Spoiler Alert: Because It’s Better for our Customers
New customers often ask us whether we can discount the price of bio safety cabinets by either leaving the old HEPA filters in place or not providing any filters. The short answer to this question is, “Sure, but you’re going to end up paying more later.” Purchasing a bio safety cabinet without HEPA filters is like buying a car without tires: you can do it, but you’d better know what you’re doing and have plan in place before you hand over a check and get the keys.
Here’s a quick primer on how bio safety cabinets work. Biological safety cabinets (also called BSCs, biosafety cabinets or bio hoods) are designed to provide three basic levels of protection. Class I units provide personnel and environment protection for the safe handling when working with chemicals and powders. Class II designated units must meet the requirements for personnel, environmental and product protection. Class III biosafety cabinets are aerosol-tight enclosure with a non-opening, completely sealed, front window, so the operator is separated from their work by a physical barrier (sometimes referred to as “gloveboxes.”) There are different variations and level of safety within each of these categories, but broadly speaking every bio safety cabinet falls under one of these three designations.
Class II, Type A2 bio safety cabinets are the most common designation and require two HEPA filters. During operation air-flow is drawn into the work chamber via the front aperture and continues under the worktop and up the back plenum, where 70 % is recirculated through the main supply HEPA filter to provide down flow and 30 % exits out through the exhaust HEPA filter and out of the chamber. The vertical laminar flow biological safety cabinet provides operator protection by means of inflow, product protection by means of down flow and environmental protection by means of the filtered exhaust. This is the most common type of bio safety cabinet that you’ll typically find in a tissue culture lab.
To change the filters in these hoods the front cover has to be removed and many manufacturer’s include an interior cover that has to be removed as well. After that, depending on the make and model of the unit the motor may have to be loosened, a HEPEX bag needs to be removed/replaced, and brackets removed or loosened, among other small steps. Then the gaskets on the new filters must be coated with grease to help insure a seal and the processed reversed. And here’s the kicker: the media in these filters CANNOT BE TOUCHED AT ALL OR ELSE THEY WILL BE DAMAGED AND UNUSABLE. Tightening the brackets with a wrench and graze the filters with an elbow? Forget it – you’re not going to pass certification, so you’d better order a new filter. For around $750. Or more.
But here at American Instrument Exchange we work with bio safety cabinets extensively. On average we’re installing three or four sets of filters a week and collectively our team here has over 75 years’ experience working with BSCs and installing filters as of the time of this writing. We know that we can install filters quickly and correctly.
So if you’re looking to purchase a bio safety cabinet, let us remove some of the stress and aggravation from the process for you. Call us today for a quote on a refurbished unit from Baker, Nuaire, Labconco, Thermo, or any other manufacturer. We’ll install the HEPA filters here and put the unit through certification to make sure that it works properly and to manufacturer’s specifications. When it arrives in your lab it will be ready to go, hassle-free!
American Instrument Exchange has been a reliable source for used laboratory and scientific equipment for over 50 years, buying and selling equipment since 1969. Our surplus lab equipment is reconditioned for many types of laboratories, including biotech, biomedical, medical research, chemical, pharmaceutical, and university and hospital research laboratories. All lab equipment listed on our website is in stock and ships from our 30,000 square foot warehouse in Massachusetts. Our facilities include a fully equipped shop with highly trained technicians who thoroughly test each instrument before it reaches your laboratory. Please visit our website at https://www.americaninstrument.com/.