PPE reuse

Government of West Bengal Department of Health and Family Welfare Directorate of Health Services
Wing- A, 4th Floor, Swasthya Bhavan
GN 29, Sector- V, Salt Lake, Kolkata- 700091

Memo No: HPH/9M-21/2020/95

The MSVP, Medical College and Hospital (All) The Chief Medical Officer of Health (All) West Bengal

Sub: Guidelines for reuse of PPE & Masks for Health Care Workers

Dated: 24/04/2020

Please find herewith attached the recommendation of the Expert committee in respect of reuse of PPE and masks for Health Care Providers for your information.

You are requested to inform all concerned for strict compliance.

Director of Health Services Government of West Bengal

Memo No: HPH/9M-21/2020/95/1(8) Dated: 24/04/2020 Copy forwarded for kind information please to:

1. The Mission Director & Secretary, Government of West Bengal

2. The Secretary, PHP, Government of West Bengal

3. The Principal, all Medical College and Hospitals

4. The Jt. Director of Health Services (PH&CD), Government of West Bengal

5. The Dy. Director of Health Services (Malaria), Government of West Bengal

6. The Dy. Director of Health Services (PH), Government of West Bengal


Director of Medical Education Government of West Bengal

7. Web copy

8. Guard file


Director of Medical Education Government of West Bengal

Director of Health Services Government of West Bengal


Guidelines for reuse of PPE & Masks for Health Care Workers

One meeting was held on 13/04/2020 in the Green Room, Swasthya Bhawan, with different Experts from the field of Microbiology, Medicine and Tropical Medicine on the issue of re-utilization of N95 masks, PPE, Coveralls and Face shields during this acute crisis of COVID19 Pandemic, jointly chaired by the DME and DHS, Government of West Bengal. The following protocols are recommended.

• The face shields, PPE, Coveralls, gowns, surgical masks, N95 masks etc. should be used properly and judiciously.

• Use of N95 masks may be restricted to fever clinics, suspect and confirmed COVID wards, prioritizing the aerosol generating procedures like the sample collection, intubation of a COVID- 19 positive case, during CPR, during bronchoscopy etc.

• For proper utilization of the PPE, masks etc. these should be decontaminated and reused as per following protocols:

Heat sensitive equipment (PPE): Preferably with Hydrogen peroxide vapor, Ethylene oxide sterilization technique.

o Single warm cycle (55°C and 725 mg/l 100% EtO gas). Items and a chemical indicator placed in an individual standard poly/paper pouch. EtO exposure for 1 hour followed by 4 hour of aeration.

o Standard Autoclaving can also be used in facilities where the above methods are unavailable. Taking into account that the PPE may be discarded if the elasticity of the rubber materials of the PPE is lost after repeated autoclaving.

 Cloth items (gowns, cloth masks): Preferably Autoclaving or washing with soap and hot water.

 Face shields and goggles: Immersion in 0.5% Sodium Hypochlorite solution or cleaning with
70% alcohol.

 Heat sensitive equipment like N95 masks directly coming in contact of the skin: Though Hydrogen peroxide vapor is the preferable method, UV C radiation may be utilized, if available.

o The laminar flow machine can be used for decontamination of the N95 masks, which will be properly labeled with the name of the users, and will be exposed to the UV C rays, 15 minutes each side (outer and inner), to 176–181 mJ cm2 exposure of the masks, with a 40- W UV-C light (average UV intensity experimentally measured to range from 0.18 to 0.20 mW cm2). The masks will be kept 3 feet from the 40 W UV-C light source for 15 minutes.

• The HCW are advised to wear a surgical mask over the N95 mask for better protection and to prolong the life of the mask. The surgical mask will be discarded after 1 shift (8 hours) of usage and the N95 mask may be reutilized as noted below.

• Disposable N95 respirators may be re-used or worn for extended use as long as they are able to seal, were not worn during an aerosol generating procedure or have reached the end of their use by being soiled, damaged or moist from sweat or insensible fluid loss through breathing. The N95 masks can be utilized up to 5 cycles of usage and decontamination. DO NOT use ALCOHOL AND CHLORINE [bleach]-based disinfection methods.

