Risk assessment of educational support staff’s work in schools

Abstract

BACKGROUND:

Educational support staff (educational staff) in schools perform widely distinctive activities according to their occupation and work process.

OBJECTIVE:

This study analyzes the possible incidents for each occupation and work process, and suggests a risk matrix prioritizing the risks of educational staff’s work.

METHODS:

A total of 1,566 injuries of educational staff, registered for occupational injuries and illnesses between 2015 and 2016, were used to develop the risk matrix considering injuries, sick leave days, and disabilities.

RESULTS:

Among the 1,566 injuries, ‘Cook-cooking/serving: Burn’ (8.5%) was the most frequent incident. ‘Cook-manual materials handling (MMH): musculoskeletal disorders (MSDs)’ (241.6 sick leave days) was the most severe incident, and the number of disabilities was high in the forms of ‘Cook-cooking/serving: MSDs.’ According to risk assessment results, possible incidents predicted as ‘High’ level of risk management were in the forms of ‘Cook-cooking/serving: MSDs,’ ‘Cook-MMH: Slip and trip,’ ‘Cook-cleaning/repairing: Fall from a height,’ ‘Cook-walking: Slip and trip,’ ‘Cook-MMH: MSDs,’ ‘Cook-cooking/serving: Burn,’ ‘Cook-cleaning/repairing: Slip and trip,’ ‘Custodian-cleaning/repairing: Fall from a height,’ and ‘Instructor-walking: Slip and trip.’

CONCLUSIONS:

The results can be used to develop an effective injury prevention policy, and to allocate resources for risk management in ensuring school safety.

Keywords

Occupational injury accident analysis school safety safety management risk matrix

1 Introduction

The school is one of the essential institutions of society, and the school-related industry is a large sector comprising a big portion of the service industry [1]. Faculty members in schools can be divided into three distinct categories, including school leader, teacher, and educational support staff (educational staff) [2]. According to the Korean Standard Classification of Occupations (KSCO) [3], the occupations in the educational staff are classified as after-school instructor, custodian, and cooking staff. After-school instructors offer science, physical activity, foreign language, or arts education services [2]. Custodians have patrol duties to ensure the safety of school facilities as well as a responsibility to clean and repair school facilities [4]. The cooking staff prepare and serve the meals of students and teachers, and clean the school kitchen [2].

School safety is an essential issue for public health [4]. Even though educational staff’s work commonly requires heavy physical work with uncomfortable posture [4], most of the studies on school safety have addressed characteristics of accidents among teachers or students [5 –7]. Since educational staff perform very different activities according to their occupation, they are exposed to various risk factors [2 , 9]. Unfortunately, educational staff are usually employed as temporary workers, and perform their duties in various environments without sufficient training to prevent occupational accidents in South Korea [2, 4].

Furthermore, school administrators have no sufficient information to ensure the safety of educational staff. Thus, they have difficulties in allocating resources to minimize the risks involved. Ko and Jeong [2] investigated the characteristics of work-related injuries in educational staff that have occurred within schools. This paper is a follow-up on the previous literature by Ko and Jeong [2], and aims to prioritize the risks involving educational staff’s works.

Risk management is the identification, evaluation, and prioritization of risks, and is an inherent part of an overall risk management strategy [10]. Risk assessment is often used to prioritize incident prevention policies for managing the risks [11]. A risk matrix is used as a tool for ranking and displaying risks by defining ranges for consequence and likelihood [12].

This study investigates the educational staff’s works according to work process and analyzes possible incidents for each work process. Finally, this study suggests the risk matrix to prioritize the risks, considering the frequency and severity of possible incidents.

2 Methods

2.1 Classification of work process and analysis

This study analyzes only the work-related accidents occurring in schools among educational staff, such as the after-school instructor, custodian, and cooking staff [3].

A systematic analysis of the work process is needed to develop a risk matrix for risk management. A focus group interview was carried out in order to obtain information on educational staff’s work process and environment. Six educational staff members were chosen and asked to discuss the work process along with relevant hazardous factors. Cooking staff’s work processes were classified as cooking, food services, cleaning, repairing, manual materials handling (MMH), and walking. Instructor tasks were classified as teaching, activity, cleaning, repairing, MMH, and walking. Custodian tasks were classified as cleaning, repairing, MMH, and walking. Through the process of grouping similar types of work by job type, shown in Table 1, educational staff’s work was classified into five work processes such as teaching, cooking/serving, cleaning/repairing, MMH, and walking.

Table 1
Classification of educational staff’s work

Work process Task Educational support staff Hazardous factors

Cooking staff Instructor Custodian

Teaching Teaching o Unstable objects; Sharp edges;

Activity o Slippery floor/stairs

Cooking/serving Cooking o High temperature; Heavy equipment/objects;

Food serving o Sharp blade; Slippery floor/stairs

Cleaning/repairing Cleaning o o o High temperature; Slippery floor; Sharp edges;

Repairing o o o Unstable fixture; Unstable objects

MMH o o o Heavy objects; Slippery floor; Unstable objects

Walking o o o Slippery floor/stairs; Unstable objects

Work process	Task	Educational support staff	Hazardous factors
Teaching	Teaching		o		Unstable objects; Sharp edges;
	Activity		o		Slippery floor/stairs
Cooking/serving	Cooking	o			High temperature; Heavy equipment/objects;
	Food serving	o			Sharp blade; Slippery floor/stairs
Cleaning/repairing	Cleaning	o	o	o	High temperature; Slippery floor; Sharp edges;
	Repairing	o	o	o	Unstable fixture; Unstable objects
MMH		o	o	o	Heavy objects; Slippery floor; Unstable objects
Walking		o	o	o	Slippery floor/stairs; Unstable objects

Note: MMH = manual materials handling.

