SIST-TS CEN/TS 15279:2006

SLOVENSKI STANDARD
01-maj-2006
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Workplace exposure - Measurement of dermal exposure - Principles and methods
Exposition am Arbeitsplatz - Messung der Hautbelastung - Grundsätze und Verfahren
Exposition sur les lieux de travail - Mesurage de l'exposition cutanée - Principes et
méthodes
Ta slovenski standard je istoveten z: CEN/TS 15279:2006
ICS:
13.100 Varnost pri delu. Industrijska Occupational safety.
higiena Industrial hygiene
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

TECHNICAL SPECIFICATION
CEN/TS 15279
SPÉCIFICATION TECHNIQUE
TECHNISCHE SPEZIFIKATION
March 2006
ICS 13.100
English Version
Workplace exposure - Measurement of dermal exposure -
Principles and methods
Exposition sur les lieux de travail - Mesurage de l'exposition Exposition am Arbeitsplatz - Messung der Hautbelastung -
cutanée - Principes et méthodes Grundsätze und Verfahren
This Technical Specification (CEN/TS) was approved by CEN on 22 November 2005 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, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania,
Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2006 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TS 15279:2006: E
worldwide for CEN national Members.

Contents Page
Foreword.3
Introduction .4
1 Scope .5
2 Terms and definitions .6
3 Principles and methods .9
4 Quality issues.10
5 Report .11
Annex A (informative) Interception methods.13
Annex B (informative) Hand wash methods .18
Annex C (informative) Wipe methods.22
Annex D (informative) Tape-stripping method .26
Annex E (informative) In-situ methods.31
Bibliography .38

Foreword
This Technical Specification (CEN/TS 15279:2006) 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.
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.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to announce this Technical Specification: Austria, Belgium, Cyprus, Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden,
Switzerland and the United Kingdom.
Introduction
Dermal exposure assessment explores the dynamic interaction between environmental contaminants and the
skin. In contrast to inhalation exposure assessment, the assessment of dermal exposure remained a nascent
field of scientific research and applied occupational hygiene for most of the twentieth century, although
multiple fatalities and occupational skin diseases due to dermal exposure have been described in literature.
During the last decade, dermal exposure has received more attention, and one of the important results was
the development of a conceptual model for dermal exposure (see [1]). The model systematically describes the
transport of contaminant mass from exposure sources to the surface of the skin. The model provides a
structure for evaluating dermal exposure both qualitatively and quantitatively.
The purpose of evaluating dermal exposure can differ substantially, as exposure analysis (to give guidance to
control), risk assessment, and evaluation of exposure control can all be objectives to undertake assessments.
In order to give guidance and to harmonise measurements, requirements and test methods for measurement
of dermal exposure are proposed.
1 Scope
This Technical Specification establishes principles and describes methods for the measurement of dermal
exposure in workplaces. It gives guidance on the commonly used approaches to the measurement of dermal
exposure, their advantages and limitations and how these might be assessed in specific circumstances for
specific compounds.
This Technical Specification should enable users of dermal sampling methods to adopt a consistent approach
to method validation and provide a framework for the assessment of method performance.
This Technical Specification describes the requirements against which sampling methods need to be
assessed. It will then indicate methods for agreement with these requirements. Requirements include
specification of the following:
NOTE Not all requirements are applicable to all methods.
 sampling efficiency;
 recovery efficiency;
 sample stability;
 maximum capacity;
 bias, precision, overall uncertainty;
 core information;
 contextual information.
2 Terms and definitions
For the purposes of this Technical Specification, the following terms and definitions apply.
NOTE The definitions are based on CEN/TR 15278.
2.1
agent
any chemical or biological entity on its own or admixed as it occurs in the natural state or as produced by any
work activity, whether or not produced intentionally and whether or not placed on the market
NOTE Adapted from EN 1540.
2.2
bias
consistent deviation of the measured value from the value of the air quality
characteristic itself or the accepted reference value
[ISO 6879:1995, 5.2.3.1]
2.3
dermal contact volume
volume containing the mass of the agent that contacts the exposure surface
NOTE 1 The dermal contact volume is given in litres (l).
