A Study on the Factors Affecting Safety Behaviors and Safety Performance in the Manufacturing Sector: Job Demands-Resources Approach

Abstract

(1) Background: The dynamic nature of workplaces highlights the urgent need for effective strategies to promote a safe working environment and enhance workers’ well-being. These strategies must address both organizational safety performance and individual safety behaviors. (2) Methods: This study employed the job demands-resources (JD-R) model to examine the impact of workplace factors on safety behaviors and organizational safety performance among 3255 manufacturing companies. The data utilized in this study originate from the 10th Occupational Safety and Health Status Survey by the Korea Occupational Safety and Health Research Institute (KOSHA). (3) Results: Occupational stressors involving physical and psychological risks (job demand) significantly reduced employees’ adherence to safety practices while increasing workplace diseases and accidents. Conversely, when job resources were effectively mobilized to bolster individual resources, safety behaviors improved, and the incidence of workplace diseases and accidents decreased. Middle managers’ safety competency emerged as a critical moderating factor in these relationships, amplifying the positive impact of job resources. (4) Conclusions: The results highlight the necessity of managing physical and emotional hazards while enhancing middle managers’ abilities to promote workplace safety. A multidimensional approach is essential for preventing workplace accidents and improving safety outcomes. Implementing a comprehensive stress management system is particularly vital to safeguarding workers in the manufacturing industry.

1. Introduction

The workplace, where individuals spend more than 70% of their time, is evolving from a mere site for task execution to a space where daily life unfolds [1,2,3]. As the workplace’s role transforms, its psychological meaning for individuals is also shifting, becoming an integral part of their overall well-being. Consequently, the modern workplace is increasingly seen as a domain oriented toward the pursuit of happiness and safety [4,5,6].

Research on workplace safety has primarily concentrated on methods to provide a safe work environment that enhances individual well-being [5,6,7,8]. With the expanding concept of the workplace, there is a growing need to broaden the management perspective that highlights the importance of providing an environment where individuals can safely perform their tasks [9,10].

To ensure the safe and sustainable operation of an organization, an integrated perspective is essential. This includes the establishment of management policies and guidelines that address field-specific risks while ensuring operational continuity. Additionally, providing a safe workplace as a living space is increasingly recognized as a component of a company’s social responsibility. Therefore, this study proposes that the establishment of a comprehensive safety and health management system within an organization can serve as a critical job resource, promoting safe work practices among employees and positively influencing their safety engagement and attitudes.

This study explores the establishment and implementation of an occupational safety and health management system as a crucial job resource and examines its impact on individual safety behaviors and organizational safety performance in manufacturing environments characterized by high physical and mental risk factors. This study, based on the Job Demands-Resources (JD-R) model [11,12,13,14], considers workplace (industrial site) risk factors as independent variables reflecting job demands. The organization’s safety and health management attitude, culture, system, and competency are considered moderating variables that indicate job resources. Meanwhile, workplace safety behaviors and the incidence of occupational accidents and diseases are analyzed as dependent variables.

Applying the JD-R model is theoretically appropriate, as it offers a structured approach to understanding the impact of workplace characteristics on employee well-being and performance. The JD-R model posits that job demands, including physical and psychological stressors, place substantial strain on employees, potentially leading to adverse outcomes such as burnout, diminished safety behaviors, and heightened accident risks [15,16,17,18]. Conversely, job resources—such as an effective occupational safety and health management system—can mitigate the negative effects of job demands by providing employees with the necessary support, training, and organizational commitment to safety [1,9,10].

Given that manufacturing environments are inherently associated with high levels of physical hazards and mental stressors, the JD-R model offers a strong theoretical framework for examining the complex interplay between workplace risk factors, safety management practices, and safety outcomes [12,15,19]. Prior research has highlighted the importance of safety climate, managerial engagement, and training programs in enhancing safety behaviors and reducing workplace risks [2,5,20]. By incorporating both job demands and job resources, this study broadens the application of the JD-R model to occupational safety, offering insights into how organizations can strategically implement safety management systems to improve individual and organizational safety performance [6,8,17,21].

The decision to focus on manufacturing workers as research subjects was driven by the unique characteristics of manufacturing environments, where the diversity of risks posed by physical factors is greater and the likelihood of accidents is higher compared to other industries [11,12]. Consequently, the manufacturing sector was selected as the target industry for this study.

