values are plotted against time. Exposure is expressed as concentration multiplied by time with resultant units such
as ppm-h or mg/m -h. The relevant exposure measure depends on the type of biological effect. Some effects, for example, allergic
sensitization, may depend more on frequency of peak exposure above a certain limit than on the exposure measures described here.
6.1.2 Dose is the quantity of chemical or physical agent that enters an organism or target organ (see Terminology E609), with
units such as mg. Dose also can be expressed as a rate, with mass/time units such as mg/day. The dose rate can be normalized in
relation to body mass, with units such as mg/kg-day. A specific term that often is used in risk characterization is potential inhaled
dose—the product of average concentration in an environment (mg/m ) times the duration in the environment (h) times the average
breathing rate while in the environment (m /h), commonly expressed in mass units such as mg.
6.1.3 Chronic exposure generally refers to a long-term perspective such as repeated exposures or the cumulative exposure for
more than 3 months.
6.1.4 Acute exposure refers to a short-term exposure to a substance occurring from a single incident or over a period less than
24 h. In the case of occupational exposures, exposure limits have been defined for certain chemicals for 8-h workday periods and
short-term, 15-min periods.
6.2 Chronic Effects:
6.2.1 The risk of cancer, due to lifetime exposure to a contaminant, typically is calculated using the slope for the low-dose linear
portion of the dose-response curve for the contaminant. For cancer, a threshold for dose-response may not be known or, if one does
exist, it may be very low and cannot be reliably identified. If the slope for the low-dose linear portion of the dose-response curve
for the contaminant is unknown or uncharacterized, methodologies are available in the peer-reviewed literature to approximate the
dose-response curve (2).
6.2.2 For chronic toxic effects other than cancer, one generally accepted procedure used for evaluating health effects involves
identifying the highest exposure among all experimental studies at which no toxic effect has been observed, that is, the “no
observed adverse effect level” or NOAEL. The U.S. Environmental Protection Agency (USEPA) has developed chronic and
non-chronic inhalation reference concentrations (RfCs) for some contaminants for comparison with the average concentration to
which an individual has been exposed over a relatively long period; the sub-chronic RfCs pertain to exposures of less than 7 years
(3). Minimum risk levels (MRLs) have been derived by the Agency for Toxic Substances and Disease Registry (ATSDR) for
chronic exposure periods of 365 days and longer (4).
6.3 Acute Effects:
6.3.1 Specific guidelines available for considering acute effects of exposure to contaminants in air are quite limited. Minimum
risk levels (MRLs) have been derived for acute exposures of one day to 14 days (4). Other guidelines such as Acute Exposure
Guidelines Levels (AEGLs) developed by the National Advisory Committee Acute Exposure Guideline Levels for Hazardous
Substances (NAC/AEGL Committee) are applicable only for one-time, short-term hazardous exposures during chemical
emergency situations (5). For occupational settings, the National Institute for Occupational Safety and Health (NIOSH) develops
and recommends criteria for preventing disease or hazardous conditions. NIOSH recommended exposure limits (NIOSH RELs)
are expressed as a time-weighted average for up to 10 h/day during a 40-h workweek. The NIOSH RELs are also expressed as
a short-term exposure limit (STEL) that should never be exceeded over a specified time—usually 15 min or as ceiling limit that
should never be exceeded even instantaneously (6). In conjunction with recommendations from NIOSH, the Occupational Safety
& Health Administration (OSHA) has promulgated permissible exposure limits (PELs) for certain chemicals that relate to an 8-h
work period (7). The American Conference of Governmental Industrial Hygienists (ACGIH) has defined threshold limit values
(TLVs) for 8-h work periods as well as STELs for 15-min work periods (8). Guidelines or data on irritation effects are not available
in a single database and need to be gleaned from multiple databases (2-5).
