An integrated holistic approach to health and safety in confined spaces

CO2 utilization for methanol production: a review on the safety concerns and countermeasures

The catalytic conversion of carbon dioxide is one of the important ways to achieve the goal of carbon neutralization, which can be further divided into electrocatalysis, thermal catalysis, and photocatalysis. Although photocatalysis and electrocatalysis have the advantages of mild reaction conditions and low energy consumption, the thermal catalytic conversion of CO2 has larger processing capacity, better reduction effect, and more complete industrial foundation, which is a promising technology in the future. During the development of new technology from laboratory to industrial application, ensuring the safety of production process is essential. In this work, safety optimization design of equipment, safety performance of catalysts, accident types, and their countermeasures in the industrial applications of CO2 to methanol are reviewed and discussed in depth. Based on that, future research demands for industrial process safety of CO2 to methanol were proposed, which provide guidance for the large-scale application of CO2 thermal catalytic conversion technology.

Gas migration characteristics in vehicle tank under different ventilation conditions

In recent years, due to the frequent occurrence of accidents in confined space operations, horizontal ammonia tank trucks with higher accident frequencies were selected for numerical simulation research through comparative analysis. The ammonia concentration variation characteristics of horizontal ammonia tank cars were simulated under four conditions: natural ventilation with 0° incoming air, natural ventilation with 45° incoming air, mechanical ventilation with extraction, and mechanical ventilation with compression. The results indicate that natural ventilation requires 48 h to reduce the ammonia concentration to a safe range for operation, while mechanical ventilation reduces the ammonia concentration to infinity and approaches zero within 30 min according to regulations, making the working environment safer; Set up monitoring points inside the tank to monitor the gas disturbance inside the tank at different wind speeds. Based on the ammonia concentration cloud map and the monitoring point wind speed, it can be concluded that local ammonia accumulation is more likely to occur on both sides of the tank due to poor ventilation. Comparing and analyzing the simulated values with theoretical calculations and experiments, it was found that there are differences in the degree of gas change but the overall trend is the same. This indicates that ventilation simulation and the determination of ammonia migration characteristics have practical significance for guiding on-site operations.

Helmet-Mounted Real-Time Toxic Gas Monitoring and Prevention System for Workers in Confined Places

Occupational health and safety hazards associated with confined places are mainly caused by exposure to toxic gases and oxygen deficiency. Lack of awareness, inappropriate monitoring, and improper evacuation methods can lead to worker fatalities. Although previous studies have attempted to develop systems to solve this issue, limited research is available on their application in confined places. In this study, a real-time helmet-mounted system was developed to monitor major toxic gases (methane (CH₄), hydrogen sulfide (H₂S), ammonia (NH₃), and carbon monoxide (CO)), oxygen, temperature, and humidity. Workers outside and inside confined spaces receive alerts every second to immediately initiate the rescue operation in the event of a hazard. The test results of a confined environment (wastewater treatment unit) highlighted that concentrations of CH₄ and H₂S were predominant (13 ppm). Compared to normal atmosphere, CH₄ concentration was 122- and 130-fold higher in the landfill and digestion tanks, respectively, while H₂S was 36- and 19-fold higher in the primary and secondary clarifiers, respectively. The oxygen content (18.2%) and humidity (33%) were below the minimum required limits. This study will benefit future research to target appropriate toxic gas monitoring and alert workers by studying the existing issues and associated factors in confined places.

