Food and Nutrition Sciences, 2013, 4, 315-320
http://dx.doi.org/10.4236/fns.2013.43042 Published Online March 2013 (http://www.scirp.org/journal/fns)
GUIDEA—Guidance for Dietary Intake and Exposure
Assessment—A New Resource for Exposure
Assessment Professionals
John Howlett1, Neil Buck2, Matthew Buck3, Jeanne H. M. de Vries4, Veronika Ehrlich5, Melody Hove4,
Astrid G. Kruizinga6, Pratima R. Jasti7*, Benjamin Smith8, David Tennant9
1West Hill, Wembl ey Park, UK; 2DSM, Basel, Switzerland; 3RatwareUK, Skelmersdale, UK; 4Wageningen University, Wageningen,
The Netherlands; 5Nestec LTD., Lausanne, Switzerland; 6TNO, Zeist, The Netherlands; 7ILSI Europe A.I.S.B.L., Brussels, Belgium;
8Firmenich S.A., Geneva, Switzerland; 9Food Chemical Risk Analysis, Brighton, UK.
Received December 13th, 2012; revised January 13th, 2013; accepted January 21st, 2013
ABSTRACT
Exposure assessment is a key component of any risk-benefit assessment, yet it is clear that there is a lack of reliable
methodology in this area for assessing consumer exposures to both food constituents and nonfood products. The Inter-
national Life Sciences Institute (ILSI) Europe Food Intake Methodology Task Force has in the past explored methods to
assess the intake of nutrients/additives and exposure to contaminants/residues from food. In December 2008, a work-
shop was held to d iscuss the differences between different types of exposure assessments as well as the difficulties in-
volved in the practical app lication of the meth ods availab le. It was noted that although no two assessments are the same
in terms of data required and its availability, or the assumptions made, there is also wide and perhaps unnecessary
variation between the approaches taken by different assessors. As a result, the ILSI Europe Food Intake Methodology
Task Force initiated an activity ai med at producing a practical gu ide for conducting intake /exposure assessments in the
form of an interactive web-based application. During the course of this work it became clear that the best form in which
to present the guide would be a web-based MediaWiki-type system. A website was developed and launched in October
2012, at which time global experts and practitioners in dietary exposure assessment were invited to register to use the
site and help keep the knowledge contained within it, relevant and up-to-date. It is hoped that the guide will be an im-
portant reference source for a wide group of stakeholders, providing concise guidance on the planning, conduct, report-
ing and interpretation of exposure assessments and contributing to greater harmonisation of the dietary intake/exposure
methodolo gi e s used.
Keywords: Exposure Assessment; Intake Assessment; Risk Assessment; Online Resource
1. Introduction
Dietary exposure and intake assessments are required for
a number of reasons ranging from the notification of a
new food substance on the market through to under-
standing nutrient intake. All such assessments, however,
are done for two main reasons: safety/risk assessment
and/or health-benefit assessment. Usually, the term ex-
posure assessment is used in relation to chemicals other
than nutrients and most often the interest is in the high
consumers. The term intake assessment is usually used in
relation to nutrients, where the in terest is in both the high
and low consumers. In this paper, the term exposure as-
sessment is generally used and relates to both nutrients
and other chemicals. Exposure assessment can be defined
as the qualitative and/or quantitative evaluation of the
likely intake of biological, chemical and physical agents
via food as well as exposures from other sources if rele-
vant [1]. It is a key component of any risk-benefit analy-
sis of the presence of chemicals in the diet. Risk analysis
provides a scientific basis for the setting of regulatory
limits pertaining to undesirable substances (including
intentionally added substances) and contaminants in food
where high levels have a potential to cause harm, and
also to nutrients where low levels of in take have a poten-
tial to impact adversely on public health. Its ou tcome can
be used, for example, by risk managers to establish sci-
ence-based levels of exposure that will not compromise
consumer health and safety. Whatever the level at which
hazardous or beneficial agents may occur in the food
chain, it is the level of exposure to them that determines
*Corresponding author.

GUIDEA—Guidance for Dietary Intake and Exposure Assessment—A New Resource for
Exposure Assessment Professionals
316
whether or not adverse effects will be experienced by
consumers and it is for this reason that exposure assess-
ment is of key importance to any risk-benefit analysis.