2. Materials and Methods

2.1. Research Subjects

In this study, we conducted a comprehensive analysis of the factors that influence workplace safety behaviors and outcomes using the JD-R model. Excessive job demands, including environmental, physical, and mental hazards, may drain employees’ physical and emotional reserves, potentially leading to burnout. This depletion may result in reduced safety behaviors and an increased incidence of occupational accidents and diseases. However, our goal was to investigate if creating a workplace with adequate job resources—including senior executives’ dedication to safety, robust systems and culture oriented toward safety, and competent middle-management safety leadership—could help restore workers’ depleted resources and improve safety outcomes.

The study utilized data from the 10th Occupational Safety and Health Status Survey conducted by KOSHA. This data aims to provide empirical evidence for shaping industrial safety and health policies in response to the evolving complexity of modern workplaces in South Korea. Traditionally, safety measures focused on machinery and chemical hazards, but recent approaches have expanded to encompass safety culture, organizational structure, and communication systems. This survey captures these shifts, offering a comprehensive overview of safety conditions across multiple industries.

The survey targeted safety and health managers or business owners in workplaces insured under the national industrial accident compensation system, covering the manufacturing, seven other industries, and construction sectors. Data were collected through in-person interviews using tablet-based electronic questionnaires. For this study, we specifically focused on data from manufacturing workplaces, which were structured as panel data. From the data, we extracted a sample of 3255 manufacturing companies for analysis.

Table 1. Sample Characteristic: Company Size.

Company Size by Number of Employees	No. of Companies	Percentage (%)
20~49	2273	69.8
50~99	572	17.6
100~299	301	9.3
300~	109	3.3
Total	3255	100

shows the breakdown of organizations according to their size in the research sample.

2.2. Measurement and Research Hypotheses

The JD-R framework serves as a solid foundation for exploring the impact of job environments on employees’ psychological well-being, thereby impacting safety behavior, burnout, and organizational commitment [13,14,15,16]. This model highlights two primary mechanisms: (i) burnout intensifies as job demands increase, though it can be alleviated through the provision of job resources, and (ii) motivation is positively correlated with the availability of sufficient job resources, thereby promoting work vitality and engagement [16].

In this study, we conceptualized the independent, dependent, and moderating variables in alignment with the JD-R model. Specifically, the independent variable of job demands was split into three categories: environmental hazards, physical risks, and mental stressors. Each of these categories contributes to safety risks and employee burnout. The moderator, job resources, encompassed key elements including senior management’s attitudes toward safety, the existing safety systems and culture, along with middle managers’ proficiency in safety practices. The dependent variable was operationalized at two levels: individual-level safety behaviors and organizational-level outcomes, the latter encompassing the incidence of accidents and occupational diseases, which were quantified by incidents per employee, with adjustments made for severity.

2.2.1. Measurement Instrument

In this study, all items, with the exception of the company’s safety outcomes, a 5-point Likert scale was used to measure these variables (1 = not at all dangerous/not at all serious/not at all true, 5 = very dangerous/very serious/very true). Job demands were evaluated through a set of 15 items examining environmental hazards, 5 items targeting physically strenuous factors affecting workers, and 7 items addressing psychological factors. Job resources were evaluated using 3 items concerning senior management’s attitudes toward safety, 10 items examining the organization’s safety and health practies and culture, and 4 items assessing the safety-related competency of middle managers.

Workplace safety outcomes were analyzed at both the individual and organizational levels. At the individual level, we examined workers’ safety behaviors, which were assessed using 3 items. At the organizational level, we evaluated the incidence of occupational accidents and diseases. Specifically, the number of accidents and diseases was quantified based on total incidents per worker during 2020 and 2021. The severity of cases was adjusted by assigning weights: incidents with a treatment period of 90 days or more were weighted twice as heavily as those with a treatment period between 4 and 89 days, and fatalities were weighted three times as much as those cases with a treatment period of 4 to 89 days [17].

Key variables in this study were measured using specific items designed to capture various dimensions of job demands and resources and employees’ safety behavior. The “Job Demand (Environment)” dimension includes items that assess environmental hazards, such as noise, extreme temperatures, vibration, and exposure to chemicals (Cronbach’s Alpha = 0.911), indicating high internal consistency. The “Job Demand (Body)” dimension focuses on physical demands, such as prolonged standing, awkward postures, and repetitive movements (Cronbach’s Alpha = 0.860).