Assessment of Knowledge, Attitude, and Practice on Safe Working in Confined Space among Male Water Services Workers in the Central Region of Malaysia

Employee performance in terms of knowledge of job scope, safe working practices, and safety-related attitude at work are used to measure an organization’s success in managing employee welfare and safety to prevent workplace injury and death. This study aims to determine the level of knowledge, attitude, and practice on safe working in confined space among water services workers. A cross-sectional study involving a randomly selected 207 water services workers working in a confined space was performed in the central region of Malaysia. The assessment was performed using a validated Malay self-administered questionnaire. Descriptive statistics, Chi-square test and Logistic regression were used for data analyses. The study’s participants were all men, with a mean (SD) age of 35.2 (8.83) years. The average working duration was 10.8 years. Overall, 67.1% of participants had good knowledge, while 65.7% had a positive attitude. The majority of the workers (60.4%) were found to follow safe working practices. Regression analysis revealed that significant predictors for knowledge were age [Adjusted odds ratio (Adj. OR) 2.793; 95% CI: 1.310, 5.955; p = 0.008] and attitude (Adj. OR 2.127; 95% CI: 1.011, 4.526; p = 0.048). Attitude was influenced by marital status (Adj. OR 4.126; 95% CI: 2.079, 8.186; p < 0.001) and knowledge level (Adj. OR 2.224; 95% CI: 1.025, 4.824; p = 0.043). A positive attitude was the sole predictor influencing the safe practice (Adj. OR; 1.878; 95% CI: 1.041, 3.388; p = 0.036). In conclusion, the workers’ levels of knowledge, attitudes, and practices were relatively satisfactory. Extensive investment in workplace safety and health programs, appropriate training, growth opportunities, and effective employee performance evaluation methodologies may assist workers in performing at their best.

Towards a software architecture to manage occupational safety at grain handling and storage facilities

The study had as objective to evaluate occupational hazards on grain storage unit to define a conceptual model, implemented in an algorithm to manage the grains storage facilities safety standards compliance. Sampling points location were defined for static quantification of noise, dust and heat stress hazards in grains pre-processing operations to indicate the effectiveness of the control measures implemented. Safety standards applied to grain handling and storage facilities were identified and selected. Chart flows were elaborated to the algorithm logics and conceptual modeling. The highest level of noise was present in the grain cleaning operation (99.1 dB), while the expedition operation has the highest level of dust (20.27%). The heat stress was present in the grain drying operation (43.64 WBGT). Noise analysis did not show a difference between grains, only between operations. The flow of corn grain mass caused higher dust concentrations in the expedition operation. The method applied to characterize and quantify the hazards in grain storage units was satisfactory, and it is recommended as standard, for use in corn and soybean grains handling and storage units. The algorithm to manage occupational safety at storage facilities collaborates to monitor the safety compliance on postharvest operations.

Development and Validation of Knowledge, Attitude, and Practice Questionnaire: Toward Safe Working in Confined Spaces

Confined space workers do a wide range of tasks, many of which have a significant risk of hazardous exposure. Hence, a reliable and valid questionnaire is important in assessing the knowledge, attitude, and practice (KAP) of workers in this field. The present study was conducted to develop and validate a questionnaire that could assess the KAP for safe working in a confined space. The questionnaire went through a development and validation process. The development stage consisted of a literature review, expert’s opinion, and evaluation by experts in the field via cognitive debriefing. The validation stage encompassed exploratory and confirmatory parts to investigate the psychometric properties of the questionnaire. A total of 350 participants were recruited among confined space workers from two oil and gas companies in Malaysia. The two-parameter logistic item response theory (2-PL IRT) analysis was used for the knowledge section. Exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) were used in the attitude and practice sections of the validation stage. The development stage resulted in 30 items for knowledge, attitude, and practice sections. Items in the knowledge section showed an acceptable difficulty and discrimination, as noted during the 2-PL IRT analysis. The EFA resulted in a one-factor model for attitude and practice sections, and contained 18 items, with factor loading > 0.4. The Cronbach’s alpha was 0.804 and 0.917 for attitude and practice sections, respectively. The CFA for attitude and practice sections indicated a good model fitness (Raykov’s rho = 0.814 and 0.912, respectively). All items indicated good reliability and valid psychometrics for determining KAP on safe working in a confined space.

Systematic review of occupational hazards at postharvest grain operations

INTRODUCTION

Agriculture stands out in relation to the high number of occupational incidents and diseases. In this sense, grains postharvest operations, such as receiving, precleaning, drying, storage and shipping the grains, are highlighted in the number of injuries and fatalities.

