Technical Information/Training

Definition of Surgical Masks:

A Surgical Mask is a Medical Device covering the mouth, nose and chin providing a barrier to minimise the direct transmission of infective agents between staff and patient. The main intended use of surgical masks is to protect the patients from infective agents from the noses and mouths of the staff and in certain situations, additionally protect the wearer against splashes of potentially contaminated liquids.

Information for Users of Surgical Masks (Source: EN 14683 Annexure A):

When breathing, speaking, coughing, sneezing etc. One releases smaller or larger amounts of droplets or secretions from the mucous membranes in the mouth and nose. Those droplets quickly evaporate and leave nuclei suspended in the air. The majority of the nuclei are between 0.5 and 12 in diameter and especially the larger droplets can contain micro-organisms from the source site. Nuclei can subsequently spread through the air to a susceptible site such as an open operating wound or sterile equipment.

The surgical masks intended to be used in operating theatres and health care settings with similar requiremnts are designed to protect the working environment and not the wearer. When the primary intention is to protect the wearer from infection, the use of respiratory protrective devices should be considered.

A special case, also covered by the European Medical Devices Legislation, is that in which the wearer wishes to protect him/herself against splashes of potentially contaminated fluids. For this application this European Standard specifies performance requirements and gives a test method for a special of surgical masks offering protection against splashes.

The degree of protection offered by a mask depends on a number of factors such as the filtration capacity and effiecincy of the material and the fit of the mask on the wearer’s face. Different designs are suited for different applications and the careful choice of mask is therefore important in order to achieve the desired result.

The filtration capacity of mask materials can vary depending on the filter media. The fit of masks varies considerably from those which are held in place by ear loops fastened behind the wearer’s ears to those with tie bands around the head and a nose clamp that can be shaped to the wearer’s nose. The effect of a very good or less good fit can be tested in vivo whereas the filtration efficiency may be reproducibly tested in vitro.

The considerable variations in results when masks are tested in vivo results in the need for large groups of tests subjects and observations. It is thus usual to characterize mask performance using in vito tests of the material from which the mask is made. It is, however, imporatnt to consider the fit of the mask carefully when a mask for a certain application is chosen. Users should request such information from their suppliers.

A further factor to be considered is the capacity of the mask to absorb moisture from the exaled air and thereby to maintain its performance over a longer period of time. The more advanced designs easily maintain their performance throughout, even very long operations, whereas the less advanced ones are intended only for short procedures.

The contamination risk resulting from hand conatct with a used mask means that it is essential that the mask is taken off and disposed of when no longer worn over nose and mouth. When there is a further need for protection then a new mask should be put on. Touching a used face mask or putting on a new one should always be followed by a full hand disinfection procedure and a used mask should always be disposed of when no longer needed or between two procedures.

In summary, to use an appropriate mask is an effective means to protect the working environment from droplet contamination from nose and throat during health care procedures. Masks with very different performance are, however, available. Therefore such factors as infection risk and mask fit should be carefully considered when choosing a mask.

Performance Requirements (European Market/EN 14683):

	Type I	Type 1 R	Type II	Type II R
Bacteria Filtration Efficiency (%)	≥ 95	≥ 95	≥ 98	≥ 98
Differential Pressure (Pa)	< 29,4	< 49,0	< 29,6	< 49,0
Splash Resistance (mm Hg)	Not required	≥120	Not required	≥120

Performance Requirements (USA Market – FDA):

Performance Requirements for ASTM F2100 (USA Market)	Low Barrier	Moderate Barrier	High Barrier
Bacterial filtration efficiency ASTM F2101, %	≥95	≥98	≥98
Differential pressure, mm H2O/cm2	<4.0	<5.0	<5.0
Resistance to penetration by synthetic blood, minimum pressure in mm Hg for pass result, ASTM F 1862	80	120	160
**Sub-micron particulate filtration efficiency at 0.1 micron ASTM F2299, %	Not required	≥98	≥98
**Flame spread 16 CFR Part 1610	Class 1	Class 1	Class 1
** 2 x Additional Performance Requirements for US Standard

Particulate Respirators

(Information Source: CDC/NIOSH/NPPTL)

What is a Respirator ?:

A respirator is a personal protective device that is worn on the face, covers at least the nose and mouth, and is used to reduce the wearer’s risk of inhaling hazardous airborne particles (including dust particles and infectious agents), gases, or vapours. Respirators are considered as a "last line of defence" in the occupational hierarchy of controls. They are recommended when engineering and administrative controls are not feasible or sufficient to control the hazard, or until these other controls can be put in place.

Respirators protect the user in two basic ways; either by filtering contaminated ambient air or by providing a clean source of air. Respirators that remove contaminants from the air are called air-purifying respirators (APRs). APRs include particulate respirators, which filter out airborne particles, and “gas masks,” which remove gasses and vapours from ambient air.

