Download Plumbing Design for Arthropod Laboratories (Insectaries)

Designer’s Notebook
By Joseph V. Messina, CPD
Plumbing Design for
Arthropod Laboratories (Insectaries)
Everyone should know what arthropods are from high school
biology class, but if you cannot remember, they are invertebrate animals with segmented bodies and jointed limbs, such
as mosquitoes, spiders, roaches, ticks, fleas, tsetse flies, black
flies, and sand flies. The laboratories in which these types of
animals are studied are called insectaries, and the person who
studies arthropods is called an arachnologist. What will be
discussed in this article is how plumbing designers and engineers design plumbing systems for an insectary.
Insectaries where living arthropods are reared and maintained for research have been around for decades. The insects
are infected with pathogens, which can be a risk to whomever
comes into contact with them. Extreme precautions are taken
within the plumbing, HVAC, and electrical systems to protect
the public by ensuring the infected insects cannot escape. It is
also important to take precautions against the escape of uninfected insects as well. Plumbing designers and engineers can
help by designing certain precautions (discussed later) into
the plumbing systems.
Arthropod Containment Levels
Insectaries are classified in different levels called Arthropod
Containment Levels, similar to the Biological Safety Levels.
(For more information on Biological Safety Levels, see “A
Primer on Infectious and Biological Waste Drainage Systems,”
PS&D March/April 2006, and “Designing Biosafety Laboratories,” PS&D July/August 2005.) These levels are recommended
by the American Committee of Medical Entomology, a special
committee of The American Society of Tropical Medicine and
Hygiene, for work with a variety of uninfected arthropods and
those that are carrying infectious agents. The classifications
set requirements for the level of protection to be designed for
the insectary. If the arthropod is infected with an agent, the
containment level is increased to at least what is required for
that particular agent.
Arthropod Containment Level 1 (ACL-1). This level is suitable for working with arthropods that are not infected or those
that are infected with a non-pathogen. Precaution should
be taken from the arthropod escaping through the sanitary
sewer by specifying screens over the sink drains. Even though
floor drains are not highly recommended to be installed in an
insectary, specifying screens to be placed between the drain
strainer and drain body will prevent loose arthropods from
escaping through or breeding in the floor drain.
Arthropod Containment Level 2 (ACL-2). This level is
practiced when working with indigenous arthropods infected
with a BSL-2 agent associated with animal or human disease,
or even suspected of being infected with such agents. BSL-2
agents are moderate-risk agents that are present in the community and associated with human disease, such as hepatitis,
HIV, and salmonellae. As with ACL-1, screens specified for the
sink drains are required to prevent any life stages of the arthropod being washed into the drainage system when personnel
26 Plumbing Systems & Design JANUARY/FEBRUARY 2007
wash their hands after handling cultures or infected arthropods. Moreover, before any infected or uninfected arthropods
are disposed of they should be destroyed by heat or freezing.
It is preferable for them to be autoclaved or incinerated. You
also can destroy by heat by using an instantaneous hot water
dispenser, such as used for making coffee, and very hot water
(120°F to 140°F) may work as well. If a central vacuum system
is installed for use under this containment level, each inlet is
required to be fitted with a suitable filter to prevent an arthropod from escaping. HEPA-type filters are usually used. These
filters can be attached to each inlet, or if the central vacuum
system is strictly dedicated for the use of this insectary, the
HEPA filter can be installed on the inlet side of the vacuum
system or on the exhaust side of the system. If floor drains are
installed in the insectary within this containment level, not
only is the use of screens between the floor drain strainer and
the floor drain body recommended, but a chemical treatment
also should be applied in the floor drain trap. All penetrations
through the walls, floors, and ceilings shall be sealed with
caulking to prevent the chance of escape.
Arthropod Containment Level 3 (ACL-3). Under this level,
arthropods may be infected with BSL-3 agents associated
with human disease. Arthropods that are infected or potentially infected with a BSL-3 pathogen can pose additional
hazard when or if the insectary is located in an area where
the arthropod is indigenous. The ACL-3 insectary has similar
practices, procedures, and containment equipment and facility requirements as an ACL-2 insectary. The central vacuum
system is treated the same way it is treated in an ACL-2 facility. Floor drains are not recommended; however, if installed,
they should be treated as in an ACL-2 facility, or ideally, they
should be plumbed to a holding tank where either heat or
chemical treatment can be introduced to kill all stages of the
arthropod prior to disposal into the building or public sanitary
waste system.
Access into an ACL-3 insectary is more restricted than that
into an ACL-2 facility. Access into an ACL-3 facility is through a
shower. Personnel are required to shower before going into the
facility as well as when exiting the facility (sometimes referred
to as a shower-in, shower-out facility). The way arthropods are
handled is also different than in an ACL-2 facility. In an ACL3 insectary, the handling of arthropods is within a biological
safety cabinet. The Centers for Disease Control’s Biosafety in
Microbiological and Biomedical Laboratories states: “All procedures involving the manipulation of infectious material are
conducted within biological safety cabinets or other physical
containments devices, or by personnel wearing appropriate
protective clothing and equipment.” These biological safety
cabinets are equipped with a HEPA filter to prevent any possibility of insects escaping while being manipulated.
Arthropod Containment Level 4 (ACL-4). This containment level is for the most dangerous pathogen-infected arthroPSDMAGAZINE.ORG
The requirements depend on the arachnologist. It has been my
experience that each has his own way of handling and disposing
of arthropods. That is what makes it interesting because there is
always the chance of learning different ways of designing.
Resources
Arthropod Containment Guidelines, Version 3.1. American
Committee of Medical Entomology, American Society of Tropical Medicine and Hygiene.
Biosafety in Microbiological and Biomedical Laboratories, 4th
Edition. U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, and National Institutes
of Health.
Joseph V. Messina, CPD, is the discipline director
of plumbing engineering for CUH2A Inc., Architecture,
Engineering, Planning in Atlanta. He has more than
30 years experience specializing in plumbing and fire
protection design of instructional, research, and medical
facilities. For more information or to comment on this
article, e-mail [email protected].
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pods and shall meet all the requirements of Arthropod Containment Levels previously mentioned as well as added procedures.
An escape of the arthropods is absolutely not acceptable. BSL-4
agents are studied at this level and are associated with the highest risk of infection from aerosol exposure and life-threatening
diseases. Of the 12 viruses requiring BSL-4 containment in the
United States, five are transmitted by arthropods. These are central European encephalitis, Congo-Crimean hemorrhagic fever,
Kyasanur forest disease, Omsk hemorrhagic fever, and Russian
spring-summer encephalitis.
Laboratories in this level are required to decontaminate all
waste by means of autoclaving. All personnel entering and leaving the laboratory must wear the appropriate protective suit with
breathing air. All work shall be preformed within a biological
safety cabinet. If there is a central vacuum system, it can only be
used within the biological safety cabinet and must be provided
with an in-line HEPA filter on the inlet. Other liquids and gases
used shall be provided with a backflow device. All sanitary waste
coming from the ASL-4 space shall be plumbed to an approved
heat treatment process, which includes floor drains and sinks.
It is not recommended to install water closets or urinals for this
containment level of insectary, but if these fixtures are installed,
they too must be taken to the approved heat treatment process
system.
Designing plumbing systems for an insectary can be very
interesting because not all insectary requirements are the same.
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