Baker SG403A

American Instrument Exchange now provides NSF accredited field service work for biosafety cabinets, laminar flow clean benches, chemical fume hoods, and other clean air systems throughout Greater Boston and New England. 

 These on-site services include: 

  • Installations
  • Certifications
  • Filter Replacements
  • Diagnostics and Repairs
  • Decontaminations and Removals

Contact Us


Sales and Installations

Upon receipt of an order for a biosafety cabinet or clean bench, our technicians will order and install new filters at our site. We then test the biosafety cabinets and clean benches in accordance with the manufacturer and other applicable standards in order to ensure that it’s working properly prior to leaving our warehouse. We use local movers with years of experience installing these, to bring them from our warehouse to your site, and set them up on-location. This includes assembling the stand (if applicable), and placement in the desired location.

We then send our NSF accredited technician to your location to test and certify the biosafety cabinet or clean bench at no additional cost. The certification is valid for 12 months, and we offer annual testing and certification thereafter at market pricing.

Testing and Certifications

All biological safety cabinets are certified to meet NSF-49 guidelines. In order to verify that the cabinet provides protection to your product, person, and environment. Field certification is an essential practice to ensure that the cabinets maintain their specifications, as HEPA filters will collect particles over time and need adjustments to maintain their proper airflow. NSF recommends that BSC’s go no more than 12 months between certifications, with some applications requiring semi-annual certifications. This ensures that research material is properly contained and protected to produce accurate results.  

The following are the potential tests performed as described by NSF:

  • Pressure decay / Soap Bubble – Determines the overall seal integrity of the cabinet outer hull, including exterior surfaces of all plenums, welds, gaskets, plenum penetrations, and seals.
    • Pressure decay – The cabinet shall hold 2 inches w.g. (500 ± PA) ± 10% for 10 minutes.
    • Soap bubble – All weds, gaskets, penetrations, and seals on exterior surfaces of air plenums shall be free of soap bubbles when at 2 inches w.g. (500 ± PA) ± 10% pressure above atmospheric.
  • HEPA/ULPA filter leak test – Determines the integrity of downflow and exhaust HEPA/ULPA filters, filter housings, and filter mounting frames.
  • Site installation assessment tests – These tests are performed to verify that the biosafety cabinet is integrated properly into the facility. This includes:
    • Sash alarms
    • Exhaust airflow alarms and interlock
      • Exhaust alarm systems – Type B1 or B2 hoods
      • Exhaust alarm system – Type A1 or A2 canopy connection
      • Exhaust alarm system – Type C1
    • Cabinet alarm systems – Type A1, A2, or C1
    • Airflow alarm system – Type A1, A2, or C1
    • Internal supply /exhaust fan interlock alarm – Type A1, A2, or C1
  • Electrical leakage and ground circuit resistance and polarity tests – All new cabinets shall conform the requirements of the current edition of any national standard that is based on IEC610-1. Cabinets initially qualified under versions of NSF/ANSI 49 prior to the 2009 edition shall conform to UL61010A-117 or may refer to NSF 49-1992 for Electrical Leakage, Ground Circuit Resistance, and Polarity tests if necessary.
  • Light intensity test – Determines the light intensity on the work surface of the cabinet in fc (lux).
  • Vibration test – This test determines the amount of vibration in the operating cabinet.
  • Noise level test – This test provides a uniform method for measuring the noise level produced by the cabinet. The methods can be performed in most acoustically ordinary rooms
  • Stability tests – These tests demonstrate the structural integrity and stability of a biosafety cabinet for the following:
    • Resistance to overturning under applied forces
    • Resistance to distortion under applied forces
    • Resistance to deflection of work surfaces under load
    • Stability with respect to tipping under load.
  • Motor / blower performance – This test demonstrates that when the cabinet is operated at the nominal set point velocities and without readjusting the fan speed control, a 50% increase in pressure drop across the new filter shall not decrease total air delivery more than 10%.
  •  Downflow velocity test – This test measures the velocity of air moving through the cabinet workspace 4 inches (100 mm) above the bottom edge of the sash.
  •  Inflow velocity (face velocity) test – This test determines the measured and calculated inflow velocity through the work access opening and the calculated exhaust flow volume rates.
  •  Personal, product, and cross-contamination protection (biological) tests – These tests determine whether aerosols will be contained within the cabinet, outside contaminants will not enter the cabinet work area, and aerosol contamination of other equipment in the cabinet will be minimized.
  • Airflow smoke patterns test – This test determines the airflow along the entire perimeter of the work access opening is inward, that airflow within the work area is downward with no dead spots or refluxing, that ambient air does not pass on or over the work surface, and that there is no escape to the outside of the cabinet at the sides and top of the sash.
  •  Drain spillage trough leakage test – Demonstrates the containment capability of the spillage trough under the work surface.

