Workplace exposure - Assessment of exposure by inhalation of nano-objects and their aggregates and agglomerates

This European Standard describes different levels of assessment of inhalation exposure to nano-objects and their agglomerates and aggregates (NOAA), as well as the evaluation of the results either as stand-alone assessment or embedded in a tiered approach framework.
While the focus of this European Standard is on the assessment of nano-objects, the approach is applicable for exposure to the associated agglomerates and aggregates, i.e. NOAA, and particles released from nano composites and nano-enabled products.

Exposition am Arbeitsplatz - Beurteilung der inhalativen Exposition gegenüber Nano-Objekten und deren Agglomeraten und Aggregaten

Diese Europäische Norm bietet eine Leitlinie zur Beurteilung der Exposition durch Einatmen gegenüber Nanoobjekten und deren Aggregaten und Agglomeraten (NOAA). Sie enthält Leitlinien zu anzuwendenden Probenahme- und Messstrategien sowie Verfahren zur Datenauswertung.
Obgleich der Schwerpunkt dieses Dokuments auf der Beurteilung von Nanoobjekten liegt, gilt diese Herangehensweise auch für die Exposition gegenüber zugehörigen Aggregaten und Agglomeraten, d. h. "NOAA", sowie für Partikel, die von Nanokompositen und nanotechnologischen Produkten freigesetzt werden.

Exposition sur les lieux de travail - Évaluation de l’exposition par inhalation aux nano-objets et à leurs agglomérats et agrégats

La présente Norme européenne fournit des lignes directrices pour évaluer l’exposition par inhalation aux nano-objets et à leurs agrégats et agglomérats (NOAA) sur les lieux de travail. Elle contient des recommandations relatives aux stratégies d’échantillonnage et de mesurage à adopter, ainsi que des méthodes pour l’évaluation des données.
Bien que le présent document soit essentiellement axé sur l’évaluation des nano-objets, l’approche est également applicable à l’exposition aux agrégats et agglomérats associés, c’est-à-dire aux NOAA, et aux particules libérées des nanocomposites et des produits obtenus par nanotechnologies.

Izpostavljenost na delovnem mestu - Ocena izpostavljenosti pri vdihavanju nanopredmetov ter njihovih agregatov in aglomeratov

Ta evropski standard opisuje različne stopnje ocene izpostavljenosti pri vdihavanju nanopredmetov ter njihovih agregatov in aglomeratov (NOAA) ter vrednotenje rezultatov v obliki samostojne ocene ali vdelano v okvir večstopenjskega pristopa. Medtem ko se ta evropski standard osredotoča na oceno nanopredmetov, se pristop uporablja za izpostavljenost povezanim aglomeratom in agregatom, tj. nanopredmetom ter njihovim agregatom in aglomeratom, ter delcem, ki se sproščajo iz nanokompozitov in izdelkov, ki jih omogoča nanotehnologija.

General Information

Status
Published
Public Enquiry End Date
09-Jan-2017
Publication Date
09-Dec-2018
Technical Committee
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
06-Dec-2018
Due Date
10-Feb-2019
Completion Date
10-Dec-2018

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SLOVENSKI STANDARD
SIST EN 17058:2019
01-januar-2019
Izpostavljenost na delovnem mestu - Ocena izpostavljenosti pri vdihavanju
nanopredmetov ter njihovih agregatov in aglomeratov

Workplace exposure - Assessment of exposure by inhalation of nano-objects and their

aggregates and agglomerates

Exposition am Arbeitsplatz - Beurteilung der inhalativen Exposition gegenüber Nano-

Objekten und deren Agglomeraten und Aggregaten

Exposition sur les lieux de travail - Évaluation de l’exposition par inhalation aux nano-

objets et à leurs agglomérats et agrégats
Ta slovenski standard je istoveten z: EN 17058:2018
ICS:
13.040.30 Kakovost zraka na delovnem Workplace atmospheres
mestu
SIST EN 17058:2019 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 17058:2019
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SIST EN 17058:2019
EN 17058
EUROPEAN STANDARD
NORME EUROPÉENNE
November 2018
EUROPÄISCHE NORM
ICS 13.040.30
English Version
Workplace exposure - Assessment of exposure by
inhalation of nano-objects and their aggregates and
agglomerates

Exposition sur les lieux de travail - Évaluation de Exposition am Arbeitsplatz - Beurteilung der

l'exposition par inhalation aux nano-objets et à leurs inhalativen Exposition gegenüber Nanoobjekten und

agrégats et agglomérats deren Aggregaten und Agglomeraten
This European Standard was approved by CEN on 25 June 2018.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this

European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references

concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN

member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by

translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management

Centre has the same status as the official versions.