6.4 Odor Thresholds:
6.4.1 Data relating to odor thresholds are available for the general population (9) or for workers (10).
6.5 Consideration of Uncertainty Factors:
6.5.1 To account for the known and unknown variations in the toxicological response of organisms, including the variability
across species and among individuals within the same species, uncertainty factors are used. Such factors are applied by adjusting
a value derived from experimental data by a multiplier or divisor that reflects the degree of uncertainty.
6.5.2 The National Research Council, NRC (11, 12), provides guidance on uncertainty factors. For example, an uncertainty
factor of 10 is applied to NOAEL values derived from animal testing if the most sensitive species is not used in toxicological
studies, if the mechanism or mode of physiologic or metabolic response is unknown, or if the data are inadequate. An uncertainty
factor of 3 applies if the most appropriate species is used in laboratory studies, or if the mechanism or mode of action does not
differ between humans and the species studied in the laboratory. An uncertainty factor of 1 may be applied when there is a high
D7034 − 18
degree of confidence that the animal model tested is a sensitive surrogate for humans or more sensitive than humans. The
magnitude of uncertainty factors can also depend on the type of effect under consideration. For example, the uncertainty factor
could range from 3 for local tissue irritation to 10 or more for serious systemic effects.
6.5.3 In addition to the uncertainty factors mentioned above, additional modifying factors may be used to account for
uncertainties or for known differences in toxicity among structurally similar chemicals. For further extrapolation from the reported
exposure duration and chemical concentration of a toxic endpoint to an equivalent concentration for a specified period such as one
hour, a time-scaling method has been used by the AEGL committee (11) and by California Office of Environmental Health Hazard
Assessment (13).
6.6 Effects of Mixture of Chemicals:
6.6.1 There generally is a paucity of information on effects of mixtures, except for selected types of mixtures such as jet engine
oil (14). Whenever health-effects data on mixtures are available, such data should be considered in conjunction with the toxicity
of individual chemicals.
6.6.2 In the absence of health-effects information on mixtures, the effects of mixtures chemicals affecting the same target organ
should be considered additive. For example, the following expression is used for deriving a combined TLV from TLVs for
individual compounds (8).
TLV of mixture 5 1/$C /TLV 1C /TLV 1…1C /TLV % (1)
1 1 2 2 n n
where:
C and TLV = concentration and TLV of compound 1,
1 1
C and TLV = concentration and TLV of compound 2, and
2 2
C and TLV = concentration and TLV of compound n.
n n
6.7 No Health Effects Data:
6.7.1 If some chemical has no health guideline values or toxicity data available, then guideline values for compounds of similar
type and structure should be considered. However, given the uncertainty in extrapolating from other substances, steps should be
considered to reduce the concentration of that compound to as low a level as possible.
6.8 Effects of Altitude:
6.8.1 It should be recognized that most toxicity data for chemicals are for ground-based environments and the cabin pressure
regulation (14 CFR 25) is not to be less than pressure at 8000 ft [2438 m]. 2438 m. Two types of effects need to be considered
with respect to cabin pressures: (i1) the reduced pressure would tend to increase the inhalation rate in persons that are not
acclimatized to such pressures; and (ii2) the lower pressure could cause adverse effects or could exacerbate effect(s) of chemicals.
These effects of pressure should be considered for chemicals for which such data are available.
6.8.2 There is a possibility that the flow rate of sampling pumps under reduced pressures may vary from a value pre-set and
calibrated under different pressure conditions (for example, at sea-level). The manufacturer should be consulted to determine
whether a specific pump type is affected, or preferably, the pumps should be calibrated under the conditions of use. Certain types
of flow meters (for example, rotometers) are strongly affected by pressure differences, and should either not be used, or should be
calibrated under the conditions of useuse. (It may also be possible to calculate the magnitude of the effect for a specific pressure
and apply a correction to the reading.).reading.) Rotometers provided with certain types of pumps are for flow indication purposes
only and cannot be used for accurate measurement of flow rate.
