Working Safely
with Biological Materials
GENERAL OBJECTIVE:
 Develop student’s awareness in laboratory safety standards and precautions when working
with biological materials.
Specific Learning Objectives:
 List some of the most essential laboratory practices and procedures.
 Associate the different levels of risk groups to biosafety level, laboratory type, laboratory
practices and safety equipment.
 Enumerate the different necessary precautions on essential laboratory practices and
procedures.
 Discuss proper handling of laboratory wastes.
 Discuss standard code of practice for Biosafety Levels 1 and 2.
Introduction
Compliance to the general standard laboratory practices is the most basic method of
prevention. Persons handling laboratory reagents and specimens should always treat them as
potentially hazardous materials. Therefore, it is the responsibility of inexperienced or novice
laboratory students, and laboratory personnel in general to identify and obey proper work guidelines
and containment requirements when working with biohazardous material.
Risk Assessment - The pillar of the practice of biosafety is risk assessment. Professional judgment
plays an essential role in determining risk. It is performed by an individual who is most familiar with
the specific characteristics of the specimen being considered for use, procedures to be employed,
and materials (reagents/equipment). Once accomplished, risk assessments should be re-evaluated
routinely and revised when necessary, as an addition to acquired new data having a bearing on the
degree of risk and other relevant new information from the scientific literature.
World Health Organization (WHO) describes risk group classification for laboratory work (See
Table 1).
Table 1. Classification of infective microorganism by risk group
Risk Group 1 (no or low individual and community risk)
A microorganism that is unlikely to cause human or animal disease.
Risk Group 2 (moderate individual risk, low community risk)
A pathogen that can cause human or animal disease but is unlikely to be a serious hazard to laboratory
workers, the community, livestock, or the environment. Laboratory exposure may cause serious
infection, but effective treatment and preventive measures are available and the risk of spread of
infection is limited.
Risk Group 3 (high individual risk, low community risk)
A pathogen that usually causes serious human or animal disease but does not ordinarily spread from
one infected individual to another. Effective treatment and preventive measures are available.
Risk Group 4 (high individual and community risk)
A pathogen that usually causes serious human or animal disease and that can be readily transmitted
from one individual to another, directly or indirectly. Effective treatment and preventive measures
are not usually available.
From World Health Organization’s Laboratory Biosafety Manual
Other factors that should be considered, as appropriate, include:
1. Pathogenicity of the agent and infectious dose
2. Potential outcome of exposure
3. Natural route of infection
4. Other routes of infection, resulting from laboratory manipulations (parenteral, airborne, or
ingestion)
5. Stability of the agent in the environment
6. Concentration of the agent and volume of concentrated material to be manipulated
7. Presence of suitable host (human or animal)
8. Information available from animal studies and reports of laboratory-acquired infections or
clinical reports
9. Laboratory activity planned (sonication, aerosolization, centrifugation, etc.)
10. Any genetic manipulation of the organism that may extend the host range of the agent or
alter the agent’s sensitivity to known, effective treatment regimens.
11. Local availability of effective prophylaxis or therapeutic intervention.
Basic – Biosafety Level 1, Basic – Biosafety Level 2, Containment – Biosafety level 3, and
Maximum Containment – Biosafety Level 4 are designations of laboratory facilities. They are based
on the composition of design features, constructions, containment facilities, equipment, practices
and operational procedures required for working with agents from various risk groups.
Table 2. Relation of risk groups to biosafety levels, practices and equipment
RISK GROUP
BIOSAFE
TY
LEVEL
LABORATORY LABORATOR
TYPE
Y PRACTICES
SAFETY
EQUIPMENT
1
Basic
Biosafety
Level 1
–
Basic
teaching,
research
Good
microbiological
techniques
None;
open
bench work
2
Basic
Biosafety
Level 2
–
Primary
health
services;
diagnostic
services, research
GMT
plus
protective
clothing,
biohazard sign
Open Bench plus
biological safety
cabinet
for
potential
aerosols
3
Containment –
Special diagnostic As level 2 plus
Biosafety Level 3 services, research special
clothing,
controlled
access,
directional
airflow
As level 3 plus Class III BSC or
airlock
entry, positive pressure
shower
exit, suits
in
special
waste conjunction with
disposal
Class II BSCs,
double-ended
autoclave
(through
the
wall), filtered air
BSC, Biological safety cabinet; GMT, good microbiological technique
4
Maximum
containment –
Biosafety
Level 4
Biological safety
cabinet and/or
other
primary
devices for all
activities
Dangerous
pathogen units
Risk assessment is the basis when assigning an agent to a biosafety level for laboratory work.
