Skin problems related to Indonesian leather & shoe production and the use of footwear in Indonesia Febriana, Sri Awalia

Transcription

1 University of Groningen Skin problems related to Indonesian leather & shoe production and the use of footwear in Indonesia Febriana, Sri Awalia IMPORTANT NOTE: You are advised to consult the publisher's version (publisher's PDF) if you wish to cite from it. Please check the document version below. Document Version Publisher's PDF, also known as Version of record Publication date: 2015 Link to publication in University of Groningen/UMCG research database Citation for published version (APA): Febriana, S. A. (2015). Skin problems related to Indonesian leather & shoe production and the use of footwear in Indonesia [Groningen]: Rijksuniversiteit Groningen Copyright Other than for strictly personal use, it is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license (like Creative Commons). Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. Downloaded from the University of Groningen/UMCG research database (Pure): For technical reasons the number of authors shown on this cover page is limited to 10 maximum. Download date:

2 CHAPTER 5 Occupational skin hazards and prevalence of occupational skin diseases in shoe manufacturing workers in Indonesia Sri Awalia Febriana 1,2, Hardyanto Soebono 1, Pieter-Jan Coenraads 2 1 Department of Dermatology & Venereology, Gadjah Mada University, Yogyakarta, Indonesia; 2 Department of Dermatology, University Medical Centre Groningen / University of Groningen, Groningen, the Netherlands. Int Arch Occup Environ Health 2014; 87:

3 Abstract Purpose Shoe manufacturing workers are exposed daily to an extensive range of potential physical and chemical occupational hazards. Shoe manufacturing in Indonesia is one of the industrial sectors that has shown sustained growth amongst the newly industrialized countries (NICs). In this study, we investigated the possible potential exposure of the workers to physical and occupational hazards and determined the prevalence of occupational skin diseases at a shoe manufacturing factory in Indonesia Methods A cross-sectional study on the observation of the working process and an inventory and risk assessment of exposure to the chemicals used. Classification of chemicals as potential sensitizers/irritants and qualitative assessments of these chemicals were done. Workers were examined and interviewed using the Nordic Occupational Skin Questionnaire- 2002/LONG. Results The risk of Occupational skin diseases (OSD) at the shoe factory o potential physical and chemical hazards in hot and humid environmental conditions. From a total of 514 workers, 8.5% reported current OSD and 4.8% reported a history of OSD. Occupational skin diseases were diagnosed in 29% of the workers by dermatologists and 7.6% had an occupational contact dermatitis (OCD). Of the 39 workers with contact dermatitis, 33 consented to being patch tested, 14(3%) workers showed a positive results and considered as having an occupational allergic contact dermatitis (OACD) and 25(4.9%) had an occupational irritant contact dermatitis (OICD). Conclusion We observed a repeated and prolonged exposure of the workers to numerous physical and chemical skin hazards at this factory. Keywords shoe manufacturing; occupational skin diseases; skin exposure

4 Introduction Workers in the shoe manufacturing industry exposed daily to an extensive range of potential occupational hazards (physical or chemical). In shoe production, there are many possible occupational exposures to a broad spectrum of allergens contained in many adhesives, preservatives, acrylic resins, leather, rubber, dyes and many kind of glues (neoprene, epoxy resin and rubber glues). Adhesives and solvents used in production process may also be potential irritants. 1, 2 Occupational skin disease in shoe manufacturing workers has been rarely reported. A study over the years at 5 shoe manufacturers in Italy showed a prevalence of occupational contact dermatitis of 14.6%; hyperkeratosis of fingertips 6% and pruritus sine materia 3.2%. 3 Low labour costs, easy supply of leather and a tradition of shoe making allowed shoe manufacturing industries to move to newly industrialized countries. 4 Shoe manufacturing in Indonesia is one of the industrial sectors that have shown sustained growth. The industry is labour intensive and concentrated in the small cottage industry for the in-country production and in large scale units for export products. Indonesia is the largest footwear exporter after China and Vietnam 5 and accounted for about 75.2% of a global production of 12.5 billion pairs of shoe in In 2009, the Indonesian footwear export amounted to $ 1.7 billion 7 with approximately 115,000 workers and has been a major supplier for well-known brands of shoes with the biggest market being Europe for many years. 6 Despite the significant number of workers in shoe manufacturing industry in Indonesia, there is still no published study on the actual risk and the prevalence of occupational skin diseases in shoe manufacturing industry in Indonesia The objective of this study was to investigate the possible source of potential chemical and physical hazards to which the workers were exposed to at a shoe factory and to determine the prevalence of occupational skin diseases in workers involved in shoe manufacturing industry in Indonesia as one of the NICs.