AIM

To identify and extract qualitative and quantitative data related to the main occupational hazards present in grains postharvest operations at preprocessing and storage facilities.

METHODS

A systematic review was carried out in the databases of Science Direct, Scopus and Web of Science for papers published between 1980 and 2019. The abstract should have described a study related to any occupational hazard (physical, chemical, biological, ergonomic and mechanical) and at least one of the occupational hazards should be related to any postharvest operations.

RESULTS AND DISCUSSIONS

In total, 42% of 38 analysed papers were published between 2015 and 2019. Three journals were responsible for 45% of publications related to occupational hazards present in grains postharvest operations. The most part of analysed publications related to confined spaces, grain entrapment, machine entanglement and falls hazards are related to Purdue University's Agricultural Safety and Health Program which applied research in occupational safety at grains postharvest.

CONCLUSIONS

The creation of standardised internationals can collaborate to reduce occupational risks in grain storage units. It is suggested the development of monitoring technologies to obtain real-time information on noise, dust, gases and heat in postharvest operations and equipment. The use of intelligent algorithms can create prevention mechanisms for possible occupational risks and avoid injuries to employees.

Drone-Assisted Confined Space Inspection and Stockpile Volume Estimation

The accuracy of stockpile estimations is of immense criticality to process optimisation and overall financial decision making within manufacturing operations. Despite well-established correlations between inventory management and profitability, safe deployment of stockpile measurement and inspection activities remain challenging and labour-intensive. This is perhaps owing to a combination of size, shape irregularity as well as the health hazards of cement manufacturing raw materials and products. Through a combination of simulations and real-life assessment within a fully integrated cement plant, this study explores the potential of drones to safely enhance the accuracy of stockpile volume estimations. Different types of LiDAR sensors in combination with different flight trajectory options were fully assessed through simulation whilst mapping representative stockpiles placed in both open and fully confined areas. During the real-life assessment, a drone was equipped with GPS for localisation, in addition to a 1D LiDAR and a barometer for stockpile height estimation. The usefulness of the proposed approach was established based on mapping of a pile with unknown volume in an open area, as well as a pile with known volume within a semi-confined area. Visual inspection of the generated stockpile surface showed strong correlations with the actual pile within the open area, and the volume of the pile in the semi-confined area was accurately measured. Finally, a comparative analysis of cost and complexity of the proposed solution to several existing initiatives revealed its proficiency as a low-cost robotic system within confined spaces whereby visibility, air quality, humidity, and high temperature are unfavourable.

Exploring the Contributory Factors of Confined Space Accidents Using Accident Investigation Reports and Semistructured Interviews

Background

The oil and gas industry is one of the riskiest industries for confined space injuries. This study aimed to understand an overall picture of the causal factors of confined space accidents through analyzing accident reports and the use of a qualitative approach.

Methods

Twenty-one fatal occupational accidents were analyzed according to the Human Factors Analysis and Classification System approach. Furthermore, thirty-three semistructured interviews were conducted with employees in different roles to capture their experiences regarding the contributory factors. The content analyses of the interview transcripts were conducted using MAXQDA software.

Results

Based on accident reports, the largest proportions of causal factors (77%) were attributed to the organizational and supervisory levels, with the predominant influence of the organizational process. We identified 25 contributory factors in confined space accidents that were causal factors outside of the original Human Factors Analysis and Classification System framework. Therefore, modifications were made to deal with factors outside the organization and newly explored causal factors at the organizational level. External Influences as the fifth level considered contributory factors beyond the organization including Laws, Regulations and Standards, Government Policies, Political Influences, and Economic Status categories. Moreover, Contracting/Contract Management and Emergency Management were two extra categories identified at the organizational level.

Conclusions

Preventing confined space accidents requires addressing issues from the organizational to operator level and external influences beyond the organization. The recommended modifications provide a basis for accident investigation and risk analysis, which may be applicable across a broad range of industries and accident types.