HEPA Filter Patch Considerations 

Most companies which utilize HEPA filters, or are involved in the routine certification of HEPA filters in the pharmaceutical industry, are well aware of the Institute of Environmental Sciences recommended practices concerning the testing of HEPA filters.  The “recommended practice”, which outlines the acceptable testing and repairing of the HEPA filter is IEST-RP-CC034.2, HEPA and ULPA Filter Leak Test.  The recommended practice states the following:

Field repair should not block or restrict more than an additional 3% of the filter face area, and no single repair should have a lesser dimension exceeding 3.8 cm (1.5 in.).

When reading this statement it appears that it is in line with how a recommendation should be phrased.  Verbiage is very important in the pharmaceutical industry, as most know; “should” has a very different meaning than “shall”.  The recommended practice goes on to state:

…  Repairs to filter leaks may be made by procedures acceptable to the customer and the supplier…  Filter integrity requirements are a matter for agreement between the customer and the supplier.

For many past years this did indeed seem to be a recommendation.  Recently many pharmaceutical companies have been required to enforce the maximum recommendation patch size and filter coverage percentage as an absolute pass or fail criteria.  It is as if this recommended practice has now become a requirement concerning acceptable HEPA filter patches.

It appears that the location of the patch does not seem to be of any concern currently.  Take for example a HEPA filter located within an equipment pass through airlock or vestibule.  If this filter has a repair that exceeds the minimum dimension of 3.8 cm (1.5 in.) should the filter be replaced?  Again, apparently this is the case now within the pharmaceutical industry.  Location of the patch or proximity to any critical operation does not seem to be of any concern.  One would certainly agree that if a patched area of the HEPA filter was located directly above a critical filling operation it would be prudent to replace the HEPA.  What about a filter located twenty feet from any critical operation?  What about a filter which has a patch which measures two inches by two inches, and is located in the ceiling over the beginning of a fill line and is eight feet from the line?  Is the suggestion from the “required” replacement of the filter due to patch size because of the thought that the airflow will be impacted negatively?

As anyone who is somewhat knowledgeable within the HEPA filter testing industry can see, this example of a patched HEPA will not negatively impact the operation of the cleanroom, or quite frankly the airflow of the HEPA.  Why does the industry still recommend measuring the airflow “no more than 30 cm (12 in.) from the supply source.”¹?  If one is so concerned about the patch affecting airflow, shouldn’t the measurement of the airflow be at the precise critical operation level?

It appears that the industry as a whole has gotten away from the idea that we as an industry can make sensible proper decisions without being told exactly how to do it.  It is in the best interest of the pharmaceutical companies to maintain safety for their clients of the items they manufacture; otherwise they will loss in the end.

Where will this all end?  Maybe the next requirement will be that no patching of any HEPA filters is acceptable.  Believe it or not, there are already pharmaceutical companies implementing this in there own procedures.  Hooray for the HEPA manufacturers’, so sorry for the end users of the pharmaceutical items being produced, because as we all know, someone will be paying for it in the end.

Gertrude Stein once said:  “Everybody gets so much information all day long that they lose their common sense.”  Wouldn’t we all agree, in this industry there is much information, let’s not lose our common sense.

Michael D. Alleman

President

Air Safe, LLC. 

1.  IEST-RP-CC006.3; Testing Cleanrooms

  Over 20 Hoods discounted for sale NOW! 

We have used laminar flow clean benches & biological safety cabinets for sale at extremly reduced prices to move them so our next load can be refurbished.  This is your chance to buy a hood far below the cost of a new unit and at costs well below the average used market prices!

Call us at 888-924-7723.  There are only a portion of our hoods listed here on our site.

Here is a sampling of the hoods we have available:

The standard Laminar flow hood certification includes air velocity testing to document and obtain an acceptable airflow and calculated total CFM volume, meeting the manufacturer’s specifications.  The HEPA filter integrity test is also performed to document acceptance, no leak in excess of .01% of the upstream challenge concentration.

Additional testing includes:  sound level testing, florescent light testing, ultra-violet light testing, electrical testing, vibration testing, particle count classification and temperature testing.

All reporting is printed out electronically on-site via computer, and a compliance certificate is issued and applied to the unit denoting test date, status, and re-certification due date.