7. Procedure
7.1 Select Population to be Considered:
7.1.1 A first step in deriving an acceptable level for an airborne contaminant in aircraft cabins is to select the population to which
such levels will apply. Two major population groups in aircraft cabins are the cabin crew and the passengers. If the selected
population were the cabin crew, then occupational guidelines would be influential in determining the acceptable level. However,
occupational guidelines need to take into account the atmosphere at cruise conditions rather than ground-level environments. On
the other hand, if only the passenger population is of interest, then public health guidelines will have stronger influence in
determining the acceptable level. Further, if a highly sensitive subset of passengers (for example, those with a pre-existing
condition that may make them more sensitive to chemical exposures) is considered, then the selected level will be need to address
the higher level of protection that may need to be provided for such individuals.
7.2 Choose Effects to be Considered:
7.2.1 One of the primary considerations in choosing the type of effect(s) is the frequency/duration of exposure. The two major
types of exposures to be considered are (1) repeated exposures to the routine or typical cabin environment and (2) infrequent
exposures to episodic conditions in the cabin. The first type can contribute to long-term exposure, whereas the second can result
in elevated short-term exposure.
7.2.2 The types of effects to be considered include (1) cancer and other chronic endpoints for long-term exposure (see 6.2) and
(2) acute effects, including exceedenceexceedance of irritation/odor thresholds (see 6.3 and 6.4), for short-term exposure. While
all possible effects should at least be considered, the final choice may be dictated in part by availability of appropriate data.
D7034 − 18
7.3 Develop a Summary of Standards/Guidelines and Health Effects Data:
7.3.1 The first step in developing a summary involves compiling standards, guidelines, and health-effects data that pertain to
the contaminant under consideration, based on the type of effect(s) considered (see 7.2). Table 1 presents an example format for
summarizing human regulatory standards or guidelines for chronic and sub-chronic effects. Table 2 presents a similar format for
information on acute effects, including acute inhalation MRLs and immediately dangerous to life or health (IDLH) concentrations
(15). The “Notes” column in the table can be used to record information on data sources or references or for details such as the
duration of exposure on which the value is based.
7.3.2 In addition to the chronic, sub-chronic and acute guidelines, it is useful to develop a summary of the data reported for
laboratory animals or humans on NOAELs or LOAELs (see Table 3).
7.3.3 Leading examples of information resources that compile and summarize such data appear in Appendix X1.
7.4 Develop Scenarios for Exposure:
7.4.1 Development of a realistic and reasonable scenario is necessary for an accurate estimation of exposure. Short-term
exposure scenarios often are straightforward, requiring only specification of an exposure duration (for example, 30 min or 1 h).
Long-term exposure scenarios commonly require a number of assumptions, as described below.
7.4.2 Long-term exposure scenarios involve time periods that span a lifetime or a substantial portion thereof. A bounding
estimate for passengers and crew on commercial flights can be based on the assumption that such an individual might log an
average of 40 h per month, or 480 h per year, over 30 years (16). This assumption corresponds to an estimated upper limit of 14 400
lifetime hours of exposure (equivalent to 1.64 years).
7.4.3 For a less extreme scenario, but one that is still at the upper end of the distribution for frequency and duration of flying,
it is appropriate to consider a subgroup of passengers who travel fairly frequently (for example, 10 h of flight time every two
weeks). Over a 30-year period, members of this subgroup would travel 10 h × 26 biweekly periods per year × 30 years, for a
lifetime total of 7800 h or about one year.
7.4.4 The durations for these long-term exposure scenarios are, thus, 12 to 24 % of the customary OSHA exposure duration of
40 h per week over 30 years.
7.5 Select Risk Levels of Concern (where appropriate):
7.5.1 For some effects the exposure level of concern may be directly defined in a standard or guideline, as in the case of an RfC
(2, 3) or an MRL (4). For cancer effects, however, the exposure level of concern depends on the choice for a lifetime risk of cancer
that should not be exceeded. Common choices for a lifetime cancer risk of concern are 1 in 100 000 and 1 in 1 000 000 (2).
