study on occupational safety & health associated spray painting
TRANSCRIPT
i
STUDY ON OCCUPATIONAL SAFETY & HEALTH ASSOCIATED SPRAY
PAINTING ACTIVITIES AT FURNITURE INDUSTRY
AZMARINI BINTI AHMAD NAZRI
A Master’s Project Report submitted in fulfilment of the requirement for the
award of the
Master of Mechanical Engineering
Faculty of Mechanical and Manufacturing Engineering
Universiti Tun Hussein Onn Malaysia
JULY 2015
v
ABSTRACT
There were much study reported that the operational work of spray painting process involves
the use of hazardous and highly toxic chemical such as paint and solvent. Hence, the issue
become a conflict that concern not only about the occupational safety and health of the workers
but also on protecting the environment as well. In a Small and medium (SME) scale spray
painting process, therefore, proper safety and health risk management with an efficient
engineering control such as ventilation system must be provided for human health. In this
study, Hazards Identification, Risk Assessment and Risk Control (HIRARC) method with
chemical monitoring was implemented and three suggested CFD based modelling of
ventilation system have been analysed in a paint spray booth of a SME scale spray painting
process. Based on HIRARC, the overall risk level at the selected spray painting working area
can be classified to be at MEDIUM level due to lack of awareness among workers on
practicing safe working procedures in workplaces. Based on chemical monitoring analysis,
Toluene chemical exposure concentration was high while concentration of Xylene and
Paraffin was measured lower than Permissible Exposure Limits (PEL) of USECHH.
For CFD based modelling of ventilation system, the inclusion of ventilation system has
been shown to improve the indoor air velocity with variation of 0.3 – 1 m/s and reduced
chemical concentration in the working area. The result shows that careful design of
work space is needed to maintain allowable concentration, which may depend on the
position of inlet and outlet. Sufficient exhaust flow rate and inlet velocity also
influences the effectiveness of ventilation system.
vi
ABSTRAK
Terdapat banyak kajian menyatakan bahawa operasi kerja semburan cat melibatkan
penggunaan bahan kimia berbahaya dan toksik seperti cat dan pelarut. Oleh demikian,
isu ini telah menjadi konflik yang membimbangkan bukan sahaja mengenai
keselamatan dan kesihatan pekerja tetapi juga dari segi melindungi persekitaran.
Dalam industri semburan cat berskala kecil dan sederhana (IKS), pengurusan risiko
keselamatan dan kesihatan yang baik serta kawalan kejuruteraan yang cekap seperti
sistem pengudaraan perlu disediakan untuk kesihatan manusia. Dalam kajian ini,
kaedah Pengenalpastian hazad, Pentaksiran Risiko dan Pengawalan Risiko (HIRARC)
beserta pemantauan bahan kimia telah dilaksanakan dan tiga permodelan CFD bagi
sistem pengudaraan telah dianalisis dalam bilik penyemburan cat berskala kecil dan
sederhana. Berdasarkan HIRARC, tahap risiko keseluruhan di kawasan kerja
semburan cat yang dipilih boleh diklasifikasikan berada pada tahap SEDERHANA
kerana didapati kesedaran di kalangan pekerja untuk mengamalkan prosedur kerja
yang selamat berada pada tahap yang rendah. Berdasarkan analisis pemantauan bahan
kimia, kepekatan pendedahan Toluene adalah tinggi manakala kepekatan Xylene dan
parafin diukur lebih rendah daripada Tahap Pendedahan Dibenarkan (PEL)
berdasarkan USECHH. Untul permodelan CFD bagi sistem pengudaraan, penggunaan
sistem pengudaraan telah terbukti untuk meningkatkan halaju peredaran udara dengan
kadar 0.3 – 1 m/s dan mengurangkan kepekatan bahan kimia di kawasan kerja. Hasil
kajian ini juga menunjukkan bahawa reka bentuk ruang kerja yang teliti mungkin
bergantung kepada kedudukan laluan masuk dan laluan keluar bagi mengekalkan tahap
kepekatan bahan kimia berada pada tahap yang dibenarkan. Kadar aliran keluar dan
masuk yang mencukupi turut mempengaruhi keberkesanan sistem pengudaraan.
vii
CONTENTS
TITLE i
DECLARATION ii
DEDICATION iii
ACKNOWLEDGEMENT iv
ABTRACT v
LIST OF TABLES x
LIST OF FIGURES xii
LIST OF SYMBOLS AND ABBREVIATIONS xv
LIST OF APPENDICES xvi
CHAPTER 1 INTRODUCTION 1
1.1 Project background 1
1.2 Problem statement 2
1.3 Objectives of the study 3
1.4 Scope of the study 3
1.5 Research question 3
1.6 Significant of study 4
CHAPTER 2 LITERATURE REVIEW 5
2.1 Introduction 5
2.2 Types of paints 5
2.3 Health hazards during spray painting activities 6
2.3.1 Volatile Organic Compound (VOC) 7
viii
2.4 Chemical exposure monitoring during paint spray
activities
8
2.5 Hazard identification and risk assessment 10
2.6 Ventilation system 11
2.7 Computational Fluid Dynamics (CFD) modelling
on spray painting ventilation system
13
2.8 Regulation on chemical hazardous exposure 18
2.9 Spray painting equipment 20
2.9.1 Spray painting booth 20
2.9.1.1 Downdraft booth 22
2.9.1.2 Semi-downdraft booth 23
2.9.1.3 Cross draft booth 23
2.9.2 Spray gun 24
2.9.2.1 Conventional Air Spray Guns 24
2.9.2.2 High Volume Low Pressure
(HVLP) Spray Guns
25
2.9.2.3 Low Volume Low Pressure
Spray Guns
26
2.9.2.4 Electrostatic Spray Guns 26
2.9.3 Compressed Air Supply 27
2.10 Personal protective equipment (PPE) 27
CHAPTER 3 METHODOLOGY 29
3.1 Introduction 29
3.2 Research flow chart 29
3.3 Industrial visit / Walkthrough Inspection 31
3.3.1 HIRARC method
31
3.3.2 Chemical monitoring 35
ix
3.4 Modelling ventilation system using Computational
Fluid Dynamics (CFD).
39
3.4.1 Introduction to CFD 39
3.4.2 Research model 41
3.4.2.1 ANSYS design modeller 41
3.4.3 Problem formulation 43
3.4.4 Meshing 43
3.4.5 Governing equation 44
3.4.6 Boundary condition 46
CHAPTER 4 RESULTS AND DISCUSSION 47
4.1 Introduction 47
4.2 Results and Discussion 48
4.2.1 Industrial visit / walkthrough inspection 48
4.2.1.1 Industry detail of Wasaniaga
Sdn. Bhd.