The “Job Demand (Stress)” dimension evaluates stressors, including emotional labor, long working hours, and workplace violence (Cronbach’s Alpha = 0.842), suggesting solid reliability in measuring stress-related job demands. The “Job Resource (Top Management Safety Attitude)” dimension is assessed through items related to leadership’s commitment to safety (Cronbach’s Alpha = 0.885), reflecting strong internal consistency. The “Job Resource (Safety/Health Culture & System)” dimension includes items that evaluate the company’s safety culture, employee involvement in safety discussions, and the effectiveness of safety regulations (Cronbach’s Alpha = 0.923).

The “Job Resource (Middle Managers’ Safety Competency)” dimension is measured using items that assess middle managers’ roles, competence, and contributions to safety management (Cronbach’s Alpha = 0.923). In addition, “Workers’ Safety Behavior” is measured using items that evaluate adherence to safety procedures, willingness to refuse unsafe work, and proactive safety behaviors (Cronbach’s Alpha = 0.829).

All Cronbach’s Alpha values exceed the threshold of 0.7, confirming that the measurement items exhibit sufficient internal consistency and are suitable for use in this study.

2.2.2. Research Hypothesis

This study aims to examine the impact of job demands on workers’ safety behavior and the prevalence of occupational accidents and diseases, using the JD-R model as a conceptual framework. Our analysis positioned job demands as stressors that deplete workers’ resources, leading to burnout [13,14,15,16]. We propose that these job demand factors likely impair safety behaviors and increase workplace accidents and diseases. Hence, we formulated Hypothesis 1 (H1) as follows:

• H1: Job demands will negatively impact workers’ safety behavior and organizational safety outcomes.
• H1a: Workers’ safety behavior will decrease as environmental, physical, and psychological hazards (job demands) increase.
• H1b: The incidence of occupational accidents and diseases will increase as environmental, physical, and psychological hazards (job demands) increase.

We further investigated whether job resources weaken the job demands’ influence on safety outcomes at individual and organizational levels. Specifically, we investigated whether factors such as safety attitudes of top executives, organizational culture and system of safety, and safety competence of managers could mitigate the job demands’ negative impact. Our aim was to assess whether these job resources could enhance safety behaviors and reduce the occurrence of occupational accidents and health issues.

• H2: Safety attitude of top management, the culture and systems oriented toward safety, and competency of middle managers regarding safety (job resources) will have a moderating effect on the relationship among job demands, workers’ safety behavior, and organizational safety outcomes.
• H2a: The negative relationship between job demands and workers’ safety behavior will be weakened as job resources increase.
• H2b: The positive relationship between job demands and the incidences of occupational accidents and diseases will be weakened as job resources increase.

3. Results

3.1. Reliability, Validity, and Correlation Between Variables

The relationships among variables were analyzed using SPSS version 25.0, employing exploratory factor analysis (EFA), correlation assessments, and hierarchical regression techniques. To validate the measurement items, we conducted an EFA using principal component analysis with varimax rotation. The results indicated that all items had factor loadings above 0.50, confirming that each variable was appropriately classified under its designated construct.

We assessed the reliability of each construct using Cronbach’s alpha, with all values exceeding 0.80, indicating high internal consistency among the measurement items. Specifically, we found that Cronbach’s alpha for job demands—hazardous work environment (0.911), physically demanding tasks (0.860), and mental stress (0.842)—demonstrated strong reliability. Similarly, we confirmed the reliability of job resources, including safety attitude of top executives (0.885), culture and systems of safety and health (0.923), and middle managers’ safety competency (0.923). Additionally, we verified that worker safety behavior exhibited a Cronbach’s alpha of 0.829, further supporting the internal consistency of the construct.

Table 2. Descriptive Statistics and Correlation Analysis Results.