2.2 Data collection and subjects

In South Korea, employers must take out industrial accident compensation insurance under the Occupational Safety and Health Act [13 –16]. The statistics of industrial accidents are compiled and maintained by the Ministry of Labor. From the national compensation data, this study examined a total of 1,566 occupational injuries of industrial accidents for the educational staff between 2015 and 2016. Subjects, who were registered for occupational injuries and illnesses, include injured persons of accidents in schools that have taken 4 or more days off following the accident.

Among 1,566 injured educational staff, 1,334 (85.2%) were women, and 232 (14.8%) were men. The 1,566 injured persons were categorized as 269 (17.2%) after-school instructors, 214 (13.7%) custodians and 1,083 (69.2%) cooking workers.

This study concerns the frequency and severity of the injured person. The frequency of injury was represented by the number of injured persons, and the severity of injury was represented by sick leave days. Since there was no death in this study, disability was used as an auxiliary measure of injury severity. Disabilities, approved by ‘procedure for review of award on workers’ compensation insurance eligibility’ under the Industrial Safety and Health Act, refer to any permanent incapacity of body part as a consequence of work-related accidents [17]. Thus, this study investigated the characteristics of injured persons and disabilities. Among 1,566 injured persons, accident-related injured persons were categorized by the work process based on the situation at the time of the accident, and illness-related injured persons such as MSDs were classified by the work process based on the status of the main work that worker performed. Also, injured persons were analyzed in terms of gender of injured persons, age, accident type, and source of accident. In this study, the χ² test was used to test the equality of distribution between dependent and independent variables. SPSS version 18.0 was used with a confidence level of 0.05.

2.3 Risk assessment

This study identified the hazardous factors for each work process from data on occupational injuries. Risk assessment was also carried out to classify the levels of risks [10].

Table 2 shows the classification criterion for the level of incident frequency (frequency level) and the level of incident severity (severity level) and how to obtain the class of risks [10]. The frequency level (F) is indicated by 3 levels, according to the number of injured persons (n₁). The severity level (S) is classified into 3 levels, according to the mean number of sick leave days (M), or the number of disabilities (n₂). The risk score is expressed as F×S. According to the risk scores, the grade of risk management (risk grade) is expressed in 3 degrees: 1 = low: green zone (<3), 2 = medium: yellow zone (3–5), 3 = high: red zone (≥6). The reference values for grading were confirmed through focus group interviews.

Table 2
Definition and classification of incident frequency, incident severity, and risk level

Level Frequency (F) Severity (S) Risk level (C)

F n ^† S d^†† or SL^††† C=F×S Grade Description

High 3 n≥53 3 d ≥8, or SL≥145.0 >5 3 Red zone

Medium 2 30≤n < 53 2 4≤d < 8, or 85.6≤SL<145.0 3–5 2 Yellow zone

Low 1 n<30 1 Otherwise <3 1 Green zone

Level	Frequency (F)	Severity (S)	Risk level (C)
High	3	n≥53	3	d ≥8, or SL≥145.0	>5	3	Red zone
Medium	2	30≤n < 53	2	4≤d < 8, or 85.6≤SL<145.0	3–5	2	Yellow zone
Low	1	n<30	1	Otherwise	<3	1	Green zone

^†Number of injured persons; ^††Number of disabilities; ^†††Mean of sick leave days.

Focus group attendants also addressed the classification criterion for the frequency level and severity level. The Pareto chart is used to set the level of a reference value since the majority of injuries come from a minority of sources. High level of frequency was determined by items which contributed to 60%of injuries. Medium level of reference was determined by items which contributed to 60%of the remaining injuries (= 40%×60%). In Table 2, using the number of injured persons (n₁), 53 and 30 were determined as ‘High’ and ‘Medium’ reference values. In this study, the severity level was determined by the mean of sick leave days (M). The level of ‘High’ severity was derived by the reference value of 145.0 days (= 241.6 days×60%), which is 60%of the average value of the highest group, and 85.6 days (= 142.6 days×60%), which is the remaining 60%. Since the number of disabilities (n₂) was used as an auxiliary measure, the reference value was defined with the frequency which contributed to 30%of total disabilities. By the number of disabilities (n₂), 8 and 4 were determined as ‘High’ and ‘Medium’ reference values.

3 Results

3.1 Characteristics of injured persons and accidents in work processes

3.1.1 Distributions of injured persons by occupation, gender, and age

Table 3 presents the distribution of injured staff by occupation, gender, and age. The result of the χ² test shows that the distribution of injured persons between occupation and gender was significantly different (χ²= 140.9, p < 0.001). Also, there is a significant difference in the distribution of injured persons between gender and age (χ²= 259.2, p < 0.001). The table shows that 67.7%of injured instructors were female, and 75.9%of females were < 50 years old. Injured female instructors provided after-school science experiments, foreign language exercises, and art education services. On the other hand, 72.4%of injured male instructors were < 40 years old, and they mainly directed after-school physical education activities. Among injured custodians, 63.1%were male, and 58.5%of male injured were≥60 years old. Male custodians were mainly in charge of repairing and guarding facilities. In the case of female custodians, 57.0%of injured persons were≥50 years old. They were primarily responsible for administrative assistance and cleaning services. However, 99.1%of injured cooking workers were female, and 65.6%of female workers were≥50 years old. They were responsible for preparing, cooking, serving, and cleaning activities in the kitchen.