Conducting an exposure assessment requires the inte-
gration of many differ ent types of information and draw s
on a large number of guidelines currently available in the
field of dietary exposure assessment. Dietary exposure
assessments combine data on concentrations of a chemi-
cal substance present in food with data on the quantity of
those foods consumed. It is often the case that direct data
are not available on the occurrence, concentration and/or
consumption patterns of a particular constituent of a food ;
and therefore reference data need to be used (such as
pre-existing food consumption databases). To be able to
combine these different types of data in a meaningful
way it is necessary to consider standardisation of associ-
ated metadata, in particular, those relating to the descrip-
tion of the foods and the characteristics of the popula-
tions who consume them. A number of different methods
exist to combine or integ rate food consumption estimates
with chemical concentration data, ranging from quick
worst-case estimations to refined methods aimed at as-
sessing actual exposure. The selection of the method usu-
ally depends on a number of factors, including the pur-
pose of the assessment (target chemical substance, popu-
lation group, degree of accuracy required, etc.) and, a bov e
all, the availability of information [2,3].
While guidance o n the conduct of exposure assessment
is often available, it comes from a variety of sources and
there is no single source which covers all aspects of the
methods, principles and approaches to conducting and
reporting dietary intake/exposure assessments on the com-
plete range of components of the diet. This short com-
munication aims at introducing ILSI Europe’s web-based
resource, GUIDEA (Guidance for Dietary Intake and
Exposure Assessment), which could be used as a source
of reference by a number of different stakeholders and
thus may fill this gap of consolidating dietary exposure/
intake information.
2. ILSI Europe GUIDEA
During 2009 , the ILSI Europe Food Intake Methodology
Task Force initiated an activity aimed at producing a
practical guide which identifies best practice for con-
ducting intake/exposure assessments for different goals/
scenarios across a wide range of chemicals in the diet.
The ILSI Europe activity has resulted in an interactive,
web-based system, GUIDEA (Guidance for Dietary In-
take Exposure Assessment), constructed on the Media
Wiki platform. This platform was chosen for GUIDEA
because it is accessible to a wide audience and can be
maintained as a “living” and interactive system with the
potential for continuing growth and development over
time through the contributions of users who are experts
in the field. It also has the potential to be further devel-
oped into a teaching tool for remote, interactive use by
students. As each intake assessment is unique, the system
is designed to help the user find the information they
need in a flexible way. It is intended that the guide will
be an important reference source for stakeholders (expo-
sure and risk assessors, experts and students in the re-
spective fields), providing concise guidance on the plan-
ning, conduct, reporting and interpretation of exposure
assessments, and will also be capable of development
into materials for future training courses. By condensing
information on the topic of dietary exposure assessments
into a single place it is hoped that GUIDEA will contrib-
ute to great e r harmonisation.
The Principles on Which GUIDEA Is
Constructed
The assessment of dietary exposure relies on two key
inputs: knowledge of the concentration of a component/
chemical in foods; and knowledg e of the consumption of
those foods by individuals. Broad general guidance is
available for regulatory purposes from various sources
for the assessment of exposure, however these allow for
differences in the conduct and reporting of assessments.
Differences arise from:
 Differences in the paradigm of the assessor, for ex-
ample “protectionist” versus “realist”.
 Varying interpretations of the exposure scenario un-
der consideration which may result in different as-
sumptions being used in the calculation methodology.
 Different approaches to investigate and manage sour ce
data uncertainty.
 Differences in the determination of the level of accu-
racy required, and therefore the calculation method-
ology.
It is the recognition of the importance of exposure as-
sessment in combination with the inherent difficulties,
which has led to the production in recent years of nu-
merous expert publications [3,4]. Furthermore, there ex-
ists a body of assessments from regulatory submissions,
authority opinions and other sources from which to draw
an insight into current practices. There is also a large
body of know ledge on practices used by nutritionists an d
epidemiologists to assess the nutritional intake of popu-
lations. These practices may share some of the same dif-
ficulties inherent to exposure assessment, but may also
help in fo rmulat ing best prac tice.
Application of a tiered approach is generally recom-
mended [2] bu t there is little gu idance av ailab le on wh ich
tier to use in an assessment. International guidelines [5]
propose that an assessment should begin with a highly
conservative tier and compare the result with the hazard

GUIDEA—Guidance for Dietary Intake and Exposure Assessment—A New Resource for
Exposure Assessment Professionals
317
3. The ILSI EUROPE-GUIDEA Project characterisation level; if the assessment output compares
unfavourably with the hazard characterisation, the as-
sessment of intake/exposure should then progress to an
assessment with less conservatism. This guidance is ba sed
on the purely practical consideration that more conserva-
tive assessments are invariably less resource-intensive to
conduct. Although th is approach has merit, it is clear that
no useful purpose is served by conducting an assessment
with greater conservatism than is required for the pur-
pose of the assessment, especially when the available
data would permit a more refined assessment. Therefore,
identifying the appropriate method(s) for an assessment
relies on balancing the degree of conservatism that is
acceptable for the purpose of the assessment, and an un-
derstanding of what type of calculation the available data
will support.