	Variables	M	SD	1	2	3	4	5	6	7	8	9	10	11	12
1	Size 20~49	0.70	0.46
2	Size 50~99	0.18	0.38	−0.70
3	Size 100~299	0.09	0.29	−0.49	−0.15
4	Safety Dept.	0.11	0.32	−0.36	0.05	0.24
5	ISO 45001	0.25	0.43	−0.16	0.03	0.11	0.16
6	JD (Environment)	10.73	0.59	−0.18	0.04	0.14	0.22	0.00	(0.91)
7	JD (Body)	20.08	0.78	−0.18	0.08	0.11	0.14	−0.02	0.71	(0.86)
8	JD (Stress)	10.70	0.56	−0.11	0.04	0.08	0.05	−0.03	0.49	0.48	(0.84)
9	JR (Top Management Safety Attitude)	40.54	0.59	0.07	0.00	−0.05	−0.03	0.02	−0.21	−0.21	−0.27	(0.89)
10	JR (Safety Systems & Culture)	40.23	0.60	0.01	0.01	0.01	0.03	0.12	−0.21	−0.24	−0.32	0.71	(0.92)
11	JR (Middle Manager Safety Competency)	40.21	0.66	0.09	0.00	−0.07	−0.07	0.07	−0.24	−0.25	−0.32	0.58	0.70	(0.92)
12	Safety Behavior	40.23	0.66	0.06	0.00	−0.04	−0.04	0.05	−0.28	−0.30	−0.33	0.62	0.77	0.66	(0.83)
13	No. of Diseases & Accidents	0.01	0.04	0.01	−0.01	−0.01	−0.01	0.01	0.08	0.08	0.04	−0.01	−0.02	−0.04	−0.06

Notes: Job Demand (JD); Job Resource (JR); Numbers on the diagonal indicate Cronbach’s alpha coefficients; Company size dummy variables use firms with 300 or more employees as the reference group; Coefficients equal to or greater than |0.04|are significant at p < 0.05.

presents correlation analysis results, which generally support the proposed hypotheses. We identified significant positive correlations among job demands, including hazardous work environments (r = 0.71, p < 0.05), physically demanding tasks (r = 0.48, p < 0.05), and mental stress (r = 0.49, p < 0.05), indicating that these workplace risk factors tend to occur together. Similarly, job resources, such as safety attitude of top executives (r = 0.71, p < 0.05), safety and health culture and systems (r = 0.58, p < 0.05), and safety competency of middle managers (r = 0.70, p < 0.05), exhibited positive correlations, indicating that organizations with strong safety leadership tend to establish well-developed safety systems and employ competent middle managers.

The correlation coefficients were negative for job demands and job resources (r = −0.24 to −0.32, p < 0.05), as well as for job demands and worker safety behaviors (r = −0.28 to −0.33, p < 0.05). These findings suggest that higher workplace risk factors are associated with lower availability of safety resources and reduced compliance with safety behaviors. Conversely, we found that job resources were positively correlated with worker safety behaviors (r = 0.62 to 0.77, p < 0.05), supporting the hypothesis that stronger safety management enhances employees’ adherence to safety protocols.

Furthermore, worker safety behavior was negatively correlated with the incidence of occupational accidents and diseases (r = −0.06, p < 0.05), which show that higher levels of safety compliance are associated with fewer workplace injuries and illnesses. In contrast, job demands were positively correlated with occupational accidents and diseases (r = 0.04 to 0.08, p < 0.05), further reinforcing the adverse effects of workplace stressors on safety outcomes.

Additionally, company size variables followed expected trends. Smaller firms (20–49 employees) exhibited negative correlations with the presence of a safety department (r = −0.36, p < 0.05) and ISO 45001 certification (r = −0.16, p < 0.05) [18], suggesting that larger organizations are more likely to implement formal safety management systems.

3.2. Hypothesis Verification of the Main Effect of Job Demands

The hierarchical regression analysis results for hypothesis verification are presented in

Table 3. Results of Hierarchical Regression Analysis (Job Demand: Environment).

Variables		Safety Behavior		No. of Diseases/Accidents
		Model 1	Model 2	Model 3	Model 4
Control Variable	Size 20~49	0.166 ***	0.008	−0.024	−0.040
	Size 50~99	0.139 ***	0.006	−0.044	−0.055
	Size 100~299	0.090 ***	0.000	−0.014	−0.024
	Safety Department	0.034	−0.019	−0.030	−0.034
	ISO 45001	0.055 ***	−0.014	−0.018	−0.019
Independent Variable	Environment (JD)	−0.287 ***	−0.164 †	0.135 ***	0.348 **
Moderator	Top Management Safety Attitude (JR) (A)		0.211 ***		0.128
	Safety Systems & Culture (JR) (B)		0.604 ***		−0.171 †
	Middle Manager Safety Competency (JR) (C)		−0.031		0.194 **
Interaction	Environment (JD) × (A)		−0.239 †		−0.170
	Environment (JD) × (B)		−0.177		0.300
	Environment (JD) × (C)		0.484 ***		−0.338 †
R2		0.091	0.641	0.018	0.023
ΔR2			0.550 ***		0.005 †
F		44.469 ***	394.976 ***	8.143 ***	5.075 ***

Note: † p < 0.10, ** p < 0.01, *** p < 0.001.