The classification of air-purifying respirators can be further subdivided into three categories:

Filtering face piece respirators (FFRs) – Sometimes referred to as disposable particulate respirators because the entire respirator is discarded when it becomes unsuitable for further use due to considerations of hygiene, excessive resistance, or physical damage. These are also commonly referred to as “N95s.”
Elastomeric face piece respirators – Sometimes referred to as reusable respirators because the face piece is cleaned and reused while the filter cartridges and canisters are discarded and replaced when they become unsuitable for further use
Powered air-purifying respirators (PAPRs) – A battery-powered blower moves the air through the filters to the user.

The other types of respirators, which protect by supplying clean air from another source, are called air-supplying respirators (ASRs). This type of respirator is comprised of airline, or supplied air, respirators (SARs), which use compressed air from a remote source; and self-contained breathing apparatuses (SCBAs), which include their own breathing gas (compressed air or oxygen) supply.

What is a N95 Respirator? :

The NIOSH respiratory protection approval regulation (42 CFR 84) defines the term “N95” to refer to a filter class, not a respirator. However, many filtering face piece respirators have an N95 class filter and many people refer to them, and have come to know them, as N95 respirators. A filtering face piece respirator that filters out at least 95% of airborne particles during “worse case” testing using a “most-penetrating” sized particle is given a 95 rating.1 There are nine classes of NIOSH-approved particulate filtering respirators available at this time. 95% is the minimal level of filtration that will be approved by NIOSH. The N, R and P designations refer to the filter's oil resistance as described in the table below.

Filter Class	Description
N95, N99, N100	Filters at least 95%, 99%, 99.97% of airborne particles. Not resistant to oil.
R95, R99, R100	Filters at least 95%, 99%, 99.97% of airborne particles. Somewhat resistant to oil.
P95, P99, P100	Filters at least 95%, 99%, 99.97% of airborne particles. Strongly resistant to oil.

All NIOSH-approved filtering face piece respirators are marked with the manufacturer’s name, the part number (P/N), the protection provided by the filter (e.g., N95, P100), and “NIOSH.” Some filtering face piece respirators approved by NIOSH may have the NIOSH approval number (TC-84A-xxxx) as an additional identification marking. This information is printed either on the face, exhalation valve (if one exists), or head straps (see Figure 1). The lot number or date of manufacture may appear on the respirator or may be located on the packaging. NIOSH also maintains a separate database of all NIOSH- approved respirators, inclusive of all respirator types on the Certified Equipment List.

If a particulate filtering face piece respirator does not have these markings as identified above and does not appear on one of these lists, it has not been certified by NIOSH for occupational use.

Example of markings for a particulate filtering facepiece respirator
FIGURE - 1 (TT-DBN95)

Who is NIOSH and what do they have to do with respirators?

The National Institute for Occupational Safety and Health (NIOSH) is the federal agency responsible for conducting research and making recommendations to prevent workplace injuries and illnesses. As part of the Centres for Disease Control and Prevention (CDC) within the Department of Health and Human Services (HHS), NIOSH helps assure safe and healthful working conditions by conducting scientific research, developing guidance and authoritative recommendations, disseminating information, and responding to requests for workplace health hazard evaluations.
The National Personal Protective Technology Laboratory (NPPTL) is the division within NIOSH responsible for the certification and approval of respirators for use in occupational settings, including those under the jurisdiction of the Occupational Safety and Health Administration (OSHA). This authority is implemented through regulations in Part 84 of Title 42 of the Code of Federal Regulations (42 CFR 84).
This NIOSH regulation defines the following authority:

establish certain procedures and requirements, which manufacturers must meet when filing applications for NIOSH certification of newly developed respirators or modification to previously approved respirators;
establish a schedule of fees charged to each applicant for inspections, examinations, and testing conducted by the Institute under the provisions 42 CFR 84;
issue certificates of approval, or modifications to certificates of approval, for respirators which have met the applicable construction, performance, and respiratory protection requirements set forth in 42 CFR 84; and
Specify minimum requirements and to prescribe methods to be carried out by both the Institute and by the applicant in conducting inspections, examinations, and tests to determine the effectiveness of respirators used during entry into or escape from hazardous atmospheres.

Is a surgical mask an N95 respirator?

No. Surgical masks are not designed for use as particulate respirators and do not provide as much protection as an N95 respirator. Surgical masks provide barrier protection against droplets including large respiratory particles. Most surgical masks do not effectively filter small particles from the air and do not prevent leakage around the edge of the mask when the user inhales.

Can the products with an exhalation valve be used in healthcare?

Respirators with exhalation valves can be used in a healthcare setting when it is not important to maintain a sterile field (an example of an acceptable practice would be when taking the temperature or blood pressure of a patient). Respirators with exhalation valves should not be used in situations where a sterile field is required (e.g. during an invasive procedure in an operating or procedure room) because the exhalation valve allows unfiltered exhaled air to escape into the sterile field.