Table 3
Distributions of injured persons by gender and occupation

Occupation Gender Age (years) Total

<40 40–49 50–59 ≥60 sum Mean ^† n %_occup ^†† %

Instructor Male 72.4% 20.7% 1.1% 5.7% 100.0% 36.66 87 32.3% 5.6%

Female 47.3% 28.6% 21.4% 2.7% 100.0% 41.29 182 67.7% 11.6%

Instructor 55.4% 26.0% 14.9% 3.7% 100.0% 39.79 269 100.0% 17.2%

Custodian Male 16.3% 11.1% 14.1% 58.5% 100.0% 56.63 135 63.1% 8.6%

Female 25.3% 17.7% 36.7% 20.3% 100.0% 49.52 79 36.9% 5.0%

Custodian 19.6% 13.6% 22.4% 44.4% 100.0% 54.00 214 100.0% 13.7%

Cook Male 50.0% 20.0% 30.0% 0.0% 100.0% 38.90 10 0.9% 0.6%

Female 2.6% 31.8% 59.9% 5.7% 100.0% 51.48 1073 99.1% 68.5%

Cook 3.0% 31.7% 59.6% 5.6% 100.0% 51.36 1083 100.0% 69.2%

Total Male 38.8% 15.1% 9.9% 36.2% 100.0% 48.38 232 14.8% 14.8%

Female 10.0% 30.5% 53.3% 6.1% 100.0% 49.97 1334 85.2% 85.2%

Total 14.3% 28.2% 46.9% 10.6% 100.0% 49.73 1566 100.0% 100.0%

Occupation	Gender	Age (years)	Total
Instructor	Male	72.4%	20.7%	1.1%	5.7%	100.0%	36.66	87	32.3%	5.6%
	Female	47.3%	28.6%	21.4%	2.7%	100.0%	41.29	182	67.7%	11.6%
	Instructor	55.4%	26.0%	14.9%	3.7%	100.0%	39.79	269	100.0%	17.2%
Custodian	Male	16.3%	11.1%	14.1%	58.5%	100.0%	56.63	135	63.1%	8.6%
	Female	25.3%	17.7%	36.7%	20.3%	100.0%	49.52	79	36.9%	5.0%
	Custodian	19.6%	13.6%	22.4%	44.4%	100.0%	54.00	214	100.0%	13.7%
Cook	Male	50.0%	20.0%	30.0%	0.0%	100.0%	38.90	10	0.9%	0.6%
	Female	2.6%	31.8%	59.9%	5.7%	100.0%	51.48	1073	99.1%	68.5%
	Cook	3.0%	31.7%	59.6%	5.6%	100.0%	51.36	1083	100.0%	69.2%
Total	Male	38.8%	15.1%	9.9%	36.2%	100.0%	48.38	232	14.8%	14.8%
	Female	10.0%	30.5%	53.3%	6.1%	100.0%	49.97	1334	85.2%	85.2%
	Total	14.3%	28.2%	46.9%	10.6%	100.0%	49.73	1566	100.0%	100.0%

^†Mean of age; ^†† %in occupation.

3.1.2 Distributions of injured persons by work process and accident type

Table 4 shows the distributions of injured persons by accident type according to the work process. As shown in Table 4, cleaning/repairing work was most frequently involved with injuries (34.9%), followed by cooking/serving (19.9%), MMH (18.9%), walking (18.3%), and teaching (8.0%). While cleaning/repairing work led to the most disabilities (29.7%), followed by cooking/serving (26.1%), walking (18.9%), MMH (18.0%), and teaching (7.2%).

Table 4
Distributions of injured persons and disabilities by accident type and work process

Work process Accident type Injury Disability

n % n %

Teaching Total in Teaching 125 8.0% 8 7.2%

Slip and trip 52 3.3% 3 2.7%

Struck by 39 2.5% 2 1.8%

Cooking/serving Total in Cooking/serving 312 19.9% 29 26.1%

Burn 134 8.6% 5 4.5%

MSDs 96 6.1% 14 12.6%

Cut/wound 33 2.1% 4 3.6%

Caught in object 22 1.4% 4 3.6%

Slip and trip 19 1.2% 1 0.9%

Cleaning/repairing Total in Cleaning/repairing 546 34.9% 33 29.7%

Slip and trip 136 8.7% 11 9.9%

Burn 118 7.5% 1 0.9%

Falls from a height 103 6.6% 11 9.9%

Struck by 97 6.2% 2 1.8%

Caught in object 41 2.6% 5 4.5%

Cut/wound 37 2.4% 3 2.7%

MMH Total in MMH 296 18.9% 20 18.0%

Struck by 95 6.1% 3 2.7%

Slip and trip 79 5.0% 8 7.2%

Burn 56 3.6% 0.0%

MSDs 32 2.0% 7 6.3%

Caught in object 23 1.5% 2 1.8%

Walking Total in Walking 287 18.3% 21 18.9%

Slip and trip 250 16.0% 18 16.2%

Struck by 26 1.7% 2 1.8%

Total 1566 100.0% 111 100.0%

Work process	Accident type	Injury	Disability
Teaching	Total in Teaching	125	8.0%	8	7.2%
	Slip and trip	52	3.3%	3	2.7%
	Struck by	39	2.5%	2	1.8%
Cooking/serving	Total in Cooking/serving	312	19.9%	29	26.1%
	Burn	134	8.6%	5	4.5%
	MSDs	96	6.1%	14	12.6%
	Cut/wound	33	2.1%	4	3.6%
	Caught in object	22	1.4%	4	3.6%
	Slip and trip	19	1.2%	1	0.9%
Cleaning/repairing	Total in Cleaning/repairing	546	34.9%	33	29.7%
	Slip and trip	136	8.7%	11	9.9%
	Burn	118	7.5%	1	0.9%
	Falls from a height	103	6.6%	11	9.9%
	Struck by	97	6.2%	2	1.8%
	Caught in object	41	2.6%	5	4.5%
	Cut/wound	37	2.4%	3	2.7%
MMH	Total in MMH	296	18.9%	20	18.0%
	Struck by	95	6.1%	3	2.7%
	Slip and trip	79	5.0%	8	7.2%
	Burn	56	3.6%	0.0%
	MSDs	32	2.0%	7	6.3%
	Caught in object	23	1.5%	2	1.8%
Walking	Total in Walking	287	18.3%	21	18.9%
	Slip and trip	250	16.0%	18	16.2%
	Struck by	26	1.7%	2	1.8%
Total		1566	100.0%	111	100.0%

Note: MMH = manual materials handling; MSDs = musculoskeletal disorders. Other is ignored, and items with both injury and disability rate of less than 1%are also ignored.