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. EN 17058:2018 E

worldwide for CEN national Members.
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Contents Page

European foreword ....................................................................................................................................................... 4

Introduction .................................................................................................................................................................... 5

1 Scope .................................................................................................................................................................... 6

2 Normative references .................................................................................................................................... 6

3 Terms and definitions ................................................................................................................................... 6

4 Symbols and abbreviations ......................................................................................................................... 8

5 Measurement strategy ............................................................................................................................... 10

5.1 General ............................................................................................................................................................. 10

5.1.1 Objectives ........................................................................................................................................................ 10

5.1.2 Source domains ............................................................................................................................................. 11

5.2 Measuring devices and measurement methods................................................................................ 11

5.3 Levels of exposure assessment ............................................................................................................... 12

5.3.1 General ............................................................................................................................................................. 12

5.3.2 Initial assessment – Determination of the potential for release and emission of NOAA

into the workplace air ................................................................................................................................ 13

5.3.3 Basic assessment – Indication of exposure to NOAA ....................................................................... 14

5.3.4 Comprehensive assessment – Comprehensive characterization of the airborne

particles in the breathing zone ............................................................................................................... 18

6 Embedding of levels of exposure assessment in a tiered-approach framework .................. 21

6.1 General ............................................................................................................................................................. 21

6.2 Building blocks for a tiered-approach .................................................................................................. 22

6.3 Evaluation criteria and decision rules ................................................................................................. 23

6.3.1 General ............................................................................................................................................................. 23

6.3.2 Initial assessment (Tier 1) ........................................................................................................................ 23

6.3.3 Basic assessment (Tier 2) ......................................................................................................................... 24

6.3.4 Comprehensive assessment (Tier 3) ..................................................................................................... 26

Annex A (informative) Instruments ................................................................................................................... 27

A.1 General ............................................................................................................................................................. 27

A.2 Real-time monitors ...................................................................................................................................... 27

A.2.1 General ............................................................................................................................................................. 27

A.2.2 Aerosol photometer .................................................................................................................................... 27

A.2.3 Optical Particle Counter (OPC) ................................................................................................................ 28

A.2.4 Condensation Particle Counter (CPC) ................................................................................................... 28

A.2.5 Diffusion charger .......................................................................................................................................... 28

A.2.6 Differential Mobility Analysing System (DMAS) ............................................................................... 29

TM 2)

A.2.7 Electrical Low Pressure Impactor (ELPI ) .................................................................................... 29

TM 2

A.2.8 Tapered Element Oscillating Microbalance (TEOM ) .............................................................. 29

A.3 Aerosol sampler ............................................................................................................................................ 29

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A.4 Off-line analysis ............................................................................................................................................. 30

Annex B (informative) Checklist for minimum required information during the initial

assessment ...................................................................................................................................................... 32

Annex C (informative) Template for contextual information for comprehensive assessment

(NECID) ............................................................................................................................................................. 34

C.1 General ............................................................................................................................................................. 34

C.2 Structure and contents of the database ................................................................................................ 34

Annex D (informative) Statistical analysis of time series ........................................................................... 36

D.1 General ............................................................................................................................................................. 36

D.2 Statistical analysis of a size integrated time series dataset .......................................................... 36

D.2.1 ARIMA ............................................................................................................................................................... 36

D.3 Statistical analysis of size resolved time series data ....................................................................... 40

Annex E (informative) Decision rules for basic assessment ...................................................................... 42

Annex F (informative) Example for calculation of fraction deposited in the gas exchange

region ................................................................................................................................................................ 43

F.1 General ............................................................................................................................................................. 43

F.2 Particle size distribution............................................................................................................................ 43

F.2.1 Particle equivalent diameters .................................................................................................................. 43

F.2.2 (Number- or mass-weighted) size distributions ............................................................................... 45

F.2.2.1 Particle size distribution 1 ........................................................................................................................ 45

F.2.2.2 Particle size distribution 2 ........................................................................................................................ 45

F.3 Estimation of the fraction of particles deposited in a region of the respiratory tract......... 45

F.3.1 Deposition by diffusion .............................................................................................................................. 45

F.3.2 Deposition by aerodynamics .................................................................................................................... 46

F.4 Deposited dose .............................................................................................................................................. 47

F.5 Numerical example ...................................................................................................................................... 48

Bibliography ................................................................................................................................................................. 54

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European foreword

This document (EN 17058:2018) has been prepared by Technical Committee CEN/TC 137 “Assessment

of workplace exposure to chemical and biological agents”, the secretariat of which is held by DIN.