All biosafety cabinets certifications are performed with standard operating procedures which are updated regularly to comply with federal guidelines.

Due to the specialized knowledge required for a proper and safe certification of biosafety cabinets, NSF International administers an accreditation program to accredit field certifiers. Field certifiers must pass a written and practical test administered by NSF before becoming accredited. In addition, continuing education and periodic reexaminations are required for accreditation.

Filter Replacements and Calibrations

It is typical for HEPA filters to last five to ten years, depending on usage and lab conditions (i.e. humidity, quantity of use, and air quality). A full gaseous decontamination of the biosafety cabinet must be done before old filters are removed and new ones are installed. American Instrument Exchange is capable of providing Chlorine Dioxide, Vaporized Hydrogen Peroxide, or surface decontaminations depending on your needs. These services can be applied to (but not limited to) Class I, Class II, Laminar Flow Benches, and ductless fume hoods.

Our NSF-certified biosafety cabinet field certifiers will ensure your biosafety cabinet contributes to accurate and repeatable results. Furthermore, we are committed to providing calibration services that help you meet your industry regulatory needs. This includes a wide variety of industries, as well as many manufacturers and models.

Routine Maintenance and Repairs

To protect workers and the environment, precautions such as a biological safety cabinet may be used to prevent exposure to microbiological contamination. If this equipment is not working properly, the risk increases, especially if the user is unaware of the failure.

Poor placement, poor inflow velocity or downflow velocity, failed HEPA filters, elevated sashes, crowded work area and poor user techniques can compromise the biosafety cabinet’s containment capacity, and these problems will not be noticed unless a BSC test is conducted or if they become seriously contaminated and consequently ill. Because of this, biological safety cabinet validation is extremely important.

Proactive routine maintenance can prevent future biological safety cabinet contamination issues with decontamination and filter change outs. Proper maintenance of a biosafety cabinet assures effective use of the containment device. The life span of a HEPA filter will depend on the type of particles generated inside the biosafety cabinet. Changing the filter can be done after the cabinet has been decontaminated or a “bag-in/bag-out” procedure, can be used for cabinets used with hazardous materials that cannot be decontaminated 

We offer many repair services in addition to routine maintenance, including:

  • HEPA filter replacement for virtually any makes and models of biosafety cabinets, laminar flow clean benches, and ductless fume hoods.
  • Servicing or replacing AC and DC motors and electrical components critical to their function.
  • Sash system replacement including sash window, cable, and balance
  • UV/Lighting repairs and replacement including bulb, ballast, switch, and wiring
  • Custom installations of accessories such as UV and fluorescent light kits, airflow monitors, and castors

Decontaminations and Removals

Contamination can have disastrous effects throughout an organization, from patient safety and research to production. Biological safety cabinets are essential to many researchers’ work and preventing contamination is critical to protecting the integrity of the experiment. For an effective decontamination, we use chlorine dioxide gas, which as a “true gas” doesn’t create condensation issues. This method for decontamination of biological safety cabinets is validated by NSF/ANSI Standard 49. Some reasons for decontamination include:

  • Maintenance on the cabinet.
  • Decommissioning the cabinet
  • Moving the cabinet
  • Changing experiments
  • Contamination issues

If you’re thinking of upgrading from your current biosafety cabinet to a newer one, we may be able to remove yours after decontamination, depending on its age and condition.

Whether you purchased the unit from American Instrument Exchange or from another vendor we can provide the initial certification as well as annual certifications and any necessary diagnostics or repairs with a trained and NSF accredited certifier. 

The addition of these on-site services simplifies the process of purchasing and installing biosafety cabinets and other clean air systems. There’s no need to coordinate multiple vendors – simply call American Instrument Exchange and we can schedule delivery and certification of a refurbished unit, along with decontamination and removal of any units you need to decommission.

So, if you're looking to purchase, sell, trade, or repair a biosafety cabinet or other clean air system, or simply want schedule an annual certification, please give us a call at 978-521-2221 or fill out the form below.

