TARGET LEVELS Chapter 6

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TARGET LEVELSChapter 6

• BJARNE W. OLESEN
• DOMINGO L. MORENO-BELTRÁN
• MARIO GRAU-RIOS
• ESKO TÄHTI
• RAIMO NIEMELÄ
• LARS OLANDER
• KIM HAGSTRÖM

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Contents of Chapter 6

• Measurements on Individuals
• Other and Future Standards
• Conclusion
• Examples
• References
• TARGET LEVELS FOR INDUSTRIAL AIR QUALITY
• Introduction
• Grounds for Assessing TLs for Industrial Air
  Quality
• Target Levels for Common Contaminants
• Use of TLs
• References
• REQUIREMENTS DUE TO BUILDING CONSTRUCTION,
  EQUIPMENT, PROCESSES, AND TYPE OF PRODUCTION
  PREMISES
• Introduction
• Ventilation Parameters That Influence the
  Building Construction And Process Design
• Building and Process Parameters That Influence
  the Ventilation System
• Summary
• References

• DEFINITIONS AND CONNECTION TO DESIGN METHODOLOGY
• Introduction
• Use of Target Levels
• Combination of Target Levels and Design
  Methodology
• References
• OCCUPATIONAL EXPOSURE LIMITS
• Introduction
• OELs
• Types of OELs
• Assessment of Exposure to Chemical Agent
• References
• TARGET VALUES FOR THERMAL FACTORS AN OVERVIEW OF
  INTERNATIONAL STANDARDS
• Introduction
• The Thermal Environment
• Moderate Thermal Environments
• Hot Environments
• Cold Environments
• Supporting Standards

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DEFINITIONS AND CONNECTION TO DESIGN METHODOLOGY

• Use of target levels
• Combination of target levels and desing methods

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Main steps in defining target levels
STEP 1 Musts Ascertain the requirements of
laws, regulations, and standards related to
legislation, processes, and equipment, and
compare them with customer needs. Of course,
before this step, needs of the end user - for
example, economical boundary conditions - are
identified. At this stage the tentative target
levels have also been selected.
STEP 2 Needs Ascertain nonbinding standards,
human comfort standards, guidelines, codes of
practice, and custom needs.
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Main steps in defining target levels (contd)
STEP 3 Target levels Define the target levels
based on musts and needs.
STEP 4 Design conditions Suggest and confirm
with customer the outdoor or process conditions
within which the target levels must be met (e.g.,
absolute maximum temperature versus 95 percentile
temperature).
STEP 5 Reliability Find out the customer
reliability requirements of the process. Define
and obtain the customer's acceptance of the needs
for ventilation system reliability (e.g., what is
the allowed break-off time).
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OCCUPATIONAL EXPOSURE LIMIT VALUES

• Setting OELs
• Types of OELs
• Assessment of exposure to chemical agents

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Calculation of the occupational exposure
concentration (OEC)
Calculation of the OEC depends on the type of
OEL. For example, when the limit value has been
set as an eight-hour time-weighted average, the
cumulative exposure for an eight-hour work shift
should be computed as follows
DE Sciti / Sti (c1t1 c2t2 ... cntn)/8,
where DE is the equivalent exposure for the
working shift, or daily exposure ci is the
concentration during any period of time t where
the concentration remains constant ti is
the duration in hours of the exposure at the
concentration ci When the limit value is a STEL
type, usually based on a 15-minute period, the
exposure concentration is
SE (Sciti)/15,
where ci is the measured concentration from
direct-reading instruments or from air samples
during a 15-minute period.
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Combined exposure
If workers are exposed simultaneously or
successively to more than one chemical agent, the
risk shall be assessed on the basis of the risk
presented by all such chemical agents in
combination. Usually, additive effects are
assumed for the mixture of chemical agents, so
the cumulative exposure is calculated as follows
E(m) S(DE/TWA)i (DE/TWA)1
(DE/TWA)2 ... (DE/TWA)n,
where E(m) is the equivalent exposure index for
the mixture DE is the daily exposure for
particular substance TWA is the OEL for that
chemical agent To comply with the OEL, the value
of the cumulative exposure index shall not exceed
unity.
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TARGET VALUES FOR THERMAL FACTORS AN OVERVIEW OF
INTERNATIONAL STANDARDS

• The thermal environment
• Moderate thermal environments
• Hot environments
• Cold environments
• Supporting standards
• Measurements on individuals
• Other and future standards