NOTE 2 The dermal contact volume is equivalent to the volume of the skin contaminant layer, and for practical reasons
it is defined by the mass in kilograms (kg) of all substances contained in this compartment.
2.4
dermal exposure
process of contact between an agent and human skin at an exposure surface over an exposure period
2.5
dermal exposure concentration
exposure mass divided by the dermal contact volume or the exposure mass divided by the mass contained in
the skin contaminant layer
NOTE The dermal exposure concentration is expressed in grams per litre (g/l) or grams per kilogram (g/kg)
respectively.
2.6
dermal exposure loading
exposure mass divided by the exposure surface
NOTE For practical reasons it can be expressed as the time-averaged mass divided by area-averaged skin
contaminant layer surface area in grams per square centimetre (g/cm ).
2.7
dermal exposure mass
mass of agent present in the dermal contact volume
NOTE 1 For practical reasons it is defined by the amount of agent in grams (g) present in the skin contaminant layer.
NOTE 2 The outcome of the process of dermal exposure, i.e. the contact, can be expressed by different parameters of
exposure.
2.8
dermal exposure surface
skin surface area where an agent is present
NOTE For practical reasons this is represented by a two dimensional representation of the skin contaminant layer in
square centimetres (cm ).
2.9
exposure period
time the agent is present in the skin contaminant layer, i.e. contact time
NOTE 1 The process by which an agent crosses an outer exposure surface of a target is called intake. In case of the
concentration driven transport from the skin contaminant layer into the skin, i.e. crossing the (exposure surface) interface
between SCL and the stratum corneum as an absorption barrier, the process is called uptake. Therefore, relevant for
uptake would be the time- exposure concentration profile for an identified area of the skin contaminant layer over a defined
period of time.
NOTE 2 Other relevant types of time intervals, e.g. sampling time (B-C), immission or loading time (A-D), and post
emission time (D-E), are illustrated in Figure 1.

Key
X time
Y exposure loading
A-E exposure/contact time
A-D immission/loading time
D-E post immission time
B-C sampling time
Figure 1 — Different types of time intervals relevant in view of dermal exposure
2.10
immission
transport of an agent from a defined source to the skin or outer clothing contaminant layer compartment
2.11
limit of detection
LOD
background level plus three times estimated standard deviation of measured blank substrate mass
NOTE Adapted from ISO 15767.
2.12
limit of quantitation
LOQ
background level plus ten times estimated standard deviation of measured blank substrate mass
NOTE Adapted from ISO 15767.
2.13 overall method efficiency
2.13.1
overall method efficiency
sampling efficiency multiplied by recovery efficiency
2.13.2
overall method efficiency
mass of agent detected divided by mass of agent in analysed contact volume
NOTE Mass of agent detected either directly or indirectly by use of a tracer.
2.14
overall uncertainty
quantity used to characterise as a whole the uncertainty of
the result given by an apparatus or measuring procedure
NOTE It is expressed, as a percentage, by a combination of bias and precision usually according to the formula:
x − x + 2s
ref
x
ref
where
x is the mean value of results of a number (n) of repeated measurements;
x is the true or accepted reference value of concentration;
ref
s is the standard deviation of the measurements.
[EN 1540:1998, 3.17]
2.15
potential dermal exposure mass
mass retrieved from (outer and inner clothing contaminant layer and exposure mass, i.e. mass retrieved from
the covered and uncovered by clothing) parts of the skin contaminant layer compartment
NOTE For practical reasons related to sampling methodology and strategy the term potential exposure mass has
been introduced. It refers to the agent mass that has the potential the reach the skin (contaminant layer) since it has
landed on the clothing and the agent mass that has actually reached the skin. The conceptual model distinguishes
between outer and inner clothing contaminant layer compartment, respectively, and characterises the clothing itself as a
buffer layer.
