More than a year after the discovery of the SARS-CoV-2 coronavirus, new habits have been adopted – perhaps, permanently – to protect against the infectious agent, such as washing hands and wearing protective masks. However, it is possible that some precautions may not necessarily be protective against COVID-19. In this scenario, it is always worth keeping an eye on what works and what doesn’t, according to experts.
As for the prevention of COVID-19, the scientist and pharmacist Mariane B. C. Nardy, PhD in Genetics from UNICAMP and professor at MUST University, in Florida (USA), revealed a series of habits that are adopted to protect against the coronavirus, but are not always effective. Part of this knowledge, the specialist shares and discusses in the Master in Health Care Management course at the North American college, where she teaches.
Washing your hands too quickly
To protect yourself from coronavirus after arriving home or before meals, “washing with soap and water is still the best way to sanitize your hands. But it should last at least 40 seconds. This is the estimated time for the lipid component of the virus wrapping to dissolve and, consequently, destroy it,” explains scientist Nardy.
Be careful with alcohol gel
Besides washing hands, another option for sanitizing is the use of alcohol, both in gel and liquid versions, as long as it has a concentration higher than 70%. However, alcohol under these conditions may evaporate too quickly, depending on where it is stored or if it is exposed to the sun, for example. In these circumstances, the action to eliminate the virus is compromised. Thus, the recommendation is to use alcohol only in places where there is no tap and soap available.
Cleaning shoes on sanitizing mats
The use of sanitizing mats is a complex issue when thinking about protection against coronavirus. According to the professor at MUST University, several conditions need to be strictly followed in order for this cleaning method to be effective. For example, most footwear is not designed to be sanitized in this way and has, for example, recesses. Other types of footwear are open and allow the disinfectant liquid to reach the skin and cause irritation. In these cases it is important to make sure that the entire sole is cleaned and only that.
“The effectiveness of the disinfectant, its concentration, the evaporation time, the time that the sole remains in contact with the disinfectant, among other factors, should also be considered,” says researcher Mariane. Given these needs, the specialist says that the best alternative not to take coronavirus and other micro-organisms into the house is to leave the shoes at the entrance.
Passing through ultraviolet light cabins for disinfection
Some hypermarkets and commercial establishments have adopted the use of ultraviolet light cabins to sanitize customers’ purchases, for example. However, Dr. Mariane reminds us that this practice, even if adopted with some frequency, has no official recommendation due to the many variables that involve its application to be effective and safe.
Wash packages and fruits only with water
Hygiene of food and other packaged products is a measure that should be practiced at all times, regardless of the COVID-19 pandemic, explains Professor Mariane. “Although there is no evidence of virus transmission by food, fruits, vegetables and greens should be washed and disinfected with chlorine solution,” she adds.
For effective cleaning, the Federal Chemical Council recommends a chlorine solution of 15 ml (1 shallow tablespoon) of bleach (with a concentration between 2% and 2.5%) for every 1 liter of water, immersing the fruits, vegetables and greens for 15 minutes. It is worth pointing out that only cleaning with water is insufficient to remove possible infectious agents.
Sanitize surfaces and packages with liquid alcohol
“Product packages should be sanitized with 70% gel alcohol,” recommends specialist Mariane. However, it is necessary to be careful with liquid alcohol, regardless of the concentration, and its sanitizing capacity. This is because, as already mentioned, it evaporates very quickly, which may affect its ability to destroy the coronavirus. In these cases, it is important to ensure the correct storage of the cleaning material.
Using masks with too fine fabrics
The professor advises that N95 or PFF2 masks (filtering face piece) – those used by health professionals on the front line to fight coronavirus – are the most effective to avoid aerosol infections. In addition, medical and surgical masks can be an alternative resource, as can those made of fabric. However, cloth masks must have double or triple fabric, otherwise if they are too thin, contaminated aerosol particles can pass through. In such cases, there is no protective effect against COVID-19.
Wearing acrylic masks
Acrylic masks have also become popular because they maintain full view of the wearer’s face, however, they are not effective in effectively protecting against coronavirus, as we pointed out here. This is because the more rigid protection does not guarantee a good adherence to the face and, mainly, the material is not able to filter the inhaled or exhaled air, i.e., the person may breathe air contaminated with the coronavirus.
Besides these habits, there are other issues that can reduce the effectiveness of the fight against coronavirus, such as the use of infrared thermometers at the door of commercial establishments, in an inadequate way. It is common that the responsible employee does not check the person’s temperature and, even so, allows the entrance without making the correct temperature measurement, for example.