SIST-TS CEN/TS 17276:2019

SLOVENSKI STANDARD
01-februar-2019
Nanotehnologija - Smernice za ocenjevanje življenjskega cikla - Uporaba EN ISO
14044:2006 za izdelane nanomateriale
Nanotechnologies - Guidelines for Life Cycle Assessment - Application of EN ISO
14044:2006 to Manufactured Nanomaterials
Nanotechnologien - Leitfaden für Life Cycle Assessments (LCA) - Anwendung der EN
ISO 14044:2006 auf industriell hergestellte Nanomaterialien
Nanotechnologies - Lignes directrices pour l’analyse du cycle de vie - Application de l’EN
ISO 14044:2006 aux nanomatériaux manufacturés
Ta slovenski standard je istoveten z: CEN/TS 17276:2018
ICS:
07.120 Nanotehnologije Nanotechnologies
13.020.60 Življenjski ciklusi izdelkov Product life-cycles
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

CEN/TS 17276
TECHNICAL SPECIFICATION
SPÉCIFICATION TECHNIQUE
December 2018
TECHNISCHE SPEZIFIKATION
ICS 07.120
English Version
Nanotechnologies - Guidelines for Life Cycle Assessment -
Application of EN ISO 14044:2006 to Manufactured
Nanomaterials
Nanotechnologies - Lignes directrices pour l'analyse du Nanotechnologien - Leitfaden für Life Cycle
cycle de vie - Application de l'EN ISO 14044:2006 aux Assessments (LCA) - Anwendung der EN ISO
nanomatériaux manufacturés 14044:2006 auf industriell hergestellte
Nanomaterialien
This Technical Specification (CEN/TS) was approved by CEN on 28 September 2018 for provisional application.

The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to
submit their comments, particularly on the question whether the CEN/TS can be converted into a European Standard.

CEN members are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS
available promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in
parallel to the CEN/TS) until the final decision about the possible conversion of the CEN/TS into an EN is reached.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2018 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TS 17276:2018 E
worldwide for CEN national Members.

Contents Page
European foreword . 4
Introduction . 5
1 Scope . 9
2 Normative references . 9
3 Terms and definitions . 9
4 Uncertainty analysis . 14
4.1 Introduction to uncertainty . 14
4.2 Characterization . 15
4.3 Identity and grouping . 16
4.4 Life Cycle Inventory Data. 16
4.5 Exposure assessment . 16
4.6 Toxicity assessment . 17
4.7 Impact assessment . 17
5 Goal and scope definition (see EN ISO 14044:2006, 4.2) . 18
5.1 General . 18
5.2 Scope of the study (see EN ISO 14044:2006, 4.2.3) . 18
5.3 Function and functional unit (see EN ISO 14044:2006, 4.2.3.2). 18
5.4 System boundary (see EN ISO 14044:2006, 4.2.3.3). 19
5.5 LCIA methodology and types of impacts (see EN ISO 14044:2006, 4.2.3.4) . 19
5.6 Types and sources of data (see EN ISO 14044:2006, 4.2.3.5) . 19
5.7 Data quality requirements (see EN ISO 14044:2006, 4.2.3.6) . 20
5.8 Comparisons between systems (see EN ISO 14044:2006, 4.2.3.7) . 20
5.9 Examples . 20
6 Life cycle inventory analysis (LCI) (see EN ISO 14044:2006, 4.3) . 23
6.1 General (see EN ISO 14044:2006, 4.3.1) . 23
6.2 Collecting data (see EN ISO 14044:2006, 4.3.2) . 24
6.3 Calculating data (see EN ISO 14044:2006, 4.3.3) . 25
6.4 Available LCA models. 27
6.5 Allocation (see EN ISO 14044:2006, 4.3.4) . 28
6.6 Examples . 28
7 Life cycle impact assessment (LCIA) (see EN ISO 14044:2006, 4.4) . 30
7.1 General . 30
7.2 Ecotoxicity studies . 30
7.3 Human toxicity . 30
7.4 Other midpoint categories . 31
7.5 Damage categories . 31
7.6 Spatial and temporal differentiations . 31
7.7 Examples . 31
8 Life cycle interpretation (see EN ISO 14044:2006, 4.5) . 37
9 Reporting (see EN ISO 14044:2006, Clause 5) . 39
9.1 General . 39
9.2 Examples . 39
10 Critical Reviews (see EN ISO 14044:2006, Clause 6) . 42
Annex A (informative) Uncertainty Analysis in LCA of Manufactured Nanomaterials . 45
Annex B (informative) LCA case studies in area of manufactured nanomaterials . 48
Bibliography . 53

European foreword
This document (CEN/TS 17276:2018) has been prepared by Technical Committee CEN/TC 352
“Nanotechnologies”, the secretariat of which is held by AFNOR.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document has been prepared under a mandate given to CEN by the European Commission and the
European Free Trade Association.