2.16
precision
the closeness of agreement between independent test results obtained under stipulated conditions
[ISO 6879:1995, 5.2.16]
2.17
quality control sample
blank substrate that undergoes the same handling as the sampling substrate and can either be fortified with
the agent or not
2.18
recovery efficiency
mass of agent recovered from collection substrate divided by mass of
agent present on the substrate immediately after collection
NOTE For in situ methods recovery efficiency is not applicable.
2.19 sampling efficiency
NOTE For in situ methods sampling efficiency is not applicable.
2.19.1
sampling efficiency
mass of agent on collection substrate at end of sampling divided by immission of
agent to sampled area integrated over sampling time
2.19.2
sampling efficiency
mass of agent on collection substrate divided by dermal exposure loading by agent
times sampled area
2.20
skin contaminant layer compartment
compartment on top of the stratum corneum of the human skin
NOTE The skin contaminant layer compartment is formed by sebum lipids, sweat and additional water from
transepidermal water loss, rest products from cornification and unshed corneocytes, and is given by its three dimensional
volume.
2.21
workplace
the defined area or areas in which the work activities are carried out
[EN 1540:1998, 3.36]
3 Principles and methods
3.1 Measurement principles
Table 1 gives the three major measurement principles for dermal exposure assessment and an overview of
the more frequently used sampling methods. Agents collected by interception techniques can be detected by
e.g. chemical analysis of extracts from the removal matrix such as wash liquid, wipe fabrics. Agents collected
by removal techniques can be detected by e.g. chemical analysis of extracts from the collection matrix.
The measurement methods do not attempt to quantify the role of dermal uptake. Choice of measurement
methods in cases where dermal uptake is an issue described in CEN/TR 15278.
Table 1 — Measurement methods for dermal exposure assessment
Measurement principle / sampling technique Sampling method
interception techniques, patch
i.e. interception of agent mass transport by the use of collection media
whole body
placed at the skin surface or replacing work clothing during the sampling
time
removal techniques, manual wipe
i.e. removal of the agent mass from the skin surface (i.e. the skin
tape-stripping
contaminant layer) at any given time
hand wash
hand rinse
direct assessment, detection of UV fluorescence of agent or added
i.e. In situ detection of the agent or a tracer at the skin surface, e.g. by tracer as a surrogate for the agent by video
image acquisition and processing systems, at a given time imaging, Attenuated Total Reflection FTIR, or
using a light probe
The measurement results should be interpreted in relation to the measurement strategy as described in
CEN/TR 15278.
Since the results obtained by different sampling principles are influenced by a range of mass transport
processes (see Table 1), and may have to be extrapolated beyond the sampled contact volume, all sampling
methods are faced with fundamental problems, such as:
 interception and retention characteristics of interception techniques differ from real skin or clothing;
 removal methods, e.g. tape stripping, solvent washing, and use of surfactants, can influence the
characteristics of the skin. They can also be of limited use for repeated sampling;
 removal techniques, e.g. skin washing, are not appropriate for all body parts;
 extrapolation from small areas sampled, e.g. patches or skin strips, to the whole exposed area can
introduce substantial errors;
 the behaviour of a (fluorescent) tracer introduced in the mass transport when using in situ-techniques can
differ from the behaviour of the substances of interest.
3.2 Selection of sampling methods
Selection of the appropriate sampling method will depend on a range of factors. These include the sampling
objectives, the compartment or transport process of interest, and the nature of the agent and the analytical
methods to be used. Selection of sampling methods should be part of a coherent and documented sampling
strategy. More information about sampling strategies can be found in CEN/TR 15278.
Details of the various test methods are provided in Annexes A to E. In these annexes the principles behind
each of the approaches, the test methods themselves, the materials that have been used and how the
procedures are carried out are described. Applications and limitations of each of these test methods are also
described.
4 Quality issues
4.1 General
Various quality issues that are important to some or all of the methods are described in a generic sense in 4.2
to 4.7.
4.2 Sampling efficiency
In practice, sampling efficiency can only be determined approximately due to methodological limitations.
