Table of Contents
N95 respirator or N95 is a particulate filtering face mask that meets the US National Institute for Occupational Safety and Health (NIOSH) N95 classification of air filtration, which means that filter at least 95% of the particles in suspension.
This standard does not require that either respirator oil resistant; another standard, P95, added that requirement. Type N95 is the most common particulate filtering face respirator. It is an example of a mechanical respirator filter, which provides protection against the particles, but not against gases or vapors.
N95 respirators are considered functionally equivalent to some respirators regulated jurisdictions, U.S. not like FFP2 respirators EU and China KN95 respirators. However, slightly different criteria are used to certify their performance, such as the effectiveness of the filter, test agent and flow, and the allowable pressure drop.
N95 mask requires a fine mesh of synthetic polymer fibers, in particular a fabric of non-woven polypropylene. It is produced by blowing the molten state and form the internal filter layer that filters hazardous particles.
Infographic on three key factors necessary for a respirator to be effective.
Guide for a user seal check, which is required each time a respirator is put on.
The fitness test is an essential element to a respiratory protection program each time that workers use tight-fitting respirators. OSHA requires an initial respirator fitting test to identify the correct model, style, and size of respirator for each worker, as well as annual fit testing.
In addition, tight-fitting respirators, including N95, require a user seal check each time one is on. facial hair to the respirator seal area cause a leak.
Respirators need a medical evaluation before use because they can make breathing more difficult. Some conditions that could prevent the use of respirators include heart disease, lung disease and psychological conditions like claustrophobia. In the medical evaluation in the United States is required once before the initial fit test and use, but it can be repeated if signs or adverse symptoms are observed.
For people who are medically disqualified negative pressure respirator, or who can not pass a test of adjustment because of facial hair or other reasons, an air-purifying respirator is a possible alternative.
Face masks during the COVID-19 pandemic § N95 and FFP masks
The masks were in short supply and high demand during the pandemic Covid-19, which causes the price gouging and hoarding, often leading to the confiscation of masks.
Production of N95 masks has been limited due to constraints on the supply of tissue non-woven polypropylene (which is used as main filter), and the cessation of exports from China. China controls 50% of world production of masks and faces its own epidemic coronavirus, dedicated all its production to domestic use, exports by allowing humanitarian aid allocated by the government.
More and more countries have restricted the export of N95 masks, Novo Textiles BC intends to become the number one manufacturer in Canada. AMD Medicom Quebec also plans to become the second Canadian manufacturer of N95 masks, with a contract to provide the Government of Canada.
In 2020 March, President Donald Trump has applied the Act on the production of defense against the US company 3M that allows the Federal Emergency Management Agency to get as N95 respirators because it needs from 3M.
In early April 2020 policy of Berlin Andreas Geisel alleged that a shipment of 200,000 N95 masks he commanded the American producer 3M factory China were intercepted in Bangkok and diverted to the United States.
President of ploice Barbara Slowik Berlin said she believed “this is related to the US Government export ban. “However, the Berlin police will correct later and confirmed that the consignment has not been seized by US authorities, but said simply have been purchased at a better price, widely considered to a German dealer or in China.
N95 respirators were originally designed for industrial use in sectors such as mining, construction and painting. They have also been proven effective as protection against manufactured nanoparticles.
According to the selection logic RESPIRATOR respirators with filters in the N, R, and P series are recommended for concentrations of hazardous particles that are greater than the limit of relevant occupational exposure, but less than the immediately dangerous to life or level of health and the years of the manufacturer maximum use, subject to the respiratory system with sufficient protection factor.
Serial respirators, including N95, are effective in the absence of oil particles, such as lubricants, cutting fluids, or glycerine. For dangerous substances for the eyes, a respirator with a full face shield, helmet or hood is recommended.
They are not effective in case of fire, in a low-oxygen atmosphere or in a strange atmosphere; in these situations SCBA is recommended instead. They are not effective against gases or dangerous vapors for which a cartridge respirator is recommended.