48
4.2.1.2 Personal Protective Equipment
(PPE)
48
4.2.1.3 Hazard identification, risk
assessment and risk control
(HIRARC)
49
4.2.1.4 Chemical Exposure Monitoring 59
4.2.2 Modelling ventilation system using
Computational Fluid Dynamics (CFD)
67
4.2.2.1 Paint spray booth without
ventilation system
68
4.2.2.2 Paint spray booth with
ventilation system
69
CHAPTER 5 CONCLUSSION 74
5.1 Introduction 74
5.2 Conclusion 75
REFERENCES 76
x
LIST OF TABLES
2.1 Types of organic and inorganic compounds
include in industrial paint
6
2.2 USECHH limits 19
2.3 Exposure limits of certain types of solvent used in
spray painting industries 19
2.4 USGIH spray booth design criteria 21
2.5 OSHA spray booth design criteria 21
2.6 Air change every hour for an adequate ventilation
by USECHH
22
2.7 List of Personal Protective Equipment (PPE) used
during paint spray process
28
3.1 Classification of hazards 32
3.2 Likelihood rating 34
3.3 Severity rating 34
3.4 Risk Matrix 34
3.5 Summary of NIOSH 1501 method 38
3.6 Number of element and node 44
3.7 Boundary condition 46
4.1 Industry detail of Wasaniaga Sdn. Bhd.
48
4.2 Personal Protective Equipment (PPE) checklist 49
4.3 HIRARC at spray painting area 50
4.4 Work activities and hazards classification risk
level
55
4.5 Risk range 56
xi
4.6 Environmental factor of Chemical Exposure
Monitor
59
4.7 Methodology and regulation of chemical being
monitored
60
4.8 Data for Chemical Exposure Samplings with
Result
60
4.9 USECHH Permissible Exposure Limits (PEL) 61
4.10 Summary of chemical monitoring results 65
xii
LIST OF FIGURES
2.1 Different orientation of paint spray worker in cross
draft ventilation studied by Flynn et al (1999)
13
2.2 A schematic diagram of the case of ventilation
method: (a) Displacement and (b) mixing studied
by Bin et al (2003)
14
2.3 The velocity distribution for the two cases of
ventilation method (a) displacement; and (b)
mixing studied by Bin et al (2003)
15
2.4 Schematic diagram of the 2D room studied by Kim
et al (2002)
16
2.5 Toluene concentration in some case studied by
Kim et al (2002)
16
2.6 Downdraft paint spray booth modelling studied by
Li et al (2013)
17
2.7 Averaged VOCs concentration inside the different
case of paint spray booth studied by Li et al (2013)
18
2.8 Downdraft air booth 22
2.9 Semi-downdraft air booth 23
2.10 Cross draft air booth 23
2.11 Conventional air spray gun 25
2.12 High Volume Low Pressure (HVLP) spray gun 25
2.13 Low Volume Low Pressure (LVLP) spray gun 26
2.14 Electrostatic Spray Guns spray gun 26
2.15 Compressed Air Supply 27
3.1 Research flow chart 30
xiii
3.2 Schematic diagram of spray painting area at
Wasaniaga Sdn. Bhd.
31
3.3 Production flow process at spray painting area 32
3.4 Flow Chart of Risk Assessment 32
3.5 The separation flow in Gas Chromatograph 36
3.6 Parts in Gas Chromatograph 36
3.7 Diagram of Flame Ionization Detector (FID) 37
3.8 Steps involve in CFD modelling 40
3.9 Schematic diagram of downdraft ventilation by
using Design-modeller
41
3.10 Schematic diagram of semi downdraft ventilation
by using Design-modeller
42
3.11 Schematic diagram of cross draft ventilation by
using Design-modeller
42
3.12 Meshing of spray painting booth 44
4.1 Hazards risk rating based on work activities 56
4.2 Concentration of toluene for both similar and zero
exposure
65
4.3 Concentration of xylene for both similar and zero
exposure
66
4.4 Schematic diagram of the paint spray booth 67
4.5 Air velocity distribution at paint worker zone in
paint spray booth without ventilation system
68
4.6 Contour of air velocity for paint spray booth
without ventilation on the x-y plane
69
4.7 Air velocity distribution at paint worker zone in
paint spray booth with ventilation system
70
4.8 Contour of air velocity for paint spray booth with
(a) Downdraft (b) Cross draft (c) Semi downdraft
ventilation system on the x-y plane
71
xiv
4.9 Contour of VOCs concentration for paint spray
booth with (a) Downdraft (b) Cross draft (c) Semi
downdraft ventilation system on the x-y plane
72
4.10 VOCs concentration at paint worker in paint spray
booth with ventilation system
73
4.11 Air velocity distribution at paint worker zone in
paint spray booth with cross draft ventilation
system
73
xv
LIST OF SYMBOLS AND ABBREVIATIONS
Vs - Volume in Standard Temperature and Pressure
P1 - Pressure at Calibration Lab
P2 - Pressure at Site
T1 - Temperature at Calibration Lab
T2 - Pressure at Site
TWA - Time Weighted Average
ppm - part per million
PPE - Personal Protective Equipment
PEL - Permissible Exposure Limit
USECHH - Use and Standard of Exposure of Chemicals Hazardous
to Health
DOSH - Department of Occupational Safety and Health
OSHA - Occupational Safety and Health Administration
NIOSH - National Institute for Occupational Safety and Health
ACGIH - American Conference of Governmental Industrial
Hygienists
CFD - Computational Fluid Dynamics
xvi
LIST OF APPENDICES
APPENDIX TITLE PAGE
A Gantt chart for master project 1 81
B Gantt chart for master project 2 82
C HIRARC guideline 83
CHAPTER 1
INTRODUCTION
1.1 Project background
In the last few decades, Malaysia has witnessed rapid development in the
manufacturing sector compared with other countries of ASEAN. With the
development and proliferation on this industry, it shows growth trend of the businesses
that dedicated to maintenance, repair and customization. Today, there are thousands of
small to medium sized shops that using paint spray system all across the Malaysia.
One of the major activities is spray painting of vehicles, furniture, and etc. which lead
the workers exposes to paint hazards. Some survey conducted by Environmental
Protection Agency (EPA) (2011) shows that the major operational work of paint spray
shop involves the use of hazardous and highly toxic such as paint and solvent.
According to Liu et al. (2006) because of lack of knowledge and managing resources
on these paint spray shop, there were some problem occur during on handling and
dispossess those harmful substances. Hence, the issue become a conflict that concern
not only about the occupational health and safety of the workers but also on protecting
the environment as well. To protect the workers from harmful substances generated
from spray paint operation, employers need to provide suitable Personal Protective
Equipment (PPE) and engineering control method such as a spray booth; a ventilation
system which is necessary for removing the paint particles and hazardous compound
contained air continuously into the drain system. A study conducted by Heitbrink et
al. (1995) in auto body repair shops found that the type of spray painting booth and the
choice of spray painting gun can be used to minimize worker exposure to paint
overspray. There are few types of ventilation system such as downdraft booths, semi-
2
downdraft booths, cross draft booths and etc. There were few types of spray gun used
in paint spray shops which is a manual process where painters use spray guns to apply
successive coats of paint. Manual paint spray method often used in small to medium
size industry due to irregularly shaped of parts to be paint.
In this research, focused were more on how to control and minimizing the
chemical exposure during paint spray activities through industrial visit, Hazard
Identification Risk Assessment and Risk Control (HIRARC) method, chemical
monitoring and CFD based modelling of paint spray ventilation system. For CFD
based modelling, concentration were on three types of ventilation system namely
downdraft, cross draft and semi downdraft paint spray booth involved the conventional
spray gun to predict the relationship of ventilation system with airflow pattern inside
paint spray booth.