5 Materials and Methods Subjects 5 90 A survey to obtain information on the working process and the skin exposure followed by a cross-sectional study to assess the prevalence of occupational skin diseases was conducted between January-March 2010 at a shoe factory in Sidoarjo Industrial Area, East Java, Indonesia. This shoe factory was chosen for the following reasons: it had more than 500 workers, used modern equipment and exported its products to leading brands in Europe, United States and other Asian countries. According to the footwear and leather industry competitiveness report, the shoe manufacturing process and the machinery used in the export quality shoe factories are more or less the same. 8 All 514 employees engaged in the production process and exposed to potential physical and chemical hazards were included in the study. A flow chart of the workers that were investigated is shown in Fig.1. Figure 1. Flowchart of interviews and skin examinations

6 Observation of the workplace Preceding the cross-sectional study of skin symptoms and signs, the different workplaces were observed with regard to the nature of skin exposures to occupational hazards. Observation was done by an occupational dermatologist when the shoe production was running during a whole day. This included: 1. Observing the working area to get an overview of the floor space, ceiling height, lighting, circulation and ventilation and the indoor microclimate inside the factory. 2. Observing and making detailed report on the working cycle, job tasks, the duration and the frequency of different chemical and physical exposures at each working stage, handling procedures and preventive measures used by the workers Making a list of the materials and chemicals the workers were exposed to in the factory. All chemical exposure data were doublechecked with the researchers and the database at the Centre for Leather, Rubber and Plastic Agency for Research and Development, Ministry of Industry and Trade, Republic of Indonesia and Indonesia Footwear Service Centre (IFSC). 4. Obtaining information on the content of contact allergens/ sensitizers (including the CAS number of all ingredients) in chemicals the workers were exposed to through product labelling and declaration. The potential risk of all chemicals as a skin irritant /sensitizer was assessed using the Material Safety Data Sheets (MSDS). If the MSDS or product declaration was not available, we contacted the manufacturer or the supplier. We also used on-line databases from the National Institute for Occupational Safety and Health Institute (NIOSH) website 9, PubMed and a reference book Listing of potential sensitizers in the raw materials the workers were exposed to in the factory based on previous studies.

7 Questionnaire study and physical examination 5 92 All subjects provided informed consent prior to their inclusion in the study. All exposed employees were interviewed by trained interviewers guided by using the Indonesian translation of The Nordic Occupational Skin Questionnaire 2002 long version (NOSQ-2002/LONG) following the guideline from Nordic Occupational Skin Questionnaire Group. 11 The validity and the relevance of this questionnaire in the epidemiology of occupational skin diseases were reported in the publication from the Nordic Occupational Skin Questionnaire Group. 12 The interviewers were medical students and anthropologists who were all trained in interviewing skills by an occupational dermatologist. Since the level of education and the reading skills of the workers were limited, the interviewers read all the questions in the questionnaire and filled in the answers without giving a personal interpretation of the response. In accordance with the NOSQ procedures, the questionnaire was translated, adapted and modified for the specific circumstances in shoe manufacturing in Indonesia following the guideline from the Nordic Occupational Skin Questionnaire Group. 11 Adaptations were made on the question regarding the location of the eczema (question D2), the specification of the workstation (question G1) and the list of chemicals the workers were exposed to (question G10). Since In line with the interview process, all workers were examined by two dermatologists and a dermatologist with additional training in contact and occupational dermatology to determine the prevalence of occupational skin diseases. Skin examinations by a derma the knowledge of the responses to the questionnaire) as a reference standard in order to evaluate the accuracy of our results. In half of the workers, patch testing was done with allergens from the European baseline series, the shoe series (Chemotechnique Diagnostics, Vellinge, Sweden) and additional allergens specific for shoe factory work. Patch test results were read on days 2,4,7 as recommended by the International Contact Dermatitis Research Group (ICDRG). 13 Detailed results of the patch-testing will be reported in a separate paper.