Among 1,566 injured persons, slip and trip during walking (16.0%) was the most frequent, followed by slip and trip during cleaning/repairing (8.7%), burns during cooking/serving (8.6%), burns during cleaning/repairing (7.5%), fall from a height during cleaning/repairing (6.6%), struck by during cleaning/repairing (6.2%), MSDs during cooking/serving (6.1%), struck by during MMH (6.1%), and slip and trip during MMH (5.0%).

On the other hand, among 111 disabilities, slip and trip during walking (16.2%) was the most frequent, followed by MSDs during cooking/serving (12.6%), slip and trip during cleaning/repairing (9.9%), fall from a height during cleaning/repairing (9.9%), slip and trip during MMH (7.2%), and MSDs during MMH (6.3%).

3.1.3 Distributions of injured persons by source of accident and accident type

Table 5 shows the distributions of injured persons and disabilities by source of accident in relevance to accident type. As shown in Table 5, most of the injured persons were caused by slip and trip (34.2%), followed by burn (20.5%), struck by (16.9%), musculoskeletal disorders (MSDs) (9.0%), and fall from a height (7.0%). While most of the disabilities were caused by slip and trip (36.9%), followed by MSDs (18.9%), caught in (10.8%), fall from a height (9.9%), and struck by (9.0%).

Table 5
Distributions of injured persons and disabilities by accident type and source of accident

Accident type Source of accident Injury Disability

n % n %

Slip and trip Total in ‘Slip and Trip’ 536 34.2% 41 36.9%

Floor/stair 443 28.3% 33 29.7%

Building structure 29 1.9% 1 0.9%

School facilities 21 1.3% 2 1.8%

Burn Total in ‘Burn’ 321 20.5% 7 6.3%

Cooking equipment 263 16.8% 7 6.3%

Machinery/tools 19 1.2%

Struck by Total in ‘Struck by’ 264 16.9% 10 9.0%

Cooking equipment 59 3.8% 3 2.7%

School facilities 56 3.6% 3 2.7%

Building structure 44 2.8% 1 0.9%

Cart 43 2.7% 1 0.9%

Machinery/tools 32 2.0% 1 0.9%

Fall from a height Total in ‘Fall from a height’ 110 7.0% 11 9.9%

School facilities 67 4.3% 8 7.2%

Building structure 38 2.4% 3 2.7%

MSDs Total in ‘MSDs’ 141 9.0% 21 18.9%

Cooking equipment 67 4.3% 8 7.2%

Cart 28 1.8% 4 3.6%

Cut/wound Total in ‘Cut/wound’ 88 5.6% 8 7.2%

Machinery/tools 61 3.9% 7 6.3%

Caught in Total in ‘Caught in’ 90 5.7% 12 10.8%

Machinery/tools 44 2.8% 7 6.3%

Building structure 16 1.0% 2 1.8%

Cooking equipment 14 0.9% 2 1.8%

Total 1566 100.0% 111 100.0%

Floor/stair 447 28.5% 33 29.7%

Cooking equipment 424 27.1% 22 19.8%

School facilities 173 11.0% 14 12.6%

Machinery/tools 167 10.7% 16 14.4%

Building structure 139 8.9% 7 6.3%

Cart 101 6.4% 7 6.3%

Accident type	Source of accident	Injury	Disability
Slip and trip	Total in ‘Slip and Trip’	536	34.2%	41	36.9%
	Floor/stair	443	28.3%	33	29.7%
	Building structure	29	1.9%	1	0.9%
	School facilities	21	1.3%	2	1.8%
Burn	Total in ‘Burn’	321	20.5%	7	6.3%
	Cooking equipment	263	16.8%	7	6.3%
	Machinery/tools	19	1.2%
Struck by	Total in ‘Struck by’	264	16.9%	10	9.0%
	Cooking equipment	59	3.8%	3	2.7%
	School facilities	56	3.6%	3	2.7%
	Building structure	44	2.8%	1	0.9%
	Cart	43	2.7%	1	0.9%
	Machinery/tools	32	2.0%	1	0.9%
Fall from a height	Total in ‘Fall from a height’	110	7.0%	11	9.9%
	School facilities	67	4.3%	8	7.2%
	Building structure	38	2.4%	3	2.7%
MSDs	Total in ‘MSDs’	141	9.0%	21	18.9%
	Cooking equipment	67	4.3%	8	7.2%
	Cart	28	1.8%	4	3.6%
Cut/wound	Total in ‘Cut/wound’	88	5.6%	8	7.2%
	Machinery/tools	61	3.9%	7	6.3%
Caught in	Total in ‘Caught in’	90	5.7%	12	10.8%
	Machinery/tools	44	2.8%	7	6.3%
	Building structure	16	1.0%	2	1.8%
	Cooking equipment	14	0.9%	2	1.8%
Total		1566	100.0%	111	100.0%
	Floor/stair	447	28.5%	33	29.7%
	Cooking equipment	424	27.1%	22	19.8%
	School facilities	173	11.0%	14	12.6%
	Machinery/tools	167	10.7%	16	14.4%
	Building structure	139	8.9%	7	6.3%
	Cart	101	6.4%	7	6.3%

Note: MSDs = musculoskeletal disorders. Other is ignored, and items with both injury and disability rate of less than 1%are also ignored.

Table 5 also shows the distributions of injured persons and disabilities by source of accident. Overall, the most injured persons involved the floor/stairs (28.5%), followed by cooking equipment (27.1%), school facilities (11.0%), and machinery/tool (10.7%), while the most disabilities were concerned with the floor/stairs (29.7%), followed by cooking equipment (19.8%), machinery/tool (14.4%), and school facilities (12.6%).