1.2 Problem statement
There were much study reported that Volatile Organic Compounds (VOCs) affect
human health and productivity in a significant way. During spray painting process, a
number of cross-sectional surveys have detected that large proportions of the
population suffer from eye and respiratory discomfort, headaches and feelings of
lethargy in industrial sites of painting process with poor indoor air quality (Kim et al.,
2000; Feldman et al., 1999). Therefore, regulations are required for controlling organic
vapour pollutants in air and also from an environmental point of view it is necessary
to control and limit vapour emissions. Occupational exposure to hazardous
contaminants is the main concern for the employee despite a small numbers of workers
in Small and Medium Enterprise (SME). Therefore, providing a systematic hazards
risk management and proper ventilation system can reduce the effect of VOCs. Even
though there is much study of mechanism to control the exposure from harmful
substance among workers, it is necessary to optimize the design and the operation
parameters to meet the environmental requirement. In this study focus were on
identifying the chemical hazards associated with spray painting activities and finding
alternative solutions by the development of ventilation system in the spray booth by
using CFD software.
3
1.3 Objectives of the study
This research in concentrating on how to control and minimizing the chemical
exposure during spray painting activities such as:
i. To identify and evaluate the hazards that exposed to workers in furniture
industry.
ii. To determine the chemical exposure of common chemical used in
furniture industry.
iii. To suggest an efficient engineering control by introducing ventilation
system using CFD based modelling.
1.4 Scope of the study
The scopes of the study are as follows:
i. Study are based on small or medium scale of furniture industry.
ii. HIRARC method was implemented at Wasaniaga Sdn. Bhd.
iii. Chemical monitoring were on Toluene, Xylene and Paraffin at Wasaniaga
Sdn. Bhd.
iv. Used of Fluent ANSYS software in analysis.
v. CFD 3D modelling of paint spray booth and simulation on steady state
condition
vi. The exposure is limited to toluene as solvent for spray painting activities in
CFD modelling.
1.5 Research question
i. What are the hazards associated during paint spray activities?
ii. How do the different types of ventilation system affect the airflow pattern
and level of concentration inside paint spray booth?
4
1.6 Significant of study
These study focusses on minimization of chemical hazardous during spray painting
activities. Combination of hazards risk management and efficient engineering control
was identified as effective way on reducing the occupational exposure. Focus were on
spray painting activities at furniture industry. This industry is normally used manual
paint spray without proper mitigation method such as ventilation system and expected
to promote an effective ways to reduce occupational exposure among workers. The
results of the industrial visit through HIRARC and chemical monitoring are beneficial
in designing of safe spray painting operation procedures among painters which can be
adopted by employer especially in SME painting shop. By identified the best
ventilation technique, these results also motivate the industry for making a good
decision in selection of spray booth especially in Malaysia.
CHAPTER 2
LITERATURE REVIEW
2.1 Introduction
This chapter review the literature and current study related to spray painting activities
and sources that contribute exposure to chemical hazards among spray paint workers.
This chapter also looks into how to controlling and minimizing the chemical exposure
by using HIRARC method, chemical monitoring and suggestion of ventilation system
using CFD modelling. Any relevant ideas related to the research help to provide better
understanding towards achieving the improvement of the study. This topic highlight
more on types of paints, health hazards during spray painting activities including sub
topics of Volatile Organic Compounds (VOCs), chemical exposure monitoring during
paint spray activities, hazard identification and risk assessment, ventilation system,
Computational Fluid Dynamics (CFD) modelling on spray painting ventilation system
and regulation on chemical hazardous exposure. On the other hand, spray painting
equipment also will be discussed.
2.2 Types of paints
Paints is a type of polymeric material and can be categorized into two groups: organic
solvent-soluble and water-soluble. The organic solvent soluble paints contain
substances that can be evaporate into air such as fungicides, pesticides, preservatives,
foam control agents, acrylic resins, isocyanides and formaldehyde. Conventional
organic solvent-based paints contain approximately 50% of petroleum based solvents,
while conventional water-based paints contain only 7%. Water-based paints consist of
6
a variety of chemicals such as glycols that dispersed in water. Since the 1970s, there
have started research in development a new group of paints which more environmental
friendly. They try to reduce the liability of petroleum and its industrial by-products to
these new invention of paint used natural ingredient that derive from plant, natural
resins and waxes, earth and mineral colour. From that is suggested that natural paint
products may have less emission problems. (Livos, 1996)
2.3 Health hazards during spray painting activities
Most substances in paint contain toxic material that contribute to health hazard to the
users. During spraying activities paint mists spread out the volatile matters to the
surrounding air. Table 2.1 show certain types of organic and inorganic compounds
include in industrial paint.
Table 2.1: Types of organic and inorganic compounds include in industrial paint
Compound Description
Toluene - Toluene or methylbenzene is a colourless, flammable, volatile liquid with a
distinctive aroma. Toluene is found in gasoline, acrylic paints, varnishes,
lacquers, paint thinners, adhesives, glues, rubber cement, airplane glue, and
shoe polish. At room temperature, toluene is a colourless, sweet smelling, and
volatile liquid.
- Permissible exposure limit = 100 ppm / 0.05 mg/m3 based on eight hour time
weighted average (OSHA, 2012a):
Chromium - Chromium has many different forms including hexavalent chromium, a well-
known carcinogen. Examples of paints pigments containing hexavalent
chromium are zinc chromate and lead chromate, also known as chrome yellow
and chrome green. According to the Agency for Toxic Substances and Disease
Registry (ATSDR.,. 1989), the risk of developing lung cancer depends on the
amount of chromium in the air, duration of exposure and the use of personal
protective equipment (PPE).
- OSHA has set the permissible exposure limit for cadmium at 5 µg/m3 (OSHA,
2012i).
Xylenes - Xylene is solvent that can be found in thinners, basecoats, clear coats, and
primers. Xylenes are released into the atmosphere as fugitive emissions from
7
industrial sources, from auto exhaust, and through volatilization from their use
as solvents. Commercial or mixed xylene usually contains about 40-65% m-
xylene and up to 20% each of o-xylene and p-xylene and ethyl-benzene.
- OSHA and NIOSH have both set the maximum amount of xylene allowed in
the air during an eight hour workday to be 100 ppm (OSHA, 2012b)
Ethyl-benzene - Ethyl-benzene is mainly used in the manufacture of styrene. Occupational
exposure to ethyl-benzene occurs in factories that use ethyl-benzene to produce
other chemicals; for gas and oil workers; and for varnish workers, spray
painters, and persons involved in gluing operations.
- The permissible exposure limit for ethyl-benzene established by both OSHA
and NIOSH is 100 ppm (OSHA, 2012c)
Lead - It is classified as a toxic metal, cumulative poison and ability to cause a number
of adverse health effects. This exposure can result in an array of harmful
outcomes, from nervous system and cardiovascular effects, to decreased kidney
function, brain damage, reproductive problems such as miscarriage, and
anemia.
- The permissible exposure limit determined by both OSHA and NIOSH is no
more than 0.05 milligrams per cubic meter (mg/m3) of lead in the air over an
eight hour period (OSHA, 2012i).