The purpose of this Technical Specification is to assist the use of the following Life Cycle Assessment
standards in their application to manufactured nanomaterials:
— EN ISO 14040:2006, Environmental management — Life cycle assessment — Principles and
framework (ISO 14040:2006)
— EN ISO 14044:2006, Environmental management — Life cycle assessment — Requirements and
guidelines (ISO 14044:2006)
This document follows a similar structure to that used for ISO/TR 14047:2012 and ISO/TR 14049:2012,
which also provide guidance to the application of EN ISO 14044:2006 in terms of explaining more fully
the terminology; as follows:
— ISO/TR 14047:2012, Environmental management — Life cycle assessment — Illustrative examples on
how to apply EN ISO 14044 to impact assessment situations
— ISO/TR 14049:2012, Environmental management — Life cycle assessment — Illustrative examples on
how to apply EN ISO 14044 to goal and scope definition and inventory analysis
The main text is “normative” and represents best practice in the application of EN ISO 14044:2006 to
Manufactured Nanomaterials. However, it is generally not possible to obtain all the required data, in
particular the human and eco-toxicity data, so that alternative approaches are necessary. The current
approaches possible are described by three “informative” examples (see Introduction) drawn from
different areas of nano-materials that are used to illustrate each stage of the application of
EN ISO 14044:2006. It is intended that these examples be updated or replaced as more reliable data
becomes available.
Annex A (informative) includes additional discussion on measurement uncertainty.
Annex B (informative) records recent life-cycle-analyses that are provided to give further examples and
sources of data.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to announce this Technical Specification: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Introduction
This Technical Specification provides guidelines on the application of Life Cycle Assessments (LCA) to
manufactured nanomaterials (MNMs), in the context of EN ISO 14044:2006. It does not cover incidental
nanomaterials. This document is not applicable to life-cycle based Risk Assessment (see [1], [2], [3] for
such studies).
The structure of this document follows the structure of EN ISO 14044:2006, and is similar to the related
technical reports from ISO [4], [5], showing illustrative examples on how to apply the various steps of the
LCA framework. Table 1 gives an overview of the linkage between the content of this Technical
Specification and the related content in EN ISO 14044:2006.