Types of Clean Air Cabinets

Class I biosafety cabinets are defined as “a ventilated cabinet for personnel and environmental protection”, by Labconco. Their applications are significantly limited because they do not offer product protection from contamination. Class I biosafety cabinets have a similar airflow pattern to a fume hood, utilizing unrecirculated airflow away from the user, but they do have HEPA filtration at the exhaust outlet (which may or may not be ducted outside). Class 1 cabinets can be used with agents that require Biosafety Level 1, 2, or 3 containment.

Class II biosafety cabinets are defined as “a ventilated cabinet for personnel, product, and environmental protection for microbiological work or sterile pharmacy compounding”, according to Labconco. Personal protection is offered from inward airflow from the open front, products are protected from the downward HEPA-filtered laminar airflow, and the environment is protected as all of the exhausted air also flows through HEPA filtration. Class II biosafety cabinets are broken down into types based on construction, airflow, and exhaust systems.

  • Class II, Type A1 cabinets exhaust 70% of recirculating air that is vented into the room through a HEPA filter or to the facility's HVAC system under a canopy exhaust connection. The remaining 30% of the air is recirculated into the work area through a HEPA supply filter. Downflow air is a mixture of recirculated and inflow air from a common plenum and will vary in total volume based on the cabinet design. The ducts and plenums containing biologically contaminated matter are either under negative pressure or surrounded by ducts and plenums under negative pressure. Intake air velocity for a Type A1 is a minimum of 75 FPM.
  • Class II, Type A2 cabinets recirculate 70% of the air that is vented into the room through an exhaust HEPA filter or to the facility's HVAC system under a canopy exhaust connection. The remaining 30% of recirculating air is recirculated into the work area through a HEPA supply filter. Downflow air is a mixture of recirculated and inflow air from a common plenum and will vary in total volume based on the cabinet design. The ducts and plenums containing biologically contaminated matter are either under negative pressure or surrounded by ducts and plenums under negative pressure. Intake air velocity for a Type A2 is a minimum of 100 FPM.
  • Class II, Type A/B3 is an older designation that was consolidated into what are now called Class II, Type A2 biosafety cabinets in 2002. These biosafety cabinets meet current Class II, Type A2 standards.
  • Class II, Type B1 cabinets exhaust 40% of its air through a dedicated duct and a HEPA filter before entering a facility's HVAC system. Must be hard connected to an exhaust system. The remaining 60% of air is mixed back into the inflow and recirculated to the work area through a HEPA supply filter. Intake air velocity is a minimum of 100FPM.
  • Class II, Type B2 cabinets provide no air recirculation within the work area. They must be connected to the exhaust system of the building. 100% of the HEPA-filtered air is immediately exhausted through a dedicated duct that is hard-connected to the HVAC system. A blower motor located near the top of the cabinet pushes room air through a HEPA supply filter into the work area. Intake air velocity is a minimum of 100 FPM.

Laminar flow Clean Benches use horizontal or vertical laminar flow but are not biosafety cabinets. They disperse HEPA-filtered air across the work surface toward the user, which can expose the user to potentially hazardous materials. These devices only provide product protection.  It is acceptable to use clean benches for certain clean activities, such as the assembly of sterile equipment or electronics, but they should not be used for handling cell culture materials or drug formulations, or when manipulating potentially infectious materials. Laminar flow hoods keep a constant, unidirectional flow of HEPA-filtered air over the work area, protecting it from dust and other airborne contaminants.  There can be a horizontal flow, blowing parallel to the work surface, or a vertical flow, blowing onto the surface from the top of the cabinet. 

Chemical fume hoods are designed to prevent dangerous substances from being released into the laboratory space by controlling and then exhausting hazardous and/or odorous chemicals through an external exhaust system or activated carbon filter. These systems do not provide any product protection for agents inside them Fume hoods contain spilled chemicals and exhaust the fumes away from the user and laboratory area in the event of an accidental spill.

Contact us today for pricing and information on our field services!

All of the equipment shown on our website is in stock and available. Orders ship from our 30,000 square foot warehouse in Haverhill, MA. Our surplus lab equipment is reconditioned for many types of laboratories, including biotech, biomedical, medical research, chemical, pharmaceutical, and university and hospital research laboratories. We have been a reliable source for used laboratory and scientific equipment since 1969.

American Instrument Exchange, Inc.
1023 Western Avenue
Haverhill, MA 01832

Phone: 978-521-2221
Fax: 978-521-8822

EMAIL: info@americaninstrument.com

 Smoke testing a biosafety cabinet