2.3.1 Volatile Organic Compound (VOC)
VOC is an organic compound that evaporates easily. VOC contributes to the ozone
and smog formation. Fumes that are coming from industrial practice including paints,
welding and printing activity contain significant amount of VOCs (Yuan, 2004). A
high concentration of contaminant produced in vapours are depending on the type of
the spray gun used, the pressure and the nebulizer. Those contaminant especially
produced by solvent is harmful to human health when inhaled. But even now several
hundred million tonnes of solvents are used annually throughout the world. Based on
U.S Department of Health and Human Services data, (1992); solvent such as Volatile
Organic Compound (VOCs) produced or used in paint industries have been associated
with effects in a number of organs like lungs, skin, eyes, neurological system, heart,
gastro-intestinal system, kidney and reproductive system. VOCs present as vapours at
room temperature and comprise a wide variety are hydrocarbons and hydrocarbon
derivatives, including aliphatics, aromatics, alkylbenzenes, ketones, and chlorinated
and polycyclic hydrocarbons. According to Oanh & Hung (2005) through sampling
method, VOCs are defined as organic compounds that have a lower boiling point and
8
upper boiling point limit between 50C - 100C and 240C - 260C respectively. They
also conclude that common organic pollutant level were found to be two to five time
higher in indoor compare to outdoor.
2.4 Chemical exposure monitoring during paint spray activities
There are few method that have been done by researcher to investigate and predict the
exposure of paint solvent. Through multivariate regression models Qian et al (2010)
conclude that this method could be used to predict solvent exposure during bridge
painting. He concentrate on study of the relationship between air concentrations of
VOCs during bridge painting and potential influencing factors. Bunkuea et al (2014)
studied about occupational exposure of Toluene in wood furniture manufacturing.
NIOSH method 1501 and research questionnaire was used for sample collection and
analysis. This study showed that even if the workers are not exposed to the high
concentration of toluene, this chemical can be accumulated in their bodies which might
lead to many adverse health effects. Therefore, the employers should give attention to
the toluene exposure in order to decrease the health risk of their workers. Kim (2011)
also conducted a workplace walk-through survey and experimental analysis of
hexavalent chromium to a 46-year-old man who had worked as a bumper spray painter
in an automobile body shop for 15 years developed lung cancer and provided the
results of an exposure analysis conducted to determine the lung cancer carcinogen
They were assessed the level of exposure to carcinogens during spray painting,
sanding, and heat treatment. For spray painting, they only focus on two types of paint:
one type was classified as “normal paint” and the other was eco-friendly paint. The
results showed that spray painting with normal paint increased the concentration of
hexavalent chromium in the air to as much as 118.33 mg/m3.
There were certain type of chemical involved named hexane, benzene, toluene,
ethylbenzene, m,p-xylene, o-xylene, styrene, tetrachloro-ethylene (PCE),
trichloroethylene (TCE), 1,2-dichloroethane (EDC), 1,2-dichloropropane (DCP),
chloroform, and limonene during indoor investigation of office building in Bangkok
conducted by Ongwandee et al (2011). He try to quantify levels and source strengths,
and determining indoor/outdoor relationships. The results demonstrate that many air-
conditioned office buildings have very low ventilation rates, which could be due to
energy conservation measures enacted in Thailand.
9
Wilson et al (2007) conducted a study in the vehicle repair industry to quantify
exposures to VOCs such as hexane, acetone, and toluene during typical vehicle repair
tasks among workers. By using a statistical method, the results shows that there is a
correlation between the task-based solvent emission rate (g/min) and the breathing
zone VOC’s exposure concentration (mg/m3) (R2= 0.45). From the study, he conclude
that the characteristic pattern of aerosol solvent use that is largely independent of the
task type, shop, or individual. The other study also concerning on Toluene or
methylbenzene which is commonly used as a solvent. Health affects exposed with
toluene such as drowsiness, dizziness, headache, nausea, and loss of coordination,
confusion and unconsciousness. Liu et al (2007) conducted a review online and
manual searching, as well as expert discussions aimed at providing insight into factors
affecting benzene exposure levels in paint/coatings industries from 1956 to 2005 and
found mean benzene exposure was significantly lower for paint manufacturing than
paint spraying. He found that there is no significant difference among paint types and
benzene exposure for paint application. Because of poor ventilation, the exposure of
benzene in workplace was significantly higher.
Another survey conducted by Enander, Gute & Missaghian (1998) focus on
how to prevent and control the hazards in spray painting activities. From a survey of
pollution prevention, environmental control, and occupational health and safety
practices on the use of spray paint booth in auto shops, he found that only 38% of
downdraft booth are effective and will affected workers during spray paint activity.
Pronk et al, (2006) study on inhalation and dermal exposure to hexamethylene
diisocyanate (HDI) and its oligomers in refinishing industry sector of the Rhode Island.
As a result he found that the painter and also as a repair technician have a highly
potential exposure to workplace contaminant because of their double work. The result
shows inhalation exposure was strongly associated with tasks during which
aerosolisation occurs. Dermal exposure occurred during tasks that involve direct
handling of paint.
Olufunsho et al (2014) conducted survey through questionnaire and
experiments to the 400 selected paint workers in Nigeria. They focus on the awareness
of occupational safety and mass concentration of heavy metals in the urine samples.
The results show that 72.5% of the respondents are aware of the hazards associated
with their jobs; 30% have had formal training on hazards and safety measures; 40%
do not use personal protective devices, and 90% of the respondents reported symptoms
10
relating to hazard exposure. From the study, they conclude that a lack of adequate work
safety practices in the paint factories become the major causes that associated to the
increases of the occupational hazards.
Other study in Australia conducted and found that solvent exposure are relate
with Spray Painters in repair workshop by Winder & Turner, (1992). They interviewed
to 50 apprentices and 14 experienced spray painter at breathing-zone samples. They
found that solvent exposure was highest when spraying acrylic paint in the open
workshop and lowest when spraying two pack paint in a spray booth. In conclusion,
workers who involve in spray paint activity are closely exposed to chemical hazards
emission. Workers are exposed to chemical can cause harm. There are the available
evidence indicates that VOCs can cause adverse health effects to the building
occupants and may contribute to symptoms of Sick Building Syndrome investigated
by Yu & Crump, (1998).
2.5 Hazard identification and risk assessment
Risk assessment and evaluation is not something new. Risk assessment is used in
decision making processes that could impact the society as a whole. According to
Hubbard (2009) risk management is the identification, assessment, and prioritization
of risks followed by coordinated and economical application of resources to minimize,
monitor, and control the probability and/or impact of unfortunate event. The definition
given by Hubbard is the basic framework for any risk assessment exercises. A report
by National Research Council (NRC) in 1983 became of one of the founding basis for
the four step risk assessment procedure, e.g. hazard identification and characterization
followed by exposure assessment and risk characterization. In the field of occupational
safety and health, a popular risk assessment tool is HIRARC (Hazard Identification,
Risk Assessment and Risk Control). HIRARC is used to identify and control the risks
associated with hazards in the workplace. Employers often use this tool as part of the
meeting the occupational safety and health requirements in the workplace. HIRARC
has proved to be an indispensable tool in the prevention of workplace accidents. The
initial starting point for a risk assessment exercise would be the identification of
hazards in the workplace. Hazard is defined as condition or a situation that could
potentially cause harm to personnel, property and environment or a combination of
these (DOSH, 2008). Identification of hazards is an important step in a risk assessment
11
exercise and it needs to be performed carefully. More often than not, hazards in the
workplace are not readily apparent. Hazard identification needs to be performed in a
team to ensure that most, if not all, the hazards are identified. According to Maragakis
et al (2009), hazard identification can be performed by individuals or in a team, but
both has its own advantages and disadvantages. Individual identification of hazards
will require a strong technical experience in detecting hazards, but the results of the
identification may be questionable as it may not be comprehensive. Hazard detection
in a team combines years of technical experience of many individuals, but “peer
pressure” may contaminate the results. After the identification of hazards, the
quantification of risk is necessary for the purpose of knowing the likelihood of the
hazard to occur as well as its severity. Each numbers assigned to likelihood and
severity will have distinct meanings of its own. For example, a value of 5 indicates the
highest likelihood of an accident to occur. Criticisms have been directed to the
numerical values assigned to the likelihood and severity.
