Masks, sanitization and reuse. Military Chemical Pharmaceutical Plant Procedure.


Faced with the contingent unavailability of masks and respirators at this stage of the Covid-19 emergency, the Stabilimento Chimico Farmaceutico Militare (SCFM) in Florence developed a procedure for internal use. For the sanitization and reuse of personal protective equipment (PPE) designed to protect the nose and mouth.


The procedure to follow is contained in a document for internal use, as yet not officially approved. This act meets the sole purpose of coping with the contingent unavailability of replacement masks and respirators. (1)

There is no experimental evidence about whether such treatment can be used by ‘personnel who are working with infected people (or in environments with a high risk of infection).’ Nor can employers’ responsibility for worker safety be excluded in any way.

Please note that surgical masks and respirators (see previous article) are generally indicated by their manufacturers as disposable devices. And specific technical tests are awaited to assess the effectiveness and limitations of the procedure under consideration.


Following are the ‘Instructions for Use for Sanitizing Individual Disposable Protective Masks in the Event of a COVID 19 Coronavirus Health Emergency’ from SCFM.

Disinfectant solution

Sanitization is to be performed ‘with a 70% hydroalcoholic solution (70° alcohol) in environmentally friendly spray dispenser or other suitable dispenser to allow spraying of the solution.’

Removal of the template

Note well, both the outer surface of the mask worn and the hands (or gloves) can be contaminated with the virus. It is therefore essential following its use:

Handle the device with special care,

Never touch the inside of the mask (which should always be kept sterile),

– Carefully follow the order of operations described below.

Sanitization, order of operations to be followed

1) Wash hands thoroughly, following the pattern already given. (2)

2) Remove the mask worn on the face using the rubber bands, avoiding touching its inner part.

3) Wash hands again, wear a new pair of disposable gloves, or alternatively sanitize hands with 75-85% hydroalcoholic solution or other suitable disinfectant. (2)

4) Lay the mask, with the outside facing upward, on a surface previously cleaned/sanitized with soap and water or (better) with 75-85% hydroalcoholic solution or other suitable disinfectant. (3)

5) Uniformly spray the entire surface of the template, including rubber bands, with the 70% hydro-alcoholic solution. Without over-wetting. Simply spray an even layer of disinfectant over the entire surface.

6) Turn the template over and repeat the operation.

7) Leave the solution until completely evaporated, in a protected place, for at least 30 minutes (drying time may vary depending on environmental conditions).

8) After drying, after the above time has elapsed, the mask is sanitized. (4) Therefore, one must avoid contaminating it, especially on the inside. In case of persistence of alcohol odor, it is recommended to let the device dry again on a clean and sanitized surface. Otherwise, store the mask in a plastic bag (uncontaminated) until next use.


1) Never store the sanitized device inside or on top of unsanitized surfaces without the protection of the plastic bag.

2) In case of obvious alterations , do not reuse the mask (or respirator).

3) The inside of the mask or respirator must never be touched under any circumstances. Otherwise running the risk of contamination.

4) Do not repeat the treatment more than three times. And in any case, do not reuse the device in case of its obvious deterioration. (5)

5) After the (last) use of masks and respirators, dispose of them properly in a closed container and wash your hands (with an alcohol-based cleaner or with soap and water). (6)

Dario Dongo


(1) See also. APIC Position Paper: Extending the Use and/or Reusing Respiratory Protection in Healthcare Settings During Disasters. 4.12.09,

CDC (Center for Disease Control and Prevention, USA). (2020). Recommended guidance for extended use and limited reuse of N95 filtering facepiece respirators in healthcare,

(2) Instructions on hand washing and sterilizing solutions, at

(3) How to sanitize surfaces and objects, at

(4) It is emphasized that:

this procedure represents good hygienic practice to be adopted only under emergency conditions, when replacement masks or respirators are not available,

the effective sanitization of the mask thus treated compared with Covid-19 is to date lacking scientific validation,

– the effectiveness of the treatment also depends on the condition of the mask (or respirator)

(5) The number of treatments given meets the need for caution, pending specific experimental tests (and their relative nature, given the variety of devices on the market)

(6) Use of masks, WHO recommendations at