Methods for determining sampling efficiencies are given in Annexes A to E.
4.3 Recovery efficiency
Fortified quality control samples (generated by dispersing a known and relevant quantity of the agent under
investigation onto sampling the sampling substrate) may be used to quantify the recovery efficiency. Fortified
quality control samples should be collected, handled, transported and stored in conjunction with the
experimental samples. Ideally a separate set of quality control samples should be included at each site on
each day of monitoring for each relevant dosimeter. The same approach may be used in laboratory
experiments to determine recovery efficiency.
4.4 Background and contamination
Blank quality control samples should be used to determine the upper limit of the agent in question present in
the sampling substrate dosimeters or skin not arising from direct sampling but due to background
contamination and/or contamination due to sample handling, transport and storage. The blank quality control
samples should be handled, transported and stored in conjunction with the experimental samples. Ideally a
separate set of quality control samples should be included at each site on each day of monitoring for each
relevant sampling substrate.
4.5 Maximum capacity
The maximum capacity of the dosimeter against the test agent should be assessed. If it is considered that this
may be exceeded in the experimental study, the maximum capacity should be quantified experimentally.
4.6 Sample stability
The sample stability will vary by storage and transport method and by agent and should be assessed as part
of the field recovery investigation.
4.7 Analytical method
The analytical method used, should be validated according to standard laboratory analysis quality control
protocols. Details, specific for the various sampling methods are given in Annexes A to E.
5 Report
The report should contain all necessary information (core information) to carry out the measurements:
a) purpose of the assessment;
b) sampling strategy used;
c) sampling method;
 description of each procedure. The description should contain all necessary information to carry out
the sampling procedure, information about the attainable overall uncertainty, specified measuring
range, averaging time, interferences and information on environmental or any other conditions, which
can influence the performance of the procedure. It should include, where appropriate for the specific
sampling method:
 sampling medium;
 surface area of sampling medium;
 sampled or measured surface area and body part;
 definition of t = 0;
 sampling interval and history of subject;
 sampling efficiency;
 recovery efficiency;
 maximum capacity;
 sample stability.
d) the analytical method;
 results obtained with appropriate statistical analysis:
 bias;
 precision;
 overall uncertainty;
 limit of detection;
 limit of quantitation, where applicable, should be expressed according to 2.12.
Detailed specification for the core information is given in Annexes A to E. Other contextual information should
also be collected and reported including information about:
 location;
 exposure scenario;
 worker;
 environment;
 agent.
Annex A
(informative)
Interception methods
A.1 Description of approach
A.1.1 Sampling principle
The principle of sampling is interception and consecutive retention of the mass transported towards the skin
contaminant layer, i.e. immission, by a collection substrate attached to the skin or clothing. Mass recovered
from the collection substrate is a surrogate of the exposure mass:
 in the case where the collection substrate is attached to the outside of the outermost layer of clothing, the
mass recovered from the collection substrate is a surrogate of the potential exposure mass (see
CEN/TR 15278);
 in the case where the collection substrate is attached to the covered (protected) skin contaminant layer,
the mass recovered from the collection substrate is a surrogate of the exposure mass;
 in the case where the collection substrate is attached to the uncovered (unprotected) skin contaminant
layer, the mass recovered from the collection substrate is a surrogate of both the potential exposure mass
and the exposure mass.
The main types of interception methods are patch, whole suit, and glove methods. These methods are
conceptually simple. In interception sampling, absorbent or retentive dosimeters, e.g. patches, whole suits,
and gloves, are attached to an operator’s clothing or skin at various locations on the body prior to exposure.
Following exposure, the dosimeters are removed and the amount of an agent retained by each patch is
determined by an appropriate analytical method.
A.1.2 Sampling materials
Physical properties, e.g. roughness and porosity, and absorbance capacity of the collection material, will
determine both capture/collection and retention properties, i.e. sampling and recovery efficiency, respectively.