8 Statistical analyses were performed using chi-square test to compare the differences between interview-based prevalence and examination-based prevalence and to compare the prevalence of OSD between departments based on the interview and examination. All analyses were performed using commercially available software (SPSS, version 20). Results Working process and chemicals that the workers were exposed to The shoe making itself involves five steps: 1. Preparation (raw material warehouse, design, pattern making and cutting); 2. Preparing /upper sole (sewing preparation, sewing/stitching, folding and gluing); 3. Assembling (lasting, heating, buffing, outsole attaching, pressing, cooling, and last removing); 4. Finishing and 5. Packing. The exposure of the skin to a potential skin hazards in the factory are shown in Table 1. The relevant in was exposed to are shown in Table 2a and 2b. The chemicals were mostly irritants, but several sensitizers were also encountered Table 1. Potentially hazardous skin exposures in shoe factory workers Potential skin hazards Working process Physical Chemical Skin effects 1. Preparation Raw material ware house Design and pattern making Cutting - Skin cuts and skin friction from the knives and blades - Repetitive friction - Airborne exposure to the leather, polyurethane and rubber dust - Skin sensitization from the sensitizers potentially present in materials used (leather, polyurethane and rubber) - Localized itching on uncovered skin caused by dust - Hyperkeratosis and callus from friction - Cuts and lacerations

9 Potential skin hazards Working process Physical Chemical Skin effects 2. Preparing/upper sole Sewing preparation (skiving, embossing, embroidery, perforating, folding) Sewing/stitching Folding Glueing - Piercing injury from punch presses and sewing machines. - Repetitive friction - Skin exposure from spilling adhesives and solvent ingredients such as methyl ethyl ketone, acetone, ethyl acetate, cyclohexane and butyl acetate - Airborne exposure to dust from leather, polyurethane and rubber - Cuts and laceration - Hyperkeratosis and callus from friction - contact dermatitis to solvents, adhesives, and varnishes. - Allergic contact dermatitis to sensitizers potentially present in the materials used (leather, rubber, polyurethane and neoprene) 5 94 Lasting Heating Buffing Outsole attaching Pressing Cooling Last removing Accessories assembling 4. Finishing - Heat exposure from oven and press machines that heat and form shoe parts, stockfit machines used to assemble parts, heaters used to singe and remove stray fibres. - High ambient temperature (mean 34 o C) and high ambient humidity (mean 80%) - Heat exposure from cementspraying operations. - Repetitive vibrations from machinery parts - Exposure to a variety of solvents and organic chemicals such as methyl ethyl ketone, acetone, ethyl acetate, cyclohexane and butyl acetate. - Exposure to nickel sulphate - Airborne exposure to solvent and adhesive vapours - Hyperkeratosis and callus from friction - Miliaria. - contact dermatitis to solvents, adhesives and varnishes. - Allergic contact dermatitis to sensitizers potentially present in materials used (leather, rubber, polyurethane and neoprene) and accessories (nickel). Checking whether the shoe is clean and without excess adhesive. - Repetitive friction - Exposure to waterproof agents (acetone and methyl ethyl ketone) - contact dermatitis caused by waterproof agents - Localized itching in uncovered skin caused by dust. 5. Packing - Repetitive friction - - Hyperkeratosis and callus from friction

10 Tables 2a. Materials used in shoe making and their potential sensitizers Raw material exposing all workers irrespective of work station Finished leather* s Preservatives/biocide - 2-N-octyl-4-isothiazolin-3-one - Cl + Me-Isothiazolinone - Metam sodium - Sodium diethyldithiocarbamate - 2- Thiocyanomethyl benzothiazole Tanning agents - Potassium dichromate - 2-Mercaptobenzothiazole - Formaldehyde - Glycine - Chlorbenzene - Glutaraldehyde Dyeing process - Disperse orange 3 (CI 11005) - Acid yellow 36 (CI 13065) - N-isopropyl-n-phenyl 4-phenylenediamine - 4-Aminoazobenzene - Benzidine 5 95 Rubber Polyurethane Neoprene *Described in details in Febriana et al (2011) Finishing process - Epoxy resin - Polyethylacrylate - Colophony - N-Isopropyl-N-phenyl-4-phenylenediamine - Hydroquinone monobenzylether - Thiuram mix - 4-Phenylenediamine base - Mercaptobenzothiazole - Mercapto mix - Carba mix - 1,3 Diphenylguanidine - Sodium diethyldithiocarbamate - Colophony - Toluene diisocyanate - Dodecyl mercaptan - Diphenyl methane-4, 4-diisocyanate - Dodecyl mercaptan - Diphenylthiourea - Diethylthiourea - Dibuthylthiourea - p-tert-butylphenol-formaldehyde resin