This European Standard shall be given the status of a national standard, either by publication of an

identical text or by endorsement, at the latest by May 2019, and conflicting national standards shall be

withdrawn at the latest by May 2019.

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 standardization request given to CEN by the European

Commission and the European Free Trade Association.

According to the CEN-CENELEC Internal Regulations, the national standards organisations of the

following countries are bound to implement this European Standard: 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.
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Introduction

The rapidly advancing field of nanotechnologies and concern on its potential impact on occupational

health and safety has initiated efforts by Standardization bodies to provide guidance how health and

safety issues can be appropriately addressed. ISO has published a series of documents, which focus on

various aspects of exposure and risk assessment and risk mitigation, for example, ISO/TR 12885 [1],

ISO/TS 12901-1 [2], ISO/TS 12901-2 [3].

The present document focuses on the assessment of occupational exposure by inhalation of nano-

objects and their aggregates and agglomerates (NOAA). In general the objectives of an exposure

assessment can vary widely and can include exposure exploration and determination, evaluation of the

effectiveness of exposure control measures, check for compliance with any occupational exposure limit

or other benchmark level, and can contribute to risk assessment and epidemiological studies. The

measurement strategy used for the assessment will depend amongst other factors on the objective of

the assessment. ISO/TS 12901-1 for example, provides guidance for the measurement strategy for

evaluation controls. No EU legal workplace exposure limits for NOAA are established at the time of the

publication of this European Standard. However, existing non-nano OELs for many substances are in

force and these are measured as prescribed in national regulations/EN 689. Therefore, this document

concerns the elements of exposure assessment and provides guidance for various applications. In

addition, CEN has published documents (EN 16897 [4], EN 16966) that provide guidance of the use of

commonly used devices for detection of nano-sized and submicron-sized aerosols using different

metrics in the workplace air.
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1 Scope

This European Standard provides guidelines to assess workplace exposure by inhalation of nano-

objects and their aggregates and agglomerates (NOAA). It contains guidance on the sampling and

measurement strategies to adopt and methods for data evaluation.

While the focus of this document is on the assessment of nano-objects, the approach is also applicable

for exposure to the associated aggregates and agglomerates, i.e. NOAA, and particles released from

nanocomposites and nano-enabled products.
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 1540, Workplace exposure — Terminology

EN 689:2018, Workplace atmospheres — Guidance for the assessment of exposure by inhalation to

chemical agents for comparison with limit values and measurement strategy

EN 16966:2018, Workplace exposure — Metrics to be used for the measurements of exposure to inhaled

nanoparticles (nano-objects and nanostructured materials) such as mass concentration, number

concentration and surface area concentration
3 Terms and definitions

For the purposes of this document, the terms and definitions given in EN 1540, EN 16966 and the

following apply.

Note 1 to entry: With regard to EN 16966, in particular, the following terms are used in this document:

agglomerate, aggregate, BET method, nanomaterial, nano-object, nanoscale, particle aerodynamic diameter,

particle diffusive diameter, particle mobility diameter, particle and primary particle.

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
appraiser

person who is sufficiently trained and experienced in occupational hygiene principles, working and

measurement techniques, to conduct the part of the assessment he or she is performing according to

the state of the art
Note 1 to entry: The appraiser may be supported by a team of qualified persons.
[SOURCE: EN 689:2018, 3.1.1]
3.2
background measurement
background particle measurement

measurement of the particle concentration, at a location or a time not affected by the activity/process

under investigation
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[SOURCE: EN 16897:2017, 3.1, modified – The preferred term and its synonym have been taken over on

separate lines.] [4]
3.3
emission

transfer process of liberated nanomaterial or other material to the workplace air

Note 1 to entry: The emission is usually expressed as a flow, e.g. quantity as mass or number of particles per

unit time or unit area, or particle per mass of product.
3.4
exposure assessment

qualitative or quantitative determination of an employee’s exposure to a chemical or biological agent

performed by an appraiser
3.5
exposure monitoring

determination of exposure to airborne chemical and/or biological agents by using a sampling or

monitoring device for gases, vapours or airborne particles
3.6
far field

well-mixed compartment of the workspace that remains as the near field is centered on the worker