However, risk assessment should also include the risk group as well as other factors into
consideration in establishing the appropriate biosafety level.
MOST ESSENTIAL LABORATORY PRACTICES AND PROCEDURES
Access
1. Doors of the rooms containing microorganisms of Risk Group 2 or higher risk groups must
have a display of the international biohazard warning symbol and sign.
Figure 1. Biohazard warning sign for laboratory doors
2. Only authorized persons should be allowed to enter the laboratory working areas.
3. Laboratory doors should be kept closed.
4. Children should not be allowed to enter laboratory working areas.
5. No animals should be admitted other than that those involved in the work of the laboratory.
Personal Protection
1. Laboratory gowns or uniforms must be worn at all time for work in the laboratory.
2. When working on procedures that may involve direct contact with blood, body fluids and
other potentially infectious materials, it is very important to wear appropriate gloves. After
use, gloves should be aseptically removed and hands must then be washed.
3. Students and personnel must wash their hands after handling materials and specimens, and
even before they leave the laboratory working areas.
4. Safety goggles, visors (face shields) or other protective devices must be worn when necessary,
to protect the eyes and face from accidental splashes, impacting objects and sources of
artificial ultraviolet radiation.
5. Wearing of protective laboratory clothing outside the laboratory, e.g. classrooms, canteens,
libraries, offices, staff rooms and toilets is strictly prohibited.
6. Open-toed footwear must not be worn in laboratories.
7. Drinking, eating, smoking, using of cellular phones or handheld devices are strictly
prohibited in the laboratory working a reas.
8. Storing of human foods and beverages anywhere near the laboratory working areas is strictly
prohibited.
Laboratory Safety Precautions and Guidelines
9. Laboratory gowns and other protective materials must not be stored in the same lockers or
cupboards as usual street clothing.
Procedures
1. Mouth pipetting is strictly forbidden.
2. Labels or. any laboratory materials must not be licked or placed in the mouth
3. All technical procedures should be performed in a way that minimizes aerosol and droplet
formation.
4. Limit the use of hypodermic needles and syringes. It should not be used as alternatives for
pipetting devices or for any purpose other than parenteral infection or aspiration of for cleanup of all spills should be formulated and followed.
5. All accidental spills, untoward incidents, or potential exposures to infectious materials
fluids.
6. Written procedure
7. (specimen, reagents, or substances) should be reported to the laboratory supervisor. A
documented record of such accidents or incidents should be maintained.
8. Decontamination of contaminated liquid is necessary before discharge to the sanitary sewer.
9. All written documents expected to be removed from the laboratory need to be protected
from contamination while in the laboratory.
Laboratory working areas
1. Decontamination of work surfaces with or without any incident of spills should be
performed at the end of the working day.
2. Laboratory should be kept neat, clean and free of materials that are not relevant to
laboratory works.
3. Specimens and cultures must be decontaminated before disposal or cleaning for reuse.
4. Packaging and transportation must follow applicable national and/or international
regulations.
5. When windows can be opened, they should be fitted with arthropod-proof screens.
Waste handling
Waste is anything that is to be discarded.
Waste decontamination and disposal are closely interrelated. In daily use, contaminated
materials require actual removal from the laboratory or destruction. Laboratory clothing, instruments
and most glassware will be re-used or recycled. The general principle is that all infectious materials
require decontamination, autoclaving or incineration within the laboratory premise.
Here are the following questions that need to be put into considerations before discharging
any materials from the laboratory.
 Have the materials or objects been effectively and properly decontaminated or disinfected
by a standard laboratory procedure?