Among 1,566 injured persons, slip and trip at floor/stairs (28.3%) were most frequent, followed by burns by cooking equipment (16.8%), MSDs by cooking equipment (4.3%), fall from a height of school facilities (4.3%), cut/wound by machinery/tool (3.9%), struck by cooking equipment (3.8%), and struck by school facilities (3.6%).

On the other hand, among 111 disabilities, slip and trip at floor/stairs (29.7%) were most frequent, followed by MSDs by cooking equipment (7.2%), fall from a height of school facilities (7.2%), burns by cooking equipment (6.3%), cut/wound by machinery/tool (6.3%), and caught in machinery/tool (6.3%).

3.2 Risk assessment of work of educational staff

3.2.1 Identification of hazard factors and risk assessment

Table 6 is the hazard factor and risk assessment table. A hazard is defined as a potential source of harm to a worker. Possible incidents and hazard factors are derived from integrating the result of cross-table analysis for accident type and source of accident according to occupation. In Table 6, frequency level (F), severity level (S), and risk grade were determined by the classification criterion of Table 2.

Table 6
Risk matrix for hazard factors and possible incidents

Occupation Process Hazardous factor Possible incident Frequency Severity Risk grade^§

n % F ^† d ^‡ SL ^‡‡ S ^††

Instructor Teaching Slippery floor/stairs Slip and trip 49 3.1 M 3 121.5 M M

Unstable objects Struck by 37 2.4 M 2 80.7 L L

Sharp edges, glass Cut/wound 9 0.6 L – 46.7 L L

Walking Slippery floor/stairs Slip and trip 98 6.3 H 5 106.5 M H

Unstable objects Struck by 14 0.9 L – 50.0 L L

Custodian Cleaning/repairing Unstable fixture Fall from height 44 2.8 M 5 181.4 H H

Slippery floor/stairs Slip and trip 33 2.1 M 4 119.4 M M

Unstable objects Struck by 36 2.3 M – 62.9 L L

Sharp edges, glass Cut/wound 24 1.5 L 2 51.3 L L

MMH Unstable objects Struck by 10 0.6 L – 42.2 L L

Walking Slippery floor/stairs Slip and trip 31 2.0 M 2 127.2 M M

Cooking staff Cooking/serving Heavy objects MSDs 96 6.1 H 14 202.0 H H

High temperature Burn 133 8.5 H 5 58.3 M H

Sharp edges, blade Cut/wound 33 2.1 M 4 73.8 M M

Heavy equipment Caught in 22 1.4 L 4 126.5 M L

Slippery floor/stairs Slip and trip 19 1.2 L 1 124.3 M L

Cleaning/repairing Unstable fixture Fall from height 53 3.4 H 5 147.5 H H

Slippery floor/stairs Slip and trip 99 6.3 H 5 105.4 M H

High temperature Burn 113 7.2 H 1 43.7 L M

Unstable objects Struck by 55 3.5 H 2 64.1 L M

Heavy objects MSDs 9 0.6 L – 142.6 M L

Sharp edges, blade Cut/wound 8 0.5 L 1 149.4 H M

Heavy equipment Caught in 36 2.3 M 4 104.2 M M

MMH Slippery floor/stairs Slip and trip 69 4.4 H 8 129.7 H H

High temperature Burn 54 3.4 H – 54.7 L M

Unstable objects Struck by 82 5.2 H 2 83.9 L M

Heavy objects MSDs 30 1.9 M 7 241.6 H H

Heavy equipment Caught in 22 1.4 L 2 87.2 M L

Walking Slippery floor/stairs Slip and trip 121 7.7 H 11 122.5 H H

Occupation	Process	Hazardous factor	Possible incident	Frequency	Severity	Risk grade^§
Instructor	Teaching	Slippery floor/stairs	Slip and trip	49	3.1	M	3	121.5	M	M
		Unstable objects	Struck by	37	2.4	M	2	80.7	L	L
		Sharp edges, glass	Cut/wound	9	0.6	L	–	46.7	L	L
	Walking	Slippery floor/stairs	Slip and trip	98	6.3	H	5	106.5	M	H
		Unstable objects	Struck by	14	0.9	L	–	50.0	L	L
Custodian	Cleaning/repairing	Unstable fixture	Fall from height	44	2.8	M	5	181.4	H	H
		Slippery floor/stairs	Slip and trip	33	2.1	M	4	119.4	M	M
		Unstable objects	Struck by	36	2.3	M	–	62.9	L	L
		Sharp edges, glass	Cut/wound	24	1.5	L	2	51.3	L	L
	MMH	Unstable objects	Struck by	10	0.6	L	–	42.2	L	L
	Walking	Slippery floor/stairs	Slip and trip	31	2.0	M	2	127.2	M	M
Cooking staff	Cooking/serving	Heavy objects	MSDs	96	6.1	H	14	202.0	H	H
		High temperature	Burn	133	8.5	H	5	58.3	M	H
		Sharp edges, blade	Cut/wound	33	2.1	M	4	73.8	M	M
		Heavy equipment	Caught in	22	1.4	L	4	126.5	M	L
		Slippery floor/stairs	Slip and trip	19	1.2	L	1	124.3	M	L
	Cleaning/repairing	Unstable fixture	Fall from height	53	3.4	H	5	147.5	H	H
		Slippery floor/stairs	Slip and trip	99	6.3	H	5	105.4	M	H
		High temperature	Burn	113	7.2	H	1	43.7	L	M
		Unstable objects	Struck by	55	3.5	H	2	64.1	L	M
		Heavy objects	MSDs	9	0.6	L	–	142.6	M	L
		Sharp edges, blade	Cut/wound	8	0.5	L	1	149.4	H	M
		Heavy equipment	Caught in	36	2.3	M	4	104.2	M	M
	MMH	Slippery floor/stairs	Slip and trip	69	4.4	H	8	129.7	H	H
		High temperature	Burn	54	3.4	H	–	54.7	L	M
		Unstable objects	Struck by	82	5.2	H	2	83.9	L	M
		Heavy objects	MSDs	30	1.9	M	7	241.6	H	H
		Heavy equipment	Caught in	22	1.4	L	2	87.2	M	L
	Walking	Slippery floor/stairs	Slip and trip	121	7.7	H	11	122.5	H	H