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Aims of the standard
Title of the document
Standard
ISO EN 11399 ISO 13731 ISO 7933 (EN
12515) ISO EN 7243 ISO EN 7730
Ergonomics of the thermal environment principles
and application of international standards
Ergonomics of the thermal environment vocabula
ry and symbols Hot environments analytical
determination and interpretation of thermal
stress using calculation of required sweat Hot
environments estimation of the heat stress on
working man, based on the WBGT index (wet bulb
globe temperature) Moderate thermal
environments determination of the PMV and PPD
index and specification of the conditions
for thermal comfort
General presentation of the set of standards in
terms of principles and application
Standardization of quantities, symbols and
units used in the standards Thermal stress
evaluation in hot environments. Analytical
method Diagnostic method for hot environments
Comfort evaluation in moderate environments
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Aims of the standard
Title of the document Standard

Thermal stress evaluation in cold environments
Data collection standards for metabolic rate
Requirements for measuring instruments Clothing
insulation Evaluation of thermal strain
using physiological measures Subjective
assessment of the thermal environment
Evaluation of cold environments determination of
required clothing insulation, I req Ergonomics
determination of metabolic heat
production Thermal environments instruments
for measuring physical quantities Estimation of
the thermal insulation and evaporative resistance
of a clothing ensemble Evaluation of thermal
strain by physiological measurements Assessment
of the influence of the thermal environment using
subjective judgement scales
ISO TR ENV 11079 ISO 8996 (EN 28996) ISO
7726 ISO EN 9920 ISO EN 9886 ISO EN 10551

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Aims of the standard
Title of the document Standard

Selection of an appropriate system of medical
supervision for different types of thermal
exposure Contact with hot, moderate and cold
surfaces Vehicle environments People with
special requirements Assessment of risk in
moderate, hot and cold environments Work
practice in cold environments
ISO DIS 12895 ISO CD 13732 NP 14505
ISO CD 14415 NP 15265 NP 15743
Ergonomics of the thermal environment medical
supervision of individuals exposed to hot or cold
environments Ergonomics of the thermal
environment methods for assessment of human
responses to contact with surfaces Evaluation
of the thermal environments in vehicles
Ergonomics of the thermal environment the
application of international standards for people
with special requirements Risk assessment
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Optimal operative temperature as a function of
clothing and activity
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Predicted percentage of dissatisfied (PPD) as a
function of predicted mean vote (PMV)
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DRAFT RATING
The percentage of people feeling draft (draft
rating, DR) may be estimated from the equation
DR (34-ta)(va-0.05)0.62(3.140.37 .
SDva), where va mean air velocity (3 min),
m/s SDva standard deviation of air velocity (3
min), m/s ta air temperature, C
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Three categories of thermal discomfort
Category
Thermal state of the body as a whole
Local discomfort (PDpercentage of dissatisfied)
PD due to draft (DR)
Predicted percentage of dissatisfied (PPD)
Predicted meanvote (PMV)
PD due to vertical air temperature difference
PD due to warm or cold floor
PD due to radiant asymmetry
A B C
lt6 lt10 lt15
-0.2 ltPMVlt 0.2 -0.2 ltPMVlt 0.2 -0.2 ltPMVlt 0.2
lt15 lt20 lt25
lt3 lt5 lt10
lt10 lt10 lt15
lt5 lt5 lt10
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Acceptable mean air velocity as a function of
local air temperature and turbulence intensity
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WBGT heat stress index
Index is calculated inside buildings and outside
buildings without solar load is
WBGT 0.7tnw 0.3tg
and outside buildings with solar load as
WBGT 0.7tnw 0.2tg 0.1ta
where tnw is the natural wet bulb temperature,
C tg is the temperature at the center of a 150
mm-diameter black globe thermometer, C ta
is the air temperature, C
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Reference values for WBGT (ISO 7243)
Metabolic rate, M
Reference value of WBGT
Related to a unit skin surface area (W/m2)
Total (for a mean skin surface area of 1.8m2) (W)
Person acclimatized to heat (C)
Metabolic rate class
Person not acclimatized to heat (C)
0 (resting) 1 2 3 4
M lt 65 65 lt M lt130 130 lt M lt 200 200 lt M lt
260 M gt 260
M lt 117 117 lt M lt 234 234 lt M lt 360 360 lt M lt
468 M gt 468
33 30 28
32 29 26
No sensible air movement
Sensible air movement
No sensible air movement
Sensible air movement
25 23
26 25
23 20
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Cooling power of wind on exposed flesh expressed
as a chilling temperature, tch, under almost calm
conditions
Wind speed (m/s)
Actual thermometer reading
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TARGET LEVELS FOR INDUSTRIAL AIR QUALITY

• Grounds for assessing TLs for industrial air
  quality
• Target levels for common contaminants
• Use of TLs

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Approaches for the assessment of target level air
quality
Health and comfort effects
Risk assessment approach
Target levels of indoor air quality
Technological approach
Air quality with standard technology
Air quality with advanced technology
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Target level categories of air quality
Contaminant concentration
Nonoccupied zone
OEL
Minimum industrial zone
General industrial level
Good industrial level
Special rooms
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A classification scheme of target levels for
common air contaminants in industrial settings
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Target level category
II. Good industrial level lt 0.5 lt 10 lt
2 lt 5 lt 0.2
I. Special rooms lt 0.011)