In industrial environments where exposure to infectious disease is not a problem, users can carry and re-use a filtering facepiece respirator until it is damaged, soiled, or causing significantly increased resistance to breathing, within a period determined by the manufacturer for use.
However, in laboratories at biosafety level 2 and above, respirators are recommended to be disposed of as hazardous waste after a single use.
Respirators used in health care is traditionally a specific variant of a surgical respirator, which is both NIOSH approved as a respirator and approved by the Food and Drug Administration as a medical device similar to a surgical mask .
These can also be labeled “N95 surgery”, “medical respirators” or “respirators health care.” Under the Act the families first response coronavirus, changes were made to the liability laws and certification to enable industrial respirators for use in the health community in response to the shortage of respirators during pandemic Covid-19.
In the United States, the Administration of Occupational Safety and Health Administration (OSHA) requires that health workers who should carry out activities of patients with suspected or confirmed infected with authors Covid-19 for respiratory protection, such as an N95 respirator.
The CDC recommends the use of a respirator with at least N95 certification to protect the wearer against inhalation of infectious particles, including Mycobacterium tuberculosis, avian influenza, severe acute severe respiratory syndrome (SARS), influenza pandemic, and Ebola.
Unlike respirators, surgical masks is designed to provide a protective barrier against the droplets and does not have an air tight seal and thus does not protect the wearer against the suspended particles as virus material to the same extent.
Use during shortage
In crisis situations where there is a shortage of N95 respirators, as the pandemic Covid-19, the US Centers for Disease Control and Prevention (CDC) recommended strategies to optimize their use in environments health.
N95 respirators can be used beyond their shelf life designated by the manufacturer, although components such as straps and the nose pad material may degrade, making it particularly important that the carrier perform the leak test planned.
N95 respirators can be reused a limited number of times after being removed, as long as they are not used in the aerosol-generating procedures and are not contaminated with body fluids of patients, even if this increases the risk of contamination surface with pathogens.
The respirator manufacturer may recommend a maximum number of donnings or uses; if no indication of the manufacturer is available, preliminary data suggests limiting to five applications per appliance.
Respirators can be used that are approved according to the standards used in other countries that are similar to N95 respirators NIOSH approved, including FFP2 and FFP3 respirators regulated by the European Union.
According to NIOSH, respiratory devices can still be used in emergencies if the standard respiratory fit testing is not available, such as a respirator even better protection than a surgical mask or no mask.
In this case, the best practice for good face seal include trying different models and sizes, using a mirror or ask a colleague to verify that the respirator is in contact with the face, and make checks user multiple sealing.
Since the global personal protective equipment offer (PPE) is insufficient for the pandemic, the World Health Organization recommends to minimize the need for PPE through telemedicine, physical barriers such as clear windows which allows persons involved in direct care to enter a room with a patient Covid-19, using only the necessary PPE for the specific task, the continued use of the same respiratory do not remove while taking care of multiple patients with the same diagnosis, monitoring and coordination of the EPP supply chain, and to discourage the use of masks for asymptomatic individuals.
When not be more for all healthcare workers to wear breathing N95 masks when caring for patients Covid-19, CDC recommends that respirators be a priority for workers performing aerosol-generating procedures on symptomatic persons, located within three feet of a symptomatic person unmasked.
Under these conditions, the masking of symptomatic patients with a surgical mask and maintaining the distance from the patient are particularly important to reduce the risk of transmission.
In the absence of respiratory protection are left, workers are more at risk of serious illness may be excluded from care for the sick and workers who have clinically recovered from Covid-19 may be preferred to care for patients.
Portable fans with HEPA filters can also be used to increase ventilation in isolation rooms where surgical masks are used instead of respirators.
If neither respirators or surgical masks are available as a last resort, it may be necessary for the health workers use masks that have never been evaluated or approved by NIOSH or homemade masks, such as cloth masks, but we have to be careful when examining this option.
Filtering facepiece respirators for single use such as N95 masks are not approved for routine decontamination and reuse as standard care. However, decontamination and reuse may need to be considered a crisis of capacity strategy to ensure continuous availability.
