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Knowledge and Practices Regarding Usage of Biological Safety Cabinets
Article · January 2017
DOI: 10.1177/1535676016685790
14 authors, including:
Martin Bundi Mwebia
Ernest Wandera Apondi
National Biosafety Authority
Kenya Medical Research Institute
Erick Odoyo
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Knowledge and Practices Regarding Usage
of Biological Safety Cabinets
Applied Biosafety:
Journal of ABSA International
ª ABSA International 2017
Reprints and permission:
DOI: 10.1177/1535676016685790
Gabriel Miring’u1, Martin Bundi2, Betty Kathomi Muriithi1,
Ernest Wandera Apondi1, Amina Ababa Galata1,
Cyrus Njogu Kathiiko1, Eric Omondi Odoyo1, Sora Huka Guyo1,
Obed Nyang’ate Ongubo1, John Odhiambo Ouko1,
Mohammad Karama3, Mohammad Shah1, Shingo Inoue1,
and Yoshio Ichinose1
When properly used and adequately maintained, a biological safety cabinet (BSC) provides protection to the laboratory worker,
the products, and the environment. Knowledge about proper use of the BSC is therefore important. This study evaluated BSC
usage knowledge and practices and the effect of prior experience on training outcomes. Thirteen participants randomly selected
from research centers were evaluated through a structured questionnaire covering biosafety considerations involved in using a
BSC as per the World Health Organization’s Laboratory Biosafety Manual, third edition. The questionnaire was administered before
and after the training. Training was conducted using the NUITM-KEMRI biosafety training program, enhanced to include more
modules on BSCs. Differences in the participants’ knowledge and practices regarding BSC usage were observed. After training,
the participants were able to give correct responses. Furthermore, participants who had fewer years of experience showed the
greatest improvement. Results indicate the need for proper training of laboratory workers early in their careers, coupled with
close supervision, mentorship, and regular refresher training.
biosafety cabinet, laboratory acquired infection, laboratory exposure, training, standard operating procedure
Primary containment is defined as ‘‘the protection of personnel
and the immediate laboratory from exposure to infectious
agents, provided by both good microbiological techniques and
use of appropriate safety equipment.’’1 Biological safety cabinets (BSCs) are primary containment equipment that have been
used to protect experimental materials from crosscontamination and to protect the user and environment from
infectious or hazardous aerosols generated when manipulating
such materials.2 The absence of protection for laboratory workers has largely been linked to laboratory-associated infections
(LAIs). However, Pike3 reported that >80% of LAIs studied
were not traceable to incidents that may have caused them,
indicating the need for close observation of all biosafety strategies. BSCs are capable of separating a laboratory worker
from microorganisms and infectious aerosols produced during
laboratory procedures.4 When properly maintained and used in
combination with good laboratory techniques, BSCs are effective in protecting the environment, reducing LAIs, and decreasing cross-contamination of experimental materials due to
aerosol exposure.5,13
The first design of a BSC was a ventilated hood fitted with a
vacuum pump that drew in air through a cotton filter.4 Earlier,
prototype clean air cubicles were designed to protect the materials being manipulated from environmental or workergenerated contamination rather than to protect the laboratory
worker. To protect the worker, the earliest designs for primary
containment devices were essentially nonventilated ‘‘boxes’’
built of wood and later of stainless steel, within which simple
operations such as weighing materials could be accomplished.
Early versions of ventilated cabinets; the forerunners of the
Class I BSC, did not have adequate or controlled directional
air movement. Thus, since the air was unfiltered, the cabinet
was contaminated with environmental microorganisms and
other undesirable particulate matter. In the 1940s, the High
Institute of Tropical Medicine, Nagasaki University, Nairobi, Kenya
National Biosafety Authority–Biosafety Training and Accreditation, Nairobi,
Umma University, Kajiado, Kenya
Corresponding Author:
Yoshio Ichinose, Institute of Tropical Medicine, Nagasaki University, Kenya
Research Station, NUITM-KEMRI Project, C/O CMR, Nairobi, Kenya.
Email: ichinose@nagasaki-u.ac.jp
Efficiency Particulate Air (HEPA) filter was developed to provide dust-free work environments.4 Later, BSCs incorporating
many of the design features of today’s modern cabinet were
made available, followed by the evolution of the laminar flow
principle in the 1960s. Since then, different companies have
developed and improved their safety cabinets to enhance
There are 3 classes of BSCs: Class I, Class II, and Class III.