3.7
median diameter
median particle diameter

particle size of a particle distribution for which one-half the total number of particles are larger and

one-half are smaller
[SOURCE: ISO 16972:2010, 3.47] [5]
3.8
nano-activity
activity/task related to handling or processing nanomaterial
3.9
release

liberation of nanomaterial during a natural or technical process at any given lifecycle stage

Note 1 to entry: Liberation can occur in three main release forms, i.e. air dispersed (aerosols), liquid dispersed

(suspensions) and undispersed material, e.g. debris. Release can be expressed without a specific metric, as a

dispersion-specific fraction or percentage (in relation to air dispersed, liquid dispersed and undispersed) of the

total release, or as a mass per unit area or unit quantity of the matrix. Release will be dependent on the physical-

chemical properties of the nanomaterial and operational and environmental conditions.

3.10
sensitivity
true positive rate

proportion of actual positives which are correctly identified as such, and is complementary to the false

negative rate
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3.11
source domain

generation mechanism that determines particle emission characteristics for a particular life cycle stage

Note 1 to entry: Different mechanisms determine the emission rate, particle size distribution, source location

and transport of NOAA during the various life cycle stages (synthesis, downstream use, application or treatment of

products and end of life)

Note 2 to entry: The source domain can comprise similar exposure situations including the vast majority of

current and near future exposure situations [6].
[SOURCE: CEN ISO/TS 21623:2018-02, 3.17, modified – Note 2 to entry added] [7]
3.12
near field

well-mixed compartment consisting of a virtual cube with 2-m sides centred on the source of particles,

with volume of 8 m

Note 1 to entry: This near field space is a nominal definition and no sharp decline in concentration is envisaged

to occur at the boundary between the near field and the far field.
3.13
specificity
true negative rate

proportion of negatives which are correctly identified as such, and is complementary to the false

positive rate
4 Symbols and abbreviations

For the purposes of this document, the following symbols and abbreviations apply.

ACF Autocorrelation Function
AIC Aikaike Information Criterion
AR AutoRegressive
APS Aerodynamic Particle Sizer
ARIMA AutoRegressive Integrated Moving Average
BIC Bayesian Information Criterion
CCF Cross Correlation Function
CMD Count Median Diameter (the number-weighted median diameter)
CNF Carbon NanoFiber
CNT Carbon NanoTube
CPC Condensation Particle Counter
d Particle aerodynamic equivalent diameter
d Particle diffusive equivalent diameter
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d Particle mobility equivalent diameter
d Optical diameter
opt
DC Diffusion Charger
DEMC Differential Electrical Mobility Classifier
DMAS Differential Mobility Analysing System
DR Decision Rule
DRI Direct Reading Instrument
EDS Energy Dispersive X-Ray Spectroscopy
ELPI Electrical Low Pressure Impactor
EM Electron Microscopy
EoL End of Life
ESP Electrostatic Precipitator
FF Far Field
FMPS Fast Mobility Particle Sizer
HVAC Heating, Ventilation and Air Conditioning
ICP-AES Inductively Coupled Plasma – Atomic Emission Spectroscopy
ICP-MS Inductively Coupled Plasma – Mass Spectroscopy
LSL Lower Size Limit
MA Moving Average
MNO Manufactured Nano-Object
MSDS Material Safety Data Sheet
NECID Nano Exposure and Contextual Information Database
NF Near Field
NM NanoMaterial
NOAA Nano-Objects and their Aggregates and Agglomerates
NPV Negative Predictive Value
NSAM Nanoparticle Surface Area Monitor
OECD Organisation for Economic Co-operation and Development
OEL Occupational Exposure Limit
OPC Optical Particle Counter
PACF Partial Autocorrelation Function
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PEROSH Partnership for European Research in Occupational Safety and Health
PGNP Process Generated NanoParticle
PM Particle size fraction with the aerodynamic cut-size equal to 2,5 µm
2,5
PM Particle size fraction with the aerodynamic cut-size equal to 10 µm
PSD Particle Size Distribution
QA Quality Assurance
QC Quality Control
R&D Research & Development
REL Recommended Exposure Limit (by NIOSH)
SD Source Domain
SEM Scanning Electron Microscopy
SMPS Scanning Mobility Particle Sizer
SOP Standard Operating Procedure
TEM Transmission Electron Microscopy
TEOM Tapered Element Oscillating Microbalance
TP Thermal Precipitator
TWA Time Weighted Average
XRD X-Ray Diffraction
XRF X-ray Fluorescence
5 Measurement strategy
5.1 General
5.1.1 Objectives