III. General industrial level 0.5 - 2.5 10
- 100 2 - 10 5 - 20 0.2 - 1
IV. Min. 2) industrial level 2.5 - 10 100 -
500 10 - 50 20 - 100 1 - 5
Contaminant Inorganic dust (mg/m3) Cr-(III)-c
ompounds (g/m3) Cr-(VI)-compounds
(g/m3) Nickel compounds (g/m3) Oilmist (mg/m3
)
1) As an example of special rooms, air quality
requirements in electronics work rooms according
to standard IEC 721-3-3 were used. 2) The
upper limit is the current OEL in Finland.
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Target level category
II. Good industrial level lt 0.1 lt 0.2 lt
3 lt 50 lt 12
I. Special rooms 0.023) lt 0.11) 101)

III. General industrial level 0.1 - 0.2 0.2
- 1.4 3 - 12 50 - 75 12 - 120
IV. Min. 2) industrial level 0.2 - 0.37 1.4 -
5.7 12 - 35 75 - 100 120 - 1200
Contaminant Formaldehyde (mg/m3) Nitrogen
dioxide (mg/m3) Carbonmonoxide (mg/m3) Ozone
(µg/m3) Acetone (mg/m3)
1) As an example of special rooms, air quality
requirements in electronics work rooms according
to standard IEC 721-3-3 were used. 2) The
upper limit is the current OEL in Finland. 3)
A premilinary proposal, based on the fact that 5
of the current concentrations of formaldehyde are
equal to or below this level.
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Target level category
I. Special rooms
II. Good industrial level lt 2 lt 10 lt 5 lt
5 lt 5 lt 1
III. General industrial level 2 - 20 10 -
100 5 - 50 5 - 40 5 - 40 1 - 20
IV. Min. 2) industrial level 20 - 150 100 -
1200 50 - 500 40 - 190 40 - 440 20 - 86
Contaminant Butanol (mg/m3) Aliphatic mineral
spirits (mg/m3) Isopropanol (mg/m3) Toluene
(mg/m3) Xylenes (mg/m3) Styrene (mg/m3)
2) The upper limit is the current OEL in
Finland
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Target level category
I. Special rooms
II. Good industrial level 0.1.OEL
III. General industrial level 0.1.OEL -
0.25.OEL
IV. Min. 2) industrial level lt OEL
Contaminant General model for other
contaminants
2) The upper limit is the current OEL in
Finland
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REQUIREMENTS DUE TO BUILDING CONSTRUCTION, EQUIPME
NT, PROCESSES, AND TYPE OF PRODUCTION PREMISES

• Ventilation parameters that influence the
  building
• Construction and process desing
• Building and process parameters that influence
  the
• ventilation system

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Building Ventilation Process
Humans Equipment Outdoor environment
Relationship of the items in assessing target
levels
Outdoor environment - Emissions Immissions
Emissions Immissions - Emissions Immissi
ons -
Equipment - Corrosion Materials Corrosion
Materials - - Layout
Building - Corrosion Materials Pressure
difference Corrosion, Materials, Life cycle,
Heavy loads, Layout, Air tightness, Orientation,
Openings Layout Openings Heavy
loads Materials Materials Insulation Heating
/Cooling
Ventilation - - IAQ
Corrosion Materials, Life cycle, Layout, Air
tightness, Air distribution, Heating
cooling Heating cooling Thermal targets Air
distribution IAQ targets Thermal
conditions IAQ Heating cooling Heating
cooling Air distribution
Process Tightness Corrosion Thermal
conditions Materials Openings Tightness - -
- Emissions Immissions
Humans - Comfort IAQ Comfort IAQ -
- -
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Simplified table of building parameters that
influence the ventilation system
Building parameter Large Variable
Small Wall, ceiling materials I,
II III IV,
V Tightness I, II
III-V Windows I, II
III IV, V Fire and waste
systems I II, III
IV, V Building orientation I
II III-V Openings
(doors, air intakes, etc.) I-III
IV, V Energy system
I, II III IV, V
Numbers refer to the target level classes
presented in chapter 6.4.
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Simplified table showing how parameters, mainly
of the ventilation system, influence the building
and process
Ventilation parameter Large
Variable Small Temperature limits
I, II
III-V Humidity levels I, II
III, IV V Air velocities
I
II-V Airflow rate I
II-IV V Contaminant
concentration I,II III
IV, V Mechanical load (including
pressure I-II II, III
IV, V
difference) Equipment demands I
II-V
Numbers refer to the target level classes
presented in chapter 6.4.