Selection and use of the appropriate BSC must be based on a
thorough risk assessment, considering the risk groups and
nature of the organisms to be handled, manipulations to be
conducted, equipment needed, and the nature of the hazards
involved (biological, chemical, and/or radioactive). The overall
risk must also be matched with the biosafety level and the
chemical safety level of the laboratory used.1
To ensure adequate protection for the operator, the laboratory environment, and the experimental materials, one must
therefore choose the appropriate type of BSC, adhere to good
microbiological practices, and ensure that the BSC is properly
maintained and serviced. To achieve this, every employee
working in a BSC must be adequately trained on its correct
use to a level of competence that ensures that each can safely
work with infectious agents.
Nagasaki University Institute of Tropical Medicine, in collaboration with Kenya Medical Research Institute (NUITMKEMRI), conducts annual biosafety training workshops for
new biosafety level 3 users. The program is aimed at enhancing
competency and proficiency among new biosafety level 3 users
and promoting appropriate behaviors and practices that
enhance biosafety and biosecurity. The training has 3 phases:
initial assessment, training phase (including theory and handson practice), and a final assessment.6,7 The objective of this
study was to evaluate participants’ knowledge and practical
skills in BSC usage. The impact of biosafety and biosecurity
training on BSC usage, as well as the effect of prior experience
on training outcomes, were also examined.
Materials and Method
Thirteen laboratory workers attending a 3-day biosafety training workshop participated in the study. These were drawn from
parasitology, bacteriology and virology research laboratories.
Before commencement of the study, participants received a
detailed description of the study and consented to participate
in the survey.
The study had 3 components: a preworkshop survey, training program delivery, and a postworkshop survey. The
NUITM-KEMRI biosafety training program was used.6 Usually, the training program is delivered through an annual workshop and divided into initial assessment, training phase, and
final assessment sessions. In the initial assessment session, a
written test is given to establish the participants’ initial knowledge, which also helps to identify training needs. A similar test
is administered during the final assessment phase. The training
phase covers biosafety and biosecurity theory and practicum. In
this study, the survey questionnaire was administered to the
Applied Biosafety: Journal of ABSA International
Table 1. BSC Aspects Covered in the Training Workshop.
Pre- and posttraining
Written pre- and posttraining
assessment questionnaire
Training program
Concept and
Theoretical lectures on BSCs,
biosafety, and biosecurity
Hands-on practice How to use a BSC properly including
working principle, laminar flow,
material arrangements,
decontamination, and application
1, 3
2, 3
Abbreviation: BSC, biological safety cabinet.
participants before and after training. Further, the training program was adjusted to include more theory and practical modules on BSCs to provide more comprehensive training on
proper BSC usage. Practical training was achieved through a
demonstration and a hands-on session with the participants
divided randomly into 3 groups to allow for closer instruction
and supervision. Table 1 shows a description of the aspects of
BSCs covered in this study.
Design of the survey questionnaire was based on guidelines
on BSC usage from the World Health Organization’s (WHO)
Laboratory Biosafety Manual, third edition,5 and consisted of
closed- and open-ended questions. Closed questions were
designed to qualify a statement through true/false answers,
while the open-ended questions allowed participants to support
their answers by giving their opinions. The questionnaire
included questions on location of a BSC, material placement,
open flames, operation and maintenance, and supplementary
information regarding usage of a BSC.
The preworkshop survey examined the diversity in knowledge and practices among the participants regarding usage of
BSCs, while the postworkshop survey assessed the impact of
the training. Data was analyzed using Stata 13. Descriptive
statics were used to summarize the data, while differences in
means were examined using Student’s t test.
Of the 13 participants, there were 6 (46%) virologists, 5 (38%)
bacteriologists, and 2 (16%) parasitologists. The length of their
experience ranged from half a year to >20 years. The most
commonly used BSC was BSC class II.
Out of the 13 WHO biosafety considerations regarding use of a
BSC,5 10 were included in the survey as shown in Table 2. The
other 3 biosafety considerations (certification, alarms, and operator) were emphasized during the theoretical and hands-on training.
The location consideration presented the highest score, at
92%. The greatest variation was observed on questions covering personal protective equipment (PPE), with an average score
of only 50%. On the open-ended questions, some participants
seemed to be aware of a concept, but in some instances they
could not correctly justify their responses.