• Equipments which are subjected to decontamination or reutilization/reuse should be used or worn as per the standard protocol of Donning and Doffing of PPE and Masks.
The detailed protocols and procedures for the different equipments as mentioned above are noted in the following Annexure:


Annexure-I & Annexure-II: Protocol for Decontamination of Coveralls and N95 Respirators, Annexure-III: Protocol for Re-use of Face shields and Goggles, Annexure-IV: SOP to make 0.5% hypochlorite

Annexure-I: Protocol for Decontamination of Coveralls and N95 Respirators

Segregation: Used coveralls, PPE [manufactured by Dupont (Tyvek- white/ Tychem- Grey color) OR by Kimberly Clark (A30- white color)] and N95 respirators (all types) should be deposited into separate clearly labeled Yellow bins for Masks, and Red bin for PPE.

Note: Used coveralls should be kept in closed bins/sealed bags in separate locked room until they are collected for reprocessing and decontamination.


• Minimum two designated adjoining rooms (one decontamination room for actual decontamination process & one processing room with clean areas for packing and dispatching decontaminated coverall).

• Hydrogen Peroxide Vapor (HPV) generator + clothes-clips (plastic/wooden)+ clothes-lines/ curtain lines with hooks (for N95)

• 11% commercially available stabilized Hydrogen Peroxide ( e.g. Baccishield or Ecoshield in hospital supply)

• Measurement cylinders

• Closed bins/large plastic bags

• Stool/chair for standing while clipping the coveralls

• Permanent markers.

• Sealing machine with plastic pack rolls.

• PPE requirement for the processing staff [gown, N95 masks, nitrile gloves, heavy duty gloves, goggles, face shield, long boots, sterilium).

• Logbooks
Working solution: Make doubling dilution of 11% Hydrogen Peroxide according to volume of the
room (see table).
Choose cycle/running time depending on the volume of the room as indicated below:

Room Volume

Hydrogen Peroxide (11%) in ml

RO water in ml

Final volume

Cycle/Running time at 32 ml /min in SATEJ PLUS machine/ Fogger machine available for OT sterilization

1000 cu ft

100 ml

100 ml

200 ml

6 min

2000 cu ft

200 ml

200 ml

400 ml

12 min

3000 cu ft

300 ml

300 ml

600 ml


4000 cu ft

400 ml

400 ml

800 ml


5000 cu ft

500 ml

500 ml

1000 ml


6000 cu ft

600 ml

600 ml

1200 ml


Annexure-II: Protocol for Decontamination of Coveralls and N95 Respirators Procedure: Have the clothes line placed at a height of around 7 ft. Keep a gap of 3ft between each

line. Seal entire room (including AC vents), except the door, using brown tape.

• Clip coveralls to clothes-lines suspended at each shoulder or hand using hangers. Ensure that the zip is open to expose the inner part. Keep a gap of at least 1 foot between each coverall.

• N95 masks can be clipped by the elastic band/ or hung on hooks on the clothes line with a gap of half foot between each mask.

• Ensure that HPV generator is plugged in and in position (45 degree angle), and there are no obstructions between HPV generator and suspended coveralls.

• Exit decontamination room and doff the gloves and gown at threshold. Discard in red bin. Perform hand hygiene.

• Start the HPV generator

• Let the room be sealed for at least 2 hours after the cycle finishes

• This completes the decontamination cycle.

• Open door- you will see fog; check the machine container to confirm that the solution was used.

• Aerate by switching on ceiling fans for 4 hours.

• After completion of decontamination cycle, collect decontaminated PPE in a clean container. The staff should don fresh PPE again.

• The collected PPE should then be moved to the adjacent room.

• The coveralls should be folded properly and packed in plastic bags

• The N95 masks should be placed in a separate box and sealed—NEED to work this out as there are different types.
Note: Biological indicator containing Geobacillus stearothermophilus spores may be used weekly, in separate locations inside the room, for quality control purpose.