There have been efforts to evaluate methods of cleaning respirators for emergency shortages, although there is concern that this may reduce the filter performance, or affect mask shaped by deforming the mask.
Duke University have published a method for cleaning N95 respirators without damage by using the vaporized hydrogen peroxide to allow the reuse of a limited number of times. Battelle has received emergency use authorization from the US Food and Drug Administration for the sterilization of N95 masks.
OSHA currently has no standards for disinfection of N95 masks.
NIOSH recommends N95 respirators in case of shortage may be used up to five times without cleaning, as long as the aerosol-generating procedures are not performed and respirators are not contaminated by body fluids of patients.
The contamination can be reduced by wearing a face shield cleaned on an N95 respirator, and the use of clean gloves and put on a respirator Check the seal used N95 and drop the gloves immediately after.
According CDC, ultraviolet sterilization, hydrogen peroxide in vapor form and moist heat showed the most promise as a possible method for decontaminating N95 masks and other protective breathing devices respirator.
Contrast with surgical mask
A surgical mask is a large disposable device which creates a physical barrier between the mouth and the wearer’s nose and potential contaminants in the immediate environment.
If worn properly, a surgical mask is intended to help block large particle droplets, splashes, sprays, or splashes which may contain viruses and bacteria. Surgical masks can also help to reduce the exposure of saliva and respiratory secretions User other.
A surgical mask, by design, does not filter or block very small particles in the air that can be transmitted by coughing, sneezing or certain medical procedures.
Surgical masks also do not provide complete protection against germs and other contaminants because of the loose fit between the surface of the mask and face. collection efficiency of surgical masks of filters may vary from less than 10% to almost 90% for masks from different manufacturers, as measured using the test parameters for the NIOSH certification.
However, one study showed that even surgical masks with “good” filters, 80-100% of subjects failed a qualitative fit test accepted OSHA, and a quantitative test showed 12-25% leakage.
The US Centers for Disease Control and Prevention recommends surgical masks in proceedings where there may be a user aerosol generation so small aerosol can produce a disease to the patient.
What are N95 masks?
A standard N95 respirator is a tight-fitting respiratory protective face mask, designed to help reduce the user’s exposure to airborne particles including very small particles (0.3 microns) and large droplets. N95 respirator face mask literally has a filtration efficiency of at least 95% against non-oily particles.
What’s the difference between N95, KN95, FFP2 and KF94 mask rating?
The N95 mask has a full name of NIOSH-approved N95 respirator, which means these respirators are tested of 95% filtration and certified by the U.S. National Institute of Occupational Safety and Health (NIOSH).
And the KN95, FFP2 and KF94 mask is as effective as NIOSH-certified N95 mask with the same filtration efficiency, but are tested by different nation criteria. The KN95 respirator is a particulate-filtering mask tested using the China criteria.
To simply put, we could put these respirators into an equation as below:
N100 (99.97%) = FFP3 (99.95%) > N95 (95%) = KN95 (95%) = FFP2 (94%) = KF94 (94%) > KN90 (90%).
According to a study by respirator company 3M,all these respirators offer nearly the same level of protection.