Respirators versus Surgical Masks (Source: OSHA)

It is important that employers and workers understand the significant differences between these two types of personal protective equipment. The decision whether or not to require workers to use either surgical masks or respirators must be based upon a hazard analysis of the workers' specific work environments and the different protective properties of each type of personal protective equipment.

The use of surgical masks or respirators is one practice that may reduce the risk of infectious disease transmission between infected and non infected persons. Since there is limited historical information on the effectiveness of surgical masks and respirators for the control of influenza during any previous pandemics, the effectiveness of surgical masks and respirators has been inferred on the basis of the mode of influenza transmission, particle size and professional judgment.

To offer protection, both surgical mask and respirators need to be worn correctly and consistently. If used properly, surgical masks and respirators both have a role in preventing different types of exposures. During an influenza pandemic, surgical masks and respirators need to be used in conjunction with interventions that are known to prevent the spread of infection, such as engineering and administrative controls (e.g., installing sneeze guards, teleworking) and work practices (e.g., cough etiquette, hand hygiene, and avoiding large gatherings).

Respirators
Respirators are designed to reduce a worker's exposure to airborne contaminants. Respirators come in various sizes and must be individually selected to fit the wearer's face and to provide a tight seal. A proper seal between the user's face and the respirator forces inhaled air to be pulled through the respirator's filter material and not through gaps between the face and respirator.
Respirators offer the best protection for workers who must work closely (either in contact with or within 6 feet) with people who have influenza-like symptoms. These generally include those workers who work in occupations classified as very high exposure risk or high exposure risk to pandemic influenza.

Where workers are required by employers to wear respirators, they must be NIOSH-certified, selected, and used in the context of a comprehensive respiratory protection program, It is important to medically evaluate workers to ensure that they can perform work tasks while wearing a respirator. For many workers, medical evaluation may be accomplished by having a physician or other licensed healthcare provider review a respiratory questionnaire completed by the worker to determine if the worker can be medically cleared to use a respirator. Employers who have never before needed to consider a respiratory protection plan should note that it can take time to choose an appropriate respirator to provide to workers; arrange for a qualified trainer; and provide training, fit testing and medical evaluation for their workers. If employers wait until an influenza pandemic occurs, they may be unable to implement an adequate respiratory protection program in a timely manner.

Surgical Masks
Surgical masks are used as a physical barrier to protect the user from hazards, such as splashes of large droplets of blood or body fluids.
Surgical masks also protect other people against infection from the person wearing the surgical mask. Such masks trap large particles of body fluids that may contain bacteria or viruses expelled by the wearer.

Surgical masks are used for several different purposes, including the following:

Placed on sick people to limit the spread of infectious respiratory secretions to others.
Worn by healthcare providers to prevent accidental contamination of patients' wounds by the organisms normally present in mucus and saliva.
Worn by workers to protect themselves from splashes or sprays of blood or bodily fluids; they may also keep contaminated fingers/hands away from the mouth and nose.

Surgical masks are not designed or certified to prevent the inhalation of small airborne contaminants. These particles are not visible to the naked eye but may still be capable of causing infection. Surgical masks are not designed to seal tightly against the user's face. During inhalation, much of the potentially contaminated air can pass through gaps between the face and the surgical mask and not be pulled through the filter material of the mask. Their ability to filter small particles varies significantly based upon the type of material used to make the surgical mask, so they cannot be relied upon to protect workers against airborne infectious agents. Only surgical masks that are cleared by the U.S. Food and Drug Administration to be legally marketed in the United States have been tested for their ability to resist blood and body fluids.

About Non Woven Fabric:

Nonwovens are unique engineered fabrics offering cost effective solutions for an increasingly wide variety of applications. Nonwovens are products with many different qualities. Products that you use every day, often without knowing it. Products whose outstanding qualities are frequently hidden from view. Products of a startling versatility. We are talking about a material with a fabric like structure. A material that can be combined with other materials. Nonwovens are a product for our time, created by a modern and innovative industry.

Advantages of Non Woven Fabrics over Traditional Textiles:

The main reason is for the properties that are inherent in nonwovens. Some of these qualities are listed as follows: Breathable, Drapeable, Impermeable, Fluid Repellent, Sterilizable, Sewable, Lint-Free, Protective, Soft, Comfortable etc etc. The list goes on..... In fact, nonwovens provide a more cost effective, safer and hygienic alternative to traditional out-dated cotton re-usable textiles. Additionally, nonwovens can be treated for specific qualities such as anti-stacity, alcohol repellency, flame retardency etc.

Different Types of Non Woven Fabrics:

The main types used in the medical field are Polypropylene (PP) Spunbond, Meltblown, SMS and Spunlace. The fabrics vary in their cost and in the properties/characteristics they offer.

