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Biosafety Cabinet (BSC) Certification
What are you actually certifying?
Who requires that my biosafety cabinet be certified?
When does my biosafety cabinet need to be certified?
What does field certification involve?
How long does a certification take?
As a customer, what do I need to do to prepare for a BSC certification?
What is a "decontamination"?
When is decontamination required?
Can we work in the lab during a decontamination?
What does ENV do with the parts or filters that are replaced?
Does ENV offer service agreements?
What types of equipment can be covered by a service agreement?
Does your hood really need to be ducted?
What makes an effective chemical fume hood management program?
What safety programs is a lab supervisor required have?
So how do we start complying with the lab standard?
Biosafety Cabinet (BSC) Certification
What
are you actually certifying?
A field certification confirms that an installed cabinet is operating
in accordance with the field test specifications of NSF Standard 49 (if
currently listed by NSF) or the manufacturer. Field certification does
not include the microbiological challenge and cross contamination tests
that are performed in the factory by the manufacturer.
Who
requires that my biosafety cabinet be certified?
The most important question is why you wouldn't have your cabinet certified.
Certification is both a safety and quality assurance function. Reestablishing
the proper cabinet settings gives you the peace of mind that the cabinet
will provide its specified personnel, product and Environmental protections.
Recommendations and requirements to certify biosafety cabinets come from a variety of sources. All manufacturers and NSF International recommend field certification of biosafety cabinets. JCAHO has now required proper maintenance (certification) of BSCs. CDC and NIH state that it is "imperative" that Class I and II biosafety cabinets be tested and certified (BMBL, 4th edition) and NIH funded research grants require cabinet certification. Individual state boards of pharmacy require certification of biosafety cabinets used in pharmacies. Finally, proper maintenance, including certification, of biosafety cabinets falls under the OSHA General Duty clause.
When
does my biosafety cabinet need to be certified?
Class I and II biosafety cabinets should be tested and certified at the
time of installation and at least annually thereafter. In addition, recertification
should be performed any time HEPA filters are changed, maintenance repairs
are made to internal parts, or a cabinet is relocated.
What
does field certification involve?
Field certification consists of required tests related to containment
(personnel, product and environmental protection), and optional tests
related to worker comfort and safety.
Required tests include airflow velocity profiles (downflow and inflow), airflow smoke patterns, HEPA filter leak test, cabinet integrity test (for cabinets with exterior contaminated plenums). In addition, a site installation assessment is performed for cabinets connected to facility exhaust systems.
Worker comfort and safety tests include electrical safety (when appropriate), lighting intensity, noise level and vibration.
How
long does a certification take?
Depending on the tests performed, a standard certification of a Class
II, Type A BSC will generally take approximately 1½ hours. A standard
certification of any Class II, Type B BSC will generally take approximately
2 hours. Additional time would be required to perform a cabinet integrity
test, decontamination or other maintenance.
As
a customer, what do I need to do to prepare for a BSC certification?
Before our technician can begin to test your cabinet, you will need to
remove any materials and equipment from the cabinet. You should also wipe
down the work surface, interior walls and grille with an appropriate disinfectant
for the type of work you are doing.
What
is a "decontamination"?
A microbiological decontamination involves the deactivation/destruction
of organisms that are contained within the biosafety cabinet. ENV uses
Vapor Phase Hydrogen Peroxide (VPHP) and Formaldehyde to perform decontaminations.
ENV is the North American exclusive provider of VPHP and will be making
a company wide shift to this technology. ENV will not perform Formaldehyde
decons at all in the near future. For more information on VPHP, refer
to http://www.envservices.com/services/hp.htm
ENV's decontamination procedures are available upon request. An industry
standard decontamination procedure can be found in NSF Standard 49, Annex
G.
When
is decontamination required?
Decontamination is required when maintenance work, filter changes and
performance tests require access to any contaminated portion of the cabinet.
Decontamination may be desirable prior to certification testing when the
cabinet has been used with certain BSL-2 agents and recommended when it
has been used with any BSL-3 agent. Decontamination should also be performed
prior to relocation of the biosafety cabinet in order to protect the movers.
Can
we work in the lab during a decontamination?
Before we begin to decontaminate a cabinet, the ENV technician will review
the procedure with you and post warning signs on the cabinet and entrances
to the lab where the decontamination will be performed.