A measurement strategy for workplace exposure assessment might have a number of objectives to fulfil

including
a) determination of the substances to which exposure may take place;
b) measurement of the existing OELs for those substances in air;
c) selection of appropriate metrics and instruments to monitor exposure;
d) analysis and interpretation of the results.

The exposure measurements are part of risk assessment and the objectives can be exposure

assessment, compliance with any occupational exposure limit or benchmark level, evaluation of the

effectiveness of exposure control measures or epidemiology. The design of the actual measurement

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strategy shall be consistent with the study objectives. Exposure measurement studies that attempt to

identify exposure pathways (transport processes of the contaminant from source to the receptor (the

worker)) and exposure-modifying factors/determinants shall include both measurements at the source

as well as at the receptor, i.e. the breathing zone. Exposure assessments for use in compliance

assessment, epidemiologic studies, or risk assessment shall focus on the individual worker using

breathing zone samples collected over a full work shift or a suitable time weighted average. In contrast,

studies of the efficacy of a technical control measure may for example be carried out using static

measurements at or near the workstation or the location where the task is performed.

Depending on the objective of the assessment, the resources and the expertise, the assessment can be

performed at a specific level. The levels of exposure assessment are addressed in 5.3.

5.1.2 Source domains

For exposure assessment to NOAA, the concept of the source domains (SD) was developed [6], which

describes different processes during the lifecycle of a nanomaterial:

— During the production phase (synthesis) prior to harvesting the bulk material, point source or

fugitive emission, e.g. emissions from the reactor, leaks through seals and connections, and

incidental releases, can take place (SD1). In these cases, discrete nanoparticles and agglomerates

will be formed;

— During the manufacturing of products, the handling and transfer of bulk manufactured

nanomaterial powders with relatively low energy can release nanoparticles, e.g. collection,

harvesting, bagging, bag dumping, bag emptying, scooping, weighing, dispersion/ compounding in

composites (SD2). However, the powders are already in agglomerated stage and high shear forces

are needed for deagglomeration [8], [9]. Therefore, the majority of the released particles will be

agglomerates;

— During further processing or in the use phase of a ready-to-use nanoproduct, release can be

expected during the relatively high energy dispersion of either a) solid, powdery or (liquid)

intermediates containing highly concentrated (> 25 %) nanoparticles or b) application of

(relatively low concentrated < 5 %) ready-to-use products (SD3). Examples of SD3a are pouring,

injection molding, (jet) milling, stirring, mixing. As higher shear forces can occur during high energy

dispersion de-agglomeration can occur. Examples of SD3b are application of coatings or spraying of

solutions that can form nanosized aerosols after evaporation of the liquid phase component,

usually of mixed composition;

— During the use phase of a product or its end-of-life (EoL) phase, activities resulting in fracturing

and abrasion of manufactured nanoparticles-enabled end products at work sites, e.g. low energy

abrasion, manual sanding, or, high energy machining, e.g., sanding, grinding, drilling cutting,

shredding. High temperature processes like incineration which can occur during the EoL of a

material or product are included (SD4). Most likely it will be multi-composed aerosols, and in case

of machining also matrix-bound nanoparticles, whereas during thermal processes nanoparticles

can also be formed following nucleation and condensation of vapours [10].

Relevant contextual information achieved during the identification of a source domain will facilitate the

selection of an appropriate measurement strategy, since the source domain concept reflects different

mechanisms of release and consequently possible different nature of released aerosols, e.g. state of

agglomeration and composition.
5.2 Measuring devices and measurement methods

A range of metrics and hence measurement instruments are currently used, because there are NOAA

without a nanospecific OEL, and there is no agreed measurement metric to measure the exposure.

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Hence, exposure assessment methodologies and measurement strategies often rely on multiple metrics

and instruments, including real-time monitors and sampling devices to enable off-line analysis, in order

to conduct an adequate exposure assessment. The most commonly reported combination of real-time

and off-line instruments include direct-reading, handheld instruments (Condensation Particle Cou

...

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