,

Table 4. Results of Hierarchical Regression Analysis (Job Demand: Body).

Variables		Safety Behavior		No. of Diseases/Accidents
		Model 1	Model 2	Model 3	Model 4
Control Variable	Size 20~49	0.158 ***	0.008	−00.024	−0.036
	Size 50~99	0.144 ***	0.010	−0.049	−0.059
	Size 100~299	0.081 **	−0.002	−0.014	−0.019
	Safety Department	0.012	−0.028 *	−0.020	−0.021
	ISO 45001	0.049 **	−0.014	−0.016	−0.019
Independent Variable	Body (JD)	−0.294 ***	−0.192 *	0.130 ***	0.394 **
Moderator	Top Management Safety Attitude (JR) (A)		0.210 ***		0.057
	Safety Systems & Culture (JR) (B)		0.605 ***		−0.067
	Middle Manager Safety Competency (JR) (C)		−0.043		0.171 **
Interaction	Body (JD) × (A)		−0.251 †		−0.015
	Body (JD) × (B)		−0.208		0.083
	Body (JD) × (C)		0.564 ***		−0.325 †
R2		0.097	0.641	0.018	0.022
ΔR2			0.544 ***		0.004 †
F		47.461 ***	3940.091 ***	70.853 ***	40.857 ***

Note: † p < 0.10, * p < 0.05, ** p < 0.01, *** p < 0.001.

and

Table 5. Results of Hierarchical Regression Analysis (Job Demand: Stress).

Variables		Safety Behavior		No. of Diseases/Accidents
		Model 1	Model 2	Model 3	Model 4
Control Variable	Size 20~49	0.189 ***	0.027	−0.063	−0.078
	Size 50~99	0.157 ***	0.018	−0.068	−0.079 †
	Size 100~299	0.098 ***	0.002	−0.031	−0.036
	Safety Department	−0.010	−0.037 **	−0.016	−0.015
	ISO 45001	0.057 ***	−0.013	−0.021	−0.021
Independent Variable	Stress (JD)	−0.308 ***	−0.132	0.035 †	−0.011
Moderator	Top Management Safety Attitude (JR) (A)		0.167 **		0.058
	Safety Systems & Culture (JR) (B)		0.538 ***		−0.158
	Middle Manager Safety Competency (JR) (C)		0.096 †		0.120
Interaction	Stress (JD) × (A)		−0.115		−0.008
	Stress (JD) × (B)		−0.011		0.225
	Stress (JD) × (C)		0.205 **		−0.168
R2		0.108	0.633	0.003	0.006
ΔR2			0.525 ***		0.003
F		53.687 ***	380.762 ***	1.144	1.213

Note: † p < 0.10, ** p < 0.01, *** p < 0.001.

. Concerning Hypothesis 1a, which posits that job demands negatively influence workers’ safety behaviors, we find robust support for this hypothesis. Specifically, our analysis reveals that hazardous work environments (β = −0.287, p < 0.001), physically demanding work (β = −0.294, p < 0.001), and mental stress (β = −0.308, p < 0.001) are all significantly negatively associated with safety behaviors (Model 1 in Table 3, Table 4 and Table 5). The findings indicate that heightened job demands detrimentally impact the safety behaviors of employees, underscoring how hazardous working conditions weaken workers’ compliance with safety guidelines and practices. The magnitude of the coefficients further emphasizes the substantial role job demands play in shaping employees’ safety-related behaviors.

For Hypothesis 1b, which hypothesizes a positive relationship between job demands and the incidence of accidents and diseases, we obtain mixed but insightful results. In Model 3 of Table 3, Table 4 and Table 5, we observe that dangerous work environments (β = 0.135, p < 0.001) and physically demanding work (β = 0.130, p < 0.001) significantly increase the number of accidents and diseases, providing strong support for the hypothesis that certain physical job demands contribute directly to the occurrence of occupational incidents. However, mental stress (β = 0.035, p < 0.10) shows only a marginally significant positive relationship with the incidence of accidents and diseases. This suggests that while mental stress may influence the occurrence of occupational accidents, its effect is less pronounced compared to environmental and physical job demands. These results imply that environmental and physical job demands are more strongly associated with adverse safety outcomes at the organizational level, while mental stress has a less immediate effect on accident rates and disease incidence.