Miring’u et al
Table 2. Summary of the Participants’ Performance as per the Biosafety Considerations.a
Participants With Correct
Answers, No. (%)
Questionb Considerationc
Preassessment, Postassessment,
n ¼ 13
n ¼ 13
Personal protective
Cleaning and
Operation and
Material placement
Cleaning and
Open flame
Operation and
Ultraviolet lights
Operation and
Personal protective
12 (92)
12 (92)
1 (8)
8 (62)
6 (46)
10 (77)
10 (77)
11 (85)
13 (100)
13 (100)
9 (69)
11 (85)
8 (62)
8 (62)
13 (100)
10 (77)
10 (77)
11 (85)
11 (85)
13 (100)
11 (85)
10 (77)
9 (69)
11 (85)
9 (69)
12 (92)
12 (92)
12 (92)
13 (100)
13 (100)
The average score during the pretraining assessment was 75%, as shown in
Figure 1. A significant improvement (P ¼ .01) was noted after the training, with
an average score of 86% recorded in the posttraining assessment.
Per the questionnaire.
Per the World Health Organization manual.5
Figure 1. Mean score of pre- and posttraining survey scores (n ¼ 13).
On grouping participants based on length of experience, 5
participants had <5 years of experience. This group had a lower
average score (68%) in the pretraining assessment but presented a significant improvement (P ¼ .02) after the training.
0-5 years
>5 years
Figure 2. Pre- and posttraining scores by duration of experience.
The other group of participants, with >5 years of experience
(n ¼ 8), scored 80% in the pretraining assessment and 83% in
the posttraining assessment, as shown in Figure 2. This
improvement was not significant. Although no significant difference in the average scores of the 2 groups after training was
noted, the scores of the participants with <5 years of experience
were noticeably higher (Figure 2).
BSCs are capable of containing contagious materials. However, several biosafety considerations must be observed for
them to function optimally. These, coupled with good microbiology practices, ensure protection of the user, product, and
the environment. The WHO biosafety manual provides 13
specifications covering the entire spectrum of proper usage of
a BSC. These are location, operators, material placement, operation and maintenance, UV light, open flames, spills, certification, cleaning and disinfection, decontamination, PPE, alarms,
and supplementary information. All 13 biosafety considerations were emphasized during the theoretical and hands-on
training. However, only 10 were included in the survey as
shown in Table 2. Given the role played by BSCs in biosafety,
knowledge and strict adherence to these biosafety considerations among laboratory workers are both of utmost importance.
In this study, diversity in knowledge and practices in usage
of BSCs was observed. Of the 10 biosafety considerations, the
highest agreement occurred in questions covering location of
a BSC. The correct answer rate was 92%, suggesting that the
participants had uniform basic knowledge about location conditions for a BSC in the laboratory. However, only 50% of
them correctly explained that the location consideration aims
to maintain directional airflow as specified in the WHO biosafety manual. 5 Concerning operation and maintenance,
material placement, and decontamination of BSCs, 85% of the
participants gave correct responses in each category. On the
prior, although the majority of the participants agreed that
one should wait a while before putting in materials after switching on the BSC, some participants could not correctly justify
the statement. For instance, most participants observed that the
purpose of the waiting period was to allow for airflow stabilization. Other participants explained that the waiting period was
to allow for proper circulation of air. Time lag to allow the BSC
to start was also indicated. The WHO biosafety manual specifies that a BSC should be turned on at least 5 minutes before
beginning work and turned off 5 minutes after completing work
to allow it to expel contaminated air.
Concerning choice of disinfectant under cleaning and disinfection biosafety consideration, 77% of the participants agreed
that sodium hypochlorite is not the best disinfectant for BSC
surfaces. 16% of the explanations cited the effectiveness of a
specific disinfectant for the target organisms; 56% named prevention of corrosion of the BSC surface; and 16% provided an
incorrect explanation. According to the WHO biosafety manual, the disinfectant of choice should be effective against the
target organisms or one that can kill any microorganisms found
inside the cabinet.5 The highest diversity was observed on the
questions covering PPE, where only 1 participant correctly
answered that the criteria for choosing the type of PPE is determined by the biosafety level of the laboratory or the nature of
material being worked on, rather than the class of BSC in use.
Hakim et al8 observed similar diverseness in biosafety
knowledge and practices while studying routine biosafety measures and proper waste disposal practices among health workers. Although BSCs from different manufacturers may have
slight structural differences, their installation and operational
procedures are rather universal. Discrepancies about their
usage and application observed in this survey could have
stemmed from personal and institutional-level factors. Among
these is lack of proper training. In some institutions, laboratory
workers are hardly provided with initial training on biosafety
and biosecurity, with most relying on prior academic knowledge and knowledge acquired on the job. Subsequently, most
laboratory workers are not thoroughly familiar with core biosafety and biosecurity principles, although they can apply the
technologies. For instance, in the preworkshop assessment, the
participants were not entirely clear on the difference between
‘‘level’’ and ‘‘class’’ in identifying the BSC that they were
using. Given the role played by BSCs in containing infectious
agents, good BSC user knowledge and skills are necessary.