Table 1 — Cross references between EN ISO 14044:2006 and the content of this Technical
Specification
EN ISO 14044:2006 This Technical Specification
Nano-specificity Example(s)
1 Scope
Clause 1
2 Normative reference Clause 2
3 Terms and definitions Clause 3 - Definition & use of term for
manufactured nanomaterials and
LCA
Clause 4 - Causes of Uncertainty &
Variability in LCA of manufactured
nanomaterials
4 Methodological
framework for LCA
4.1 General requirements
4.2 Goal & scope definition Clause 5 - Choice of an appropriate E.1 Textiles with nano-Ag
functional unit
E.2 Façade coatings with nano-TiO
4.2.1 General 2
E.3 CNTs in electronics
4.2.2 Goal of the study
4.2.3 Scope of the study
4.3 Life cycle inventory analysis Clause 6 - LCI data of production of E.1 Textiles with nano-Ag
(LCI) manufactured nanomaterials;
E.2 Façade coatings with nano-TiO2
4.3.1 General Modelling of releases of
E.3 CNTs in electronics
manufactured nanomaterials
4.3.2 Collecting data
4.3.3 Calculating data
4.3.4 Allocation
4.4 Life cycle impact Clause 7 - Assessment of releases of E.1 Textiles with nano-Ag
manufactured nanomaterials
E.2 Façade coatings with nano-TiO2
assessment (LCIA)
E.3 CNTs in electronics
4.5 Life cycle interpretation Clause 8 - Interpretation of LCA with Lessons learnt from the three examples
limited information from
manufactured nanomaterials
5 Reporting Clause 9 - Highlight important aspect Lessons learnt from the three examples
when reporting nano-specific LCA
5.1 General requirements
5.2 Additional requirements
5.3 Further reporting
requirements
6 Critical review Clause 10 - Highlight important nano Lessons learnt from the three examples
aspects of critical review
6.1 General
6.2 Critical review by experts
6.3 Critical review by panel
Annexes (informative) Annexes A and B
Three examples are provided as informative text to illustrate the application of LCA to products that
contain manufactured nanomaterials. The examples are nano-silver treated textiles [6], nano-enhanced
façade coating [7], and CNT enhanced electronics [8]. The selected examples are amongst the most
comprehensive LCA studies of manufactured nanomaterials published to date (i.e. mid - 2017). The
treatment of uncertainty is discussed in Clause 4 and Annex A. A brief overview of further examples (up
to mid-2017) is given in Annex B. The analysis shows the coverage of the studies in a form similar to an
earlier study [9].
The illustrative examples are presented in sections corresponding to the same section of the original text
in EN ISO 14044:2006 covering “inventory collection”, “environmental fate” and “impact assessment and
interpretation”. They are intended to highlight the particular features relevant to manufactured
nanomaterials when included in a LCA. “Fate” in this context refers to the presence in, and transfer
through, one or more environments or media (e.g.: air, soil and water) [10].
The presented aspects also include additional, non-published information and data that were particularly
useful and illustrative for this guidance document. The status quo of the three examples is summarized
in the three sub-sections below. It is noted that that manufactured nanomaterials (MNMs) cover an
increasing range of nano-prefixed descriptors, including nano-object, nano-film, nano-fibre and
nano-tube. In some cases, or at some points in the life cycle, the MNMs may be in aggregated or
agglomerated forms.
Example 1 – "Textiles with nano-silver (nano-Ag)"
The objective of the example is to compare the environmental benefits and impacts of nanosilver treated
T-shirts with conventional T-shirts and T-shirts treated with triclosan, a commonly applied biocide to
prevent textiles from emitting undesirable odours.
Status Quo: Technical garments have to provide extra features such as enhanced durability or protection
for workers; water or oil impermeability for firefighters; or bacterial resistance for adhesive wound tapes,
clinical uniforms or sportswear. Silver has known antimicrobial properties and is applied – beside water
purification – also to textiles, in order to release toxic ions to kill bacteria. Nanosilver is particularly
effective because it can be easily integrated into textile fibres, has higher ion release rates in comparison
to the same mass of larger particles and has a longer durability than conventional silver salts. Applied to
sports textiles, nanosilver inhibits bacterial growth and therefore reduces unwanted odours. In
comparison to other antimicrobial agents for textiles, such as quarternary ammoniums salts or triclosan
(now banned in many countries), advanced integration of nanosilver shows less washing-out while
exhibiting higher microbial toxicity, based on the same mass. Another advertised property of nanosilver
T-shirts is that a lower washing frequency in combination with a lower washing temperature allows
saving of resources. On the downside, nanosilver may be harmful to antimicrobial communities in the
wastewater treatment plant and may accumulate in the environment over the long term. Moreover,
occupational exposure during the production of nanosilver can be elevated in cases when open production
systems with poor ventilation are in place. In absence of personal protection measures nanosilver might
be inhaled. Nanosilver can enter the deep lung region (alveolar region) and pass across the lung:blood
barrier with so far unknown health consequences over the long term. Consumers are less at risk because
abrasion tests showed that the probability of releasing free manufactured nanomaterials into the air
(followed by inhalation) is minimal. Penetration through intact skin is very unlikely. At the end of life of
the nanosilver T-shirts, waste management options that prevent release of manufactured nanomaterials
into the environment are preferred.