2.6 Ventilation system
The ventilation system of building is used to maintain indoor air quality and thermal
comfort. In order to attain these objectives, airflow rate should be controlled. The
minimal airflow rate is determined by indoor air quality requirements so that the
maximal concentration for every pollutant is lower than the maximum admitted. There
are two types of common ventilation include mechanical ventilation and natural
ventilation. Mechanical ventilation is performed and forced by influence of blowers or
fan. Natural ventilation, on the other hand is due to the movement of air by natural
forces. Exhaust ventilation can be divided into two group, namely as;
i. General exhaust system
ii. Local exhaust system
General exhaust is used to remove contaminants in certain spaces by flushing
out a given space with a large quantities of air. Apart, general exhaust is used as heat
control in the area. Meanwhile, local exhaust system operate on the principle of
capturing contaminant at or near source (ACGIH, 1998). To create safe and healthy
working environment, both particulate matter and gaseous contaminant need to be
removed. Somehow, filters and air cleaners only remove particulate matter from the
12
air, but ineffective for gaseous contaminant (ACGIH, 1998; E.Mull, 1998). By
combining ventilation and filtration, it is believed to be the best method to control
indoor air contaminant.
One of the criteria to be measured to control the ventilation is air per change
per hour (ACH). Any room or occupied spaces must meet ventilation requirement of
ACH to control IAQ (Rim & Novoselac, 2010). ACH depends on the room size and
its function or its specific requirement. Ventilation refers to the exchange of air inside
any rooms or spaces to make sure the rooms have enough fresh air circulation. To
ensure the space or room have good IAQ, they must be equipped with appropriate
ventilation system and proper maintenance of the system. Reducing ventilation rate
will cause IAQ to be reduced from optimum quality (Memarzadeh, 2009). A study
conducted by Christhina et al (2008) stated that, indoor air speed should be set between
0.2 - 1.50 m/s to provide comfort condition in the occupied spaces through ventilation
system especially in hot humid climate condition. In industry plants or certain industry,
the supply system is used to supply air to work space, meanwhile, exhaust system is
used to remove contaminants generated by the operation in order to maintain a healthy
work environment (ACGIH, 1998; Peter Rojeski, 1999). The most effective way to
reduce the risk of atmospheric pollution is to enclose entire process and may be
impossible. Then, another way is to extract the polluted air from the space. Extraction
and encapsulation usually need to be supplemented by good ventilation and airflow. A
complete ventilation system usually should consider both the supply and exhaust. This
research will looking at the ventilation system in printing industry to enhance the
quality of air in printing environment. Ventilation rate formula is application to
measure actual and required ventilation and to good IAQ (ASHARE, 2009).
An efficient ventilation system can be define as the one which can provided a
good and healthy environment with adequate indoor air quality and comfortable indoor
condition with sufficient low energy consumption. The effectiveness of a ventilation
system is mainly determined by (a) the removal of internally produced contaminants
from the room and (b) the supply of fresh air of acceptable quality in the room.
According to Tabor et al. 2012; an investigation of the air quality in the paint spray
booth requires an understanding of the complex fluid flow phenomena in the occupied
space of the ventilation air, for which finite difference based and computational fluid
dynamics (CFD)-based modelling and simulation are suitable techniques.
13
2.7 Computational Fluid Dynamics (CFD) modelling on spray painting
ventilation system.
Flynn et al (1999) develop a CFD model of the cross draft ventilation booth to
predict concentrations of airborne contaminants in breathing-zone generated during
spray process with different orientation of 90 and 180 degree as shown in figure 2.1.
Figure 2.1: Different orientation of paint spray worker in cross draft ventilation
studied by Flynn et al (1999)
He simulate breathing zone concentration in a simple process of painting a flat plate.
The results show that a dimensionless breathing zone concentration is a nonlinear
function of the ratio of momentum flux of air from the spray gun to the momentum
flux of air passing through the projected area of the workers body. The results also
shows that CFD significantly as a suitable tool to determining exposure.
Bin et al (2003) compare the air flow and aerosol particle concentration
between displacement and mixing ventilation by using numerical method. A discrete
trajectory approach which is lagrangian method is employed in the particle trajectory
model. The lagrangian approach splits the particle phase into a representative set of
individual particles and tracks these particles separately through the flow domain by
solving the equations of particle movement. The following assumptions are used:
i. Heat and mass transfer between air and particles are neglected;
ii. No particle rebounds on solid surfaces, such as walls, floors and ceilings;
iii. No particle coagulation in the particle deposition process;
iv. All particles are in spherical solid shape.
14
The initial conditions for particle tracking include the starting positions and
initial velocities of particles. For this study, the particles are assumed to have the
density of the oil smoke particle, i.e. =850 kg/m3. Particles are equally divided into
four size groups of 1, 2.5, 5 and 10 µm. These sizes are of special interest for indoor
air quality since they are known as inhaled particles. To compare the particle
movement and distribution, particles are assumed to be uniformly distributed in the
room for this study. Therefore, the initial positions of particles are set up in the whole
volume of the room and the particle mass is uniformly carried by each size group. To
compare the indoor particle concentration and deposition, a full-scale room with two
different ventilation methods which is displacement and mixing method. The room
geometry scale is 5.16 m × 2.43 m × 3.65 m. The mixing and displacement case is
ventilated by one grille diffuser on a side wall. Figure 2.2 gives the schematic of the
two cases.
Figure 2.2: A schematic diagram of the case of ventilation method: (a) Displacement
and (b) mixing studied by Bin et al (2003)
As the result, they found that the air in the mixing ventilation room is better
mixed than the displacement one and the temperature is more uniform which is
influences the movement of particles show in Figure 2.3. So because of that scenario,
the airflow pattern of displacement ventilation causes large number of particles to
escape from the exhaust and a large number of particles may escape from the room.
15
Figure 2.3: The velocity distribution for the two cases of ventilation method
(a) displacement; and (b) mixing studied by Bin et al (2003)
Kim et al (2002) study about the efficiency of ventilation in a small-scale
painting process with various exits of air leaving at different suction velocities. He try
to evaluate a number of survey that have reported of workers suffer from eye and
respiratory discomfort, headaches and feelings of lethargy on account of volatile
organic compounds (VOCs) which could be because of insufficient air distribution
within the occupied space. He set up of two dimensional modelling as shown in Figure
2.4. The room model has dimensions of 8.5 m× 2.4 m. When a painting process is
being carried on, VOCs are to be spread from the top of the table. In the present study,
toluene injected from the top surface of the table enters into the room as a source of
VOC, and leaves the room through exits. Fresh air is supplied through an inlet and the
air in the room is exhausted through two exits in each case, the one in the right and the
other in the left side at the same height. For the analysis of ventilation characteristics,
the locations of the right exit are to be changed variously in different cases. Each exit
at the right and the left side have the same area. By using FLUENT, this commercial
16
CFD code will be analyse the diffusion and ventilation of toluene as the sources of
VOCs with different case of exit velocity and position.