A wide range of collection materials are used in the construction of patches. These include cotton,
rayon/polyester, dracon/cotton, flannel, filter paper, filter paper impregnated with lanolin, aluminium foil,
surgical gauze, polypropylene and 6 mm polyurethane foam pads. The WHO method (see [2]), EPA method
(see [3]) and OECD guidelines (see [4]) all recommend the use of α-cellulose paper. The OECD guidelines
also suggest that 100 % cotton or polyester cotton material can be used as alternatives. The use of charcoal
cloth for monitoring dermal exposure to volatile compounds has been suggested.
In general, when assessing exposure to liquids, the sampling material shall be absorbent enough to retain all
liquids that contact it. Sampling for particles presents its own problems, but current recommendations (e.g. [4])
are that the material used should be porous enough to retain all the particles landing on it.
The principle of complete retention of all challenge material is known colloquially as the “infinite sink” principle.
The WHO and OECD methods specify that if a sampler becomes saturated it should be replaced with a fresh
one, although no guidance is given how to tell if a sampler is saturated, and no guidance is given whether the
entire sampler shall be saturated or just one part (e.g. a glove fingertip). The OECD document is ambiguous
here; it also states that “The patch material should be absorbent enough to retain all liquid residues
anticipated to be in contact during an actual field study, as if it were the clothing or the skin, depending on the
location of the patches” (see [4], Annex I, patch method, our italics).
The principle of retention of only that fraction of challenge material that would be retained on the skin is known
colloquially as the “skin-equivalent” principle. The OECD guideline does not differentiate between the infinite
sink and the skin-equivalent principles. It does however give a hint that skin-equivalent principle is preferred.
Patches are generally backed with a waterproof material such as aluminium foil or polyethylene in order to
ensure that collected contaminants do not escape from the patch into the skin or overalls beneath it, and also
that the reverse does not occur. In addition, the backing generally adds a degree of robustness to the patch.
Alternatively the patch may be placed in a protective envelope.
The object of whole body sampling is to measure the amount of a particular agent transported to the clothing
or the skin or penetrating the outer clothing layers. Typically, lightweight overalls or similar are used to
estimate exposure to the areas of the body covered. Exposure of the head is measured either by a hood
attached to the overalls or a separate hat. Exposure of the hands and feet can be measured by using gloves
and socks respectively. Exposure of various body regions can be determined by sectioning of the suit, with
analysis of the relevant region. The whole body undersuit method can also be used to estimate exposure
mass, by sampling next to the skin layer and intercepting that contamination that would otherwise reach the
skin. Exposure mass has been measured next to the skin using close fitting long-sleeved vests and “long-
johns”.
Unlike patch sampling, a relatively limited range of materials has been used for suit sampling. Most typically
100 % cotton or a cotton and polyester mix are used, though the use of ‘corovin’ disposable overalls and very
fine, high-density polyethylene fibers coveralls have also been reported. Worn immediately underneath
protective clothing, the method has been used to provide some indication of protective clothing effectiveness.
A.1.3 Sampling procedures
Patch sampling: ‘Generic’ protocols that prescribe sizes, numbers and location and method of attachment of
patches are given e.g. by WHO [2], US-EPA [3], OECD [4]. Tailor made study designs and protocols may
deviate from these protocols. These protocols give estimates of the body area represented by each patch,
which vary slightly from each other.
OECD also provides a procedure for standard and refined whole body suit sampling. Basically, the procedure
prescribes covering by the (pre-extracted and laundered) dosimeters of the body, including the arms, the legs
to the wrist and ankles. Exposure to the head, neck and face should be determined by measuring transport to
a hood as part of the suit (coverall) or on a hat or cap. Exposure to the feet should be estimated from
measuring transport to socks. Following sampling the suits are removed and usually sectioned according the
body parts of interest in terms of distribution of exposure mass, e.g. forearms, upper arms, upper legs, lower
legs, chest/torso, and back/torso. Each section should be stored separately and the agent being monitored will
be extracted and analysed.
