Deutsche Welle (English edition)

Coronaviru­s: Face mask, face shield, FFP2, N95, KN95 — what's the difference?

In COVID-19 times, masks are mandatory in many places. After Bavaria, now also other German states are tightening regulation­s. A simple cloth mask is not enough: mouth coverings must be better, but what does that mean?

-

Since the onset of the coronaviru­s pandemic, many countries in the world have introduced mask mandates in public spaces, on local transport and in stores. In Germany, too, everyone must wear some sort of mask when shopping, entering public buildings and offices and riding in trains, buses or cabs.

Still, infection rates continue to rise despite tighter shutdowns. This has likely been triggered by virus variants. Bavaria became the first German state to go one step further: The state government has decided that a simple mask is no longer enough. In the future, masks must be FFP2 mask — known as KN95, N95 or P2 in other parts of the world. Now, other German states are preparing to implement a similar requiremen­ts for surgical-grade masks. Here, we explain what the different standards mean.

Simple face mask

The current regulation in Germany requires a simple face mask to be worn as a minimum requiremen­t in most public areas. This is a piece of cloth that completely covers the mouth and nose. Even a bandanna or scarf would qualify. When you exhale, it inhibits the flow of air and therefore the distance that germs can travel. And this already significan­tly reduces the risk of infection for other people.

The purpose of such masks is not to protect the people wearing them from infection: They protect the people everyone else from the wearers' germs. Because transmissi­on is frequently caused by asymptomat­ic people, everyone is a potential virus carrier.

The logic behind the mask requiremen­t is therefore: if everyone complies, the overall risk of infection in society will fall.

Cloth masks should be changed frequently and washed in hot water to prevent viruses from surviving.

Surgical masks

Such medical face masks are the profession­al equivalent of the cloth mask. They consist of thin disposable tissue and fleece and are used by doctors and assistants to primarily to prevent their patients on operating tables from being infected with germs and pathogens.. If the wearer of the mask coughs or sneezes, for example, most of the droplets from the mouth and throat get caught in the mask.

This only works if the mask is changed regularly and disposed of hygienical­ly and safely. In surgery, doctors must change their mask at least every two hours. If a mask of this type is worn repeatedly, it quickly loses its effectiven­ess.

During the pandemic, higherqual­ity masks with better filtration have become the standard practicall­y everywhere in the medical profession.

How much protection does the mask provide?

Although the virus usually enters the body through the mouth or eyes, the hands play an important role in infections.

If you decide to wear a mask, you should probably also opt for protective goggles. The surgical masks, albeit less effective in keeping the viruses out, merely function as a constant reminder not to touch your nose with your hands when it itches. Neither should you rub your eyes.

FFP half-masks offer better protection

In addition to surgical masks, which look more like multilayer disposable kitchen towels, there are also half-masks with a real filter effect. These are more familiar to those who work in dusty environmen­ts or with aerosols. They are available either as disposable masks, usually made of strong pressed cellulose with a filter element and an exhalation valve, or as plastic masks in which a suitable filter is then inserted.

In the European Union, these types of masks are divided into threeFFP protection classes (filtering face piece).

FFP1

Although masks of protection level FFP1 are still better than surgical masks, they do not offer the desired protection against viruses. They are intended for carpenters, for example, who work at band saws with vacuumextr­action systems. Builders may wear them to catch the coarser dust that vacuum cleaners are unable to. Bricklayer­s can put them on before mixing cement with trowels, kicking up some dust.

FFP2/N95/KN95

FFP2 masks (equivalent to other internatio­nal standards known as N95, KN95 and P2 masks) are becoming more and more prevalent for elder-care and nursing homes. They provide a certain level of protection against viruses for the wearer, but should not be used when in contact with highly infectious patients.

Given the temporary shortage of hygiene materials during the first coronaviru­s wave in 2020, Germany's Robert Koch Institute announced at the time that medical staff could wear FFP2 masks rather than the standard FFP3 masks in infectious situations if FFP3s weren't available. Now there is no longer a shortage of high-quality masks for such critical workers.

FFP3/N99/EN149/P3

Only FFP3 masks (roughly equivalent to internatio­nal standards such as N99, EN149 and P3) effectivel­y protect the wearer from droplet aerosols, protein molecules, viruses, bacteria, fungi and spores, and even from highly dangerous dusts such as asbestos fibers. Unlike simple surgical masks, such high-quality filter masks can protect the wearer — including from a highly infectious pathogen such as measles or tuberculos­is.

If a mask is needed — it needs to be the right one

Protection only works if many other protective measures are taken at the same time: Strict hygiene when putting on a mask, protective goggles, gloves and plastic aprons, proper disposal of possibly contaminat­ed disposable items, and regular handwashin­g. In addition, the surroundin­gs must always be systematic­ally disinfecte­d.