Figure 2.4: Schematic diagram of the 2D room studied by Kim et al (2002)
From the simulation, they found that is some case, the concentration of toluene
may be fairly dangerous for a person to work for a long time near the table which is
predicted toluene concentration above the table lies between 0.26 kg/m3 and 0.44
kg/m3 and the results shows in Figure 2.5. From the results, conclusion have been
made that critical attention to position of exit and fresh air inlet is needed to maintain
the allowable concentration within the spray painting zone.
Figure 2.5: Toluene concentration in some case studied by Kim et al (2002)
A study conducted by Li et al (2013) investigating the operation of a ventilation
system used in industrial paint spray-booth through CFD integrated modelling. Their
concentration are based on the optimum design and operation parameter during paint
17
spray activities. Based on industry data, typical size of paint booth (19 x 39 x 10 feet)
has been model using commercial CFD software show in Figure 2.6.
Figure 2.6: Downdraft paint spray booth modelling studied by Li et al (2013)
Four 25- horsepower motors power the exhaust fans to discharge paint fumes
outdoor, which give the exhaust air flows at 80,000 cubic feet per minute (CFM).
During the painting operation, fresh air enters the booth from the open roof and flows
down to the floor continuously. For this study, in terms of design development they
has been setup a specific threshold limit value (TLV) of VOCs emission according to
environmental regulation and health impact. Therefore the optimal solution can be
derived from the simulation result by ensuring the VOCs emission in the paint spray
activities does not exceed the TLV. In this study, ethyl alcohol is consider as the VOCs
substance. After simulate few cases with some modification to the geometry and
operational parameters, they found a variation of VOCs concentration shown in Figure
2.7. By introduced modelling and analysis technique, it shows that the applicability of
CFD to identify the key design and operational parameter of a general surface coating
application for energy efficient emission reduction.
18
Figure 2.7: Averaged VOCs concentration inside the different case of paint spray
booth studied by Li et al (2013)
2.8 Regulation on chemical hazardous exposure
Regulation on exposure of chemical hazardous have been establish by governmental
agencies to reduce and maintain the exposure level of workers to chemicals hazardous
substances. In Malaysia, USECHH (Use and Standard of Exposure of Chemicals
Hazardous to Health, Regulation 2000) the only one agency that provided a guideline
and further information on the chemical hazardous. Based on regulation 6 and 7, an
employer shall ensure that the exposure of any person to any chemical hazardous to
health not exceed the maximum exposure limit for that chemical during the work shift.
(USECHH, 2000). Table 2.2 list some limits of chemical hazardous associate with car
auto repair industries.
19
Table 2.2: USECHH limits
Exposure limits are based on 8 hour shift
ppm = parts per million
Air-bone (ppm) Concentration (mg/m3)
Acetone 500 1187
Toluene 50 188
Benzene 0.5 1.6
Xylene 100 434
Compare to US, there were three institutions publish guideline of exposure
which is Occupational Safety and Health Administration (OSHA), National Institute
of Occupational Safety and Health (NIOSH) and American Conference of
Governmental Industrial Hygienists (ACGIH). The guidelines published by NIOSH
are the result of government research and tend to be lower than the OSHA exposure
limits for any given chemical. The guidelines for exposure produced by ACGIH are
industry consensus standards that tend to allow a lower level of exposure than OSHA
and match the standards produced by NIOSH for most exposures. They has been setup
a different exposure limit value of some solvent used in car auto repair industries which
is Threshold Limit Values (TLV), short term exposure limit (STEL) and occupational
exposure limit (OEL). (Krzystowczyk, 2011). The limits shows in Table 2.3
Table 2.3: Exposure limits of certain types of solvent used in spray painting
industries
Exposure limits are based on 8 hour shift
ppm = parts per million
ACGIH (ppm) OSHA (ppm)
TLV STEL OEL TLV STEL OEL
Acetone 500 750 - - - 1000
Toluene 50 - - - - 200
Benzene 0.5 2.5 5 - - -
Xylene 100 150 100 - - -
20
Based on painting industries regulation scenario, early in 1965, the
Environmental Protection Agency of the United States of America, act of congress
entitled “The clean air act“, limited the solvent content of paints which is after that
called as VOC regulation of 1991. According to the above regulation, the VOC content
in reference to automotive coatings is limited to 250 and 350 g/l. Most of the
regulations that are aimed at protecting the environment have a positive impact on
human and animal health. One of the most stringent laws in this regard is the Montreal
protocol which is mentioned earlier, which banned the manufacture and the use of
stratospheric ozone depleting solvents (Boxal & Fraunhofer., 1977).
2.9 Spray painting equipment
2.9.1 Spray painting booth
Spray painting should always be done in a well-ventilated spray booth; defined as a
separate room with a ventilation system. In a paint spray booth, a ventilation system
provides downdraft air, semi-draft air and cross draft air which is necessary for
removing the paint particles and VOCs contained air continuously into the drain
system. Based on Li et al (2002); although most of the paint sprayed stick to the target,
ventilation air will carry out some amount of paint which is enters the drain on the
booth floor.
Based on ACGIH (1998) paint spray booths allow for the painting of a wide
range of parts, equipment including products. Booth sizes range from bench top units
for small parts to walk-in booths for product. For optimum performance, consideration
must be given to selection, design, construction, location, use, and performance.
Within a given booth the type of spray gun chosen will have a significant impact on
the amount of overspray (amount of paint that is sprayed but not deposited on the
painting surface) produced. Table 2.4 and 2.5 show the requirement and criteria on
designing paint spray painting booth based on ACGIH (1998) and OSHA respectively.
21
Table 2.4: USGIH spray booth design criteria
Table 2.5: OSHA spray booth design criteria
In Malaysia, according to USECHH (2000) regulation 2 and regulation 17 state
that any engineering control equipment which is used to control exposure of workers
from chemical hazardous to health includes local exhaust ventilation, water spray or
containment equipment need to be maintained and operated at all time while any
machinery or plant is in operation. When the natural ventilation is not more adequate
to create air flow and dilute the concentration, ventilation regulation 25 state that
mechanical ventilation need to be provided. The total free area of any ventilation air
inlets shall be at least 50% greater than the total free area of the air outlets. Air inlets
shall, so far as practicable, be located at floor level, and air outlets shall be located as
22
high as practicable. Table 2.6 show a number of air change every hour for an adequate
ventilation based on regulation 25 USECHH (2000);
Table 2.6: Air change every hour for an adequate ventilation by USECHH
Air change every hour Case
Not less than ten (10) air change/h Processes which generate little or no heat, smoke
or fume
Not less than ten (20) air change/h Processes which generate heat, smoke or fume,
Not less than ten (30) air change/h Fume generated is likely to cause bodily injury
USECHH also state that in regulation 18 which is the local exhaust ventilation
equipment installed shall be designed according to an approved standard by a
registered professional engineer and constructed according to the design
specifications; and tested by a registered professional engineer after construction and
installation to demonstrate that the equipment meets the design specifications.
2.9.1.1 Downdraft booth
Figure 2.8 shows the downdraft air booth design. Spraying of sealer, basecoat, and
clear coat is almost always done in a spray booth to protect both the workers and the
paint job. The most effective paint booths are downdraft booths which supply filtered
air to the booth through its ceiling, and exhaust the chemical-containing air to the
outside after it passes through filters below the grating on the floor. In these booths the
air is directed downward, and the paint vapours and overspray are carried downward.