7.6 Calculate Level of Concern for Each Selected Effect:
7.6.1 Carcinogenic Effects—For some contaminants an inhalation unit risk for cancer has been defined in units of (mg
-33 -1
m1/(mg/m )). . The unit risk is defined by the USEPA as the upper-bound estimate of the probability of cancer due to continuous
-3
lifetime exposure to a unit concentration (that is, 1 mg m ) of a carcinogen, assuming a 70-year life span and an average inhalation
3 -1
rate of 20 m day/day. . Multiplication of the lifetime average concentration to which one is exposed by the unit risk yields an
estimate of lifetime cancer risk. The lifetime cancer risk of concern and lifetime average daily dose (LADD) are related as follows
(2):
Lifetime Cancer Risk of Concern5 (2)
LADD 3Slope of Dose 2Response Curve
where:
TABLE 1 Example Format for Summarizing Standards/Guidelines
for Chronic and Subchronic Health Effects Data
Chemical Name: CASRN:
A
Parameter Value Notes
EPA IRIS Chronic Inhalation RfC
EPA HEAST Chronic RfC
EPA HEAST Sub-Chronic RfC
Intermediate Inhalation MRL
Chronic Inhalation MRL
Chronic REL (California)
NIOSH REL
SMAC 180 days
ACGIH TLV
OSHA PEL
Inhalation unit risk
A
Include units when completing this portion of the table.
D7034 − 18
TABLE 2 Example Format for Summarizing Standards/Guidelines
for Acute Health Effects and Odor Thresholds
Chemical Name: CASRN:
Parameter Value Notes
Acute Inhalation MRL
Odor Threshold
Detection
Recognition
Acute REL (California)
NIOSH STEL/Ceiling Limit
SMAC 1-h
OSHA STEL
NIOSH IDLH
TABLE 3 Example Format for Summarizing LOAELs and NOAELs
for Humans and Laboratory Animals
Chemical Name: CASRN:
Data Reported for Laboratory Animals
Parameter Value Notes
No-adverse-effect level (NOAEL)
Low-adverse-effect level (LOAEL)
Data Reported for Humans
Parameter Value Notes
NOAEL
LOAEL
21 21
LADD~mg kg day !5 (3)
23 3 21
Concentration mg m 3Exposure Duration h 3Inhalation Rate m h
~ ! ~ ! ~ !
Body Weight kg 3Lifespan days
~ ! ~ !
LADD~mg ⁄ kg2day!5 (3)
3 3
Concentration mg ⁄ m 3Exposure Duration h 3Inhalation Rate m ⁄ h
~ ! ~ ! ~ !
Body Weight kg 3Lifespan days
~ ! ~ !
The concentration equated to the lifetime excess risk can be determined from Eq 2 and 3 as:
Lifetime Excess Risk
Concentration 5 (4)
Slope of Dose Response Curve
Body Weight 3Lifespan
Duration of Exposure 3Inhalation Rate
-1 -1
7.6.1.1 Discussion—As an example of applying Eq 2-4, consider a contaminant with a slope of 0.01 mg kgmg/kg–day. day .
For a lifetime risk of concern of 1 in 100 000, an average body weight of 70 kg, a life span of 25 550 days (70 years), an exposure
3 -1
duration of 7800 h, and an inhalation rate of 0.5 m h/h (appropriate (appropriate for a seated population such as airline
-33
passengers), the calculated concentration is 0.66 mg mmg/m . This value can be considered an acceptable concentration for the
contaminant in the cabin environment, from the standpoint of minimizing the risk of carcinogenic effects for frequent flyers.
7.6.2 Long-term Non-carcinogenic Effects—An exposure duration equivalent to about one year, similar to the duration used in
the above example, can be considered for sub-chronic or intermediate-level exposure. Thus, in cases where they exist, sub-chronic
reference concentrations or intermediate exposure Minimal Risk Levels (MRLs) could be used as a basis for defining an acceptable
concentration from the standpoint of minimizing long-term non-carcinogenic effects.