In case of concurrent biological monitoring the dosimeters should represent as closely as possible normal
work clothing. To avoid interference of the outer dosimeters on the transport process to the skin contaminant
layer, sometimes only undergarment (T-shirt and briefs) is used to estimate exposure mass.
No specific procedures for the use of absorbent gloves have been identified.
A.2 Use/applications of methods and interpretation of results
Interception sampling, using patches, absorbent gloves and whole suit dosimeters are appropriate for
estimation of the agent mass that has the potential the reach the skin (contaminant layer) since it has landed
on the clothing and the agent mass that would have actually reached the skin. In the latter case it also
estimates the exposure mass, i.e. the hazardous agent in the skin contaminant layer. The metric is mg or
mg/body part.
The results can also be used to estimate the different mass transport rates, e.g. mass of agent transferred
from: the surface contaminant layer to the skin contaminant layer; the inner clothing contaminant layer to the
skin contaminant layer; the outer clothing contaminant layer to the skin contaminant layer. Furthermore, they
can also be used to estimate the mass of agent deposited from the air compartment to the skin contaminant
layer.
In the case where the collection substrate is not placed directly at the skin surface but outside an underlayer
of clothing, results only indicate potential exposure mass or potential mass transport rates to that clothing
layer.
A.3 Limitations
Among the limitations of interception methods are:
 different collection materials and different weights of the same type of cloth will obviously have different
absorption, retention and repellency characteristics which will affect estimated exposure. It has also been
shown that there can be substantial differences in characteristics between unwashed and washed
overalls of the same fabric. In case of wet work or exposure to liquids absorbent materials can tend to get
overloaded;
 in addition, the material from which the dosimeters are made, used to measure potential exposure mass,
can be very different from that of the normal or protective clothing worn underneath. As a result it is likely
that the repellency, retention and absorption characteristics of the sampling substrates will differ from the
worker's typical clothing which in turn will influence measured exposure levels. Hence estimated
exposure mass as measured by dosimeters can be very different to the exposure actually experienced;
 the major disadvantage of patch sampling is that it only estimates the amount of an agent deposited on a
particular area. Implicitly it assumes that contamination is uniformly distributed over the area represented
by the patch. However, the patch represents only a relatively small proportion of a particular region and
extrapolation could lead to under estimation, should droplets miss the patch when spraying, or
overestimation, should a splash land on the patch. This methodology has been derived for agricultural
exposure scenarios (see [2] and [4]), where wide dispersive application methods such as fogging and
spraying can (but not always) give rise to even deposition over body areas. The use of the same
methodology in other industrial application or exposure scenarios where distribution can be more uneven
can result in a less reliable estimation of exposure. The use of whole body suit sampling methods is
therefore becoming more widespread;
 for suits sampling, large volumes of solvent are required to extract the contaminant and since the
concentration of the contaminant can be low, concentration of the solvent can be required, making the
technique both time consuming and costly. Using an extra layer of clothing to measure exposure can lead
to problems, with the movement of the wearer being restricted. In addition, it can be uncomfortable for the
operator, particularly with respect to temperature. Where close fitting suits are used as undergarments,
the surface area of the sampler may be approximated by the equivalent body areas. Where (larger)
oversuits are used as an outer layer, the increase in surface area can cause it to oversample compared
to an equivalent body skin area. However, the calculation of clothing surface area for the Outer Clothing
Contaminant Layer (OCCL) has not generally been addressed in the literature: the surface area of a
workers clothing may also be much higher than that of the skin underneath.
A.4 Quality issues
A.4.1 Number of patches
Different protocols recommend the use of different numbers of outer patches, ranging from six (see [2]),
through ten (see [3]), to thirteen (see [4]). The HSE method (see [1]) suggests the use of what it refers to as a
full set of patches (eleven) or a reduced set of patches (six) which is based on the WHO protocol. In contrast,
generally only one or two inner patches are used and it is recommended that these be placed on areas of the
body where it is perceived that contamination will be significant (see [3] and [1]). Inner patches should not be
occluded by outer patches. In other industries fewer patches have often been used and these have typically
been placed on the skin surface.