11 Table 2b. Chemicals used in shoe making and their potential sensitizers/irritants Work process Chemicals exposing the workers skin (based on workplace observation) s/ s 1. Preparation Raw material warehouse Design and pattern making Cutting 2. Preparing/upper sole - - Sewing preparation (skiving, embossing, embroidery, perforate, folding) Printing paints Cyclohexanone resin Methyl ethyl ketone (MEK) Methyl isobutyl ketone (MIBK) 5 96 Sewing/stitching Folding Gluing Solvents Toluene (methylbenzene) Cyclohexane (hexahydroxybenzene) 3. Assembling Lasting Heating Buffing Outsole attaching Pressing Cooling Last removing Accessories assembly Solvents Acetone (2-propane) Methyl Ethyl Ketone (MEK) Toluene (methylbenzene) Adhesive hardener Polyisocyanate Ethyl acetate (acetic acid ethyl ester) Neoprene based adhesive p-tert-butylphenol formaldehyde resin Dodecyl mercaptan Polyurethane based adhesive Triethylenediamine Diphenylmethane diisocyanate (MDI) Epoxyresin based adhesive Epoxyresin Phenyl glycidyl ether Ethylenediamine dihydrochloride Other glue and adhesive components Colophony Formaldehyde 2-Mercaptobenzothiazole Primer for sponge ethyl vinyl acetate Acetone (2-propane) Tetrahydrofuran Primer for leather and sole Methyl Ethyl Ketone (MEK) Toluene (methylbenzene)

12 Work process Chemicals exposing the workers skin (based on workplace observation) DMF (N,N-dimethyl formamide) Cyclohexanone (cyclohexyl ketone) Primer for sole Methyl Ethyl Ketone (MEK) Toluene (methylbenzene) Cyclohexane (hexahydroxybenzene) Primer for oily leather Methyl Ethyl Ketone (MEK) Ethyl acetate (acetic acid ethyl ester) Primer for leather Cyclohexane (hexahydroxybenzene) Primer for rubber Acetone (2-propane) Cleaning agent Methyl Ethyl Ketone (MEK) s/ s Solvent Dichloromethane Propylene oxide Shoe accessories Nickel sulphate Finishing and trimming Waterproof agent Acetone (2-propanone) Methyl Ethyl Ketone (MEK) Ethyl acetate (acetic acid ethyl ester) Cleaning agent Methyl Ethyl Ketone (MEK) 5. Packing - 1. Preparation Preparation department was divided into 3 sections: 1) raw material warehouse, 2) design and pattern making and 3) clicking and cutting. In the raw material warehouse workers loaded and unloaded, sorted and prepared shoe materials like leather, synthetic leather, outer soles, lining materials and shoe accessories. The upper shoe is made in the clicking and cutting department. After pattern drawing and desired pattern selection, the workers cut out various patterns of upper shoes using loose-knife tools, clicking machine or in sole moulding presses to obtain all the components of a shoe. They handled all of these materials with their bare hand and never used gloves.