In conclusion, our regression results highlight the critical role that environmental and physical job demands play in shaping safety behaviors and accident and disease outcomes in the workplace, with mental stress contributing to safety-related outcomes to a lesser extent. These findings underscore the importance of addressing both physical hazards and environmental risk factors in occupational safety management strategies.

3.3. Hypothesis Verification of the Moderating Effect of Job Resources

3.3.1. Relationship Between Job Demands, Job Resources, and Safety Behaviors

Hypotheses 2a and 2b examine the moderating effects of job resources on the relationship between job demands, worker safety behaviors, and the incidence of occupational accidents and diseases. Hypothesis 2a suggests that job resources alleviate job demands’ negative impact on worker safety behavior. In analyzing hazardous work environments as a job demand (Model 2 in Table 3), we observe that the interaction between a dangerous work environment and the safety competency of middle managers (β = 0.484, p < 0.001) is statistically significant. The finding reveals that middle managers’ competence in safety significantly reduces the harmful impact of hazardous work environments on employees’ adherence to safety practices. Furthermore, the interaction between a hazardous work environment and top management’s safety attitude (β = −0.239, p < 0.10) is marginally significant, suggesting a less pronounced but still notable moderating role of top management’s safety attitude in the context of hazardous work environments.

To better illustrate these interaction effects, we categorized the moderator variables into two groups based on ±1 standard deviation from the mean and then plotted the results. The plotted interaction effect reveals a significant pattern: in hazardous work environments, a higher safety competency of middle managers is associated with improved safety behaviors among workers (see Figure 1b). This suggests that the presence of competent middle management can buffer the negative consequences of hazardous environments on safety behavior by providing more effective safety leadership, training, and support.

In contrast, the interaction between hazardous work environments and top management’s safety attitude presents a somewhat unexpected pattern (see Figure 1a). In hazardous work environments, a stronger safety attitude from top management is associated with lower worker safety behavior. This result is marginally significant and suggests that, in certain contexts, the safety attitudes of top management may not always translate into improved safety behaviors at the worker level. It may indicate a disconnect between organizational safety policies and their practical implementation on the ground or the potential for top management’s safety attitude to be perceived as insufficient or overly top-down rather than fostering a supportive environment for workers.

These findings highlight the complex interplay between hazardous work environments, job resources, and employees’ safety practices. Notably, the safety-related expertise of middle management emerges as particularly effective, while top management’s safety attitude, although important, may require further alignment with practical safety measures to effectively support worker safety behavior in high-risk environments.

The analysis of physically demanding work (Model 2, Table 4) revealed a significant interaction between physically demanding work and middle managers’ safety competency (β = 0.564, p < 0.001), indicating that higher safety competency among middle managers correlates with increased worker safety behavior (Figure 2b). Unexpectedly, the interaction between physically demanding work and top management’s safety attitude (β = −0.251, p < 0.10) was marginally and negatively significant, suggesting that a stronger safety attitude from top management is associated with lower worker safety behavior (Figure 2a).

Regarding mental stress as a job demand (Model 2, Table 5), middle managers’ safety competency (β = 0.205, p < 0.001) significantly moderated the mental stress—safety behavior relationship. Figure 3 demonstrates that employees continue to exhibit strong safety practices despite psychological stress if middle managers have a high level of safety competence. Thus, Hypothesis 2a received partial support.

3.3.2. Relationship Between Job Demands, Job Resources, and Number of Occupational Accidents and Diseases

Hypothesis 2b investigates job resources’ moderating effects on the job demands—the incidence of occupational accidents and diseases relationship. In analyzing the impact of a hazardous work environment (Model 4 in Table 3), the results reveal a marginally significant moderating effect of safety competency of middle managers (β = −0.338, p < 0.10). This suggests that when middle managers possess higher safety competency, the incidence of accidents and diseases remains relatively stable, regardless of the risk level in the work environment. Figure 1c further illustrates this moderating effect, showing that in high-risk environments, the competency of middle managers plays a critical role in controlling the rates of accidents and diseases, indicating the protective role that competent middle management can have in high-risk workplaces.

Similarly, when examining physically demanding work (Model 4, Table 4), the moderating influence of safety competence of middle management was marginally significant (β = −0.325, p < 0.10). As shown in Figure 2c, the presence of competent middle managers helped maintain accident and disease rates at a controlled level, even in the context of physically demanding work. This finding reinforces the idea that middle management’s safety competency acts as a protective resource, buffering the negative consequences of demanding physical work on the health and safety of workers. In contrast, no significant moderating effect was found for mental stress in relation to the incidence of accidents and diseases (Model 4, Table 5). This lack of significant interaction suggests that mental stress, while a notable job demand, may not have the same degree of modulation through job resources, such as middle managers’ safety competency when compared to more physically tangible demands.