PP Spunbond: This is the most basic, cheapest and widely used non-woven in the Indian market. We use a range of GSM's depending on the product. Our standard GSM's range from 12 - 40 Gsm in White, Medical Blue and Medical Green.

Meltblown: This fabric is known for its filtration qualities. It is used in the middle layer of our 3-ply mask and provides the bacteria filtration. The fabric we use provides a Bacteria Filtration Efficiency (BFE: See Below for Explanation) of minimum 98%.
SMS: SMS is a trilaminate nonwoven: 1 layer of meltblown nonwoven is in a sandwich between 2 layers of spunbond. The meltblown has a very high density web of fine fibers and is suitable for applications requiring filtration (of particulates, bacteria, fluids). The 2 layers of spunbond are added to provide the necessary strength resistance. The SMS is widely used for surgical gowns and all clothing requiring a high isolation.
Spunlace: This is a premier and more expensive nonwoven that is almost cotton like in touch. Spunlace is used when comfort is the most important factor. In the USA, most of the surgical gowns and caps are made from Spunlace, as the cost factor is irrelevant in relation to the comfort of the surgeon.

Prevention of Infection in the Operating Theatre (Source: EN 13795)

The majority of post-operative surgical site infections are acquired at the time of operation when there is a possibility for micro-organisms to reach the open wound. The source of micro-organisms is either exogenous, i.e. staff, inanimate objects, fellow patients or endogenous, i.e. operations in sterile tissue and where hollow viscus is not entered, the skin of operating room personnel and of the patient are the most important sources of micro-organisms. In infection-prone operations, e.g. orthopaedic and vascular implant surgery, the normal microbial skin flora is of significance as a cause of surgical site infection.

Routes of infection are contact or airborne. In the latter case, dispersed human skin scales are often the carriers of infection. Some of the types of barrier used to reduce surgical site infection are addressed in this series of standards.
A healthy individual can disperse to the air approximately 5000 bacteria-carrying skin scales per minute during walking. The particles are 5 to 60 in size and the average number of aerobic and anaerobic bacteria carried is estimated to be about five per skin scale. The airborne particles contaminate the wound directly by sedimentation or indirectly by first settling on instruments or other items that are then brought into contact with the wound. Fabrics with interstices larger than 80 do little to prevent the dispersal of skin scales.

Clean air suits can support the reduction of the dispersal of bacteria-carrying skin scales from the human body into the operating theatre air. Clean air suits should be used in addition to surgical gowns and not as a substitute.

Surgical gowns are used to prevent direct contact transfer of infective agents from the surgical team to the operating wound and vice versa. Surgical gowns prevent dispersal of skin scales to the operating theatre air only if they are made of a suitable material and used in combination with ultra-clean air systems.

Drapes are used to provide a microbiologically clean working area around the wound. If they enclose the wound tightly and are fixed to the skin they also reduce transfer of the patient’s skin flora into the wound. Drapes and/or collective device are also used to control the spread of potentially contaminated body fluids from the wound area.

WHO General Advice for Preventing the Spread of Influenza (Source: WHO)

For individuals who are well:
Maintain distance of at least 1 metre from any individual with influenza-like symptoms, and:

refrain from touching mouth and nose;
perform hand hygiene frequently, by washing with soap and water or using an alcohol based hand rub, especially if touching the mouth and nose and surfaces that are potentially contaminated;
reduce as much as possible the time spent in close contact with people who might be ill;
reduce as much as possible the time spent in crowded settings;
improve airflow in your living space by opening windows as much as possible.

For individuals with influenza-like symptoms:

stay at home if you feel unwell and follow the local public health recommendations;
keep distance from well individuals as much as possible (at least 1 metre);
cover your mouth and nose when coughing or sneezing, with tissues or other suitable
improve airflow in your living space by opening windows as much as possible.

If masks are worn, proper use and disposal is essential to ensure they are potentially effective and to avoid any increase in risk of transmission associated with the incorrect use of masks.

The following information on correct use of masks derives from the practices in
health-care settings:

place mask carefully to cover mouth and nose and tie securely to minimise any gaps
while in use, avoid touching the mask
whenever you touch a used mask, for example when removing or washing, clean
replace masks with a new clean, dry mask as soon as they become damp/humid
do not re-use single-use masks
discard single-use masks after each use and dispose of them immediately upon removing.

Although some alternative barriers to standard medical masks are frequently used (e.g. cloth
mask, scarf, paper masks, rags tied over the nose and mouth), there is insufficient information
available on their effectiveness. If such alternative barriers are used, they should only be used
once or, in the case of cloth masks, should be cleaned thoroughly between each use (i.e. wash with normal household detergent at normal temperature). They should be removed immediately after caring for the ill. Hands should be washed immediately after removal of the mask.