13 2. Preparing (upper sole) In the preparing (upper sole) department, all the shoe components are sewn together by highly skilled workers to produce completed upper shoe. Before sewing, skiving, embossing, embroidery, perforation, and folding of the shoe materials was done. In early stage, the pieces were sewn together on the flat machine. In the later stages, the sewing surface of the machine was elevated on a post to enable to three-dimensional sewing of the upper shoe. At this stage, the eyelets were inserted in order to accommodate the laces of the finished shoe In the shoe manufacturing industry, there were several steps in the process of binding surfaces in many kinds of shoe components. In order to ensure the good adhesive bonding, the surfaces were conditioned with priming, washing and roughening process. In this step workers were exposed to liquid adhesives, but they never wore gloves. After the surfaces were adhered, the upper and the bottom stock were sewed and the outsole, insole and heel were glued to the upper portion of the bottom shoe and assembled. In the lasting and making department, the completed upper shoe was moulded into a shape of a foot using a plastic shape simulating a foot, which is called a last. First, an insole was temporarily attached onto the shoe bottom. The upper shoe was then stretched and moulded into the insole. After the procedure was completed, the shoe last was obtained. The next stage was sewing the welt (a strip of leather or plastic) onto the shoe. The excess material was trimmed followed by stitching the sole onto the welt. 3. Assembling In assembling department, workers covered the edge of the upper shoe with latex. They put the upper shoe inside the oven. Workers glued the inner shoe layer onto the shoe upper. Shoe upper, which was already covered with latex, was then attached to insole paper board. The upper side of the shoe was covered with primer, dried and then the outer and the upper sole were put in the oven. The next step was applying the adhesives, drying and putting in the oven. In the out sole assembling department, outer soles and upper soles were attached manually and then bonded by the pressing machine. The last step

14 was to put the shoes into the cooling room. In this department workers were exposed to liquid glue and vapours. They used a face mask while working but never used gloves. 4. Finishing In the finishing department, workers put the waterproof agent and cleaned with methyl ethyl ketone and inspected whether the shoes were clean and had no excess adhesive. The bottom of the sole was lightly buffed, stained and polished. Workers were exposed to liquid cleaner and waterproof agent. They did not wear gloves or face masks while working. 5. Packing In this department, the shoes were packed in a shoebox for shipment. The workers worked with bare hands and did not wear face masks. All of the operations described above were carried out manually, usually without any protective measures. Face masks were the only protective measure that was worn by the workers in the assembling department Questionnaire study and physical examination A total of 514 workers (497 females and 17 males) were enrolled into our study. Their age and the duration of the exposure of their skin to various chemicals are shown in Table 3. The overall prevalence of the current OSD reported by workers was 8.5% (it was reported by 44 workers; 7(14%) from warehouse, shoe-design, and cutting, 23 (7.4%) from upper-sole preparation and sewing, 10(7.9%) from assembling, 3(18.8%) from finishing and 1(7.7%) from packing. Twenty five (4.8%) workers reported a history of OSD; 1(2%) from warehouse, shoe-design and cutting, 14(4.5%) workers from upper sole, preparation and sewing, 9(7.1%) workers from assembling and 1(6.3%) worker from finishing). Out of the 514 workers, 445 (86%) reported no skin problems (Table 4a). The dermatological diagnoses of occupational related skin diseases are shown in Table 4b. The prevalences of OSD based on self reported symptoms and dermatological examination are not statistically significantly different between the departments. The prevalence rate of OSD based on dermatological examination (29%) was significantly higher (p<0.05)

15 compared to the prevalence of self reported symptoms (8.5%). The overall prevalence of occupational contact dermatitis (OCD) was 7.6%; in general, most cases (5.2%) had mild disease. Most of the workers with OCD work in the upper-sole and assembling department. In the assembling department, we found some cases of facial dermatitis that was caused by exposure to vapours from solvents and adhesives From 39 workers with contact dermatitis, 33 consented to being patch tested with the European baseline series, the shoe series and additional allergens specific for shoe factory work. Of these, 14(3%) had a relevant patch test reaction and were diagnosed as having an occupational allergic contact dermatitis (OACD). Occupational irritant contact dermatitis (OICD) were diagnosed in 25(4.9%) workers. In addition, callus/hyperkeratosis was a common condition (9.7%) especially in the upper sole sewing department and the assembling department where there is repetitive friction of the workers skin with shoe materials, sewing tools and machinery parts. The prevalence of pruritus sine materia was 8.2% and frequently found in all departments except finishing. Table 3. Demographic and occupational characteristics of the 514 workers Characteristics Mean age in years (SD) Mean working time in months (SD) Mean working hours/week (SD) Warehouse, shoe design, and cutting Upper-sole preparation and sewing Assembling Finishing Packing Total 33 (5) 32 (5) 32 (5) 32 (6) 32 (5) 32 (5) 118 (63) 94 (65) 100 (66) 86 (61) 62 (83) 97 (66) 51 (10) 47 (7) 49 (9) 48 (7) 49 (13) 48 (8) Table 4a. Results from the interview based NOSQ-2002 in 514 workers * Workers without skin diseases Workers with a current skin disease related to occupation (NOSQ- 2002) ** Warehouse, shoe design, and cutting Upper-sole, preparation, and sewing Assembling Finishing Packing Total 42 (84%) 272 (88%) 107 (85%) 12 (75%) 12 (92%) 7 (14%) 23 (7.4%) 10 (7.9%) 3 (18.8%) 1 (7.7%) 445 (86%) 44 (8.5%)