In conclusion, the findings partially support Hypothesis 2b. While middle managers’ safety competency was found to have a significant moderating effect on the relationship between hazardous work environments, physically demanding work, and the incidence of occupational accidents and diseases, no significant moderating effect was observed for mental stress as a job demand. These findings imply that the safety competency of middle managers serves as a valuable asset in handling environmental and physical hazards at work, although it might be less effective in reducing the negative impact of psychological stress on safety-related outcomes.

4. Discussion

This study examines the moderating role that job resources play, particularly middle managers’ safety-related skills and knowledge, in the job demands—safety outcomes relationship in manufacturing environments. The results offer a refined understanding of how job demands—encompassing hazardous work conditions, physically demanding activities, and psychological stressors—influence employees’ safety-related behaviors and the frequency of occupational accidents and diseases. The results indicate that unsafe working conditions and physically strenuous duties deplete workers’ physical and psychological reserves, resulting in diminished safety behaviors and an increased likelihood of workplace accidents and diseases. Although these results support prior research highlighting job demands’ harmful effects on performance concerning safety [17,19], this study extends existing knowledge by illustrating the significant influence middle managers have in attenuating these adverse effects. Specifically, when middle managers exhibit strong safety competencies, they significantly enhance workers’ safety behaviors, even in high-risk environments [20,21]. This underscores the importance of middle managers in effectively translating safety policies into actionable measures at the operational level.

The interaction between job demands and middle managers’ safety competencies was particularly pronounced in hazardous and physically demanding environments. In these contexts, middle managers with higher safety competencies exhibited superior risk management capabilities, thereby fostering safer behaviors among workers. These findings suggest that middle managers, due to their direct involvement in daily operations, are well-positioned to identify potential hazards, implement safety measures, and provide hands-on leadership to reinforce safety protocols. By contrast, while the safety attitudes of top management play a critical role in shaping organizational safety culture, their direct influence on workers’ safety behaviors appeared less consistent. Notably, the moderating effect of top management’s safety attitudes was found to be marginally significant and negative. Specifically, a stronger safety attitude from top management was associated with lower worker safety behavior in hazardous work environments and physically demanding tasks. This suggests that top-level safety policies may be ineffective when they fail to address the specific, context-dependent challenges encountered by workers in high-risk settings [20]. This finding underscores a potential disconnect between strategic safety policies formulated by top management and the operational realities experienced by workers, a gap that middle managers are uniquely positioned to bridge.

Furthermore, the study highlights the pivotal role of middle managers’ safety competencies in moderating the relationship between job demands and the incidence of occupational accidents and diseases. In environments characterized by hazardous conditions and physical strain, middle managers with strong safety competencies effectively helped sustain lower rates of occupational accidents and diseases, even when job demands were high. The result extends beyond the traditional view of the role of middle managers, demonstrating their broader role in mitigating workplace risks [19,20]. The implications of this result are particularly significant in industries characterized by high physical risks, where top management’s policies alone may not be sufficient to ensure compliance with safety regulations and to reduce occupational health risks. By illustrating that middle managers serve as a critical buffer between job demands and safety outcomes, this study provides empirical support for organizational strategies aimed at enhancing middle managers’ safety competencies as a key mechanism for improving workplace safety.

While middle managers’ safety competencies clearly moderated the impact of hazardous and physically demanding job conditions, their effect in relation to mental job demands was less definitive. Despite middle managers’ safety-related skills aiding employees in sustaining better safety practices amid psychological stress, as evidenced by the significant interaction observed in Model 2 (Table 5), there was no notable interaction between psychological stress and competencies of middle management in predicting accident and disease rates. This suggests that psychological job demands may necessitate distinct intervention strategies beyond conventional safety management practices. These findings highlight the growing significance of psychological factors in workplace safety and underscore the need for further investigation into the effects of mental stress and emotional exhaustion on safety outcomes [20]. Additionally, the results indicate that safety management programs should incorporate targeted strategies that address psychological stressors alongside physical hazards to more effectively promote occupational health and safety.