With Vapor Phase Hydrogen Peroxide, there is no business interruption at all, so you may continue to work in the lab. With formaldehyde, while you may be in the lab, we recommend that you do not stay in the lab during the initial burning of the paraformaldehyde or when the unit is unsealed following neutralization. There will always be some residual odors that come from the unit immediately following the decontamination.
What
does ENV do with the parts or filters that are replaced?
All used parts and filters belong to the customer and will be left at
your facility for disposal. Filters will be put into the box from the
new filters and a "Decontaminated" label will be placed on the
box. As every facility has its own policy on disposal of these components,
please follow your facility's policy and procedures.
Does
ENV offer service agreements?
ENV offers a wide range of service agreements designed to meet our customers'
varying needs. Some basic examples of our service agreements include:
- Full Maintenance Agreements - All parts and labor included for certification and repairs
- Labor Only Agreements - Parts less than $50 and all labor included for certification and repairs
- Certification Only Agreements - Annual certification only included
Other types of service agreements are available. Please contact us for further information and to receive a sample service agreement.
What types of equipment
can be covered by a service agreement?
ENV offers service agreements that cover
biological safety cabinets, unidirectional clean air devices (i.e., clean
benches), incubators, and centrifuges.
How do I dispose
of a used HEPA filter?
High Efficiency Particulate
Air (HEPA) filters are used in biological safety cabinets (BSCs), laminar
flow clean benches, and other air handling equipment to provide clean
work environments. In the case of BSCs they also provide worker and environmental
protection by removing contaminants from the air. When a HEPA filter is
changed, the proper disposal of the used HEPA is always a concern. HEPA
filters from laminar flow clean benches and other product protection applications
may only filter room air. In these cases, the filters may contain only
the normal particulates found in air. These filters are typically not
viewed as being contaminated and have been disposed of as non-regulated
waste.
Biological
HEPA filters in BSCs used for biohazard work have been viewed as contaminated
with whatever biological agents used in the BSC. The OSHA Bloodborne Pathogen
Standard states equipment which may be contaminated with blood or other
potentially infectious materials....shall be decontaminated as necessary.
Formaldehyde gas decontamination and Vapor Phase Hydrogen Peroxide (VPHP) are the commonly accepted method for neutralizing
biological hazards in a Class II BSC. This procedure is detailed in NSF
International Standard 49. Most HEPA filters that have been decontaminated
with formaldehyde are viewed as non-hazardous and are disposed of as non-regulated
waste. Some biological agents are resistant to formaldehyde and may need
special handling in addition to, or instead of, formaldehyde gas decontamination.
In some states or localities there may be regulations that prohibit non-regulated
disposal of any perceived medical waste. So even if a HEPA filter is decontaminated,
the HEPA may still be incinerated or packaged as medical waste.
Chemical
HEPA filters used in BSCs for chemo (antineoplastic) drug preparation
pose a chemical hazard as opposed to a biological hazard. Typically, BSCs
are used for either biohazard or chemo drug work therefore mixing of these
two types of hazards are rare. Chemo drugs can pose a variety of acute
and chronic occupational exposure hazards. The current guideline document
is published by OSHA: in Chapter 21 of their technical manual. When a
HEPA filter is changed in a BSC used for chemo drugs, the old filter is
classified as hazardous drug (HD) waste. It should be bagged in plastic,
labeled, and disposed of as solid hazardous drug waste. Disposal of HD
waste can be regulated by the EPA, state, and local toxic waste laws depending
on the drugs used. It is important that the facility have in place a hazardous
drug safety and health plan which would document how HD waste should be
disposed.
Radioactive
In some BSC work, radioisotopes solutions are used. These solutions could
give off radioactive vapors which would pose a Beta and even Gamma radiation
hazard. Since a HEPA filter will not stop vapors, it is expected that
the radiation will leave the BSC and exit the building. Prior to accessing
and changing a HEPA filter, it is good practice to have a health physicist
assess and document that the BSC is free of radiation hazards or to supervise
any safety measures required by a radiation hazard if it exists. The HEPA
filter itself would be decontaminated as biological and/or chemical waste
(see the other sections), prior to removal and be disposed of a non-hazardous
waste unless otherwise regulated. If the HEPA filters did contain radioactive
waste, the health physicist would advise on proper disposal procedures.