16 Workers with history of skin disease related to occupation (12 months) (NOSQ-2002) Total number of workers Warehouse, shoe design, and cutting Upper-sole, preparation, and sewing Assembling Finishing Packing Total 1 (2%) 14 (4.5%) 9 (7.1%) 1 (6.3%) - 25 (4.8%) * Significant difference between interview-based prevalence and examination-based prevalence ** No statistically significant differences in OSD prevalence between departments Table 4b. Results from dermatological examination in 514 workers* Workers with current occupation-related skin disease (assessed by dermatologist)*** Occupational contact dermatitis of which occupational allergic contact dermatitis Callus/hyperkeratosis Pruritus sine materia Skin cut/ laceration Miliaria Warehouse, shoe design, and cutting 21 (42%) 3 (6%) 1 (2%) 9 (18%) 5 (10%) 3 (6%) - Upper-sole, preparation, and sewing 81 (26%) 21 (5.4%) 9 (2%) 23 (7.4%) 27 (8.7%) 6 (1.9%) 1 (0.3%) Assembling Finishing Packing Total 42 (33%) 12 (9.5%) 3 (4%) 17 (13.5%) 8 (6.3%) 4 (3.2%) 1 (0.8%) 5 (31%) 2 (12.5%) 1 (6.3%) - 2 (12.5%) (15%) 1 (7.7%) - 2 (15.4%) (29%) 39 (7.6%) 14 (3%) 50 (9.7%) 42 (8.2%) 13 (2.5%) 2 (0.4%) * Significant difference between interview-based prevalence and examination-based prevalence *** No statistically difference in OSD prevalence based on the examination between departments Discussion Our results confirm that workers in the shoe manufacturing industry are exposed to many potential chemicals and physical skin hazards. The highest exposure occurred in those who performed gluing and cleaning tasks. The factory has a continuous work process, without physical separation of the workplaces. Therefore, all workers were exposed to solvent vapours. Moreover, in the preparing/upper sole and assembling department, there were direct skin exposures to a wide variety of solvents and organic chemicals. The high prevalence of occupational contact

17 dermatitis (9.5%) in the assembling department may have been caused by heat exposure from heat generating machines leading to a high ambient temperature (38-40 o C) and humidity (80%). We observed that the workers were generally exposed to the same chemicals as described in other similar studies 14-16, although in addition we found skin exposure to methyl ethyl ketone, acetone, ethyl acetate, cyclohexane and butyl acetate From the questionnaire study fewer workers reported a current skin complaint (44 workers, 8.5%), whereas 151 (29%) had current occupationrelated skin diseases diagnosed by dermatological examination. A ssteatic reie of stdies soed tat agreeent eteen orers self-reports of or related diseases it te reference standard of expert opinion was mainly low to moderate: the prevalence estimated by symptom-based questionnaires was higher than the prevalence estimated by reference standards, except for hand eczema and respiratory disorders. 17 We found published cross-sectional studies on shoe manufacturing workers at shoe factories in other NICs such as India, Thailand and Portugal Among the studies in the NICs, the prevalence of occupational skin diseases (13.6%) was only mentioned in Thailand. 14 Another survey at an Italian shoe factory reported that the prevalence of occupational skin diseases was 24.7%. 3 Our study indicates a higher prealence. e ide range of reported prealence figres eteen 13.6% and 29%) can probably be explained by the differences in the definition of cases, period of screening and data collecting. Differences in the working conditions may also cause the wide range of reported point prevalence. If we look at the number of workers employed in the shoe manufacturing sector in Indonesia, we can see that the burden of occupational skin diseases in workers in shoe manufacturing is high. Our observational study on tannery workers in the same area 18 showed that in tanneries, orers ere eposed to ore inds of ceicals and et or copared to soe factor orers. erefore te occpational contact dermatitis cases in the shoe factory were milder compared to the tanneries. The prevalence of callus/hyperkeratosis (9.7%) and pruritus sine materia (8.2%) in the shoe factory was higher compare to the workers in the tannery (1%) and probably caused by more intense repetitive friction and airborne exposure to dust from leather, polyurethane and rubber. Shoe factory workers were also exposed to heat more extensively than tannery workers especially in the assembly area where there is heatgenerating machinery. Personal protective equipments in both factories were not properly applied and mostly used as a secondary prevention measure. In this study, we were able to produce a detailed scheme of the working process with a focus on the risk of occupational skin diseases in each step

