HEPA Filters for Pharma Applications Cleanrooms & Safety Applications. Gordon Farquharson June 2012

Transcription

1 HEPA Filters for Pharma Applications Cleanrooms & Safety Applications Gordon Farquharson June

2 Air Filters at work Images courtesy of CamfilFarr 2

3 How filters work Sieving Effect Straining 3

4 Filter Test Methods 4

5 Filter Specifications 5

6 Some important filter considerations Correct pre-filters protect systems & prolong life of final filters HEPA filters are required in cleanroom & safety ventilation applications Designs and installation must allow for convenient & safe filter testing Make sure you know what filters are installed in the system 6

7 HEPA Filter Standards HEPA Filters are dealt with in 4 basic ways. Filter Construction standards Factory or manufacturer s tests In-situ testing of installations Some application standards include HEPA Filter specifications (e.g. EN for Biosafety Cabinets) 7

8 Filter Test Methods MPPS = 0.2 8

9 Some Test Equipment Thermo-Pneumatic Aerosol Generator 9

10 Some Test Equipment Laskin Nozzle Cold Generator 10

11 Some Test Equipment Aerosol Photometer 11

12 New Standards from CEN TC Air Filtration 2 HEPA & ULPA Filters EN Testing Planar Filter Medium to determine the MPPS -- Most Penetrating Particle size. The processes of Interception, Diffusion & Straining give the following v1 classic curve. Performance is velocity dependent. 12

13 HEPA & ULPA Filters EN Factory Test 13

14 EN 1822 compared with Eurovent 4/4 NaCl Eurovent 4/4 EN 1822 Filter Class Efficiency % Filter Class Efficiency % H H EU H EU EU H EU H EU 14 > U U U

15 EN Filter Classifications Local efficiency = 5x 0verall Overall Effic/Pen Local Effic/Pen H / 15 % na / na H11 95 / 5 na / na H / 0.5 na / na H / / 0.25 % H / / U / / U / / U / / To avoid problems with In-situ test, always specify a face scanned filter from the supplier! 15

16 Local & Overall Efficiency H 14 MPPS Local pen < % Local pen < % Local pen < % Local & Overall Pen % must pass Overall penetration < MPPS 16

17 Leak test In-situ PAO test Local pen < 0.01 % Local pen < 0.01 % Local pen < 0.01 % 17 Overall penetration < or MPPS

18 Local & Overall Efficiency H 14 example 18

19 How do we choose our HEPA filters?? From the requirements in a Cleanroom Standard or GMP rule/guideline. Because we have chosen a certain acceptance value for the In-Situ leak test e.g % or 0.01%. Because we have calculated the efficiency of filter we need from an evaluation of the particle challenge imposed upon the filters. Because the filter gives good Uni-Directional Flow. Compliance with some other requirement e.g. Corporate. 19

20 Choosing the Right HEPA Filter EU GMP Grade A Class At Rest E 0.5 ISO M3.5 Class In Operation E 0.5 ISO M3.5 Air flow regime and final filter configuration UDAF Terminal HEPA filter Final Filter specification to EN 1822 In situ test leak test method Test acceptance criteria = stated % U15 Face scan with % aerosol & H14 photometer 0.01 % B ISO M3.5 ISO 7 10,000 M5.5 N-UDAF Terminal HEPA filter H14 Face scan with aerosol & photometer 0.01 % C ISO 7 10,000 M5.5 ISO 8 100,000 M6.5 N-UDAF Terminal HEPA filter H14 Face scan with aerosol & photometer 0.01 % D ISO 8 100,000 M6.5 Not defined N-UDAF In plant final filter H13 Volumetric overall penetration % Refers to filter grades in accordance with EN 1822 ULPA, & HEPA 20

21 The Installed HEPA Filter 21

22 Typical Aseptic Facility Design (From ISPE HVAC GPG) Outside air treatment AHU 22

23 In-Situ Testing General Select test method, aerosol, and acceptance criteria Determine challenge up-stream Scan test final filter face for leaks Determine acceptance or rejection Carry out remedial work. Agree before repairing filters. Have a clear policy. ISO allows repair, subject to manufacturer s approved method. I don t know any manufacturers who encourage repairs. Re-test 23

24 Testing is application specific Filter testing in this Isolator is a different problem from the cleanroom. 24

25 Filter Systems for Potent, Toxic, Biohazard applications 25

26 Exposure Control Potent Compound Control Bands EH & S Call the shots! EXPOSURE CONTROL BAND Band OEL Range Design 1 >1000 ug/m3 General Ventilation, Conventional open Equipment with local exhaust (LEV) ug/m3 Semi-closed to closed materialo transfer laminar flow/directionalized laminar flow engineered LEV ug/m3 Transfers using direct couplings % closed systems selected use of unidirectionalized air flow booths ug/m3 Totally enclosed processes: Transfers using direct coupling barrier/isolator technology 5 <1 ug/m3 Isolator technology; remote operations fully auotmated 26

27 Typical OSD Facility Using Multiple Air handlers (From ISPE HVAC GPG) 27

28 BIBO (Bag-In, Bag-Out Housing Fully Self contained system with fan, integrated dampers & automatic scan section optional Cover Panel Access door for BT damper Scan section Hepa Section Pre filter section Air intake levelling feet 28

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30 30 Filter Leak Test Procedure!

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32 Duct mounted double exhaust housing Safety ventilation systems - typical contemporary BSL-3 exhaust system High Total Cost of Ownership Large Each system must be specifically oriented Costly to test 32

33 Typical BSL-3 HEPA Filter Exhaust System 33 High Efficiency Particulate Air 33 (HEPA) Filter

34 Field system leak testing manual scanning Potential Risk to Certifier Requires lab shutdown and system decontamination Slow process 34

35 Field system leak testing automated scanning 35 Control Unit

36 Conclusions Be aware of the Different Standards Understand the configuration Specify filters correctly (including leak testing) Install carefully Test In-situ Plan re-testing Keep records

37 37 Thanks for your attention Questions?

38 PharmOut Unit 20, 40 Montclair Avenue, Glen Waverley, Victoria, Australia, 3150 Tel +61 (0) Thanks for your attention Slid e 38

39 S Y S CRI T ICAL E M S Gordon J Farquharson Chair BSI LBI/030; Chair CEN TC243; Convenor ISO TC209 WG1. c/o Critical Systems Ltd 4, Greencroft, Guildford, Surrey, GU1 2SY, UK. tel +44 (0) mob +44 (0) gj.farquharson@gmail.com & gjf@critical-systems.co.uk 39