[Determining service life of respirator cartridge using a simple and practical method: case study in a car manufacturing industry]

For ensuring about proper performance of air-purifying respirators in providing protection against workplace contaminates, it is necessary to change the respirator cartridges before the end of their service life. The aim of this study was determination of service life of organic vapor cartridges using a simple and practical method in a spray painting booth of a car manufacturing industry. NIOSH Multi Vapor software was used for estimating service life of respirator cartridges based on workplace conditions and cartridge specifications. Efficiency of determined service life was investigated using an apparatus for field testing of cartridges in the workplace. The result showed that existing schedule for changing the respirator cartridges is not effective and no longer provide adequate protection for sprayers against organic contaminants while working in a painting booth. It is necessary to change the cartridges before their estimated service life [every 4 hours]. NIOSH Multi Vapor has acceptable efficiency for determining respirator cartridges service life and could be used as a simple and practical method in the workplace. This software could be used as a simple and practical method in the workplace. Moreover, Service life estimated by this software was confirmed by cartridge field test apparatus

[Musculoskeletal injuries and their associated risk factors in office workplaces]

Prevalence of musculoskeletal disorders [MSDs] is high among office workers. Long time seated posture, working with computer, repetitive movements and inappropriate environmental conditions may have causal effects in these disorders. High prevalence rate of MSDs makes ergonomics assessment and working conditions improvement necessary. Designing an assessment checklist and calculating ergonomics indices can be useful in this evaluation. This study was conducted with the objectives of determination of prevalence rate, ergonomics assessment of working condition and determination of factors associated with MSDs among office workers. In this study conducted 400 randomly selected office workers participated. Nordic musculoskeletal disorders questionnaire was applied to determine prevalence rate of MSDs. Working conditions were assessed by the designed ergonomics checklist and ergonomic risk factors were identified. Data were analyzed using statistical tests including t-test, Chi-square and test of proportion by SPSS software [Version 12.0]. The highest prevalence rates of MSDs were reported in lower back and neck regions [49% and 47%, respectively]. Statistical analysis revealed that there were significant association between occurrence of MSDs and calculated ergonomics indices [p<0.05]. The mean of ergonomics index among those suffered from MSDs were less than other healthy workers indicating inappropriate ergonomics conditions. Calculation of OR also revealed that ergonomics conditions was associated with MSDs occurrence among workers [p<0.05]. Totally, 53.3% of the office workers studied had poor working conditions. Awkward working posture and inappropriate workstation design were recognized as the main risk factors in the office workplace. Most ergonomics problems were originated from bad postures and inappropriate design of workstation. Any interventional program for working conditions improvement should, therefore, be focused on these items. Inappropriate table height, improper position of monitor and other office equipment, lack of adjustability of seat and back rest of chair and deep seat were among factors to be considered for working condition improvement

[Evaluation of change schedule of organic vapor respirator cartridges in a petrochemical industry]

In the absence of End of Service Life Indicator [ESLI], a cartridge change schedule should be established for ensuring that cartridges are changed before their end of service life. The aim of this study was determining the efficiency of respirator change schedule and presenting a suitable schedule for changing the cartridges before their end of service life in a petrochemical complex. Required information for change criteria, number and time between changing the cartridges were gathered through the existing records in the industry. Also the highest values of measured environmental conditions were used as a worse case condition for estimation of service life of cartridges. Technical data and specification of used cartridges in the industry were collected through the cartridges manufactures. Manufacturer's service life software was used for estimation of cartridge service life and 10% of threshold limit values were considered for estimation of breakthrough time of cartridges. The results show that there is no effective change schedule for respirator cartridges in the studied industry. Also there was a significant difference between current schedule and developed schedule for changing the respirators in the studied industry. Relying on odor thresholds and other warning properties solely as the basis for changing respirator chemical cartridges is not allowed and a change out schedule should be developed base on workplace conditions and specification of respirator cartridges

[Comprehension of workplace safety signs: a case study in an industrial company in Shiraz]

Safety signs provide information as well as instructions concerning the hazard or dangers in the workplace. The correct comprehension of these signs is very important for doing the necessary feedback in the specific situation which they are described. In this cross sectional study, the comprehension of 10 selected safety signs were investigated in 53 randomly selected employees of an industrial company in Shiraz. The comprehension test was carried out by aid a standard questionnaire obtained from ISO 9186-1:2007. In this study the mean comprehension scores of the tested signs was 65.95 percent with standard deviation if 28.7. The highest and lowest comprehension scores were for "use hearing protectors" and "biological hazard" respectively. The comprehension of 40 percent of tested safety signs was lower than the minimum acceptable values of ISO 3864 and ANSI Z535.3 standards. This study showed that there is a significant difference in comprehensions of tested safety signs. For full comprehension of safety signs it is necessary to train the employees or adding supplementary text to the symbols in some cases

[Work schedule-related health problems in petrochemical industries workers]