Does your hood really
need to be ducted?
Many biological safety cabinets and chemo
hoods used in hospitals today are ducted to the outside. This is the only
way to protect the user from many non-particulate hazards like chemical
fumes.
Venting of the unit’s exhaust to outside the building can make solving airflow problems a lot harder for you. A ducted hood with a problem involves people from different areas of the facility. It’s like a computer problem, with the hardware people blaming the software people, the software people blaming the hardware, and you stuck in the middle.
If your hood won’t come on because of insufficient exhaust or your certifier can’t certify it because the exhaust is too low, the hardest battle can be getting everyone to understand. The certifier says it’s too low, the facilities person says it’s more than enough and you just want to get your hood certified. These newsletters will provide helpful hints on understanding and dealing with these and other kinds of problems.
There are three types of Biological Safety Cabinets. A Class I is basically a fume hood with a filter. You can’t use large amounts of chemicals in a Class I because they can eat through the filter. Class I cabinets are great for personal protection, but offer no product protection. A Class III cabinet is a ventilated glovebox. Air is filtered in and out and you use gloves mounted in glove ports to work with materials inside the hood.
The four types of Class II cabinets, A, B1, B2, and B3 (aka A/B3), are what most of us refer to when we think of a chemo hood or biohood. You reach in through an 8 or 10 high opening below a window. Air is drawn into the hood through that opening like a fume hood. Unlike a Class I cabinet, filtered air is also blown onto the work area from above, so your product is protected from outside contaminates. (Another similar type of equipment is a laminar flow hood or clean bench which blows filtered air over the work space toward the operator. Since you get product protection but no personnel protection, this isn’t considered a safety cabinet.)
Not all Class II cabinets need to be connected to your building’s exhaust. The Class II types A and B3 cabinets do not have to be connected to an exhaust duct to function properly. The other two types - B1 (sometimes called an NCI hood after the National Cancer Institute) and B2 (commonly called a Total Exhaust hood) need to be connected to an external exhaust system to function.
If you have the A or B3 type, it may be possible to solve your exhaust problem by allowing the unit to vent to the room. If you are dealing with only particulate hazards, the cabinet’s filters should be able to capture the hazard. If those particulates might offgas or if you are using non-particulate hazards like low amounts of ether or other gases, the cabinet’s exhaust may need to be ducted outside. Your facility’s safety officer can help determine this with you.
What
makes an effective chemical fume hood management program?
Chemical or laboratory fume hoods are used in thousands of labs
throughout the country to improve the safety of workers handling hazardous
chemicals and reduce personal exposure to chemicals. The Scientific Equipment
& Furniture Association defines a laboratory fume hood in part as
"a ventilated, enclosed work space intended to capture, contain,
and exhaust fumes, vapors and particulate matter generated inside the
enclosure." A chemical fume hood operates on the relatively simple
principle of drawing chemical vapors, fumes, etc. away from the work space
within the hood and out through an exhaust system. A fume hood management
program is needed to insure the effective performance of fume hoods. This
program should address the selection, usage, maintenance and testing of
the fume hoods. The need to systematically monitor and maintain the performance
of fume hoods can often be overlooked. There are several major aspects
to this type of program.
Fume Hood Selection
One of the first steps in fume hood management is the determination of
which processes need to be performed under a hood. This is typically left
to the chemical hygiene officer, a safety professional, or industrial
hygienist. Processes involving volatile chemicals are the most commonly
identified as requiring a fume hood for safe use. Other factors of chemical
use such as how often this chemical is used, how much is being used, and
the actual processes the chemical is subjected to have a bearing on this
decision. Chemical exposure monitoring data from personal and area monitoring
and lab procedure observation can also be part of this selection process.
It is important not to underestimate the chemical exposure hazard level
of a procedure.
Once the need for a hood is identified, the size and type must be selected. The size of the process and chemicals should be proportional to the fume hood selected as overcrowding in the hood is not desirable. Another important consideration is the type of fume hood selected. Hoods can be defined by sash (window) type; examples are vertical, horizontal, convertible, and walk-in. Hoods can also be defined by their exhaust system; examples are ductless, constant volume, variable air volume, and auxiliary air. Airflow monitors have become a popular and almost standard option for many new fume hoods. Because of the many options available, it is important for the fume hood program manager person to work with the laboratory manager and facility ventilation engineer to select the most appropriate combination and location for each fume hood. Perchloric acid, radioactive materials, or other agents requiring special consideration place an even higher level of safety concern and additional requirements for proper hood selection.