^† Frequency level (L: Low, M: Medium, H: High); ^††Severity level (L: Low, M: Medium, H: High); ^‡Number of disabilities; ^‡‡Mean of sick leave days; ^§Risk grade (L: Low, M: Medium, H: High); Note: MMH = manual materials handling; MSDs = musculoskeletal disorders; –=no disability

In Table 6, ‘Cook-cooking/serving: Burn’ (8.5%) was the most frequent incident, followed by ‘Cook-walking: Slip and trip’ (7.7%), ‘Cook-cleaning/serving: Burn’ (7.2%), ‘Cook-cleaning/repairing: Slip and trip’ (6.3%), ‘Instructor-walking: Slip and trip’ (6.3%), ‘Cook-cooking/serving: MSDs’ (6.1%), ‘Cook-MMH: Struck by’ (5.2%), ‘Cook-MMH: Slip and trip’ (4.4%), (3.5%), ‘Cook-MMH: Burn’ (3.4%), and ‘Cook-cleaning/repairing: Fall from a height’ (3.4%). Those possible incidents predicted as ‘High’ frequency level according to the number of injured persons (n₁ ≥53) account for 63%of cumulative injured persons. The possible incidents predicted as ‘Medium’ frequency level (30≤n₁ _< 53) is equivalent to 21.0%of cumulative injured persons, which is 58%of the remaining 37%.

Whereas, ‘Cook-MMH: MSDs’ (241.6 sick leave days) is the most severe incident, followed by ‘Cook-cooking/serving: MSDs’ (202.0 days), ‘Custodian-cleaning/repairing: Fall’ (181.40 days), ‘Cook-cleaning/repairing: Cut/wound’ (149.4 days), and ‘Cook-cleaning/repairing: Fall from a height’ (147.5 days). The severity level (S) is classified into ‘High’ level according to the mean of sick leave days (M≥145.0 days), which is 60%of 241.6 sick leave days in ‘Cook-MMH: MSDs.’ The possible incidents predicted as ‘Medium’ severity level according to sick leave days (85.6≤M< 145.0), is 60%of 142.6 days in the same category.

The severity level (S) is classified as ‘High’ according to the number of disabilities (n₂≥8), which accounts for 30%of disabilities. Possible incidents with a ‘High’ severity level are ‘Cook-cooking/serving: MSDs’ (14 disabilities), ‘Cook-walking: Slip and trip’ (11 disabilities), and ‘Cook-MMH: Slip and trip’ (8 disabilities). The possible incidents predicted as a ‘Medium’ severity level according to the number of disabilities (4≤n₂ _< 8), is the remaining 30%.

3.2.2 Risk matrix based on risk assessment

Table 7 shows the risk matrix based on risk assessment. The grading attempts in prioritization in risk management; ‘High’ risk grade (corrective actions for prevention are strongly needed), and ‘Medium’ risk grade (some corrective actions are necessary). Possible incidents predicted as a ‘High’ risk grade are ‘Cook-cooking/serving: MSDs,’ ‘Cook-MMH: Slip and trip,’ ‘Cook-cleaning/repairing: Fall from a height,’ ‘Cook-walking: Slip and trip,’ ‘Cook-cooking/serving: Burn,’ ‘Cook-cleaning/serving: Slip and trip,’ ‘Instructor-walking: Slip and trip,’ ‘Custodian-cleaning/serving: Fall from a height,’ and ‘Cook-MMH: MSDs.’

Table 7
Risk matrix for hazard factors and possible incidents

Severity (S) 3: High 2: Medium 1: Low

d^‡ ≥8, or 4≤d<8, or

Frequency (F) SL^‡‡ ≥145.0 days 85.6≤SL<145.0 days Otherwise

3: High n^†≥53 Cook-cooking: MSDs Cook-cooking: Burn Cook-cleaning: Burn

Cook-MMH: Slip Cook-cleaning: Slip Cook-cleaning: Struck by

Cook-cleaning: Fall Instructor-walking: Slip Cook-MMH: Burn

Cook-walking: Slip Cook-MMH: Struck by

2: Medium 30≤n<53 Custodian-cleaning: Fall Instructor-teaching: Slip Instructor-teaching: Struck by

Cook-MMH: MSDs Custodian-cleaning: Slip Custodian-cleaning: Struck by

Custodian-walking: Slip

Cook-cooking: Cut/wound

Cook-cleaning: Caught in

1: Low n < 30 Cook-cleaning: Cut/wound Cook-cooking: Slip Instructor-teaching: Cut/wound

Cook-cooking: Caught in Instructor-walking: Struck by

Cook-MMH: Caught in Custodian-MMH: struck by

Cook-cleaning: MSDs Custodian-cleaning: Cut/wound

Severity (S)	3: High	2: Medium	1: Low
	d^‡ ≥8, or	4≤d<8, or
Frequency (F)	SL^‡‡ ≥145.0 days	85.6≤SL<145.0 days	Otherwise
3: High n^†≥53	Cook-cooking: MSDs	Cook-cooking: Burn	Cook-cleaning: Burn
	Cook-MMH: Slip	Cook-cleaning: Slip	Cook-cleaning: Struck by
	Cook-cleaning: Fall	Instructor-walking: Slip	Cook-MMH: Burn
	Cook-walking: Slip		Cook-MMH: Struck by
2: Medium 30≤n<53	Custodian-cleaning: Fall	Instructor-teaching: Slip	Instructor-teaching: Struck by
	Cook-MMH: MSDs	Custodian-cleaning: Slip	Custodian-cleaning: Struck by
		Custodian-walking: Slip
		Cook-cooking: Cut/wound
		Cook-cleaning: Caught in
1: Low n < 30	Cook-cleaning: Cut/wound	Cook-cooking: Slip	Instructor-teaching: Cut/wound
		Cook-cooking: Caught in	Instructor-walking: Struck by
		Cook-MMH: Caught in	Custodian-MMH: struck by
		Cook-cleaning: MSDs	Custodian-cleaning: Cut/wound

