Advanced Instrument Processing Solutions

The classification of masks and respirators is a complex subject with multiple classifications for a variety of working situations, so I am going to just focus on those that pertain to working in decontamination. Let me begin with the fact that you do not need a respirator for decontamination. Although respirators would offer you great protection from aerosolized particulates, they must be fit tested and worn properly to be effective. Furthermore, the more filtration they provide, the harder they become to breathe through. Respirators are best for use in patient rooms where respiratory isolation is indicated.

I did state that a mask for decontamination should be fluid resistant, and when searching for masks, you will see different resistance qualifications and wonder what they might refer to, so I will give some examples here to help out.

If you see BFE > 99%:
This qualification is based on testing done by the ASTM (ASTM F2101-01) for Bacterial Filtration Efficiency, the material being tested is mechanically subject to 3 micron droplets of liquid aerosol containing Staphylococcus aureus at a flow rate of 28.3 L/min, and a material of this classification is capable of filtering out more that 99% of this aerosol. (Make sure this BFE rating is based on the ASTM F2101-01 testing and not on the older Modified Greene and Vesely Test, where a human subject says the word “Chew” and “Sing” distinctly at 10 second intervals for 1 minute through the material being tested in a closed container. The container is then cultured and a bacterial count is taken but there is no specific organism counted).

If you see PFE > 95%:
This qualification is based on Submicron Particulate Filter efficiency testing done by the ASTM (ASTM F2299).This test uses 0.1micron latex spheres at a flow rate 0.5 to 25cm/s the particles are counted with a light scattering photometer before and after passing through the material being tested, so a PFE>95% would mean that more than 95% of these spheres were filtered by the test material.

NIOSH Particulate Filtration Efficiency testing for respirators, (yes I know I said you don’t need a respirator for decontamination) is much more stringent. For healthcare purposes N series respirators apply (N here = Not resistant to oil, the other two classifications are R- Resistant to oil and P-Oil Proof would include oil in their testing aerosol). The challenge here is ~0.3microns liquid sodium chloride aerosol at flow rate of 85L/minute. A collection of at least 95% of this by the material gives the respirator an N95 rating, at least 99% collection would be an N99 and anything 99.7% and over gives the material an N100 rating.(These N,R and P classifications truly only apply to respirators and not face masks)

If the masks make the claim ASTM F1862 120mmhg Fluid Resistance:
This is the actual fluid resistance of the mask based on ASTM testing. In this challenge, a high velocity stream of synthetic blood is aimed at the material being tested at different pressures (80mmHg, 120mmHg and 160mmHg) to replicate blood exiting a puncture wound at a variety of blood pressures. An 80mmHg rating would be a Low fluid barrier classification, 120mmHg would be a Medium and 160mmHg a High.

Another thing you might see is a Differential Pressure Test (Delta P or ∆P) number:
The lower the number here the more breathable the mask is but, the more breathable the mask is the less protection it offers.

Now if this is not complicated enough ASTM F2100-11 has prescribed new mask standards for fluid resistant face masks as follows:

ASTM Level 1
Low Fluid Resistance     80mmHg
Filtration Efficiency      BFE>95%
PFE>95% @ 0.1micron
Breathability-∆P             <4.0mm H2O/cm2
Flame Spread                   Class 1 (low flammability)

ASTM Level 2
Moderate Fluid Resistance 120mmHg
Filtration Efficiency       BFE>98%
PFE>98% @ 0.1micron
Breathability-∆P              <5.0mm H2O/cm2
Flame Spread                    Class1 (low flammability)

ASTM Level 3
High Fluid Resistance 160mmHg
Filtration Efficiency        BFE>98%
PFE>98% @ 0.1 micron
Breathability-∆P               <5.0mm H2O/cm2
Flame Spread                     Class 1 (low flammability)

Wow that’s a lot of information… So now the choice is yours, but if it were up to me, knowing that surgical masks truly do not provided the optimum protection that a respirator does, I would at least choose one that provided me with the most protection, like an ASTM level 3 Mask, or at least one that had all those qualities.

OSHA Bloodborne Pathogens Standard 29CFR-1910.1030 states:
Gowns, Aprons, and Other Protective Body Clothing. Appropriate protective clothing such as, but not limited to, gowns, aprons, lab coats, clinic jackets, or similar outer garments shall be worn in occupational exposure situations. The type and characteristics will depend upon the task and degree of exposure anticipated.190.1030(d)(3)(xi)

So what does that mean to you as a sterile processing technician? Because you deal with liquids in decontamination, your gown choice should be impervious to liquids!

ANSI/AAMI PB70 “Liquid Barrier Performance and Classification of Protective Apparel and Drapes Intended for Use in Health Care Facilities” classifies gowns (and drapes) used for protective apparel into four levels: these levels are based on fluid penetration tests as defined by the AATCC (American Association of Textile Chemists and Colorist) and the ASTM (American Society for Testing and Materials International):

Level 1 Gowns: Are generally best used for contact isolation and not for decontamination. They allow less than 4.5g of liquid penetration under normal atmospheric conditions (based on AATCC 42 test for fabrics resistance to rain penetration)

Level 2 Gowns: Are best for small bedside procedures. They allow less than 1.0g of liquid penetration (AATCC 42 test) and are resistant to liquid penetration up to 20cm of water pressure (AATCC 127 test) 

Level 3 Gowns: Are the gowns that ANSI/AAMI suggests for use in decontamination. They offer increased barrier protection and are resistant to strike through. They allow less than 1.0g of liquid penetration (AATCC 42) and are resistant to penetration up to 50cm of water pressure (AATCC 127).

Level 4 Gowns: Are intended for the surgical field, although I would argue the fact that these should be used in decontamination too. Not only are they as resistant liquid penetration as Level 3 Gowns, but they are also resistant to penetration by blood borne pathogens (ASTM test F1671using synthetic blood and surrogate microbes to test for viral penetration under continual liquid contact).

So all that being said, make sure you are using Level 3 gowns in your decontamination area, because those yellow isolation gowns don’t provide enough protection!

Now that you’ve got me thinking about PPE, I feel the need to elaborate a little more here. Please make sure that ALL of your PPE is correct:

1. Exam length gloves that only cover your hand (up to your wrists) are not long enough! Rule of thumb: if water from the soak sink can easily get inside the gloves while you work, they are not long enough. Also make sure the gloves you are using don’t tear easily.
2. Masks should be as impervious to liquids as your gown is; and unless you don’t breath through your nose, it needs to be covered by your mask, too.
3. Your eye protection should be sufficient to protect your eyes in case of any large splashes of liquid; we have all dropped something in a sink full of water at home and know water happens. Your protective eyewear should cover your eyes so that NOTHING will splash over it and INTO your eyes. I would suggest a disposable full face shield with a foam pad that seals above the eyebrows.

I know that working in decontamination can be uncomfortable with all this gear on, especially if the temperature is above 65°F in the room (which it shouldn’t be). However, wearing proper PPE is “for your own good,” as my mother would say.

In the end, it is your employer’s responsibility to supply the proper PPE, and YOUR responsibility to wear it.