Do-it-yourself Filter Mask With Hepa Filter

The use of masks in the face of the coronavirus, which has been recommended in Western countries since recently, continues to be controversial. While some agree that the masks' effectiveness, especially for healthy people, has not been proven, others point out that the devices are actually useful in preventing transmission of the virus. by infected people, with or without symptoms. Either way, the demand for masks has exploded, causing a shortage around the world. Therefore, many people have embarked on the manufacture of homemade protective masks. It is for this reason that we have decided to share with you the idea of making a filter mask with Hepa filter. Is such a filter mask effective in protecting against the coronavirus? Find out the answer in the following paragraphs.

Filter mask with Hepa filter: can it really filter aerosols?

In general, healthcare professionals wear two types of respiratory protection masks. The first is a device called N95. This is a respiratory protection mask that protects the wearer by filtering infectious aerosols, such as droplets projected by sneezing and coughing. It is intended only for medical personnel and other workers who come into contact with sick people; it is not used by infected people who would like to avoid infecting other people. This device is particularly effective against respiratory diseases such as COVID-19. It blocks particles 0.3 microns and larger. To be effective, it must fit snugly to the face, so that it does not leak. This mask is for single use only and should be changed after high risk exposure.

The second type is the surgical mask. These devices are designed to minimize the transfer of bacteria and particles from person to person. This type of mask can be worn by healthcare professionals as well as by contagious patients. As with any type of mask, it must be correctly positioned on the face in order to be effective.

As a reminder, the wearing of masks is compulsory for sick people, and recommended for those caring for sick people. As part of the fight against the spread of the coronavirus, all people are encouraged to obtain masks. Faced with the shortage, one has to be creative in making protective masks from different household items. T-shirts and bed linen help us make the masks themselves, while paper towels and dry damp wipes serve as filters.

Recently, the question has arisen whether Hepa filters could effectively protect against viruses and bacteria. First, let's explain what a Hepa filter is. It is a device designed to filter air particles with high efficiency. These filters are also called absolute filters or THE (Very High Efficiency) filters. This suggests that these can be used in difficult conditions such as for example: very high temperatures (up to 370 °), high humidity, oxidizing environments and radioactive environments etc. All Hepa filters must meet a well-defined European standard, which classifies them into different categories, depending on their efficiency. Typically, Hepa devices are capable of filtering, in a single pass, at least 99,97% of particles with a diameter greater than or equal to 0.3 µm.

What Hepa filters are available?

As already mentioned, there are several types of Hepa filters that comply with European standard EN1822 and American standard MIL. Here is an overview:

• Hepa EU10 or H10 filters are capable of filtering up to 85% of fine particles. These filter devices are not sold in the United States.

• EU11 or H11 is able to filter more than 95% of fine particles.

• EU12 or H12 also conforms to the filtration standard and can effectively filter up to 99.97% of fine particles.

• Finally, Hepa EU13 or H13 and EU14 or H14 filters can filter over 99.99 of fine particles. These models are generally recommended for people with allergies.

In theory, Hepa filters can filter even microscopic particles of the coronavirus. However, there are currently no studies to prove it. It is therefore not clear whether a filter mask with a Hepa filter can provide effective respiratory protection against COVID-19. But at least it filters better than a fabric mask for example.

It is also unknown whether breathing through a Hepa filter is safe for health. But since filters of this kind are built into vacuum cleaners and are even recommended for people with allergies, one might assume that the devices in question actually improve air quality and cannot harm health.

If you plan to make a respiratory protection mask with a Hepa filter, first of all ask your doctor or health authorities for advice.

Babies and toddlers are not allowed to wear homemade masks. As a rule, children are only allowed to wear a respiratory protective mask after consultation with the pediatrician. In babies, there is a risk of suffocation, therefore, wearing a mask is not recommended.

Do-it-yourself coronavirus mask with Hepa filter: instructions

Making your own filter mask with Hepa filter is quite simple. First, you need to get an EU13 or EU14 filter. Cut off the ends and remove the Hepa filter cloth. You may notice pieces, resembling beads of hot glue, which serve to hold all the folds of the fabric together. These "cords" must be carefully held back to obtain a long strip of Hepa fabric. Cut out a 15cm x 20cm rectangle. Make 4 folds of about 1 cm, distributing them evenly. To make it easier for you, use a few crocodile clips. Now all you have to do is sew the folds. Your Hepa filter is already ready and you can insert it into a homemade fabric mask.

Alternatively, you can use clothespins

You can sew the filter by machine or by hand