In Costa Rica, our hot-dip galvanizing clients have had the idea of ​​manufacturing sanitary protectors like those already built using polycarbonate and acrylic. They ask us if they can defend the idea of ​​manufacturing the structure with galvanized steel and justify that it is a material where the SARS-COV-2 coronavirus does not survive too long.

The answer is difficult because, at this time, there is very little information available. Viruses are known to survive for some time on surfaces outside the human body. According to the CDC (European Centers for Disease Control and Prevention), it is possible to get the coronavirus simply by touching a surface or object with the virus and then your face. Despite this, it is believed that it is mainly spread from person to person through respiratory droplets produced when an infected person coughs or sneezes.

An investigation by the American Institute of Allergy and Infectious Diseases (NIAID) of March 17, 2020 has determined how long the virus survives in the air and on surfaces. The study tested for viruses on plastic, stainless steel, copper, and cardboard. They also used a rotating drum to suspend the virus in aerosols, a mist of small droplets, to see if the virus could remain in the air.

SARS-CoV-2 remained active on plastic and stainless steel surfaces for two to three days under the conditions of this experiment. But only 24 hours in cardboard and four hours in copper. These times vary depending on factors such as temperature, humidity, ventilation, and the amount of virus deposited. We all know that moisture on aluminum or stainless steel stays on these surfaces for a long time.

Since copper has a reduction potential more similar to zinc than stainless steel, and because zinc hydroxides (which are basic) are formed on the wet surface of zinc, it is conceivable that the durability of the coronavirus in galvanized steel it is even less than in copper. This question can be contested by some arguing that complex oxides are also formed in metals such as stainless steel or aluminum. But, to date, pharmacology is studying zinc, not chromium or nickel, to fight viruses. Zinc is known to efficiently inhibit the replication of a variety of RNA viruses, including the polio and influenza viruses, which are of the coronavirus type. This effect has been attributed to interference with the processing of viral polyproteins.

Obviously, there is no certainty for our statement. Those who rely on zinc as a cold remedy (which is a disease caused by a coronavirus) know that they should also take it when they start to feel an itchy throat. Decades of research has shown that using zinc pills along with a cold makes a difference. A 2010 study from Leiden University in the Netherlands proved that, for a brother of SARS-CoV-2, SARS-CoV-1 (the original SARS from the 2003 outbreak), zinc affects the synthesis machine of RNA of the virus.

So go ahead with the galvanized steel guard. Of course, the disinfection of its surface is carried out with alcohol and not with bleach.

References

• Persistence of coronaviruses on inanimate surfaces and their inactivation with biocidal agents. In this link.
• Aerosol and Surface Stability of SARS-CoV-2 as Compared with SARS-CoV-1. In this  link.
• Zn Inhibits Coronavirus and Arterivirus RNA Polymerase Activity In Vitro and Zinc Ionophores Block the Replication of These Viruses in Cell Culture. In this link.