Annexure-III: Protocol for Re-use of Face shields and Goggles
Segregation: Used face shields/goggles should each be deposited into separate clearly labelled RED


Equipment and materials required: 0.5% sodium hypochlorite- freshly prepared (see annexure); 70% alcohol (Bacillol solution), red buckets, flat surface for drying, clean pads/wipes.


– Immerse face shields and goggles in buckets of freshly prepared (not more than 4 hrs old) 0.5 % sodium hypochlorite solution for 10 minutes.

– Take out the face shields/goggles from the bin.
– Dry on a flat surface.
– Only after the surface is completely dry, wipe all surfaces with 70% alcohol using a clean pad/wipes. – Face shields/goggles can be used, once dry.
– Place these in a new clean container.

• PPE for re-processing staff (gown, N95 masks, nitrile gloves, heavy duty long gloves, goggles, face shield, long boots, alcohol based hand rub).

• Log book to maintain.
Annexure-IV: SOP to make 0.5% hypochlorite
I. Procedure when 10% Sodium Hypochlorite solution is in hospital supply: One part (1) of
sodium hypochlorite solution in nineteen (19) parts of water.
II. Procedure when 4% Sodium Hypochlorite solution is in hospital supply: One part (1) of sodium hypochlorite solution in seven (7) parts of water.
Change solution after every four hours.
Emptying of bin containing sodium hypochlorite should be done in the sluice room. Infection Control Nurses in each area should help to standardize the protocol.


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2. N Engl J Med. 2020 Mar 25. NHS staff ‘gagged’ over coronavirus shortages. Available at
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3. World Health Organization. https://www.who.int/news-room/detail/03-03-2020-shortage-of- personal-protective-equipment-endangering-health-workers-worldwide.

4. Mahase E. Novel coronavirus: Australian GPs raise concerns about shortage of face masks. BMJ 2020;368:m477.

5. CDC, Centers for Disease Control and Prevention. Recommended Guidance for Extended Use and Limited Reuse of N95 Filtering Facepiece Respirators in Healthcare Settings. Available from: https://www.cdc.gov/niosh/topics/hcwcontrols/recommendedguidanceextuse.html

6. CDC, Centers for Disease Control and Prevention. Decontamination and Reuse of Filtering Facepiece Respirators using Contingency and Crisis Capacity Strategies. Available at: https://www.cdc.gov/coronavirus/2019-ncov/hcp/ppe-strategy/decontamination-reuse- respirators.html

7. Schwartz A, et al. Decontamination and Reuse of N95 Respirators with Hydrogen Peroxide Vapor to Address Worldwide Personal Protective Equipment Shortages During the SARS-CoV-2 (COVID-19) Pandemic(PDF 175k) Antony Schwartz et al. Duke University, Applied Biosafety: Journal of ABSA Internationa. (Accepted manuscript). Available at: https://absa.org/wp- content/uploads/2020/03/ABJ-200326_N-95_VHP_Decon_Re-Use.pdf

8. DuPont Response to Coronavirus (COVID-19) Prevention and Control. Available at:

9. Fisher, E. et al. Development of a Test System to Apply Virus Containing Particles to Air Permeable Materials for the Evaluation of Decontamination Procedures for Filtering Facepiece Respirators. Applied and Environmental Microbiology, 75(6), 2009, 1500-1507.

10. Vo, E.; Rengasamy, S.; Shaffer, R. Development of a test system to evaluate procedures for decontamination of respirators containing viral droplets. Applied and Environmental Microbiology, 75(23), 2009, 7303-7309.

11. Viscusi D.J. et al. Evaluation of Five Decontamination Methods for Filtering Facepiece Respirators. Annals of Occupational Hygiene, 53(8), 2009, 815-827. 12. Prusa Face Shield disinfection . Available at: https://help.prusa3d.com/en/article/prusa-face-shield- disinfection_125457/

12. https://www.cdc.gov/niosh/topics/hcwcontrols/recommendedguidanceextuse.html

13. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2781738/


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