The findings of this study advocate for a comprehensive approach to occupational safety that extends beyond the management of physical hazards. By incorporating psychological job demands, such as mental stress, this study offers a more holistic perspective on workplace safety. The moderating role of middle managers’ safety competencies in physical and psychological job demands emphasizes the necessity of an integrated safety management approach. Organizations should consider broadening their middle management training programs to encompass not only hazard identification and risk mitigation but also the recognition and management of psychological stressors that affect workers’ well-being and safety performance [21]. Developing tailored training initiatives that simultaneously address physical and psychological safety challenges is essential for fostering a resilient and safety-conscious workforce.

This study complements the occupational safety literature by revealing how job resources, particularly middle managers’ safety-related skills, can buffer the negative impact of job demands on safety-related outcomes. The findings highlight the essential function middle managers serve in improving workplace safety conditions, particularly in high-risk industries. Moreover, they highlight the necessity of a balanced approach that integrates physical and psychological job demands into safety management frameworks. Future research should explore how job resources, including middle managers’ competencies, can be effectively developed and tailored to enhance safety behaviors and reduce occupational accidents and diseases across diverse industrial contexts. Given the increasing relevance of psychological job demands, subsequent studies should also investigate interventions specifically designed to mitigate the impact of mental stressors on workplace safety.

5. Conclusions

This research advances occupational safety scholarship by emphasizing the pivotal role middle management play in promoting safety behaviors and reducing the negative impact of job demands. Our results suggest that while hazardous and physically strenuous working conditions typically diminish safety behaviors and elevate accident and disease rates, middle managers’ safety competencies are instrumental in improving workplace safety-related outcomes. The ability of middle managers to effectively manage safety practices and support safety culture directly influences safety behaviors within organizations. Therefore, organizations must prioritize the development of middle managers’ safety competencies as a core component of their broader safety strategies. By enhancing the safety management capabilities of middle managers, organizations can create safer work environments and reduce risks associated with high job demands, thus improving overall safety performance [11,12,13].

Furthermore, our study highlights the need for an integrated approach to safety management that addresses both physical and psychological job demands. Our research demonstrates that mental stress significantly impacts safety performance, suggesting that psychological aspects of job demands warrant closer attention in future studies. Mental stress can affect workers’ cognitive and emotional responses to safety protocols, leading to reduced safety compliance and an increased risk of accidents [14]. We recommend that future research explore the effects of psychological job demands, such as mental stress and emotional exhaustion, on safety performance. This investigation could offer valuable insights into how psychological factors interact with physical hazards, informing the development of comprehensive safety interventions that address both physical and psychological aspects of workplace safety [20,22,23,24].

In addition to examining the psychological factors affecting safety performance, we suggest that future studies explore the safety competencies of middle managers across different industries and organizational contexts. This would help determine the applicability of our findings across various settings, including industry types, geographic regions, and organizational cultures. Exploring how these competencies differ and impact safety performance across various contexts will enhance the generalizability of our findings and offer greater insights into the challenges organizations encounter in diverse environments [21,24].

Another crucial area for future research involves developing more reliable and standardized measurement tools to assess safety competencies accurately. The absence of such tools limits the ability to consistently evaluate and compare the effectiveness of safety interventions across organizations [16]. Standardized tools would provide a robust foundation for future research and interventions, ensuring that safety programs are better tailored to support workers’ needs and reduce occupational accidents and diseases. By establishing reliable measurement criteria, organizations can also make cross-organizational comparisons, providing valuable insights into the effectiveness of their safety practices [25,26,27].

There are several limitations to consider when interpreting the study findings. A notable limitation is its cross-sectional nature, which prevents definitive conclusions about causality among the study variables. Longitudinal studies would offer a more comprehensive understanding of how these variables interact over time and allow for a better assessment of cause-and-effect relationships [16]. Second, our focus on manufacturing environments means that the generalizability of the findings to other industries or regions is uncertain. To address this limitation, we suggest that future research examine the applicability of these findings in various industries and international settings, expanding the scope and relevance of the research [15,23].

Furthermore, our study utilized participants’ self-assessments of safety behaviors and job demands, which could introduce response bias. While self-reports are commonly used in safety research, they are susceptible to social desirability bias and other inaccuracies. To mitigate this limitation, we recommend that future studies incorporate objective measures of safety performance, such as direct observations of safety-related behaviors [13,17,24]. These objective indicators would provide more accurate and reliable data, allowing for the validation and triangulation of self-reported findings. Addressing these issues will lead to a more comprehensive understanding of safety management, supporting the development of interventions that integrate physical and psychological factors to enhance overall safety performance.