A.4.2 Sampling efficiency
The sampling efficiency of the interception dosimeters should be assessed. This includes the process of a well
defined immission of an agent originating from a source and collection and retention by the sampling substrate.
In general, this type of data is the result of elaborated studies where combinations of immission types, e.g.
spraying, and substrate types are tested.
A.4.3 Recovery efficiency
The laboratory approach to verify recovery efficiency is based on fortifying the sampling substrate with known
quantities of the agent and extracting it. The method of fortifying or spiking should be realistic, and reflect the
contamination pathways in the survey. A spike whereby the entire quantity is placed on one small central
region of a patch would not reflect the average surface loading of the whole patch. This may be perfectly valid
to represent a splash, but would not represent wide dispersive sprays or fogging.
A.4.4 Sample stability
Stability over time should also be investigated by preparing sampling substrates with known quantities of the
agent and analysing them immediately and at suitable time intervals thereafter, until the maximum anticipated
storage period has been reached. It is important that both laboratory samples an exposed field samples are
stored under the same conditions throughout this time.
During the exposure measurements quality control samples should be used. These include blank samples
and fortified samples in which the amount of agent added should reflect the levels expected during the study.
These are then exposed to the same conditions under which samples are collected and are subsequently
handled, transported and stored. Quality control samples should also be analysed alongside the exposure
samples. This will allow any losses occurring to be determined and hence allow for correction of field results
should this be necessary. The OECD guidance document (see [4]) states that recovery efficiencies of 95 % or
above are acceptable. For lower recovery efficiencies it is recommended that the values obtained are adjusted
accordingly.
A.4.5 Maximum capacity
Maximum capacity of the dosimeter against the test agent should be assessed. However, this might have
been covered by the upper level of fortification quality control samples.
A.4.6 Core information
In addition to the general core information sampling results should be presented accompanied by a clear
description of sampling substrate characteristics like:
 specification type of collection substrate: material type, fabric, specific density, thickness;
 specification of size(s) of collection substrate;
 specification of backing material (if appropriate);
 description of numbers and locations of patches;
 description of surface area of patches or monitoring gloves/suits.
Metric(s) of exposure parameter: (potential) exposure mass (mg) per body part.
NOTE For patch sampling this will be an estimate obtained from the product of the mass collected by the patch and the
ratio of the patch area to the body part area.
A.5 Considerations on sampling strategy
Interception methods are appropriate for evaluating mass transport processes. For risk assessment purposes
interception methods are in general inappropriate in case of high transport rates from the skin contaminant
layer, e.g. by removal, re-suspension or evaporation. In case of high uptake rates combined with low removal
rates interception techniques might give appropriate estimates of exposure mass.
Sampling of the total body or selected body sites can be repeated several times per work-shift to get better
information about the variation of dermal exposure during work shift.
Sampling can be performed prior to start of the work-shift, before breakfast, before lunch and prior to the end
of the work-shift. However, the aim of the sampling can also be to assess exposure during specific tasks or
consistency or variability through consecutive replicate sampling of the same workers, which demands end of
task or periodic sampling.
Annex B
(informative)
Hand wash methods
B.1 Description of approach
B.1.1 Sampling principle
The principle of sampling is the removal of contaminants from the skin compartment layer by providing an
external force that equals or exceeds the force of adhesion. Three categories of external forces can be
distinguished: mechanical action, hydrodynamic drag, and wet chemical action.
Generally, two basic methods can be identified:
1) (hand)washing can be defined as scrubbing the skin by mechanical agitation exercised by
movements and pressure of both hands in liquid in a routine washing fashion. The contaminant is
detached from the skin by a combination of mechanical forces and wet chemical action (dissolution);
2) (hand)rinsing or pouring can be defined as liquid-skin contact, where the contaminant is removed by
a combination of hydrodynamic drag, and wet chemical action (dissolution).
Clearly, the basic distinction between both methods is the presence or absence of mechanical forces in the
process of detachment. Within both methods subcategories can be distinguished using flowing or contained
liquid (determines the strength of hydrodynamic drag), and the kinds of liquid (determines the strength of
solubility). Often detergents are introduced in the process to enhance the detachment of insoluble particles.