Initial and refresher training, combining theoretical and practical concepts, can help to increase knowledge and competence
of laboratory staff while enhancing biosafety and biosecurity.
Training must also factor in differences in research facilities
and activities since procedures vary from organism to organism
or laboratory to laboratory. Training should therefore allow for
facility-specific adaptation.9
Weak enforcement of biosafety and biosecurity strategies
could also explain observed diversity. Although the WHO biosafety manual provides allows for modification of biosafety and
biosecurity regulations to fit a laboratory’s operations, universal
specifications are also provided that apply to all laboratories
regardless of the organism handled. Poor enforcement reduces
adherence to safety principles, which increases the risk of exposure to hazardous agents.10 Moreover, differences in the way that
different laboratories adapt WHO guidelines to fit their settings
Applied Biosafety: Journal of ABSA International
could further explain the differences in knowledge and practices
To some extent, institutional support may also influence
biosafety knowledge and practices. Institutional factors, such
as limited funding, could affect the stability and efficiency of
biosafety infrastructure. Weak biosafety infrastructure limits
knowledge and adherence to safety regulations due to factors
such as absence of biosafety and biosecurity equipment or
poor mentorship and supervision.
An average improvement of 11% was observed after training,
although there was increased disparity on the spills and UV
irradiation biosafety consideration. In the case of a large spillage
in a BSC, some participants stated that only the working surface
should be decontaminated. However, the WHO biosafety manual recommends that not only the working surface but also the
drainage system of the BSC must be decontaminated by following up the spill with a disinfectant.5 The drainage vent should be
closed during this operation and adequate time allowed for contact with the disinfectant. As for the UV irradiation, some participants stated that it can be used as the sole method for
decontamination. However, UV irradiation alone is not recommended, since it is only a surface decontaminant and its effectiveness is limited by factors such as distance.
Generally, more participants gave correct responses to the
survey questions and provided more correct explanations of
their responses after training. This suggests that the training
increased knowledge on BSC usage among the participants and
biosafety and biosecurity awareness at large. A similar
improvement in knowledge and competence after a biosafety
training was observed by Inoue et al7 while evaluating the
effectiveness of the NUITM-KEMRI training program. Basically, training has been identified as an effective approach to
increase the competence of laboratory workers and their biosafety and biosecurity knowledge, as well as to create awareness about the hazards posed by research and diagnostic
laboratories.10 Packaging these concepts into a program and
delivering them through a formal training approach further
facilitates learning, application, and adherence.7,11
On comparing training outcomes among participants with
<5 and >5 years of experience, those with fewer years of experience presented a significant improvement in the postworkshop survey although they had a lower average score during the
preworkshop survey. Chaudry et al12 and Inoue et al7 reported
similar outcomes while assessing biosafety practices among
undergraduates and postgraduates and biosafety training outcomes in exposed and unexposed participants, respectively. On
the contrary, those with >5 years of experience would be
expected to show greater improvement after the training, due
to the higher level of understanding that comes with increased
experience. A possible explanation could be that the more
experienced participants had difficulties adopting new concepts and practices because they were different from those that
they were used to. In most instances, laboratory workers are not
offered formal biosafety and biosecurity training upon their
initial placement in a laboratory setting and probably in subsequent placements as well. Therefore, laboratory workers
Miring’u et al
mostly rely on on-the-job learning, majorly conducted by more
experienced staff. Such training may not necessarily be comprehensive or up-to-date. With more time spent adhering to
such concepts, more experienced laboratory workers may find
adopting standardized practices difficult.
In conclusion, diversity in BSC usage knowledge and practices, the importance of biosafety and biosecurity training, and
the confounding effect of prior experience on biosafety training
outcomes were observed in this study. Generally, core biosafety
and biosecurity principles as stipulated in the WHO biosafety
manual should be uniform across all laboratories, with minor
modifications to fit a laboratory’s settings and activities.
Absence of expected uniformity therefore reveals gaps in knowledge on usage of BSCs and maybe in biosafety and biosecurity
in general. To address these, proper training should be conducted. Training laboratory workers before they begin working
in the laboratory may be best. Whether conducted at the initial
placement or in the course of a laboratorian’s work life, such
training should be sufficiently comprehensive yet based on recommended principles to enable a laboratory worker to work
safely in a different laboratory. It should be accompanied by
mentoring and supervision until capability to work independently is attained, with subsequent regular refresher training.