^†Number of injured persons; ^‡Number of disabilities; ^‡‡Mean of sick leave days; Note: MMH = manual materials handling; MSDs = musculoskeletal disorders; cleaning = cleaning/repairing; cooking = cooking/serving; fall = fall from a height; slip = slip and trip.

Next, possible incidents requiring a ‘Medium’ risk grade were in the forms of ‘Instructor-teaching: Slip and trip,’ ‘Custodian-cleaning: Slip and trip,’ ‘Custodian-walking: Slip and trip,’ ‘Cook-cooking: Cut/wound,’ ‘Cook- cleaning/repairing: Caught in,’ ‘Cook- cleaning/repairing: Burn,’ “Cook-cleaning/repairing: Struck by,’ ‘Cook-MMH: Burn,’ ‘Cook-MMH: Struck by,’ and ‘Cook- cleaning/repairing: Cut/wound.’

Table 8 shows the characteristics of injured persons caused by incidents with ‘High’ risk grade. Table 3 and Table 8 show the high-risk works for which resources and countermeasures for incident prevention should be concentrated. Table 3 shows that 67.7%of injured instructors were women, and 47.3%of women were < 40 years. However, as shown in Table 8, ‘Instructor-walking: Slip and trip’ incidents were mainly occurred by women (86.7%), and 52.0%of these women were < 40 years old.

Table 8

‘High’ level accidents and relevant characteristics of injured

Occupation	Process	Accident type	Age (years)					Gender
			<30	40–49	50–59	≥60	Total	Male	Female
Instructor	Walking	Slip	52.0%	26.5%	18.4%	3.1%	100%	13.3%	86.7%
Cook	Walking	Slip	1.7%	29.8%	61.2%	7.4%	100%	2.5%	97.5%
	Cleaning	Slip	2.0%	31.3%	55.6%	11.1%	100%	0%	100%
	MMH	Slip	1.4%	21.7%	71.0%	5.8%	100%	0%	100%
	MMH	MSDs	3.3%	26.7%	60.0%	10.0%	100%	0%	100%
	Cooking	MSDs	1.0%	21.9%	72.9%	4.2%	100%	1.0%	99.0%
	Cooking	Burn	7.5%	29.3%	58.6%	4.5%	100%	0%	100%
	Cleaning	Fall	1.9%	18.9%	73.6%	5.7%	100%	0%	100%
Custodian	Cleaning	Fall	9.1%	9.1%	18.2%	63.6%	100%	93.2%	6.8%

Note: MMH = manual materials handling; MSDs = musculoskeletal disorders; Cleaning = cleaning/repairing; Cooking = cooking/serving; Fall = fall from a height; Slip = slip and trip.

On the other hand, in Table 3, 99.1%of injured cooks were women, while injured women over age 50 accounted for 65.6%. In Table 8, it was also found that the rate of injured female cooks≥50 years old was relatively high.

In Table 3, the injured male custodians accounted for 63.1%, of which≥50 years old accounted for 72.6%. However, as shown in Table 8, ‘Custodian- cleaning/repairing: Fall from a height’ incidents were mainly occurred by male workers (93.2%) and 81.8%of injured male custodians were≥50 years old. In particular, the percentage of injured male custodians≥60 years old (63.6%) was significantly higher.

4 Conclusion and discussion

Educational staff in schools play an essential role in supporting education. However, they are exposed to various hazards with little or no attention paid to their health status [2]. Thus, this study analyzed the accidents involving educational staff according to work processes, such as the after-school instructor, custodian, and cooking staff.

This study has provided a risk matrix for educational staff based on risk assessment. Also, this leads to a discussion on prevention measures for incidents requiring ‘High’ levels of risk management. According to the results of risk assessment, ‘slip and trip’ incidents during walking, cleaning/repairing, or MMH work in cooking staff were ranked as requiring ‘High’ levels of risk management. This finding confirms those of previous studies that the prevention of slips and falls should be given a high priority [2 , 18–20]. Injuries from slips and falls could be due to insufficient lighting and slippery floors [18]. Providing slip-resistant floors or slip-resistant tape on floors or stairs can be a useful complementary strategy for preventing slips and falls [2, 20]. Also, school administrators should remove water and grease regularly from the floor or stairs, and post warning signs on slippery floors and stairs with sufficient lighting [2, 18].

In the case of school food services, a small number of cooks must prepare a large number of meals for students and teachers at once. Therefore, cooking equipment or materials are large and heavy. These circumstances may yield high energy costs and difficulty in maintaining equilibrium or in securing visibility during MMH [21]. Accordingly, injuries due to slips are often associated with carrying tasks [22]. Carrying heavy and large cooking materials can be dangerous, particularly if the load impairs vision, or if there are uneven surfaces or objects on the floor [23]. A big and heavy load is harder to handle than a compact one of the same weight because it cannot be brought close to the body [21]. Excessive bending and twisting also increase the risk of MSDs [21]. Older workers are weaker and less able to work, so handling heavy objects in a bad posture can lead to back pain or MSDs [21]. Workers should be educated and trained for the correct postures and ergonomic techniques in MMH tasks [22].