7.6.3 Acute Effects—The acute minimal risk levels (MRLs) developed by ATSDR (4) provide a very useful basis for considering
acute effects for the general population. An alternative approach for considering irritation and other acute effects is to define
exposure limits for sensitive subgroups such as children, elderly people, and asthmatics. One approach (17) that can be used for
sensitive subgroups is to take ⁄40 of a time-weighted-average (TWA) occupational exposure limit such as the ACGIH TLV (8). This
uncertainty factor derives from the ratio of a work week to the entire week (that is, 40 h/168 h) and an uncertainty factor of 10
-33
for sensitivity. If, for example, the TLV were 50 mg mmg/m , then the acceptable concentration by this procedure would be 1.25
-33 -33
mg mmg/m (that is, 50 mg mmg/m ÷ 40). A similar divisor currently is not available for equating occupational STEL values
to an appropriate value for episodic exposures. In such cases, the more stringent AEGL value could be considered, as AEGL values
relate to once-in-a-lifetime exposures.
7.6.4 Odor Threshold—The odor thresholds, where such data exist, may lie within a range of odor-recognition values that span
several orders of magnitude (9, 10). No safety factor is necessary for odor thresholds. However, odor thresholds should not be
D7034 − 18
considered indicators of acute effects and by themselves do not provide a sufficient basis for determining an acceptable
concentration. Given the wide range and types of odor response, an acceptable limit above the odor threshold may be reasonable,
provided that such a limit is at or below other thresholds of concern.
7.7 Determine an Acceptable Concentration for Aircraft Cabins—The choice of acceptable concentration level is based on an
examination of the outcomes from calculations and choices described in 7.6.
7.7.1 In deriving an acceptable concentration, the population of concern and the effects of concern should be considered. In
general, an acceptable concentration is one below the highest concentration at which the effect is known not to occur for the
population under consideration. A possible exception is the case where the lowest level is an odor threshold (see 7.6.4).
7.8 Compare Acceptable Concentration with Existing Information:
7.8.1 Once a proposal for an acceptable concentration has been determined, it should be compared with existing guidelines and
with reported aircraft cabin concentrations (if such data are available).
7.8.2 Based on such information, a conclusion can be made as to whether there is a potential problem in aircraft cabins for the
contaminant under investigation. Such a conclusion would be warranted in cases where monitoring data indicate that the acceptable
concentration has been approached or exceeded on multiple occasions.
7.8.3 In cases where monitoring data are nonexistent or inadequate, preliminary conclusions can be reached by reviewing data
collection methodologies and evaluating materials and processes expected to occur in the aircraft cabin environment for any
propensity to release the chemical of concern (18-21).
8. Report
8.1 The report on acceptable concentration for aircraft cabins should contain the components listed below.
8.1.1 Hazard Assessment—Provide a list of chemicals of potential concern. For each chemical, include a compilation of toxicity,
irritancy, and odor threshold data and data sources consulted in compiling reference values.
8.1.2 Summary of Exposure Assessment—Describe the methodology and assumptions used in conducting exposure assessment.
Include brief descriptions of exposure scenarios that were used. Present results of the exposure assessment and discuss associated
uncertainties.
8.1.3 Derivation of Acceptable Concentration—Describe the methodology, assumptions, and analysis of existing data used in
the calculation of the acceptable concentration, and discuss associated uncertainties.
8.1.4 Conclusions—State conclusions associated with the derivation of the acceptable concentration and summarize limitations
of the data and methodology.
APPENDIX
(Nonmandatory Information)
X1. SUMMARY OF DATA SOURCES FOR EVALUATING NON-CANCER HEALTH EFFECTS AND TOXICITY OF CHEMI-
CAL SUBSTANCES
X1.1 There are numerous chemicals in widespread industrial and commercial use that are of potential concern for occupants of
the airliner cabin environment. As noted in Guide D6399, there is very little direct guidance for identifying contaminants and the
exposure levels that would cause concern. FAA Airworthiness Standards (14 CFR 25) constitute the only are a source of re
...