18 in shoe manufacturing. The difficulty in obtaining a random sample from shoe factories in Indonesia as the object of our study limits the interpretation of our data. Another limitation of our study is that we only have the qualitative data on the level of skin exposure to potential physical and chemical hazards. In contrast to these limitations, we realize that this is one of the few studies on occupational skin disease risk in a newly industrializing country. More research into the effect of the occupational health risk of exporting such activities from Western countries to these countries is imperative. Conclusion We observed a high frequency of exposure to potential chemical and physical skin hazards in shoe manufacturing workers in Indonesia. We noted that the prevalence of occupational skin diseases in workers in shoe manufacturing industry in Indonesia was higher than that reported in other NICs. Conflict of interest The authors declare that they have no conflict of interest References 1. Geier J, Lessmann H. Leather and Shoes. In: Kanerva's Occupational Dermatology, 2nd, Rustemeyer T, Elsner P, John SM, Maibach HI, eds. Springer-Verlag, Heidelberg New York Dordrecht London, 2012: Taylor JS, Erkek E, Podmore P. Shoes. In: Contact Dermatitis, 4th, Frosch PJ, Menne T, Lepoittevin JP, eds. Springer, Berlin, Heidelberg, 2005: Mancuso G, Reggiani M, Berdondini RM. Occupational dermatitis in shoemakers. Contact Dermatitis 1996; 34: Anonim [Internet]; Available from: Last accessed 11 March Indonesia accelerates in the footwear race [Internet]; Available from: Last accessed 11 March United nations commodity trade statistics database [Internet]; Available from: Last accessed 11 March Shoe makers expect hefty increase in exports this year [Internet] Jakarta; Available from: Last accessed 11 March 2011.

19 8. Wiryodiningrat S. Pengetahuan bahan pembuatan sepatu/ alas kaki. 1st ed. Citra Media, Yogyakarta, Indonesia, Anonim [Internet]; Available from: Last accessed 11 Macrh de Groot A, ed. Patch testing: Test concentration and vehicles for 4350 chemicals. 3rd edition ed. The Netherlands: Acdegroot publishing; Nordic occupational skin questionnairre-nosq Nordic questionnaire for surveying work-related skin diseases on hands and forearms and relevant exposures. [Internet]. Denmark: Nordic Council of Ministers, Copenhagen Available from: Susitaival P, Flyvholm MA, Meding B, et al. Nordic occupational skin questionnaire (NOSQ- 2002): A new tool for surveying occupational skin diseases and exposure. Contact Dermatitis 2003; 49: Lachapelle JM and Maibach, HI. Clinical relevance of patch test reactions. In: Patch testing and Prick testing, 2nd, Lachapelle J.M. and Maibach, H.I. ed. Springer-Verlag, Berlin Heidelberg, 2009: Todd L, Puangthongthub ST, Mottus K, Mihlan G, Wing S. Health survey of workers exposed to mixed solvent and ergonomic hazards in footwear and equipment factory workers in Thailand. Ann Occup Hyg 2008; 52: Tiwari RR. Child labour in footwear industry: Possible occupational health hazards. Indian J Occup and Environ Med 2005; 9: Mayan O, Pires A, Neves P, Capela F. Shoe manufacturing and solvent exposure in Northern Portugal. Appl Occup Environ Hyg 1999; 14: Lenderink AF, Zoer I, van der Molen HF, Spreeuwers D, Frings-Dresen MH, van Dijk FJ. Review on the validity of self-report to assess work-related diseases. Int Arch Occup Environ Health 2012; 85: Febriana SA, Jungbauer F, Soebono H, Coenraads PJ. Inventory of the chemicals and the exposure of the workers' skin to these at two leather factories in Indonesia. Int Arch Occup Environ Health 2012; 85: