1- Associate Prof., Dept of Occupational Health, School of Health,
Shiraz University of Medical Sciences, Shiraz, Iran. 2- Expert in Dept of
Occupational Health, School of Health, Student Research Committee, Shiraz
University of Medical Sciences, Shiraz, Iran. 3- Lecturer, Dept of Environmental Health Engineering, School of Health,
Shahrekord University of Medical Sciences, Shahrekord, Iran.
Abstract Received: May 2013, Accepted: March 2014
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Background: Safety signs provide information as well as
instructions concerning the hazard or dangers in the workplace. The correct
comprehension of these signs is very important for doing the necessary
feedback in the specific situation which are described.
Materials and methods: In this descriptive study, the comprehension of 10
selected safety signs were investigated in 53 randomly selected employees of
an industrial company in Shiraz. The comprehension test was carried out with
the aid of a standard questionnaire obtained from ISO 9186-1:2007.
Results: In this study the mean comprehension scores of the
tested signs were 65.95 percent with standard deviation if 28.7. The highest
and lowest comprehension scores were for “use hearing protectors” and
“biological hazard” respectively. The comprehension of 40 percent of the tested
safety signs was lower than the minimum acceptable values of ISO 3864 and
ANSI Z535.3 standards.
Conclusion: This study showed that there is a significant
difference in comprehensions of tested safety signs. For full comprehension
of safety signs it is necessary to train the employees or add supplementary
texts to the symbols in some cases.
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Key
words: Safety,
Signs, workplace, color, culture
Introduction
Safety signs
are one of the methods of informing and warning the staff regarding the type
and severity of the workplace dangers and are used considering the risk of
dangers where necessary (1-3). According to International
Standard Organization (ISO) 17724: 2003, a safety sign is a sign which transfers a safety
message. In fact, when the signs are accompanied by colors, geometrical figures
and graphical signs, they transfer a specific safety message (4).
In general,
safety signs may represent a danger, dangerous conditions, or consequences of
being exposed to dangers (5,6). Also, some signs include cautions and safety
recommendations for the individuals who execute unsafe and dangerous behaviors;
and, at the same time, show the way to prevent such behaviors (3). Based on some
studies, various factors such as the level of education, working experience,
working time (7-9), type of safety signs (10,11), backgroundcolor
of safety signs and training (12-14) affect the individuals’ comprehension of the
safety signs. Yet, cultural differences are also effective in comprehension of
safety signs (15).
For instance,
Chan et al. conducted a study in U.S. and showed that the Chinese and Korean
residents of U.S. comprehend the safety signs less than the Americans. Besides,
comprehension of some signs was quite difficult for non-Americans (16).
Furthermore,
safety signs can be beneficial if they are diverse and attractive. Also, people
should be able to understand these signs because in cases they do not
understand the messages, they will not be able to recognize the dangers and
take the necessary precautions (17). According to National Safety Council,
deficiency in the correct information transfer by the safety signs is the third
common factor in investigation of the incidents (18). The studies conducted by Chan
& Chan showed that safety signs have to be evaluated regarding their
correct comprehension by people before use (19). Thus, the staff’s familiarity
with these signs is of great importance in order to have a correct understanding
of the signs and their responsibilities in case of being exposed to dangers.
Based on what
was mentioned above and considering the fact that most safety signs in Iran are
adopted from other countries, the present study aims to determine the comprehensibility
of the workplace safety signs and present strategies for improving their
comprehensibility.
Materials
and Methods
The present
cross-sectional study was conducted in one of the industrial companies of
Shiraz, Iran in 2013. According to the sections 2, 3 and 6 of ISO 9186-1, at
least 50 individuals from each country should take part in each safety signs
comprehension test. Therefore, 53 non-colorblind staff of the above mentioned
company were randomly selected for taking part in the safety signs
comprehension test using the table of random numbers. The study data were
gathered using the standard questionnaire of International Standard
Organization (20) on quantification of safety signs comprehension. The validity
of the questionnaire was confirmed by 3 safety and ergonomics professors. This
questionnaire contained open-ended questions and consisted of 4 sections: 1-
how to complete the questionnaire, 2- demographic characteristics including
age, sex, level of education, health status and type of probable disability, 3-
an example of how to complete the safety signs comprehension test and 4- the
safety signs comprehension test.
After all, ten
8×8 colored, back labeled signs, including 4 prohibition signs, 2 mandatory
signs, 2 warning signs and 2 signs related to safe conditions, were randomly
selected and glued on ten A4 papers. The used safety signs and their meanings
are presented in table 2.
The data were
analyzed using the SPSS statistical software (v. 11.5) and the staff’s
responses to the safety signs comprehension test were compared with the
acceptable ranges of American
National Standards Institute (ANSI) Z535.3 (21)and ISO 3864 (22)standards.
Since the wrong answers which reversely transfer the safety signs’ meanings are
highly important, these answers were separately investigated.
Results
In this study,
89.1% of the participants were male and the rest were female. In addition, 35.5%, 44.6%, 19.2% and 7% of the subjects were 20-30,
31-40, 41-50 and >51 years old, respectively. Twenty three point
eight percent of the study's participants had under high school diploma
degrees, 52.1% had high school diplomas and 25.1% had academic degrees (table1).
It should be noted that all the study subjects were healthy.
Table 1: Some demographic characteristics in one industrial company
(n= 53)
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level of education
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Job tenure
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Age
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23.8%
52.1%
25.1%
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Under Diploma
Diploma
academic degrees
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43.5%
42.2%
7.5%
3.4%
3.4%
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<5
5-10
10-15
15-20
>20
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35.5%
44.6%
19.2%
0.7%
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20-30
31-40
41-50
>51
|
|
|
|
|
|
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The tested safety signs and their comprehension rate by the study
subjects are presented in table 2.
As the table depicts, the mean score of correct comprehension
(correct responses) was 70.94+27.38.
Discussion
In the present
study, correct responses were considered as the criteria for correct
comprehension of the safety signs. The relatively high standard deviation of
the correct responses (27.38%) shows that the comprehension of these safety
signs was significantly different from each other and each sign has had its own
specific comprehension pattern. According to the results, the mean of correct
responses to the studied safety signs was 70.94% which is in agreement with the
study performed by Ng et al (3) on the Chinese students in Hong Kong. In that
study, 67.54% of the participants answered the study safety signs correctly.
Based on the standard
number ISO 3864 (22) of the International Standard Organization and standard
number ANSI Z535.3 of ANSI (21), the mean of correct responses to safety signs
must be at least 67% and 85% of the study subjects, respectively.
The results
show no significant relation between some demographic characteristics such as
age, job and level of education with the mean of the correct responses to
safety signs (Pval> 0.05). These results could be existed due to
the small size of the sample.
According to
Table 2, the mean of correct responses to 5 signs investigated in this study;
i.e., “First aid”, “Use ear protection”, “Toxic material”, “No smoking” and
“Emergency exit”, was above 85%. Therefore, they had the minimum rate of American
National Standards Institute (21). Considering the International Standard Organization's
standards, in addition to the 5 above mentioned signs, the mean of correct
comprehension of “Not drinking water” sign was also above 67%. Thus, the mean
of correct responses was below the acceptable ranges in ISO 3864 and ANSI
Z535.3 (21) standards in 40% of the signs, including “Arrange correctly”,
“Biological danger”, “Do not operate the device” and “Don’t repair”. In the
study by Ng et al., (3) the mean of correct comprehension of 60% of the studied
safety signs was below the acceptable ranges of ISO 3864 (22) and ANSI Z535.3 (21)
standards. Also, in the study of Papastavrou
and Lehto (14) only 5.88% and 35.29% of the study signs satisfied the
acceptable ranges of ANSI (21) and ISO (20-22). On the other hand, Manop
conducted a study and showed that 79% of the studied safety signs in Thailand
chemical industries achieved the acceptable criterion of 85% (10). Yet, one
other study which was performed in the Intensive Care Units (ICUs) of China showed
that among the tested signs, 3 and 4 satisfied the acceptable ranges of ANSI
and ISO, respectively (19).
Based on what
was mentioned above, it seems that the differences, in the correct
comprehension rates of safety signs in various studies are related to the
cultural differences, the features of the study population, previous training
and the commonness of the sign in the study industry.
In the present
study, although the staff knew the overall concepts of the safety signs, the
results showed that the percentage of incorrect answers to the signs which were
less used in that industry was significantly high. For instance, 57.4% of the
study subjects had incorrectly answered to “Do not operate the device” sign. In
other words, this sign was not able to completely introduce itself and had low
self-explanation. This was also the case for “Biological danger” sign which
received the lowest rate of correct responses (30.18%) because it was quite
uncommon in the study industry. In contrast to the other signs, the form of
this sign was also quite unfamiliar to the study subjects. On the other hand,
98.11% of the participants provided correct answers to “No smoking” sign
because this sign is quite common in both the society and the workplace.
Overall, the signs which were more commonly used in the industry had a higher
comprehension level. This is in line with the results of other studies
conducted on the issue (14, 19).
In the case that
the concept of a safety sign is reversely transferred, its utilization in
safety conditions is of utmost importance. According to ANSI Z535.3 (21) standard,
the acceptable rate of reverse responses is 5% and a sign with above 5% reverse
responses is considered as a confusing one. As Table 2 depicts, in this study,
2 reverse responses (3.8%) were related to “Emergency exit” sign and 1 (1.88%)
was related to “Arrange correctly” sign, which is within the acceptable range
of ANSI standard. In other words, based on ISO 3864 (22) standard, the designed
safety signs were appropriate and not confusing. In spite of the fact that the “Emergency
exit” sign is one of the main safety signs and all the industrial workers are
expected to be familiar with this sign, 11.4% of the responses to this sign
were incorrect, reverse and no response and 1.9% were “I don’t know”. This
might be due to the lack of the staff’s training regarding the meaning of this
sign. In such cases, the text is recommended to be written under the sign.
Conclusions
The findings of
the current study showed differences in the rate of correct comprehension of
different study safety signs. In this study, the rate of correct comprehension
of 40% of the safety signs was below the minimum acceptable range of ISO 3864 and
ANSI Z535.3 standards. The staff’s familiarity with the signs, training them
regarding the meanings of safety signs and sometimes writing texts under the
signs can significantly affect their comprehension of the signs.
Acknowledgements
The present study was financially supported by Student
Research Committee of the research vice-chancellor of Shiraz University of
Medical Sciences, Shiraz, Iran (No; 90-5867).
Conflict of interest: Non
declared
References
1.
Cox S, Jones B, Rycraft H. Behavioral approaches to
safety management within UK reactor plants. Saf Sci 2004; 42(9): 825-39.
2.
Luria G, Rafaeli A. Testing safety commitment in
organizations through interpretations of safety artifacts. J Safety Res 2008;
39(5):519-28.
- Ng, AWY, Lo HWC,
Chan AHS. Measuring the usability of safety signs: A use of System
Usability Scale (SUS). Proceeding of the International Multi Conference of
Engineer and Computer Scientists; 2011 March 16-18; Hong Kong. IMECS 2011;
2. P1-6.
- ISO 17724:2003 graphical symbols-vocabulary. International Organization for
Standardization, Geneva, Switzerland. Available from:
http://www.iso.org/iso/catalogue_detail.htm?csnumber=33186
5.
Wogalter MS, Conzola VC, Smith-Jackson TL.
Research-based guidelines for warning design and evaluation. Appl Ergon 2002; 33(3):219-30.
6.
Jorgensen F, Wentzel-Larsen T. Optimal use of
warning signs in traffic. Accid Anal Prev 1999; 31(6):729-38.
7.
Piamonte DPT, Abeysekera JDA, Ohlsson K.
Understanding small graphical symbols: a cross-cultural study. Int J Ind Ergon
2001; 27(6):399-404.
8.
Edworthy J. The design and implementation of
non-verbal auditory warnings. Appl Ergon 1994; 25(4):202-10.
9.
Belz SM, Robinson GS, Casali JG. A new class of
auditory warning signals for complex systems: auditory icons. Hum Factors 1999;
41(4):608-18.
- Chunin M.
Factors determining compliance with safety signs in industrial settings. [PhD
Thesis]. Sydney: University of New South Wales; 2001.
- Lehto M, Salvendy
G. Warnings: a supplement not a substitute for other approaches to safety.
Ergonomics 1995; 38(11):2155-63.
- Chan AH, Ng AW.
Effects of sign characteristics and training methods on safety sign
training effectiveness. Ergonomics 2010; 53(11):1325-46.
Yu RF, Chan AHS, Salvendy G. Chinese
perceptions of implied hazard for signal words and surround shapes. Human
Factors and Ergonomics in Manufacturing & Service Industries 2004; 14(1):69-80.
13. Papastavrou JD, Lehto MR. Improving the
effectiveness of warnings by increasing the appropriateness of their
information content: some hypotheses about human compliance. Saf Sci 1996; 21(3):175-89.
- Gherardi S,
Nicolini D. Learning the trade: A culture of safety in practice.
Organization 2002; 9(2):191-223.
- Chan AHS, Han
SH, Ng AWY, Park W. Hong Kong Chinese and Korean comprehension of American
security safety symbols. Int J Ind Ergon 2009; 39(5):835-50.
- Arphorn S,
Augsornpeug N, Srisorrachatr S, Pruktharathikul V. Comprehension of safety
signs for construction workers: Comparison of existing and newly designed
signs. J Hum Ergol 2003; 32(7):87-94.
- NSC 2008. National Safety Council annual report. National Safety Council.
Available from: http://www.nsc.org/news
- Chan KL. Chan
AHS. Understanding industrial safety signs: implications for occupational
safety management. Industrial Management & Data Systems 2011; 111(9):1481-510.
- ISO 9186-1:2007.
Graphic1al symbols-test methods-part 1: Methods for testing
comprehensibility. International Organization for Standardization, Geneva,
Switzerland. Available from:
http://www.iso.org/iso/catalogue_detail.htm?csnumber=41090
- America.
American National Standards Institute. American national standard for
Criteria for safety symbols. National Electrical Manufacturers
Association. NewYork; 2011.
- ISO 3864-2:2004.
Graphical symbols-safety colours and safety signs-part 2: Design
principles for product safety labels. International Organization for
Standardization. Geneva, Switzerland. Available from:
http://www.iso.org/iso/catalogue_detail.htm?csnumber=31020.