 If not, have they been packaged in an acceptable manner for immediate on-site incineration
or transfer to another facility with incineration capacity?
 Does the procedure for disposal of decontaminated materials or objects involve any
additional potential hazards, biological or otherwise, to those who carry out the immediate
disposal procedures or who might come into contact with the discarded items outside the
facility?
Decontamination
The preferred method for all decontamination processes is steam autoclaving. Materials for
autoclaving and then disposal should be placed in containers e.g. autoclavable plastic bags that are
color-coded according to whether the contents are to be autoclaved and/or incinerated.
Handling and disposal procedures for contaminated materials and wastes
Categories for identification and separation system for infectious materials and their proper container
are as follows:
1. Non-contaminated (non-infectious) waste that can be reused or recycled or disposed of as
general, “household” waste
2. Contaminated (infectious) “sharps” – hypodermic needles, scalpels, knives and broken glass;
these should always be collected in puncture-proof containers fitted with covers and treated
as infectious.
3. Contaminated material for decontamination by autoclaving and thereafter washing and reuse
or recycling
4. Contaminated material for autoclaving and disposal
5. Contaminated material for direct incineration
Disposal for sharps
Separate discussion on next chapter
Disposal for contaminated (potentially infectious) materials for autoclaving and reuse
Do not attempt to pre-clean in any manner, repair any contaminated materials for autoclaving and
reused. It should be done after autoclaving or disinfection.
Disposal for contaminated (potentially infectious) materials for disposal
Apart from sharps, which are dealt on a separate chapter, all contaminated (potentially infectious)
materials should be autoclaved and contained in leak-proof containers, e.g. autoclavable, colorcoded plastic bags, before disposal.
References:
World Health Organization (1991). Biosafety Guidelines for Diagnostic and Research
Laboratories
working
with
HIV.
Retrieved
from
http://whqlibdoc.who.int/aids/WHO_AIDS_9.pdf
World Health Organization (2004). Laboratory Biosafety Manual (3rd Ed.). Retrieved from
http://www.who.int/csr/resources/publications/biosafety/Biosafety7.pdf
GENERAL OBJECTIVE:
 To develop students awareness in laboratory safety standards and precautions when working
with biological materials.
Specific Learning Objectives:
 List some of the most essential laboratory practices and procedures.
 Associate the different levels of risk groups to biosafety level, laboratory type, laboratory
practices and safety equipment.
 Enumerate the different necessary precautions on essential laboratory practices and
procedures.
 Discuss proper handling of laboratory wastes.
 Discuss standard code of practice for Biosafety Levels 1 and 2.
TASKS:
List the essential areas of laboratory practices and procedures that require safety precautions.
•
Waste handling
Decontamination of waste and disposal are closely related processes. Contaminated materials
used regularly need to be physically removed from the lab or destroyed. Most glassware,
laboratory supplies, and clothing will be recycled or reused. The usual rule is that all
infectious materials need to be decontaminated, autoclaved, or burned inside the lab.
•
Decontamination
Steam autoclaving has become the standard technique for all decontamination procedures.
Materials for autoclaving and subsequent disposal should be put in containers, like
autoclavable plastic bags, that are color-coded depending on whether the contents are to be
autoclaved or burned.
•
Handling and disposal procedures for contaminated materials and wastes
1. reusable, recyclable, or disposed of non-contaminated (non-infectious) waste
residential waste in general
2.
Hypodermic needles, scalpels, knives, and shattered glass are examples of contaminated
(infected) "sharps," which should always be gathered in puncture-proof containers with
lids and handled as if they were contagious.
3. .Contaminated materials for autoclaving to remove contaminants, followed by washing,
reuse, or recycling
4. Material that needs to be autoclaved and disposed of
5. .Direct incineration of contaminated material
•
•
Disposal for sharps
Disposal of contaminated (possibly infectious) goods for reuse and autoclaving
Avoid attempting to pre-clean or repair any contaminated goods before autoclaving or reusing
them. It needs to be carried out following autoclaving or disinfecting.
Discharging any materials from the laboratory.