These masks — together with all other protective clothing — are therefore used in quarantine stations, for example, where patients who are already infected are cared for.

Problems with obligatory use of FFP2 masks

A legal requiremen­t to wear FFP2 masks in supermarke­ts or public transport could cause all kinds of problems, both in implementa­tion and control.

Though it is clear that FFP2 masks provide better protection than surgical or cloth masks, they only do so if they are used correctly. All masks of that kind are disposable. Even if it is possible to sterilize them in an oven at 80 degrees Celsius (176 F), they can only be reused a few times.

The German Federal Institute for Occupation­al Safety and Health (BAUA) for example, emphasizes that reuse is "generally not intended" and may only be indicated or use in the event of an "acute shortage."

Most people will probably not buy a new mask every time they travel by train or bus or go shopping — especially as the alreadyhig­h prices for quality masks are likely to rise as mask requiremen­ts are increased and market shortages result.

It seems more likely that many people will then buy only one or a few masks to comply with the formal legal obligation. They could then wear these for weeks or months — even without sterilizin­g them, especially since this is impossible to con-

trol. In that case, it might prove more hygienic to wear cloth masks that are regularly washed.

Higher respirator­y resistance — occupation­al health and safety requiremen­ts

Advocates for workers will be keen to ensure that occupation­al health and safety is maintained.

The fact that the masks have a higher breathing resistance than simple surgical or fabric masks plays a role here. According to the occupation­al health and safety rules in force in Germany, healthy employees may only wear the masks for 75 minutes at a time. After that, they are entitled to a 30-minute break. The German Social Accident Insurance also stipulates that an individual risk assessment, which may include an occupation­al medical examinatio­n, is a prerequisi­te for the use of particle-filtering half masks.

People with preexistin­g conditions or disabiliti­es such as respirator­y diseases or reduced lung capacity are also often unable to wear particlefi­ltering masks for medical reasons.

Other approaches for better masks

In addition to the three certified FFP mask types, there are other concepts for masks that have an antiviral effect. However, these would not meet formal regulatory requiremen­ts if FFP2 masks becomes obligatory in public spaces. Even if they were found to be effective, they would lack necessary certificat­ion.

One such idea is to take advantage of the germicidal effect of copper. This is also used by hospitals, where you can find copper door handles to minimize infections. One manufactur­er produces masks with a fine copper mesh as filter material.

Another approach for home use is to spray citric acid on a face mask. Phil Sadler, a mechanical engineerin­g expert at the Arizona Controlled Environmen­t Agricultur­al Center promotes this idea on YouTube.

It has been known for some time that citric acid can protect against noroviruse­s, which cause stomach and intestinal diseases. For example, using lemon juice when eating mussels can protect a person from a norovirus infection.

US hygiene products manufactur­er Kimberly- Clark experiment­ed with citric acidbased antiviral facial tissues in the 1980s and 1990s with the intenn to counter seasonal colds and flus. Sadler told DW that 41 years ago he also participat­ed as a volunteer in a related research project at McMurdo Antarctic Station. Over the past 30 years, citric acid has also been used to some extent in N95 standard masks produced in the US as an antiviral agent.

Best protection: Don't forget to wash your hands

All masks and goggles are of little use if the most important hygienic principles are neglected. For example, if you come home after a long bus or train ride, where you touched handrails and handles, take off the mask and scratch your nose, there was no point in wearing the mask.

If you have been typing on the computer keyboard all morning at the office and then go to lunch without washing your hands first, you take a considerab­le risk. Then, wearing a mask at the computer workstatio­n would have been of little use either.

And what about tear gas?

Demonstrat­ors often also wear a variety of different protective masks — from simple surgical masks to half-masks with filters.

Surgical masks are probably only effective for concealing demonstrat­ors' identities. However, when the police fire tear gas grenades that spray an aerosol, only FFP3 filters can provide some protection. To prevent the tear gas from getting into the eyes, airtight protective goggles are absolutely necessary.

Occupation­al safety filters from the hardware store do not offer any real protection. A proper full face gas mask with a military NBC filter would do the job.

And, of course, this also provides good protection against viruses. But in everyday life nobody wants to walk around like this.

This article was last updated on January 19, 2021.

 ??  ?? Only a FFP 3-grade mask will filter out enzymes and viruses. But this mask has a valve - it will not protect others.
Only a FFP 3-grade mask will filter out enzymes and viruses. But this mask has a valve - it will not protect others.
 ??  ?? FFP2 masks are now compulsory in Bavaria
FFP2 masks are now compulsory in Bavaria

Newspapers in English

Newspapers from Germany