Figure 2.8: Downdraft air booth (source: William A., 1998)
23
2.9.1.2 Semi-downdraft booth
Figure 2.9 shows the semi-downdraft air booth design. Semi-downdraft booths, in
which the air either comes in through ceiling filters and goes out at the back of the
booth, or comes in through the door and exhausts through the floor, can also be
effective. In these booths the position of the painter is crucial. Whenever possible the
painter should orient himself so that he is upstream from the paint being sprayed,
aiming the paint gun in the direction of the exhaust and away from painters.
Figure 2.9: Semi-downdraft air booth (source: William A., 1998)
2.9.1.3 Cross draft booth
Figure 2.10 shows the cross draft air booth design. Orientation is important for cross
draft booths as well. These booths draw air in from the rest of the shop through the
filters on the door and exhaust the air through filters at the back of the booth. The
painter should again be as far as possible upstream of the surface he is painting.
Figure 2.10: Cross draft air booth (source: William A., 1998)
24
2.9.2 Spray gun
Through spray gun the paint material will atomize by uses of compress gas at high
velocity. Refer to Nelson (2009) air spray gun equipped with two fluid atomizer which
use the kinetic energy of the flowing air stream to shatter the paint into ligaments and
then into droplets. A stream of paint meets air will form the paint droplets and then are
exerted out by a pressure which will flow them out through the spray nozzle. Most
spray guns have lateral air holes provided on both sides, and compressed air is supplied
from both sides to the spray flow in order to adjust the shape of the spray pattern.
Consequently, a spray flow sprayed in a circular pattern at the centre may be flattened
by changing the airflow pressure and quantity from the lateral air holes. In the case of
this spray gun, better atomization is achieved when compressed air quantity (or
pressure) is increased, such that the painted surface is provided with a higher quality
finish as a consequence of the spraying of finer particles. There were few types of
spray gun used in auto body shops which is a manual process where automotive
painters use spray guns to apply successive coats of paint.
2.9.2.1 Conventional Air Spray Guns
Conventional air spray guns have been the standard spray equipment used to apply
coatings in the refinishing industry (Figure 2.11). Air and paint enter the gun through
separate channels and are mixed using an air cap to form a controlled pattern, known
as a ‘fan’. With this type of spray gun, a low volume (2 to 10 cubic feet per meter
(cfm)) of air is pressurized and forced through a nozzle; the paint or coating is atomized
in the air at the nozzle throat. Conventional spray guns are usually operated with air
pressures of 30 to 90 pounds per square inch (psi) at a fluid pressure of 10 to 20 psi.
76
REFERENCES
ACGIH. (1998). Industrial Ventilation: A Manual of Recommended Practice; 23rd
edition. American Conference of Governmental Industrial Hygienists, Inc.
Akbar, K.F., Bisesi, M.S., & Rivas, R.D. (1995). Comfort of Personal Protective
Equipment. Appl Ergonomics 26(3), pp.195-198.
ATSDR (Agency for Toxic Substances and Disease Registry). (1992). Toxicological
profile for 2-butanone. Atlanta, GA: U.S. Department of Health and Human
Services, Public Health Service.
Beach, J., Raven, J., Ingram, C., Bailey, M., Johns, D., & Walter, E. (1997). The effects
on asthmatics of exposure to a conventional water-based and volatile organic
compound-free paint. European Respiratory Journal, 10, pp. 563-566.
Bin, Z., Ying Z., Xian, T.L, Xu, D.Y, & Dong, T.H. (2004). Comparison of indoor
aerosol particle concentration and deposition in different ventilated rooms by
numerical method. Building and Environment, 39, pp. 1 – 8
Boxal, J.S., & Fraunhofer, J.A. (1977). Concise Paint Technology. Elek, London;10-
214.
Bunkuea, K., Khamsean, D., Upatcha, P., Tangmandee, T., & Meevasana, K. (2014).
Occupational Exposure of Toluene in Wood Furniture Manufacturing
Environment: A Case Study. Health and the Environment Journal, 5(2),
pp. 57 - 68
Chun, C., Sung, K., Kim, E., & Park, J. (2010). Self-reported multiple chemical
sensitivity symptoms and personel volatile organic compounds exposure
concentrations in construction workers. Building and Environment , 45, pp.
901-906.
Christhina Cândido, Richard de Dear, Roberto Lamberts & Leonardo Bittencourt
(2008). Natural ventilation and thermal comfort: air movement acceptability
inside naturally ventilated buildings in Brazilian hot humid zone. Proceedings
of Conference: Air Conditioning and the Low Carbon Cooling Challenge,
Cumberland Lodge, Windsor, UK, pp. 550-557
Dillon. (2000). Safe Work Procedures for isocyanates-Company Procedures
77
DOSH (Department of Occupational Safety and Health). (2008). Guidelines for
Hazard Identification, Risk Assessment and Risk Control (HIRARC).
Retrieved on February 8, 2015 from
http://www.dosh.gov.my/index.php?option=com_docman&task=cat_view&gi
d=15&Itemid=179&lang=en
Enander, R. T., Gute, D. M., & Missaghian, R. (1998). Survey of Risk Reduction and
Pollution Prevention Practices in the Rhone Island Automotive Refinishing
Industry. American Industrial Hygiene Association Journal, 59, pp. 478-489.
Feldman, R.G., Ratner, M.H., & Ptak, T. (1999). Chronic toxic encephalopathy in a
painter exposed to mixed solvents. Environmental Health Perspectives,
107(5), pp. 417–422.
Flynn, M., & Sills, E. (2000). On the Use of Computational Fluid Dynamics in the
Prediction and Control of Exposure to Airborne Contaminants - an Illustration
Using Spray Painting. The Annals of Occupational Hygiene, 44, pp. 191-202.
Flynn, M., Gatano, B., McKernan, J., Dunn, K., Blazicko, B., & Carlton, G. (1999).
Modeling Breathing- Zone Concentrations of Airborne Contaminants
Generates During Compressed Air Spray Painting. The Annals of Occupational
Hygiene, 43, pp. 67-76.
Heitbrink, W., Wallace, M., Bryant, C., & Ruch, W. (1995). Control of Paint
Overspray in the Autobody Repair Shops. Am. Ind. Hyg. Assoc. J. 56(10), pp.
1023-1032.
Hess-Kosa, K. (2012). Indoor Air Quality: The Latest Sampling and Analytical
Methods. USA: CRC press
Hubbard, D. (2009). The Failure of Risk Management: Why It's Broken and How to
Fix It. John Wiley & Sons
Kassomenos, P., Karayannis, A., Panagopoulos, I., Karakitsios, S., & Petrakis, M.
(2008). Modelling the dispersion of a toxic substance at a workplace.
Environmental Modelling & Software, 23, pp. 82-89.
Kim, C.N., Choi, W.H., Choung, S.J., Park, C.H, & Kim, D.S. (2002). Efficient
ventilation of VOC spread in a small-scale painting process. Building and
Environment, 37, pp. 1321 – 1328
Kim, B.R. (2011). VOC emissions from automotive painting and their control: a
review. Environ Eng Res, 16, pp. 1–9
Kim, B.R., Kalis, E.M., & DeWulf, T. (2000). Henry’s law constants for paint solvents
and their implications on volatile organic compound emissions from
automotive painting. Water Environment Research, 72(1), pp. 65–742.