The website demonstrates the use of GUIDEA as a con-
cise guide in exposure assessments by presenting a few
examples for specific substance groups/scenarios to high-
light some current practices. The website will be avail-
able at http://www.ilsi-guidea.org. It is based on the str uc-
ture as shown in Figure 1.
3.1. About ILSI GUIDEA
This section provides information on the background of
GUIDEA, set-up process, project planning and objectives
of GUIDEA.
3.2. Dietary Exposure Assessment
This section covers aspects with the aim of providing
guidance to the user on the data sources, calculation
methods (deterministic, probabilistic etc.), substance groups
(types of exposure assessment available/used in different
scenarios), selection of tier and the reporting template to
be used. GUIDEA he lps in identifyin g the purpose o f the
assessment such as, for example, to estimate the intake of
an established nutrient or exposure to a new contaminant.
This characterisation of the purpose of the assessment
provides information on the perspective, whether the
The purpose of the ILSI Europe-GUIDEA activ ity was
to draw together all of the above by formulating practical
guidance that provides a standardised view and high-
lights how to addr ess shortcomin gs of curren t appro aches.
Using GUIDEA, one should be able to obtain answers to
the following key questions :
 What type of assessment is appropriate for which
purpose?
 How should assessments be conducted?
 How should assessments be reported?
Figure 1. GUIDEA site map.

GUIDEA—Guidance for Dietary Intake and Exposure Assessment—A New Resource for
Exposure Assessment Professionals
318
assessment would rely on retro- or prospective data. This
gives an insight into the main areas of assumption re-
quired. The subsection on “Substance groups” describes
the current practices used in dietary intake and/or expo-
sure estimates under the following su b-headings:
 Information from regulatory bodies, directives or guid-
ance documents (currently the focus of GUIDEA is
on European regulatory aspects but it is intended to
widen the scope to international regulatory aspects
specific to each region);
 Goals to assess exposure assessment;
 Selection and description of examples and finally;
 Discussion and conclusion regarding current practice.
GUIDEA also contains a standard template for the re-
porting of an assessment. For the novice assessor, fa-
miliarization with th is te mplate befo re commen cing work
is recommended so that the desired form of the output of
the task in-hand is unders tood at the outset.
3.3. Expert Initiatives
There is a wealth of information from the large number
of exposure assessments which have been conducted ov er
the years by experts in the field. There are various activi-
ties on-going or planned on exposure assessment nation-
ally and internation ally. This section attempts to establish
links with parallel initiatives wherein the opinions of
experts will be considered. Although the aim of this web -
site is to try and centralize key information on dietary
exposure it is clear that due to the scope and complexity
of information available on this subject, a complete over-
view is necessarily not achievable.
3.4. Reference Materials
GUIDEA also considered the possibility of assembling
all possible information (currently inco mplete though on-
going) that is representative of current practices (guide-
lines, publications, recent assess ments). This section c om-
prises information on the following types of documents
from the last 10 years concerning all possible aspects of
exposure assessment:
 Guidance on any aspect of exposure assessment, from
governmental, authority or quasi-official sources.
 Accepted models that are used nationally or interna-
tionally.
 Significant Reports or Reviews.
 Data sources for concentration and consumption.
4. ILSI Europe Workshop on GUIDEA
In November 2011, ILSI Europe held a workshop to
demonstrate the GUIDEA website in its formative stage
and to provide an opportunity for scrutiny by a broad
group of experts the field of exposure assessment. The
workshop consisted of two plenary sessions with presen-
tations by invited speakers and break-out sessions in
which participants were distributed amongst five work-
ing groups to discuss and test detailed aspects of the
web-based utility. It was attended by more than 50 ex-
perts from industry, academia and governmental organi-
sations. A preliminary version of the website was pre-
sented; scientific content was reviewed and the website
was tested for its usability. The working groups reported
the outcome of their discussions back to a final plenary
session in which they were discussed. In overview, par-
ticipants noted that many organisations were engaged in
the assessment of exposure and its application to risk
analysis and that successful harmonisation of methods
and approaches between them had, to date, remained
elusive. It was acknowledged that GUIDEA might pro-
vide a catalyst to facilitate interaction between appro ach es
and thereby lead to greater harmonisation. There was
discussion of the degree of interaction to be anticipated
between users and the web-based system, with emphasis
being placed on the need to encourage contributions from
users both at the level of inputting content and at the
level of contributing to the evolution of approaches to
exposure assessment. It w as agreed that on e of the poten-
tial strengths of an interactive web-based system would
be its ability to evolve and improve continuously over
time. The necessity to integrate exposure assessment
with toxicological evaluation in an y risk analysis process
was noted and the importance of reflecting this relation-
ship on the website in order to set the value of exposure
assessment into context was agreed.