Usage
Selecting the right fume hood for a laboratory is not a guarantee of improved
worker safety. Users need to be trained in the proper use and operation
of these hoods. It is important that the fume hood not become a chemical
storage facility. The user should understand where and why the fume hood
window sash should be placed. The user needs to understand how the fume
hood works, how to verify basic operation, and in many cases, the procedure
to be used when an airflow alarm is triggered. A competent safety, chemical
hygiene, or industrial hygiene person should perform this training on
a regular basis. Workers should also be observed periodically to insure
that proper usage procedures are occurring and to identify areas where
further guidance is necessary.
Chemical fume hoods are used in thousands of labs throughout the country to improve the safety of workers handling hazardous chemicals and reduce their level of personal exposure to these chemicals. A chemical fume hood operates on a relatively simple principle of drawing chemical vapors away from the work space within the hood and out through an exhaust system or an adsorbent filter. Despite the simple principle of operation, a fume hood management program is needed to insure their effective selection, usage, maintenance and testing. Unfortunately, this can often be overlooked by a facility and it is important to develop this type of program before fume hoods are ordered and put into active usage. As indicated above, there are several major aspects to this type of program. We will discuss testing and certification and maintenance in this edition.
Testing
and Certification
Even with proper selection and usage, a fume hood must be tested on a
regular basis to insure that it is maximizing it safety value. The most
common and inexpensive form ($25-50) of testing are airflow measurements.
This allows an air velocity profile to be obtained for the face (front
opening) of the hood and for an average airflow and flow uniformity factor
to be calculated. Visual smoke tests are used to supplement the airflow
measurements and show overall fume hood containment. There are two guidance
documents for chemical fume hood velocities; ANSI/AIHA Z9.5- Lab Ventilation
Standard and SEFA 1.1- Lab Fume Hoods Rec. Practices. These documents
are also excellent sources for a wealth of information on lab ventilation
and fume hoods and are highly recommended reading for the fume hood manager.
ANSI/AIHA recommends 80-120 feet per minute (fpm) average airflow with
20% uniformity; SEFA recommends 75-125 fpm (this applies to variable air
volume hoods only).
The meeting of the above criteria is a good but not absolute measure of hood containment. ASHRAE 110 is a test method that allows for direct measurement of hood containment by the release of a tracer gas in the hood. It is a more complex and expensive form ($400-800) of testing but yields a wealth of valuable data and allows for optimization of hood containment. An alternative to ASHRAE 110 testing is to perform chemical exposure monitoring on personnel using the fume hood to insure that no overexposures are occurring during the work procedures. While this yields less data on specific hood operation than ASHRAE 110 testing , it does complement the airflow testing and can help document the effectiveness of the fume hood(s).
The fume hood manager should have an established testing frequency for hoods and also insure that individuals testing the hoods are properly trained, used calibrated equipment, and have a system of quality control and review for their testing data. For these reasons, many facilities use an outside firm to test and certify their fume hoods.
Maintenance
With the correct hoods, usage, and testing comes the need for proper maintenance
of the hoods. This includes period inspections to insure functioning sashes,
exhaust blowers and exhaust alarms. Simple preventative items such as
exhaust blower belt replacement can become a safety nightmare if they
are overlooked. As with testing, a regular program should be documented
and in place to insure that all hoods are operating and not malfunctioning.
Coordinating preventative maintenance with the hood testing can allow
for roof adjustments of exhaust blowers to insure proper hood airflows
and sash height combinations.
Fume hoods are devices that require attention from the selection and usage process to the regular testing and maintenance procedures. A fume hood management program contains these elements and is placed under the control of the right people. The dividend yielded is maximization of worker safety and minimization of an exposure incident's likelihood.
What safety programs
is a lab supervisor required have?
As a laboratory manager the volume of
paperwork (and computerwork) is ever increasing. Between quality control,
testing procedures, fiscal accountability, and a host of other demands
the lab manager is wearing more hats than ever. One of the more important
hats is the safety hat. OSHA has several Standards that specifically task
laboratory supervisors with requirements for assuring a safe workplace.