|Certification||N95||FFP2||KN95||KF94(Korea 1st Class)|
|Filter performance||≥ 95%||≥ 94%||≥ 95%||≥ 94%|
|Test agent||NaCl||NaCl and paraffin oil||NaCl||NaCl and paraffin oil|
|Flow rate||85 L/min||95 L/min||85 L/min||95 L/min|
|Total inward leakage (TIL)||N/A||≤ 8% leakage||≤ 8% leakage||≤ 8% leakage|
|Inhalation resistance||≤ 343 Pa||≤ 70 Pa (at 30 L/min) ≤ 240 Pa (at 95 L/min) ≤ 500 Pa (clogging)||≤ 350 Pa||≤ 70 Pa (at 30 L/min) ≤ 240 Pa (at 95 L/min)|
|Flow rate||85 L/min||Varied – see above||85 L/min||Varied – see above|
|Exhalation resistance||≤ 245 Pa||≤ 300 Pa||≤ 250 Pa||≤ 300 Pa|
|Flow rate||85 L/min||160 L/min||85 L/min||160 L/min|
|Exhalation valve leakage requirement||Leak rate ≤ 30 mL/min||N/A||Depressurizatio n to 0 Pa ≥ 20 sec||visual inspection after 300 L /min for 30 sec|
|Force applied||-245 Pa||N/A||-1180 Pa||N/A|
|CO2 clearance requirement||N/A||≤ 1%||≤ 1%||≤ 1%|
Based on this comparison, it is reasonable to consider KN95(China GB2626-2006), KF94 (Korea KMOEL – 2017-64) as “equivalent” to N95 (United States NIOSH-42CFR84) and FFP2 (Europe EN 149-2001) respirators, for filtering non-oil-based particles such as those resulting from wildfires, PM 2.5 air pollution, volcanic eruptions, or bioaerosols (e.g. viruses). Therefore, if N95 masks or FFP2 masks are out of stock, you could buy KN95 or KF94 masks instead.
What is the N95 mask used for?
A standard N95 mask, designed as an air-purifying facepiece respirator (particulate filtering dust mask), is mainly intended for use by healthcare professionals who work in the frontline of widespread outbreaks of infectious respiratory diseases like influenza and coronavirus, to reduce their risks of exposure to the infectious illness.
What’s the difference between a surgical N95 mask and a standard N95 filtering mask?
A surgical N95 mask is literally a combination of standard N95 particulate respirator and a disposable surgical mask. Different from standard N95 filtering respirators, N95 surgical masks include a static-electricity melt-blown filter layer, which makes the N95 surgical masks fluid-resistant to stop the viruses on the mask surface from entering the mask.
How to know if a surgical N95 respirator is real or fake?
Firstly, check the package or the printing on the N95 mask if there is a mark of surgical or medical. Secondly, cut open the N95 mask to check if there is a melt-blown filter layer. 3 steps help you to identify a melt-blown layer: ① The melt-blown layer looks very different from the other two transparent non-woven layers, it looks more like a white paper.
② Different from a paper, the melt-blown layer of very low flammability melts in case of fire but does not flame. Instead, paper burns when it comes to fire.
③ There is the static electricity in the effective melt-blown layer. If you tear the melt-blown layer into strips, you will feel the electrostatic adsorption effect, and you can also adsorb the melt-blown layer on stainless steel.
What’s different between N95 masks with a valve and without a valve?
Literally, a venting valve would not make the N95 mask better or worse in filtering viruses, but help the wearer breathe in and out easier. As a tight-fitting protective facepiece, the N95 mask without valve is not recommended to use by those who are suffered from CVD or difficult breathing. The N95 mask with an exhalation valve is recommended for people who wear glasses to avoid warm breath rise from the mask to fog the glasses. Please bear in mind, the valved N95 mask shouldn’t be used by an infected person, because the one-way venting valve couldn’t keep the wearer’s illness to himself. Besides, the N95 mask with a breathable valve is pricier than the one without a valve.
What is N95 mask fit testing?
An N95 mask fit testing mainly tests the secure fit between the respirator’s facepiece and your face. It’s originally a basic requirement for any worker who needs to use a tight-fitting respirator. Not everyone can get a good fit with one specific respirator, however, the respirator can’t protect you if it doesn’t fit your face. So before you wear a tight-fitting N95 respirator, you must be fit tested to make sure that the respirator fits you without difficult breath and leakage.
How to perform a respirator fit testing?
A fit test should only be conducted if there is:
– No hair growth (beards)
– No apparel
– No jewelry
– Any other condition or object that may compromise the fit or prevent contact of the respirator with the skin.
1. Prepare the qualitative fit test apparatus:
①Attach the hood to the collar by placing the drawstring between the flanges on the collar.
②Tighten the drawstrings and tie it with a square knot or bow.