78
Kiurski, J.S., Mari, B. B., Aksentijevi, M., Oros, I. B., Keci, V. S., & Kovac, I. M.
(2013). Indoor air quality investigation from screen printing industry,
Renewable and Sustainable Energy, 28, pp. 224 – 231.
Krzystowczyk, J.A. (2011). Exposure assessment for automotive repair tasks in an
attached garage. University of Iowa: Master’s Thesis.
Leung, M., Lui, C., & Chan, A. (2005). Occupational Exposure to Volatile Organic
Compounds and Mitigation by Push-Pull Local Exhaust Ventilation in Printing
Plants. Journal of Occupational Health, 47, pp. 540-547.
Li, J., Uttawar, R.G, Yinlun, H. (2002). CFD-based modeling and design for energy-
efficient VOCemission reduction in surface coating systems. Clean Techn.
Environ. Policy, 15, pp. 1023–1032
Liu, H., Liang, Y., Bowes, S., Xu, H., Zhou, Y., Armstrong, T. W. (2009). Benzene
Exposure in Industries Using or Manufacturing paint in China – A Literature
Review. Journal of Occupational and Environmental Hygiene , 6, pp. 659-670.
Maragakis, I., Clark, S., Piers, M., Prior, D., Tripaldi, C., Masson, M., & Audard, C.
(2009). Guidance on Hazard Identification. European Strategic Safety
Initiative.
MIDA (Malaysian Industrial Development Authority). (2010) Business opportunities
report. Malaysia.
National Institute of Occupational Safety and Health (1997). Protecting Workers.
Exposed to Lead-Based Paint Hazards: A Report to Congress. USA: DHHS
(NIOSH) Publication.
National Institute of Occupational Safety and Health (2003). Hydrocarbons, Aromatic:
Method 1501. In: Eller PM, ed. NIOSH Manual of Analytical Methods. 4th rev.
ed. Cincinnati, OH: DHHS (NIOSH) Publication.
Nelson, K.A. (2009). Automotive Paint Spray Characterization and Visualization.
Automotive Painting Technology. Netherlands: Springer Netherlands. pp. 121-
165
NRC (National Research Council) (1983): Risk Assessment in the Federal
Government: Managing the Process. Washington D.C: National Academy
Press,
Oanh, N. K., & Hung, T. Y. (2005). Handbook of Environmental Engineering, Volume
2: Advanced Air and Noise Pollution Control (2). Totowa, NJ: The Humana
Press, Inc.
Occupational Safety and Health Administration (OSHA). (2014). OSHA Technical
Manual (OTM), Section II: Chapter 1. Personal Sampling for Air
Contaminants. Retrieved on May 27, 2015 from
https://www.osha.gov/dts/osta/otm/otm_ii/otm_ii_1.html
79
Occupational Health and Safety Administration. (2012a). Chemical Sampling
Information: Toluene. Retrieved on May 27, 2015 from
http://www.osha.gov/dts/chemicalsampling/data/CH_276500 .html
Occupational Health and Safety Administration. (2012b). Chemical Sampling
Information: Xylene. Retrieved on May 27, 2015 from
http://www.osha.gov/dts/chemicalsampling/data/CH_276400 .html
Occupational Health and Safety Administration. (2012c). Chemical Sampling
Information: Ethylbenzene. Retrieved on May 27, 2015 from
http://www.osha.gov/dts/chemicalsampling/data/ CH_240000.html
Occupational Health and Safety Administration. (2012i). Chemical Sampling
Information: Cadmium. Retrieved on May 27, 2015 from
http://www.osha.gov/dts/chemicalsampling/data/CH_223897 .html
Olufunsho, A., Temidayo, D.P, Bawo, S.O, Akin, A, Herbert, A.B, & Alade, A.
(2014). Occupational Hazards and Safety Measures Amongst the Paint Factory
Workers in Lagos, Nigeria. Safety Health Work, 5(2), pp. 106–111.
Ongwandee, M., Moonrinta, R., Panyametheekul, S., Tangbanluekal, C., & Morrison,
G. (2011). Investigation of volatile organic compounds in office buildings in
Bangkok, Thailand: Concentrations, sources, and occupant symptoms.
Building and Environment , 46, pp. 1512-1522.
Pendergrass, S. M., NIOSH. (2013). Manual of Analytical Methods (NMAM), Fourth
Edition, ENVH 555/CS, Tube/Passive Badge Sampling & GC. 1(3) 1-27.
Retrieved on April 10, 2015 from
http://courses.washington.edu/envh555/iii_GC.pdf
Pronk, A., Yu, F., Vlaanderen, J., Tielemans, E., Preller, L., Bobeldijk, I. (2006).
Dermal, inhalation, and internal exposure to 1,6-HDI and its oligomers in car
body repair shop workers and industrial spray painters. Occupational and
Environmental Medicine , 63 (9), pp. 624-631.
Qian, H., Fiedler, N., Moore, D. F., & Weisel, C. P. (2010). Occupational Exposure to
Organic Solvents during Bridge Painting. The Annals Occupational Hygiene ,
54, pp. 417-426.
Ronk, A., Yu, F., Vlaanderen, J., Tielemans, E., Preller, L., & Bobeldijk, I. (2006).
Dermal, inhalation, and internal exposure to 1,6-HDI and its oligomers in car
body repair shop workers and industrial spray painters. Occupational and
Environmental Medicine, 63 (9), pp. 624-631.
Sparkman, O. D., Penton, Z. E., & Kitsson, F. G. (2011). Gas Chromatography and
Mass Spectrometry- A Practical Guide. Second Edition.
80
Streitberger, H.J., Urbano, E., Laible, R., Meyer, B.D., Bagda, E., Waite, F.A., &
Philips, M. (2011) Paints and coatings, 3. Paint systems. Ullmann’s
Encyclopedia of Industrial Chemistry.
Tabor, Z,, Krzak, M., Nowak, P., & Warszynski, P. (2012). Water diffusion in polymer
coatings containing water-trapping particles. Part 1. Finite difference-based
simulations. Prog Org Coat, 75, pp. 200–206
US-EPA. (1999). Compendium of Methods for the Determination of Toxic Organic
Compound in Ambient Air. Second Edition
Vittorio, B., Furio, C., Pierluigi, L., & Adolfo, P. (2004). A numerical approach for air
velocity predictions in front of exhaust flanged slot openings. Building and
Environment, 39, pp. 9-18.
William A. Heitbrink. (1998). A Control Matrix For Spray Painting at Autobody
Repair Shops. Applied Occupational and Environmental Hygiene
Wilson, M. P., Hammond, S. K., Nicas, M., & Hubbard, A. E. (2007). Worker
Exposure to Volatile Organic Compounds in the Vehicle Repair Industry.
Journal of Occupational and Environmental Hygiene , 4, pp. 301- 310.
Winder, C., & Turner, P. j. (1992). Solvent Exposure and Related Work Practices
amongst Apprentice Spray Painters in Automotive Body Repair Workshops.
The Annals Occupational Hygiene , 4, pp. 385-394.
Wood-Black, F. & Pasquarelli, T.( 2007). Blogs. Journal of Chemical Health & Safety
14: 37.
Yu, C., & Crump, D. (1998). A Review of the Emission of VOCs from Polymeric
Materials used in Buildings. Building and Environment, 33 (6), pp. 357-374.
Yuan, H.Z. (2004). Indoor Air Quality Engineering, CRC press