STANDARDS

The national standard used by Air Safe to certify the hood's performance is the IES-RP-CC-002.2, Laminar Air Flow Devices, as well as the manufacturer's guidelines.

Air Safe provides certification, preventative maintenance, and repairs for all types of hoods as well as other air cleaning and moving equipment:

Surgical Suites , TB Rooms, Fume Hoods , Laminar Flow Clean Benches, Biological Safety Cabinets , Isolators, In-Line HEPA systems, Glatt Dryers, Animal Units , Air Showers, HEPA Ovens, BSL-3 Containment Labs, Capture Hoods, Bone Marrow Rooms.

Air Safe supports equipment manufactured by:

Abatement Technologies, Agnew Higgins, Abbott Laboratories, Air Control, American Scientific, Atmos Tech, Baker Company, Bellco, Bio Quest, BBL, Bio Safe, Bio Clean, Capt Air, Canadian Cabinets, CCI, CCL Classic Modular, Clean Air Products, Clear Air Systems, Dexon, Duralab, EACI, Envirco, Esco, Fisher Scientific, Flow Sciences, Forma Scientific, Gelaire, Germfree Labs, Gruenburg, Hamilton Industries, Hemco, Hoffman, Holten, Howorth Air, HR Inc, I.S.O. Tech Design, Integrated Air Systems, Iroquois, Isle Industries, Johnston Labs, Kendro, Kewaunee Scientific, La Calhene, Lab Products, Labconco, Laminaire, Laminar Flow Inc, Lerner Labs, Lipshaw, MIC, Microviod, Microzone, Modular, Mopec, NuAire, Pureaire Corp, Sci-Med, Sterilaire, St. Charles, Thermo Fisher (Forma) Scientific, Torit, Veco, Weber, Westinghouse, and all forms of manufactured cleanrooms.

Air Safe works directly with the manufacturers to provide you with all of your warranty related services for your equipment.

Air Safe provides all necessary and required testing to keep your equipment and facility in compliance.

Air Flow Velocity & Total Volume, HEPA Filter Leak Test, Lighting, Ultra Violet Lighting, Noise Level, Electrical, Air Flow Smoke Testing, Pressure Testing, Vibration Testing, Particle Count Test, Air Changes.

All testing conforms to applicable current test standards, which are denoted on every electronically generated test report.  No handwritten illegible reports from Air Safe.

Other Services Provided:

Decontamination Services , Filter Repairs & Replacements, Motor Replacements, Electrical Repairs, System Upgrades, Facility exhaust fan PM On-Site Training Programs , and Consulting Services .

Air Safe stocks the most commonly needed HEPA filters and blower motors need for repairs. This eliminates the down time associated with equipment being out of service for extended periods.

If there is a particular service you are requiring for your equipment please contact Air Safe for additional information.

Just because your clean bench is brand new does not mean it is working properly!

Are your surgical suites operating within their design specifications?  Would you like to know how clean the air is being delivered to your rooms?  Do you need to know your room air change rates?

Air Safe has been providing these services to our clients for years.  Did you know that just because you have HEPA filters installed in your system does not mean that unfiltered air is entering your rooms?  HEPA filters must be performance tested in order to determine the level of performance.  This must be done every time the filters are changed as well as periodically.  We can test and validate your facility’s performance concerning the air quality.

Are you concerned about possible medical gas leakage within your operating rooms?  We provide real time VOC and surgical gas monitoring.  Why wait for a lab to send back the results.

We can calculate your air change rate using traditional methods as well as more accurately measuring air changes with the use of tracer gas.  This method allows for us to pinpoint problem areas within a room concerning airflows.

ADDITIONAL TESTING

STANDARDS

The national/international standards used by Air Safe to certify the surgical room performance are:

1.      IEST-RP-CC-006.3; Testing Clean Rooms

2.      IEST-RP-CC-002.2; Unidirectional Clean Air Devices

3.      IEST-RP-CC-007.1; Testing ULPA Filters

4.      IEST-RP-CC-034.2; HEPA and ULPA Filter Leak Test

5.      ISO 14644; Cleanrooms & Associated Environments

We are accustomed to performing these services around your hectic daily surgery schedule and work closely with your control desk personnel to minimize down time for the rooms.