③Pour approximately 1 teaspoonful or 5ml, of the sensitivity solution into the nebulizer labeled “Sensitivity Test Solution”.
④Pour the same amount of fit test solution into the second nebulizer labeled “Fit Test Solution”.
Sensitivity Test Purpose: To assure the subject can taste a dilute version of the Sensitivity Test Solution.
⑤Avoid eating, smoking, drinking or chewing gum for at least 15 minutes before the test and during the test at all times. This does not include water.
⑥Instruct the test subject to place the hood and collar assembly over their head without a respirator.
⑦Position the hood assembly forward so there is about six inches, or 15 centimeters, between the subject’s face and the hood window.
⑧Instruct the test subject to breathe normally through their mouth with their tongue slightly extended. Both plugs on the nebulizer must be removed during use.
2. Tips for Qualitative Fit Test
The respirator to be tested shall be worn for at least 5 minutes before the start of the fit testing.
The nebulizer must be held in an upright position to ensure the aerosol generation.
3. Simple Steps for Fit Testing:
– 60 seconds each
– half the number of original squeezes every 30 seconds.
1. Normal breathing – continue for 60 seconds
2. Deep breathing – continue for 60 seconds
3. Turning head side to side – repeat for 60 seconds
4. Moving head up and down – one nod per second for 60 seconds
5. Talking – for 60 seconds
6. Bending at the waist (repeatedly) – for 60 seconds
7. Normal breathing – for 60 seconds
The fit testing must be completed successfully before a health care worker can be allowed to wear a respirator.
How to clean and reuse the N95 mask?
During a shortage of face masks, knowing how to safely clean and reuse an N95 respirator will help you save more. Besides, keeping your N95 mask clean and well maintained will help ensure better protection as well as extend the lifespan of your respirators.
How to clean the N95 mask?
1. Store your used N95 in a dry and well-ventilated area (avoid to touch the surface of the respirator) after going out (when if you didn’t go to the crowded places)
2. Disinfect your used N95 mask by 30-minute oven-dry heat at 70 degrees Celsius or sterilize the face mask with the ultraviolet sterilization for 30 seconds.
Please do not clean the respirator masks with steam air, hot water, alcohols, disinfectants, or detergents of any kind as they will damage the integrity and reduce the filtration efficiency of the N95 masks.
How to reuse the N95 mask?
If the inside of the respirator mask is clean, not visibly damaged and breathing has not become more difficult, you can continue to wear the masks.
1. Clean hands with soap water or an alcohol-based hand sanitizer before and after touching the respirator;
2. Use a pair of clean gloves when putting on or adjusting a used N95 respirator. Discard the gloves after finished and ensuring the respirator is fitting securely and comfortably on your face.
What is an N95 mask made of?
An effective surgical mask for virus protection is at least 3-ply, made of SMS material. SMS material is basically referred to as Spunbond (outer Polypropylene hydrophobic non-woven layer), Melt-blown (middle Polypropylene filter layer), Spunbond (inner Polypropylene soft absorbent non-woven fabric).
An N95 mask is generally made of needle-punched cotton, melt-blown cloth, and non-woven fabric. The melt-blown cloth usually weighs 40 grams or more, coupled with the thickness of needle cotton, the N95 mask looks thicker than an ordinary flat mask in appearance, and its filtration efficiency can reach up to 95%. A surgical N95 mask is composed of 5-ply SMMMS material, and a standard N95 particulate respirator is at least 3-ply but the filter layer is not made of melt-blown cloth.
How to make N95 masks at home?
1. Prepare the melt-blown non-woven cloth as one to three middle filter layers.
2. Prepare the needle punch cotton as the outer layer.
3. Prepare the ES (Ethylene-Propylene Side By Side) non-woven fabric or medical gauze as the inner layer for soft contact to the skin.
4. Prepare some plastic surgery nose splints to get a secure fit if possible.
5. Prepare the ear loops or headband drawstrings.
6. Layer all the fabrics, stick the nose splint on the top of layers and sew them together.
7. Sew the ear loops or headbands on the sides of N95 masks.