B.1.2 Sampling materials
Wash liquids can vary between tap water, distilled or deionised possibly in combination with a commercially
available surfactant (see [5]), consumer product mild liquid hand soaps, and organic solvents. Organic
solvents with mild skin irritative effects on skin such as neat alcohols, e.g. ethanol, 2-propanol (isopropanol),
may be used pure or as a solution (10 % or 40 % mass fraction in water) (see [5]).
Bags are selected that are sturdy enough to hold 250 ml or 500 ml of solvent, either commercially available
bags or ’home made’ polyethylene bags (0,025 mm thickness) (see [6], [7]). No information is available on the
type of bowls used.
Wide-neck 5 l polyethylene containers filled with 1 l or 1,5 l tap water and detergent have also been used in
and washing procedure.
A specially developed hand washing device has been designed for hand washing with tap water flow (see [9]).
This device consists of a tube attached to the water tap of the water supply, an adjustable flow control set at a
flow rate of approximately 3 l/min and a timer, a tap, a funnel and a 5 l polyethylene bottle to collect the rinse
water.
B.1.3 Sampling procedures
During bag rinsing one hand is immersed in solvent and a technician holds the bag tightly just above the wrist
to prevent leakage. Alternatively, the bag is tightly sealed above the wrist with a rubber band. The person
should cup the hand slightly and hold the fingers a short distance apart during most of the shaking operation.
Occasionally, the thumb and fingers should be rubbed against one another and against the palm. The hand
should be shaken vigorously, either by the person or by the technician during a fixed time, e.g. 30 s (see [7],
[8] and [10]), a fixed number of shakes, e.g. fifty times (see [6]), or a fixed number of shakes (60) in a fixed
time (30 s) (see [11]).
During hand washes the subject is asked to wash his hands thoroughly in a routine fashion or according a
6-step procedure (see EN 1499). Brouwer et al. (see [7], [8]) used a procedure for solvent based routine
fashion hand washing in a bag, where workers were asked to wash their hands during 30 s. After removal
from the solvent the hands were allowed to dry above the solvent for 10 s before removal from the bag, and
the procedure was repeated a second time in a fresh handwash solution.
Marquart et al. (see [9]) also used the routine fashion hand washing for a tap water/soap-based method. After
transfer of approximately 1,5 ml of a hypo allergic soap from a dispenser onto the palm, the hands are
moisturised by a supplying a little bit of water. A hand wash procedure is performed by the worker in a routine
fashion during 15 s. Consequently the hand wash procedure is repeated during 30 s during which the hands
are kept in a water flow of approximately 3 l/min, where after the hands are allowed to drain above the funnel
during 10 s. After rinsing the funnel by deionised water and replacing the container the 30 s hand washing in
the water flow is repeated.
Table B.1 summarises the different hand wash methods.
Table B.1 — Summary of materials and procedures
Washing Solvent Device Fashion
rinsing (one hand) 250 ml solvent bag vigorously shaking
washing (two hands) 500 ml solvent bag/bowl routine fashion
washing 1,5 l to-2,0 l water 5 l container routine fashion
+ detergent
washing (soap) 1 500 ml tap water special device routine fashion
washing (soap) all all protocol (see EN 1499)
B.2 Use/applications of methods and interpretation of results
The results of hand washes could be interpreted as estimates of the exposure mass present in the skin
contaminant layer covering the hands at the time of washing. The metrics would be mg/hand(s).
Assuming a homogeneous distribution of the exposure mass over the skin contaminant layer, for example in
case of direct contact or immersion, and a known surface area of the hands/wrists the results can also be
expressed as an rough estimate of the mean exposure loading of the hands (mg/cm ).
Since all mass transport processes towards and from the skin contaminant layer of the hands are included the
results will be highly relevant in view of risk assessment.
NOTE See also CEN/TR 15278.
B.3 L
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