Workers use pushing/pulling carts to reduce physical stresses during MMH. However, occupational injury can be caused by overloading components on a cart, insufficient visibility, insufficient maintenance of the caster, or uneven floors [24]. The weight loaded in the cart should be lower than the recommended limits. Also, the workers are required to train the safe handling cart as well as maintain the workplace [24]. Previous studies showed that age has a significant association with MSDs, and the prevalence in female workers is significantly higher than that in male workers [25]. Since women and older workers are more likely to be inferior in physical abilities to handle heavy objects, more efforts are needed in terms of safety devices and technological adaptions in MMH tasks for female workers and older workers [26].

Cooks are frequently exposed to hot pans or fryers, increasing the risk of burns [20]. The hazards of burns were related to high temperatures –in the heat, working around fryers, ovens, and hot dishes [13, 15]. Also, large-sized cooking facilities and dishwashing machines are used in school kitchens. Some common types of machinery used in school kitchens utilize high temperatures and high pressures, and the use of these machines may be unfamiliar to older female workers. Misuse or improper use of this machinery can result in burns. In order to prevent these types of accidents from occurring, cooking staff should be trained before using the equipment and should follow the manufacturer’s instructions for safe operation [20]. Also, providing heat protective gloves or suitable cookware can be a useful complementary strategy for preventing burns [13, 15].

In the case of instructors, slip and trip incidents during walking were ranked as requiring a ‘High’ level of risk management. However, unlike cooking staff, the majority of instructor fall injuries in this study occurred in the female aged < 40 years old. Previous studies showed that the prevalence of slip accidents in female instructors is significantly higher than that in male workers, and most of the injured female instructor workers were < 1 year of experience [2]. Also, teachers that work part-time usually had a higher workload than those with a fixed in their contract [27].

In the case of custodians, falling from a height during cleaning/repairing work was ranked as ‘High’ level of risk management. Custodians are composed mainly of retirees or senior males [2]. Injured male custodians aged > 60 years old accounted for 63.6%. Elderly workers are more susceptible to falling from a height because aging undermines sensory function and perceptive ability, as well as the sense of balance and muscular strength [10]. Injuries caused by falling from a height could be due to insufficient lighting, inadequate maintenance of height, and unstable ladder or fixture. The fall incidents were mainly caused by misstep or loss of footing on a height/fixture, or breakage of a climbing device [10]. The appropriate climbing devices should be selected and provided to ensure natural stride [26]. Adequate training and proper supervision of heights are crucial elements in the prevention of work-related fall incidents.

The school administrators should identify and manage the risk factors of accidents that may occur in school activities. However, school administrators do not have the expertise to secure the safety of educational staff. Problems with labor turnover, low wages, and temporary employment are common in educational staff [28]. Thus, it is highly necessary for school administrators to provide information on the priorities for allocation of resources and measures to prevent accidents. The discussed measures for prevention of incidents requiring ‘High’ level of risk management are summarized in Table 9.

Table 9

Possible incidents, hazard factors, and prevention measures predicted as ‘High’ level

Occupation	Process	Possible incident	Hazard factor	Prevention measures
Instructor	Walking	Slip	Slippery floor/stairs	Slip-resistant floors, Anti-slip tape on floor/stairs
			Wet floor	Water/oil removal
			Uneven floor	Warning signs, maintenance of floor
Cook	Cooking	MSDs	Large and heavy cookware	Two-person loading/unloading
				Provide workspace with adjustable height
				Training for correct postures and techniques
			Uncomfortable posture	Signs for correct carrying
	Cooking	Burn	Hot ovens, steamer, pans	Warning device for high temperature
			Hot oil and broth	Provide heat protective gloves
				Provide suitable cookware and tools
			Unsafe act	Training for safe work
	MMH	Slip	Insufficient visibility	Ensure visibility during carrying
			Slippery floor/stairs	Slip-resistant floors, slip-resistant shoes
			Overloading on cart	Warning device for overloading
			Insufficient maintenance	Maintenance of caster, cart, and floor
	MMH	MSDs	Heavy objects	Two-person carrying
			Overloading on cart	Lading below recommended weight
				Overload warning device
			Uncomfortable posture	Training for correct postures and techniques
				Signs for correct MMH
	Cleaning	Fall	Unstable fixture	Training for safe work at height
			Unsafe act	Sign for correct loading/unloading
				Don’t load heavy objects at high position
	Cleaning	Slip	Slippery floors	Slip-resistant floors, Slip-resistant shoes
			Uneven floor	Warning signs for slips and trips
			Obstacles	Tidy up and eliminating obstacles
	Walking	Slip	Insufficient lighting,	Sufficient lighting
			Obstacles	Tidy up and eliminating obstacles
Custodian	Cleaning	Fall	Insufficient lighting	Sufficient lighting, or portable light
			Fall risk at heights	Warning signs for falls
			Unstable ladder	Appropriate climbing device with locking
				Two-person ladder work

Note: MMH = manual materials handling; MSDs = musculoskeletal disorders; Fall = fall from a height; Slip = slip and trip.

However, there are limitations to the use of these results. This study analyzed workers’ compensation insurance records, which is documented for > 4 days of absence from work. Thus, minor accidents were not included in the analysis. Also, since this study is a descriptive retrospective study of injury records, further research is required to investigate in-depth and qualitative relationships. Finally, a risk matrix for risk management depends on how decision-makers assign risk levels for the possibility and severity of accidents/illnesses. Thus, there is a limitation to the use of the risk matrix developed in this study.

Despite those limitations, this study provides information on priorities for the allocation of resources and measures to prevent accidents for educational staff in schools. The findings of this study can be used to develop accident prevention programs to reduce occupational incidents for educational staff.

Footnotes

Acknowledgments

This research was financially supported by Hansung University. The authors are grateful to the Korea Occupational Safety and Health Agency (KOSHA) for providing the raw data.

Conflict of interest

None to report.

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