One of the most obvious standards is "Occupational Exposure to Hazardous
Chemicals in Laboratories" (29CFR.1910.1450). There are also a number
of substance or hazard specific standards that address occupational exposure
to over thirty substances including formaldehyde (29CFR1910.1048), blood
borne pathogens (29CFR1910.1030), ethylene oxide (29CFR1910.1047) and
benzene (29CFR1910.1028). The Hazard Communication Standard or "right
to know" standard (29CFR1910.1200) is one of the standards most frequently
cited by OSHA. There is a listing of even more substances and allowable
limits provided in the "Air Contaminants" standard (29CFR1910.1000).
This standard establishes limits on commonly used chemicals such as acetone,
ammonia, chloroform, ethyl alcohol, toluene, and xylene. Finally, lest
anyone feel neglected the Section 5(a)(1) of the "Occupational Safety
and Health Act of 1970" requires that "Each employer shall furnish
to each of his employees employment and a place of employment which are
free from recognized hazards that are causing or are likely to cause death
or serious physical harm to his employees." This is the general duty
clause that can be used to address any unsafe situation not specifically
addressed in other regulations.
In this and successive issues of "Clearing the Air" we want to look at the listed OSHA standards and present some of the more common requirements placed on clinical and microbiological laboratories. For the complete requirements of the described standards and others that apply to your laboratory, contact your safety officer and/or appropriate regulatory authorities.
"Occupational Exposure to Hazardous Chemicals in Laboratories" (29CFR1910.1450), also called the lab standard, was designed to address the laboratory use of hazardous chemicals versus the industrial use. Laboratory use is described as where the chemical manipulations are carried out on a laboratory scale, multiple chemical procedures or chemicals are used, the procedures are not part of a production process, and protective laboratory practices and equipment are available and in common use. Laboratory scale is described as where the containers used for reactions, transfers, and other handling are designed to be easily and safely manipulated by one person.
One of the intents of the lab standard was to simplify the regulatory requirements for laboratories. The substance specific standards were typically designed to address industrial applications where larger quantities of the substances are used every day by many workers. In addition to establishing exposure limits, they describe requirements for exposure monitoring, signage, change rooms, medical surveillance, training, and other things. Some of the requirements seemed excessive for laboratories that may use a substance once or twice a month in very small quantities. Worse yet, some laboratories may use two or more of the substances regulated with substance specific standards and have to comply with multiple sets of requirements. The lab standard maintained the exposure limits set out in the substance specific standards, but provided laboratories with an alternative to the other requirements. Facilities that come under the lab standard are required to develop a chemical hygiene plan (CHP). The CHP is defined as a "written program developed and implemented by the employer which sets forth procedures, equipment, personal protective equipment and work practices" that are capable of protecting the employees from the hazardous chemicals being used in the laboratory. The CHP must protect the employees and keep the exposures below the permissible exposure limits specified in the federal regulations. The lab standard goes on to describe specific elements the CHP must address such as the standard operating procedures for working with hazardous chemicals, how the employer will determine appropriate control measures (such as personal protective equipment and hygiene practices), how the employer will assure the proper functioning of fume hoods and other protective equipment, and how are the employees informed and trained. There are other requirements for the CHP including designation of the personnel responsible to implement the plan (the chemical hygiene officer or CHO).
Although the CHP is required to be somewhat detailed, it can address many substances. Technically, a laboratory that used formaldehyde, xylene, and benzene a couple times a month in small quantities was required to demonstrate compliance to the formaldehyde standard and the benzene standard, as well as making sure that their employees were not exposed to excessive levels of xylene. The lab standard allows that lab to develop a CHP that addresses all the chemicals they work with and they only need to demonstrate that they have a good CHP and are following it.
Some laboratories may be required to meet certain substance specific standards. For example, the formaldehyde standard indicates that the standard become effective for anatomy, histology and pathology labs in it's entirety on September 1, 1988.
So how do we start complying
with the lab standard?
The first step is to get a copy of the
standard and determine if it applies to you. If it does apply to you,
list every hazardous chemical being used or stored in your laboratory.
Collect the appropriate Material Safety Data Sheets on the chemicals.
Using the guidelines in the Standard and the non-mandatory appendix, begin
putting together your CHP. ENV can help with personal exposure monitoring
and the certification of lab hoods.