Scenario analysis allows varying sensitive parameters such as washing frequency and temperature,
market penetration and technological maturity to be studied. The scenarios are directly linked to LC
inventory data in order to run complete LCA for different possible future states of the system.
Nano-specific issues are captured as far as possible and the strengths and weaknesses of the LCA
framework regarding the inclusion of nanosilver are discussed.

Example 2 – "Façade coatings with nano titanium oxide (nano-TiO2)"
The objective of the study is to review the Environmental Health and Safety (EHS) impacts of
manufactured nanomaterials in paints and coatings used in house building. The latest developments in
view of inventory data and impact assessment factors for releases of manufactured nanomaterials are
used.
Status Quo: Modern façades of buildings have to meet several functional requirements. These
functionalities can influence each other; for example does the commended thermal insulation (related to
energy savings and climate change) of a house influence the requirements concerning the outside façade
coating and can lead to an increase in the growth of algae and fungi. During their use phase the outside
façade coatings are exposed to various impacts such as UV, rain, humidity, heat, temperature differences,
air pollution and scratch damage. Indoor façade coatings are also exposed to UV and scratches damage.
An integration of manufactured nanomaterials in such façade coatings is expected to hold considerable
potential for products that offer improved or novel functionalities during the use phase of these façade
coatings and enables in the end the development of materials that fulfil several functionalities at the same
time (i.e. so-called multifunctional materials). The manufactured nanomaterials are also expected to
optimize some processes during the production of the facade coatings for example by shortening drying
time for coatings, and they may also hold a potential for environmental sustainability by saving materials,
by substituting hazardous substances, or by improving the durability of the coating.
Three different types of paints containing different types of manufactured nanomaterials (paint A1:
nano-TiO , paint B1: nano-Ag, paint C1: nano-SiO ) are compared to the same paints without the added
2 2
MNMs (paints A2, B2 and C2 respectively). Table 2 summarizes some key data for this study.
Table 2 — Main characteristics of the façade coatings (values based on input from paint
industry)
Paint Paint Paint Paint Paint Paint
A1 A2 C1 C2 B1 B2
MNM integration “Substitution” “Addendum” “Addendum”
philosophy
Application field Outdoor Outdoor Outdoor Outdoor Indoor Indoor
a a a
Lifetime [years] 27 20 27 20 10 10
Composition [% w/w]
— MNM-content 3,0 - 5 - 0.3 -
— Type of MNM TiO2 - SiO2 - Ag -
— TiO , pigment-grade 13,58 16,58 - - - -
— Silicone defoamer 10,97 10,97 0,3 0,3 0,6 0,6
— Styrene/acrylic 14,62 14,62 23,3 23,3 28,1 28,1
copolymer
— Calcium carbonate 31,75 31,75 46 46 33,2 33,5
(filler)
— Talcum (filler) 6,58 6,,58 - - 10,1 10,1
— Further ingredients 5,2 5,2 1,7 1,7 2 4,7
— Water 11,3 14,3 15,2 28,7 23 23
a
Assumption (result of a discussion with representatives from the paint industry): in outdoor
applications MNM-containing paints have a 30 % longer lifetime; in indoor applications no longer
lifetime is assumed.
Example 3 "Carbon Nano-Tubes (CNTs) in electronics"
The objective of this example is to establish a comprehensive assessment of the ecological sustainability
of a field emission display (FED) television device by the use of the latest developments in the area of LCA
of manufactured nanomaterials (i.e. inventory modelling and impact assessment) in accordance with the
EN ISO 14040:2006. In a second step this new technology is then compared to television devices using
different versions of current display technologies.