Enumerate some of the precautions listed for access, personal protection, procedures &
laboratory working areas that you already performed. Justify your answers for the precautions that
you failed to execute.
Access
1.
We were not allowed inside doors with biohazard signs when we were in our senior
high school immersion
2.
There are areas designated for waiting outside the laboratory in which the patients are
allowed to wait for their turn, and then proceed to the window of the lab to hand over
the samples to be tested, or go inside the lab to have their blood drawn, anyone can
freely open the door to the laboratory which I taught wasn’t very secure
3.
The laboratory door may be opened by anyone, but anyone visiting to have samples
collected knock first because the lab doors are closed
4.
Children should not be allowed to enter laboratory working areas unless they are to be
extracted blood from
5.
Animals are not allowed inside the laboratory.
Personal Protection
6.
We are required to wear lab gowns and our school immersion uniform when we were
in the laboratory for our school immersion program in our city laboratory
7.
We always wore blood especially when handling specimens collected from patients
and do handwashing after wearing them.
8.
We did not wear safety googles inside the laboratory as most of our role was only to
handle specimens from patients and not dangerous chemicals
9.
I have not brought my labcoat or wore them outside the laboratory as they can be
contaminated with infectious specimens
10.
We were not allowed to wear anything other than shoes in the laboratory so along with
our immersion uniform I wear closed shoes in the laboratory
11.
Since the working area for the laboratory is relatively small it cannot be helped for
some parts of the laboratory to be repurposed as resting areas and we would use our
phones there.
12.
We were not allowed to bring food inside the laboratory
Procedures
13.
There were only automatic pipettes in the laboratory so mouth pipetting is not
commonly practiced in the laboratory
14.
We are required to wear face masks so that we don’t put things in the laboratory in our
mouth
15.
We had hypodermic needles in the lab but we were not allowed to use them as they are
only a few of them
16.
Fortunately, we have not had an accidental spill throughout the whole course of the
immersion
17.
All the written procedures and reporting to the pathologist were done by our overseeing
Medical Technologist
Laboratory working area
18.
We were not part of the cleaning of the work area because we have to go back to school
to report, but we still tried to maintain the cleanliness of the laboratory and other areas
when we were in the laboratory
19.
As the lab was busy with the usual routine we did not have time to grow a culture in
the laboratory
Classify your present school laboratories to its biosafety safety level. State the areas that support its
classification. Base your answer on Table 2.
•
There are open benches in the laboratory and an autoclave for possible aerosol leak.
Laboratories in school can also cater to many experimental research design of students
when it comes to the different Medical Technology subjects like Bacteriology,
Hematology, and others. There are also. Students are also required to wear their personal
protective equipment at all times when conducting an activity at the laboratory, by this
instances the schools laboratory should be at a biosafety level of 2
Name an institution that you visited and classify it according to risk level and/or biosafety
level. Write your observations on its physical setup and areas of compliance to safety
precautions.
•
Holy Infant Academy laboratory- Biosafety level 1- only handled basic reagents and is for
simple experiments and teaching only, it does have a safety shower and eyewash station in
case of chemical spill accidents, and the chemicals are stored in proper containment. There
are fire extinguisher outside in the hallway in every floor of the building and emergency
stainrs that decends dowj
•
City Health Center Laboratory – Biosafety Level 2 – Deals with cultures of potential
infectious bacilli, the laboratory is small, and it's hard to differentiate the resting areas
where you can eat and use your gadget, but in terms of the functional equipment they are
complete, and the fire extinguisher is easily accessible, there are also smoke detectors, but
they are old, and I did not see any sprinklers.
•
Far Eastern University Laboratory- Biosafety level 2- Deals with culture preparation and
has a biosafety cabinet 2 – The laboratory has many open workbenches, and state-of-theart equipment that can help students to be more familiarized with the inner workings of a
laboratory. There are also Safety showers and eyewash station in every laboratory
concerning the use of chemicals, there are also instructions and procedures printed out in
near the equipment for better understanding and use of them. There are also maps and
diagram about evacuation routes so that students are able to easily evacuate incase of an
emergency.