Shift work is programmed in various schedules, each has its own advantages and disadvantages. The main purposes of this study were: a] to determine common shift schedules used in petrochemical industries, b] to compare shift work health-related problems among employees working in different shift schedules and c] to recommend appropriate shift schedule. This cross-sectional study was carried out at 14 petrochemical companies. Study population consisted of 987 shift workers. Data on demographic features, shift schedule and adverse effects of shift work were collected via anonymous questionnaire. Statistical analyses were performed using SPSS, version 11.5. Among 987 studied shift employees, 27% worked in 3M-3E-3N-3Res, 61% in 4M-4E-4N-4Res and 12% in 12-hour schedules. Health problems such as gastrointestinal, cardiovascular and musculoskeletal disorders among 4M-4E-4N-4Res schedule shift workers were significantly less prevalent than other schedules [P<0.05]. Furthermore, the results showed that the prevalence rates of health problems among 12-hour schedule shift workers were higher than 3M-3E-3N-3Res schedule workers. Since 12-hour schedule caused higher rates of gastrointestinal, cardiovascular and musculoskeletal disorders among shift workers as compared with 4M-4E-4N-4Res and 3M-3E-3N-3Res schedules, it should be avoided in shift system. Based on the results, 8-hour schedules with clockwise rapid rotation are recommended

[Shift work-related health problems among petrochemical industries employees]

Shift work is a major feature of working life that affects diverse aspects of human life. The objective of this study was to investigate shift workrelated health problems and their associated risk factors among employees of petrochemical industries. This cross-sectional study was carried out at 14 petrochemical companies in 2009. Study population consisted of 2357 workers [including 43.7% shift workers and 56.3% day workers]. Data on personal details, shift schedule and adverse effects of shift work were collected by anonymous questionnaire. Statistical analyses were performed using SPSS, version 11.5. The level of significance was set at <5%. The mean of age in day workers and shift workers was estimated 36.26 +/- 8.20 and 34.96 +/- 8.08, respectively. Also, the mean of job tenure in both groups was estimated 10.83 +/- 7.50 and 10.15 +/- 7.55 years, respectively. Although, the results showed that health problems among shift workers was more prevalent than day workers, but the differences were only significant in relation to gastrointestinal and psychological disorders [P<0.05]. Multiple linear regressions indicated that in addition to shift working, other variants such as long working hours, type of employment, second job, age and education were associated with health problems. Prevalence rates of gastrointestinal and psychological problems among shift workers were significantly higher than those of day workers. Although, working in shift system was the main significant factor associated with the reported problems, other demographic and work variables were also found to have association

[Assessment of organic vapor-respirator cartridge efficiency based on the EN 14387:2004 standard]

Determining the degree of conformity of respirator cartridges with the accepted standards is very important for ensuring their respiratory protection efficiency. The aim of this study was to determine the degree of conformity of organic vapor-respirator cartridges used in different petrochemical companies with the EN 14387:2004 standard. In the first phase of the study, the respirator cartridges used in petrochemical complexes were identified and their specifications obtained from their manufacturers and the relevant technical catalogues. In the second phase, 3 samples of each of the cartridge models were chosen and tested according to the EN 14387:2004 standard. An instrument was especially designed for measuring the breakthrough time of the cartridges. The results showed that the minimum and maximum breakthrough times of cartridges were 29 and 142 minutes, respectively. From all the 10 different cartridge models tested, one had a service life of lower than the minimum standard breakthrough time of 70 minutes. Considering the existence of a non-standard type of cartridge among the samples studied, it is essential to launch a program aiming at ensuring the conformity of cartridge efficiency with the respective standards. Such a program should be developed and implemented by such responsible organizations as the Institute of Standard and Industrial Research of Iran and the Center for Occupational Health and Safety Research and Training of Iran

[Safety climate in a steel-manufacturing plant]

Safety climate is a psychological phenomenon and a sub-component of safety culture, which is usually reflected in the shared workforce's perceptions about the state of safety at any particular time. It can provide an indication of the priority of safety in an organization with regard to other priorities such as production or quality. The objective of this study was to assess the safety climate profile in a steel manufacturing plant in Iran and using the results to improve the level of safety. In this cross-sectional study, the UK Loughborough University Safety Climate Assessment Toolkit was used to assess the safety climate in a steel-manufacturing industry in Iran. Information was collected through interviews and questionnaires, focus group discussions, and direct observations in the filed. Safety climate scores were calculated in 17 themes. A graphic representation of the safety climate scores obtained showed that safety climate in the company is at the medium level [4.80 +/- 2]. The highest and lowest scores were for dimensions of personal priority and need for safety [8.6 +/- 0.8] and accidents and incidents [1 +/- 0.00]. A non-significant correlation was found between worker's education and work experience on the one hand and their attitude towards safety on the other hand [p>0.05]. Both management commitment and personal priority were associated with the workers' age [p= 0.03 and 0.02, respectively], while work environment was associated only with employment status [p = 0.04]. Safety climate assessment can be a proactive safety performance indicator used to improve the level of safety in an organisation

[Assessment of human errors in an industrial petrochemical control room using the CREAM method with a cognitive ergonomics approach]

