To Valve or Not To Valve? The Debate

Aren’t valves dangerous?

We here at Cambridge Mask Co. believe valves perform a key role in safety, by reducing CO2 build-up and reducing humidity, which can encourage viral and bacterial growth. In the European Union, many products must be rigorously lab tested, which is why you will see a “CE” mark on the packaging and labelling of items like children’s toys, electronic goods, and sunglasses. Masks are regulated under a standard called EN149*, which designates masks as FFP1, 2, or 3 depending on their performance. You cannot legally sell something marketed as a ‘mask’ in the EU without certification from a ‘Notified Body’, which are test centres authorized and regulated to administer safety tests. Many companies are selling ‘face coverings’ as a way around these restrictions.

Products without a CE mark are not certified and may not have been tested for safety. EN149 includes checks on flammability, skin irritation, filtration, cleaning/disinfecting, breathing resistance, and much more. With CO2 “The carbon dioxide content of the inhalation air (dead space) shall not exceed an average of 1,0 % (by volume)”.

Without a valve, this test is incredibly difficult to pass. The test helps to protect wearers from excessive CO2 build-up. You can read more about the extensive testing we have done on Cambridge Masks here.

*EN149 is similar to but not identical to NIOSH 42 CFR part 48 which creates the N95/99 standards. For example, NIOSH uses sodium chloride (salt) in the penetration tests whereas the EU standard uses paraffin oil, which penetrates the filter material differently. Our masks meet N99 standards in the USA but FFP2 standards in the EU. Note there is also an EN standard (EN14683) for surgical masks, but these tests are for things like synthetic blood splashes to simulate medical use, not as a testing regime designed to check filtration performance.

Government Policies on Valved Masks

Previously, The Centers for Disease Control (CDC) stated their concern upon droplet exposure through a valve. This recommendation was consequently picked up by the media and many companies without outlining clearly the potential danger non-valve masks can pose. For example, some airlines prevent people from wearing certified PPE with a valve and force passengers to wear a 3-ply surgical mask instead if they do not have an alternative valve mask. However, doing so removes the wearers’ protection from any droplets they may be exposed to - which can be a serious health issue for people in high-risk categories. As explained above, 3-ply surgical masks are not designed for filtration and can allow a multitude of hazardous droplets to potentially be inhaled.

However, The CDC has recently announced ( December 2020) that they have undertaken specific research regarding the filtration efficiency between valve and non-valve facepiece respirators. After testing 13 FFR models from 10 different manufacturers, the results have shown that valve masks "can reduce particle emissions to levels similar to or better than those provided by surgical masks, procedure masks, or cloth face coverings" as well as providing "respiratory protection to the wearer". Please read the full article on their official website here.

If people wear high-quality respirators/masks they are much less likely to get infected in the first place, and exhaled droplets cease to be an issue. Hence why we believe wearing certified PPE with proven viral filtration performance should be a purchasing choice left open to those who wish to take that route to protect themselves.

Present policy on valves and masks, in general, were designed during the peak of the PPE shortages in mid-2020 and may have been developed to protect front-line medical staff access to PPE. Stocks are now replenished in most countries, and we believe policy should be adapted to reflect this change.


Fit/Seal of a Mask: A Brick to the Face

A brick would filter 100% of particles going through it. But if you hold a brick in front of your face, what happens to the air? It simply follows the path of least resistance and goes around. So it goes with masks. If you have large gaps around the edge of your mask, air and any droplets in said air will simply go around.

3-ply surgical masks and many face coverings leave large gaps around the mouth and nose, allowing air to pass in and crucially also allow droplets to come out as well. This leaves the wearer potentially exposed to incoming infectious droplets as well as letting them out through gaps around the mask. Our valve is designed in a way that reduces potential droplet spread as much as possible without compromising the overall effectiveness of the mask as a valuable piece of PPE.

Furthermore, many designs are regarded as uncomfortable, which leads to a lot of people wearing masks incorrectly. For example, many people wear a mask with their nose hanging out uncovered – thus exposing the body’s own exhalation valve! A more comfortable mask designed for long-term wear worn properly is better for overall public health.

Design of the Valve

Cambridge Mask Co valves are designed with a silicone gasket inside a casing. The cap of the valve opens downwards, pushing exhaled breath downwards and not outwards towards people who may be around you. If you look closely at the valve seal as someone is walking slowly or at rest, you will see it does not open significantly as they breathe because their exhaled breath is going out through the mask filters. It is only when breathing heavily that the valve starts to open and close widely during inhalation and exhalation. We are commissioning research on the exact volume of droplets we can detect coming out of the valve/mask as a whole during sneezing or heavy breathing but we are confident a Cambridge Mask releases a less overall volume of droplets through the valve than a surgical mask would do from the sides and or the top. The casing on our valve is designed to create a directional flow which helps to reduce droplet spread.


The Deactivator

We have developed a ‘valve deactivator’ as a way to enable those required to not have a valve on their mask to still be able to choose a Cambridge Mask. Subject to stock being available, you can add these to your order at checkout for no charge. Unlike some companies, we have chosen to make the deactivator a free option because we believe you should have peace of mind when you purchase. The deactivator comes with a sticker you can wear to show people around you that the valve has been deactivated, such as on flights. The deactivator was used by Cambridge Mask Co-Sponsor, the GB Basketball Team when travelling through airports for their matches (see photo above). Please ensure not to use the deactivator if you are wearing the mask to do sports and remove your mask if you feel dizzy at any time.

Our company was founded to help everyone get outside and enjoy life without worrying about the way you look or what you breathe. The science we have seen and the design we have developed shows us that valves deliver the best possible mask for our customers. Where legally required to, we have added the deactivator because we would rather people have a Cambridge Mask without an active valve, rather than a potentially much less safe alternative. However, our whole-hearted recommendation remains for customers to wear the Cambridge Mask as it comes. There are many options out there, and we must all gather data and make an informed choice. If you do choose a Cambridge Mask, we offer a 14-day money-back guarantee. You can get one delivered to you in a few days by ordering from our shop HERE.Cambridge-Mask-Valve-Deactivator-on-mask