Status Quo: CNTs are cylindrical carbon molecules with novel properties (extraordinary strength, unique
electrical properties) and they are efficient conductors of heat, making them particularly interesting for
the electronics industry. This material is seen as providing a large opportunity for making a new
generation of electronic and electric products – smaller, cleaner, stronger, lighter and more precise. One
of the most promising aspects is the unique electronic property of CNT. According to [11], ‘‘CNT can, in
principle, play the same role as silicon does in electronic circuits, but at a molecular scale where silicon
and other standard semiconductors cease to work’’. Therefore, ‘‘Nano’’ is considered in this industrial
sector not only as hype, but to represent a real future potential. Within the electronics sector, displays can
be seen as an important interface in machine-based communication among human beings. The area of
display technologies has been dominated by the cathode ray tube (CRT) technology since the 1920s – with
th
many different flat panel display technologies being developed since the late 20 century; among them
the field emission display (FED) technology. This FED technology can be best compared to the CRT
technology, as both of them are based on the principle of a cathode that (in a vacuum) launches electrons
towards a glass plate coated with phosphorous. However, whereas in the CRT technology just one such
cathode is used, the FED technology uses one individual cathode for each single pixel. In this way, this
technology allows the construction of devices with very promising features (e.g. thin, self-emissive screen,
distortion free image, wide viewing angle). A great challenge in the FED technology is the issue of micro
fabrication of the cathodes in order to have one cathode per pixel; with CNTs being a valuable option for
this purpose.
1 Scope
This document provides guidelines for application of Life Cycle Assessments (LCA) of specific relevance
to manufactured nanomaterials (MNMs), including their use in other products, according to
EN ISO 14044:2006. It does not cover incidental nanomaterials.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
EN ISO 14040:2006, Environmental management - Life cycle assessment - Principles and framework (ISO
14040:2006)
EN ISO 14044:2006, Environmental management - Life cycle assessment - Requirements and guidelines
(ISO 14044:2006)
CEN/TS 17010:2016, Nanotechnologies - Guidance on measurands for characterising nano-objects and
materials that contain them
ISO 5725-2:1994, Accuracy (trueness and precision) of measurement methods and results — Part 2: Basic
method for the determination of repeatability and reproducibility of a standard measurement method
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1
nanoscale
length range approximately from 1 nm to 100 nm
Note 1 to entry: Properties that are not extrapolations from larger sizes are predominantly exhibited in this
length range.
[SOURCE: CEN ISO/TS 80004-1:2015, 2.1]
3.2
nano-object
discrete piece of material with one, two or three external dimensions in the nanoscale (3.1)
Note 1 to entry: The second and third external dimensions are orthogonal to the first dimension and to each
other.
[SOURCE: CEN ISO/TS 80004-1:2015, 2.5]
3.3
manufactured nanomaterial
nanomaterial intentionally produced to have selected properties or composition
[SOURCE: CEN ISO/TS 80004-1:2015, 2.9]
3.4
incidental nanomaterials
nanomaterial generated as an unintentional by-product of a process
Note 1 to entry: The process includes manufacturing, bio-technological or other processes.
Note 2 to entry: See “ultrafine particle” in ISO/TR 27628:2007, 2.21.
[SOURCE: CEN ISO/TS 80004-1:2015, 2.10]
3.5
agglomerate
collection of weakly or medium strongly bound particles where the resulting external surface area is
similar to the sum of the surface areas of the individual components
Note 1 to entry: The forces holding an agglomerate together are weak forces, for example van der Waals forces
or simple physical entanglement.
Note 2 to entry: Agglomerates are also termed secondary particles and the original source particles are termed
primary particles.
[SOURCE: CEN ISO/TS 80004-2:2017, 3.4]
3.6
aggregate
particle comprising strongly bonded or fused particles where the resulting external surface area is
significantly smaller than the sum of surface areas of the individual components
Note 1 to entry: The forces holding an aggregate together are strong forces, for example covalent or ionic bonds,
or those resulting from sintering or complex physical entanglement, or otherwise combined former primary
particles.
Note 2 to entry: Aggregates are also termed secondary particles and the original source particles are termed
primary particles.
[SOURCE: CEN ISO/TS 80004-2:2017, 3.5]
3.7
nanotechnology
application of scientific knowledge to manipulate and control matter predominantly in the nanoscale
(3.1) to make use of size- and structure-dependent properties and phenomena distinct from those
associated with individual atoms or molecules or extrapolation from larger sizes of the same material
Note 1 to entry: Manipulation and control includes material synthesis.
[SOURCE: CEN ISO/TS 80004-1:2015, 2.3]
3.8
life cycle
consecutive and interlinked stages of a product system, from raw material acquisition or generation from
natural resources to final disposal
[SOURCE: EN ISO 14040:2006, 3.1]
3.9
life cycle assessment, LCA
compilation and evaluation of the inputs, outputs and the potential environmental impacts of a product
system throughout its life cycle
[SOURCE: EN ISO 14040:2006, 3.2]
3.10
life cycle inventory analysis, LCI
phase of life cycle assessment involving the compilation and quantification of inputs and outputs for a
product throughout its life cycle
[SOURCE: EN ISO 14040:2006, 3.3]
3.11
life cycle impact assessment, LCIA
phase of life cycle assessment aimed at understanding and evaluating the magnitude and significance of
the potential environmental impacts for a product system throughout the life cycle of the product
[SOURCE: EN ISO 14040:2006, 3.4]
3.12
reference flow
measure of the outputs from processes in a given product system required to fulfil the function expressed
by the functional unit
[SOURCE: EN ISO 14040:2006, 3.29]
3.13
functional unit
quantified performance of a product system for use as a reference unit
[SOURCE: EN ISO 14040:2006, 3.20]
3.14
output
product, material or energy flow that leaves a unit process
Note 1 to entry: Products and materials include raw materials, intermediate products, co-products and releases.
[SOURCE: EN ISO 14040:2006, 3.25]
3.15
product
any goods or service
Note 1 to entry: The product can be categorized as follows:
— services (e.g. transport);
— software (e.g. computer program, dictionary);
— hardware (e.g. engine mechanical part);
— processed materials (e.g. lubricant).
Note 2 to entry: Services have tangible and intangible elements. Provision of a service can involve, for example,
the following:
— an activity performed on a customer-supplied tangible product (e.g. automobile to be repaired);
— an activity performed on a customer-supplied intangible product (e.g. the income statement needed to prepare
a tax return);
— the delivery of an intangible product (e.g. the delivery of information in the context of knowledge
transmission);
— the creation of ambience for the customer (e.g. in hotels and restaurants).
Software consists of information and is generally intangible and can be in the form of approaches, transactions or
procedures.
Hardware is generally tangible and its amount is a countable characteristic. Processed materials are generally
tangible and their amount is a continuous characteristic.
Note 3 to entry: Adapted from EN ISO 14021:2001 and EN ISO 9000:2005.
[SOURCE: EN ISO 14040:2006, 3.9]
3.16
system boundary
set of criteria specifying which unit processes are part of a product system
[SOURCE: EN ISO 14040:2006, 3.32]
3.17
elementary flow
material or energy entering the system being studied that has been drawn from the environment without
previous human transformation, or material or energy leaving the system being studied that is released
into the environment without subsequent human transformation
[SOURCE: EN ISO 14040:2006, 3.12]
3.18
product flow
products entering from or leaving to another product system
[SOURCE: EN ISO 14040:2006, 3.27]
3.19
product system
collection of unit processes with elementary and product flows, performing one or more defined
functions and which models the life cycle of a product
[SOURCE: EN ISO 14040:2006, 3.28]
3.20
effect concentration, EC
x
calculated concentration from which an effect of x % is expected (used in ecological risk assessment)
[SOURCE: ISO/TS 18220:2016, 2.6]
3.21
characterization factor
factor derived from a characterization model which is applied to convert an assigned life cycle inventory
analysis result to the common unit of the category indicator
Note 1 to entry: The common unit allows calculation of the category indicator result.
[SOURCE: EN ISO 14040:2006, 3.37]
3.22
environmental aspect
element of an organization's activities, products or services that can interact with the environment
[SOURCE: EN ISO 14040:2006, 3.8]
3.23
benchmark dose
BMD
used in human risk assessment and is defined as the dose associated with a certain benchmark response
(e.g. BMD ), similar to the effect concentration (EC, see 3.20) which is used in ecological risk assessment
x%
[SOURCE: ISO 19020: 2017, 3.5]
3.24
adverse outcome pathway
AOP
logical sequence of causally linked events at different levels of biological organization, which follows
exposure to a chemical and leads to an adverse health effect in humans or wildlife
[SOURCE: OECD (2016), "Users' Handbook supplement to the Guidance Document for developing and
assessing Adverse Outcome Pathways", OECD Series on Adverse Outcome Pathways, No. 1, OECD
Publishing, Paris.]
3.25
measurand
quantity intended to be measured
Note 1 to entry: The specification of a measurand requires knowledge of the kind of quantity, description of the
state of the phenomenon, body, or substance carrying the quantity, including any relevant component, and the
chemical entities involved.
Note 2 to entry: In the second edition of the VIM and in IEC 60050–300:2001, the measurand is defined as the
“particular quantity subject to measurement”.
Note 3 to entry: The measurement, including the measuring system and the conditions under which the
measurement is carried out, might change the phenomenon, body, or substance such that the quantity being
measured may differ from the measurand as defined. In this case, adequate correction is necessary.
EXAMPLE 1 The potential difference between the terminals of a battery may decrease when using a voltmeter
with a significant internal conductance to perform the measurement. The open-circuit potential difference can be
calculated from the internal resistances of the battery and the voltmeter.
EXAMPLE 2 The length of a steel rod in equilibrium with the ambient Celsius temperature of 23 °C will be
different from the length at the specified temperature of 20 °C, which is the measurand. In this case, a correction is
necessary. Note 4 to entry: In chemistry, “analyte”, or the name of a substance or compound, are terms sometimes
used for “measurand”. This usage is erroneous because these terms do not refer to quantities.
[SOURCE: ISO/IEC GUIDE 99:2007, 2.3]
3.26
allocation
partitioning the input or output flows of a process or a product system between the product system under
study and one or more other product systems
[SOURCE: EN ISO 14040:2006, 3.17]
3.27
uncertainty analysis
systematic procedure to quantify the uncertainty introduced in the results of a life cycle inventory
analysis due to the cumulative effects of model inaccuracy, input uncertainty and data variability
Note 1 to entry: Either ranges or probability distributions are used to determine uncertainty in the results.
[SOURCE: EN ISO 14040:2006, 3.33]
3.28
sensitivity analysis
systematic procedures for estimating the effects of the choices made regarding methods and data on the
outcome of a study
[SOURCE: EN ISO 14040:2006, 3.31]
4 Uncertainty analysis
4.1 Introduction to uncertainty
Uncertainty is inherent to all life cycle assessment (LCA) studies and complicates interpretation of their
results. When applying LCA in the area of manufactured nanomaterials uncertainty is a particular
problem given nanotechnology’s status as an emerging technology, so that there is only incomplete data
available for many aspects.
In LCA, different types and sources of uncertainty exist and only sometimes are they specific to
manufactured nanomaterials. Here, it is necessary to distinguish between true “uncertainty” which is
used to describe uncertainty in terms of inaccurate measurement, lack of data, etc., which can be reduced
by more accurate measurement, and “variability” which stems from variations in the natural world and
thus cannot be reduced by further measurement [12], [13]. The principal causes and their sub-causes for
the variability and uncertainty of nano-specific LCAs are given in Figure 1.
NOTE Figure 1 does not distinguish between uncertainty and variability.
The individual causes might be analysed separately regarding their improvement potential for the final
uncertainty of the result.
The global uncertainties associated with a nano-specific LCA should be included, either quantitatively or
qualitatively. The analysis will then enable better-informed decisions in order:
— to reduce the environmental or human burdens; and
— to detect any improvement potential (i.e. reducing the uncertainty);
for the underlying data.