Today in most of the work environments, such as nuclear, military and chemical industries, human error may result in catastrophic events. A common characteristic of large technological systems is that massive amounts of potentially dangerous materials are kept in one single unit controlled by control room operators. A control room is indeed the heart of a system of this type and any error in task performance by the operators may have undesirable consequences which could never be compensated. In this study we aimed to identify and assess human errors in the control room of the Aromatic Unit of Bouali-Sina Petrochemical Company, Iran using the CREAM method. This was a cross-sectional and analytical-descriptive study carried out in the control room of the Aromatic Unit of Bouali-Sina Petrochemical Company, Iran with 39 operators. After a job analysis by the hierarchical task analysis [HTA], probable control modes and cognitive failure probability were determined for occupational tasks using the basic and the extended CREAM methodologies. Based on the results of the basic CREAM method, control modes for the tasks of action, Boardman and shift control supervisor were determined as Opportunistic Control mode, while for the task of control room head it was obtained as Tactical control mode. With regard to the error types, the following results were obtained on the basis of the extended method of CREAM: execution failure [51.70%], interpretation failure [19.55%], planning failure [14.94%], and observation failure [13.81%]. The basic CREAM method showed the common performance factors [CPCs] leading to reduced performance reliability to be the number of simultaneous tasks, time of day [circadian rhythm], and adequacy and quality of training and experience. These factors caused the operators to choose an opportunistic control mode. In addition, based on the extended CREAM method results, the most noticeable cognitive failure was execution failure. In addition, the most important cognitive activities related to the control process in the control room were communication, execution, diagnosis, monitoring, and planning. Based on these findings, providing instructions and guidelines for work procedures, holding training courses, shift work scheduling, optimization of the communication systems and modifications in the control software are essential to minimize human errors in the Bouali Sina Petrochemical Company control room

[Removal of reactive blue 29 dye from water by single-wall carbon nanotubes]

Anthraquinone dyes such as reactive blue29 in water resources and industrial wastewater effluents are one of the most environmental setbacks in many countries. Various methods have been considered to remove these dyes One of which is adsorption. All adsorption experiments were conducted in different pHs and various concentrations of adsorbents. The initial concentration of reactive blue 29 chosen in this study was 30mg/L.Adsorption isotherms were determined and correlated with Longmuir, Freundlich and BET models. The maximum adsorption capacity of reactive blue 29 onto single wall carbon nanotubes was 496mg/g.Results showed that the best pH for adsorption was 5 followed by pH3 and 8. Kinetic study showed that the equilibrium time for adsorption of RB 29 to SWCNT is 4 hr. According to the results obtained BET isotherm fitted well the experiment. It shows the adsorption of reactive blue 29 onto single wall carbon nanotubes is multilayers and the mechanism of SWCNTs adsorption toward RB29 is based on weak van der waals forces

[Determination of hazard distance of chemical release in a petrochemical industry by chemical exposure index [CEI]]

Toxic chemical release from process installation is one of the main hazards in chemical industries which can endanger the health of employees and public in the neighbours of industry in case of occurring chemical release accident. The aim of this study was determining hazard distance of toxic chemical release in one of petrochemical complex for its applicability in emergency response planning. Different possible scenarios for toxic chemical release was considered and the worse case scenarios including process vessels rupture was selected for hazard distance study by aid of Dow Chemical Exposure Index [CEI]. Among studied chemical tanks including Chlorine, Phenol, Epichlorohydrin [EPI], Chlorobenzene, Toluene, hydrogen chloride, the highest Chemical Exposure Index [CEI] and hazard distance was for Chlorine with CEI of 340 and hazard distance for ERPG 2 and ERPG 3 concentration were 3399 and 1339 respectively. Chemical Exposure Index [CEI] can be used for determining hazard distance of a chemical release accident. Hazard distance data can be used in process installation layout and emergency response planning

[Evaluation of half-face respirator fit in an Iranian petrochemical company's workers]

The performance of respirator-face piece is depending on a good contact between the worker's face and the respirator. Improper sealing can cause reduction in performance of respirators to protect health and safety of workers against risks related to chemical agents at work. This study is aimed to evaluate the fitness of half-face respirators and other related factors on it in an Iranian petrochemical industry. In this cross sectional study, 54 persons using half mask, in a petrochemical complex, were evaluated qualitatively by means of Moldex Kit. The effect of staff training on adjusting and doing seal-check and effects of facial hair and different mask's brand used in the industry on respirator fit was investigated. The data were analyzed using Chi-square and McNemar tests by means of SPSS software. Before intervention 17 [31.5%] of staff out of 54 passed the test. After training, the results improved from 31.5% to 92.6% [P<0.05]. Respirator-face seal in clean-shaven and bearded employees as well as relation of fit test results to different mask's brand using in the industry was not significant. Staff training about providing adequate fit can improve the performance of selection of respirators. Furthermore, by carrying out fit testing as a part of initial selection of respirators, it will be possible to check that the mask size and model chosen fit properly with the face