The main conclusions of the workshop in relation to
the structure and operation of the web-based utility can
be summarised as follows:
 There is a need to set exposure assessment in the
broader context of risk-benefit analysis;
 There is a need for an initial, clear structure to be set
out so that users can readily identif y their locus with in
the website;
 There is a need for a glossary to ensure that terminology
within GUIDEA and between GUIDEA and other
sources is aligned;
 The website should make use of visuals in preference
to text wherever possibl e i n or der t o engage the interest
of users more immediately;
 There is a need to make maximal use of inter-linking
and cross-linking between elements of the website;
 Th e we b si t e s ho u l d c le a r ly d e f in e it s us e r s , t a r ge t groups
and contributors/partners;
 There is a need to provide a sustainable resource for
the management of the website in order to ensure its
long term success;
 There is a need to define the balance betwe en ret e nti on

GUIDEA—Guidance for Dietary Intake and Exposure Assessment—A New Resource for
Exposure Assessment Professionals 319
of ownership of the website by ILSI Europe and an
evolution to free-access by interested participants/
contributors.
The discussion and conclusions generated by the Work-
shop were greatly appreciated by the GUIDEA Expert
Group. Specific comments on content, usability, presen-
tation, functionality and maintenance were noted and
taken into account in further development of the website
with a view to its launch in final form on 30 October
2012. As an interactive and “livin g” system, GUIDEA is
expected to continuously grow and develop further with
the input of experts who join as regi stered users of t he site.
Registration Process to GUIDEA
While read-only access will be available to all visitors to
the site, first-time users who wish to participate in the
website forum and to contribute to the content of the site
itself will need to register. Registration will be at no cost
to the user and full instructions for the registration proc-
ess are provided on the website.
5. Future Developments
5.1. Applicability of a Web-Based Tool to
Training
Due to an acknowledged need for more training in the
field of exposure assessment in Europe, it is anticipated
that this project will fill an important gap. Furthermore,
this exercise will help to better communicate the broader,
more technical issues impacting exposure assessment
outlined by the WHO/IPCS and EFSA. In a time when
standards-based education has taken on a greater real
world focus, it has become more important for educators
to provide students with authentic connections to a learn-
ing environment beyond the school boundaries [6]. Fur-
thermore, technological advancement calls for more in-
novative and versatile methods of instru ction for students,
and a web-based tool such as GUIDEA is one that also
simulates the student-teacher scenario, offering a plat-
form for interaction between students and experts on the
discussion forums. In total, it is intended that GUIDEA
will serve as a useful online training resource for ind ustry
and governmental scientists working in the fields of food
safety, exposure/risk assessment and regulatory affairs; it
will also provide a teaching resource for use by academ-
ics in the field of food safety and dietary intake/exposure,
and a reference resource for students/early career scien-
tists in food safety and exposure/intake assessment.
5.2. A Focus for Professional Interest
In addition to providing a platform for exposure asses-
sors to learn and share information, a future stimulation
and hope of the GUIDEA website may be the formation
of a Scientific Society for Dietary Exposure Assessment.
There is currently a lack of a professional body to reflect
the interests of experts in Dietary Exposure Assessment
and it is envisaged that the GUIDEA website could pro-
vide the seed for such a society, using as a founding
group those experts in the field of exposure assessment
who register as users. Such a professional body would
have among its guiding principles the furtherance the
practice of exposure assessment on the basis of sound
scientific principles and the encouragement through tr ain-
ing of those who wish or need to enter the field.
More information about the website in its present form
can be found at: http://www.ilsi-guidea.org.
6. Acknowledgements
This work was commissioned by the Food Intake Meth-
odology Task Force of the European branch of the Inter-
national Life Sciences Institute (ILSI Europe). Industry
members of this task force are (Ajinomoto Europ e, Bayer
CropScience BioScience, Coca-Cola Europe, Danone, DSM,
Firmenich, Givaudan International, McNeil Nutritionals,
Nes tlé , PepsiCo International and Unilever). This publica-
tion was coordinated by Dr. Pratima Rao Jasti, Scientific
Project Manager at ILSI Europe. For further information
about ILSI Europe, please email [e-mail] or
call [phone]. The opinions expressed herein and
the con- clusions of this publication are those of the au-
thors and do not necessarily represent the views of ILSI
Europe nor tho se of its member companies.
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