Given the small sample used in this survey, a bigger study is
recommended to fully ascertain the role of training in improving
BSC biosafety knowledge and practices.
Training modules
Principles of containment
Classes and types of BSCs
Proper use and maintenance
Decontamination and certification
Module 1: Principles of containment, Course overview
This module provides an overview of how BSCs function
and how they provide protection through containment. It
describes the principles of protection and the levels of protection to the environment, product, and personnel offered
by various types of cabinets. The module also provides an
essential background to understanding HEPA filters and
their mechanisms of operation.
At the end of this module, students are expected to have
mastered how BSCs offer protection through containment and
the basic concepts of how HEPA filters operate.
Course content
How a BSC provides protection through containment
HEPA filter
How HEPA filters operate
Module 2: Classes and types of BSCs, Course overview
This module provides an overview of the three classes of BSCs.
Differences among the classes regarding intake air velocity,
plenum pressure, air recirculation and exhaust, and common
uses are explained in detail. Key considerations when choosing
the appropriate BSC for a certain kind of procedure are also
At the end of this module, students are expected to know the
different classes of BSCs and their differentiating aspects. They
are also expected to know how to choose the appropriate BSC
for a certain kind of laboratory procedure and how to work
safely in a BSC.
Course content
i) Introduction
ii) Classes of BSCs
iii) Choosing the appropriate BSC iv). Proper placement
of a BSC
Module 3: Proper use and maintenance, Course overview
This module focuses on safe work procedures and proper
maintenance of BSCs. The module describes the key considerations when preparing to work in a BSC, while working, and after completing the work. These considerations are
aimed at ensuring personnel, product, and environmental
protection while working in a BSC. Students are also
trained on how to maintain a BSC including certification.
Necessary operation tools, such as standard operating procedures (SOPs) and maintenance sheets, are also described.
At the end of this module, students should have a comprehensive understanding of how to safely work in a BSC and how
to adequately maintain them.
Course content
Planning the work
Placing the materials
Working in a BSC
Emergency procedures
Module 4: Decontamination and certification, Course
While working in a BSC with infectious materials, inevitably the BSC surface will be contaminated and at times spills
will occur. This module provides information on how and
when to decontaminate a BSC. The various types and
classes of disinfectants and methods of decontamination are
explained in detail including the key considerations when
choosing a disinfectant. How to handle spills within a BSC
is also described.
Applied Biosafety: Journal of ABSA International
At the end of this module, students are expected to know
how and when to decontaminate and disinfect a BSC. They are
also expected to know how to choose the most appropriate
disinfectant while working with a certain infectious material.
Course content
When to decontaminate a BSC
Methods of decontamination
Classes of disinfectants
Risk assessment considerations when choosing a
vi) Handling spills within a BSC
vii) UV lights
We thank The Director of KEMRI for providing technical support for
our project activities. We further express our appreciation to the biosafety trainers and BSL-3 laboratory staff for facilitating our annual
biosafety workshops.
Declaration of Conflicting Interests
The author(s) declared no potential conflicts of interest with respect to
the research, authorship, and/or publication of this article.
The author(s) confirmed receipt of the following financial support for
the research, authorship, and/or publication of this article: This study
was supported by grant-in-aid for scientific research, Japan (Research
Practicum (demonstration and hands-on practice)
Practicum is very important in strengthening trainees’ knowledge and skills. This session is conducted through demonstration and hands-on practice, in two phases.
The first phase focuses on the correct procedure and considerations before, during, and after working in a BSC. The
trainer demonstrates the correct procedure during the following
1. Before working in a BSC
i) Planning the work
ii) Turning on a BSC and decontamination
iii) Arrangement/placement of materials in a BSC
2. While working in a BSC
i) Arm movements
ii) Material/item placement, sterilization of loops
iii) Cleaning up spills
iv) Disposal of wastes
3. After completing work
i) Clearing the work surface
ii) Decontaminating the work surface
iii) Filing the BSC usage records
The second phase is a trainee-led, hands-on practice session
covering an actual work session in the BSC. In executing the work
session, the trainee is expected to adhere to the recommended
procedures and techniques as earlier demonstrated by the trainer.
Each practical session takes about one hour and allows for both
practice of the concepts learned and assessment of knowledge
acquisition. The trainee executes the session based on instructions
provided on a task card, with the trainer playing a supervisory role.
During this time, the trainer assesses the correctness of the trainee’s
actions. Each trainee undergoes the assessment individually.
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