It is noted that the integration of manufactured nanomaterials into LCA may lead to additional
uncertainties, but does not necessarily compromise the informative value of the overall life cycle impact
assessment (LCIA) results in view of the total uncertainties typically associated with inventory data. The
principal causes of uncertainty and variability in LCA of manufactured nanomaterials outlined in Figure 1
are further discussed in the following clauses.
NOTE The length of the bars indicates qualitatively the strength of the influence on variability and uncertainty.
Long length/black = Strong; Medium length/hatched = Intermediate; Short length/white = low (expert judgment
for a case with comprehensive inventory data but acknowledging the current, not well adapted methods for
measurement and modelling of environmental fate, exposure, and toxicity).
Figure 1 — Principal causes and their sub-causes for the variability and uncertainty of
nano-specific LCAs
4.2 Characterization
A good fate and effect assessment relies heavily on a comprehensive characterization of the nanomaterial
(see CEN/TS 17010:2016). In addition to the elemental composition and the structure, a size distribution
and detailed analysis of any particle coating can add substantial value to the understanding of the
nanomaterial properties. The measurement technique can influence the uncertainty of the nanomaterial
characterization. Therefore, only data from calibrated instruments with known accuracy should be
included in the LCA. A variety of measurement devices can be used, depending on the environmental or
product matrix in which the nanomaterial is embedded. Relevant internationally agreed standards can
help to select and use the appropriate technique. The standards ideally provide also information on
sources of uncertainty in the measurements and give accurate data for that method obtained in
inter-laboratory trials organized according to ISO 5725-2:1994.
The LCA provides an analysis of the nanomaterial throughout its life cycle and therefore should also
consider “ageing” of the nanomaterial. Usually, a chemical compound in LCA is only characterized once
and then associated to the respective characterization factor (therefore, not only a nano-specific issue).
In view of the potentially changing physical-chemical properties of nanomaterials during their life cycle
it is important to carefully choose the point in time where the nanomaterial characterization takes place
in order to best represent a “representative” nanomaterial for the further impact assessment. Analysing
in great detail into reducing uncertainties and improving robustness is usually not feasible or economical.
Normally, the situation is less certain as the LCA analysis has to deal with a general scarcity of
characterization data for the nanomaterial under investigation.
4.3 Identity and grouping
There is probably not a single nanomaterial that is the same as another. Even batches of manufactured
nanomaterials that are claimed to be one sort of nanoparticle still show variance in size and form and
hence have different identities. For practical reasons, in LCA, similar identities, showing similar
physical-chemical behaviour, are grouped into entities which should be uniquely defined and named.
Consequently, for single entities, the values of measurands (e.g. size, composition, structure) might be
considered the same within small bandwidths. Hence, each entity consists of a combination of the
predefined banding values of individual measurands. Once the entities are clear, they can be associated
to testing strategies.
The entities of nanomaterials that behave similarly regarding Adverse Outcome Pathways (AOP) may be
grouped together. This allows using available data from already tested manufactured nanomaterials and
applying read across to a new nanomaterial of similar toxic action. Consensus finding for the relevant
endpoints to be tested in combination with a transparent and appropriate testing strategy will further
reduce the uncertainty. Although it is a structured assessment of manufactured nanomaterials, the
uncertainty of read across and the inherent variability within the entities demand further refinement of
the scheme and a careful evaluation of the results.
A simple guidance scheme for the LCA analysis on identity and grouping of manufactured nanomaterials
for inventory and impact assessment is needed to simplify the potentially overwhelming complexity into
manageable sections.
4.4 Life Cycle Inventory Data
Uncertainty and variability in Reference Flow Inventory data is a principal challenge in LCA. Spatial and
temporal accuracy along the supply chain, or life cycle, respectively, is a difficult goal to achieve, in view
of the global material and energy flows required for the Reference Flow Inventory. This is particularly
true for the background data, where the LCA usually rely on available Life Cycle Inventories. Foreground
data, i.e. the actual first level material and energy requirements for the Functional Unit can be improved
by measuring, modelling, and the use of latest knowledge on the processes under consideration. A
detailed process description is advisable with clear spatial and temporal system boundaries. A sensitivity
analysis
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