Many customers have asked us about 2 things now that COVID-19 has come to Denmark. Is it safe to use your pool or spa? What should I make sure of before I use it? The short answer is - yes, it is safe when you have treated the water with chlorine and controlled the pH properly
COVID-19 and use of pool and spa
It can be nice to know the background for why the answer is yes. If you ask those who have done their homework, you get the answer. Chemical engineer Peter Knudsen from the company behind the HTH chlorine, Spacare and Saniklar products Wendt og Sørensen is one of them.
When talking about spas and pools and things that can make us sick - we most often talk about bacteria. The most common bacteria in connection with pool and spa water are pseudomonas, legionella, e-coli (Escherichia col) and the like. We know that if we maintain a level of free chlorine of 1 mg/l in warm water, bacteria such as Pseudomonas are killed, which in water without chlorine would otherwise multiply in water up to 42 degrees.
Therefore, the requirement for free chlorine in public hot-water pools and spas (water that is warmer than 34 degrees) must be at least 1.0 mg/l - the same recommendation we have always had for private ones.
COVID-19 is not a bacterium - but a virus
To our knowledge, there have NOT yet been any studies that prove that Covid-19 viruses live in bathing water. We assume that it can do so like the viruses we know (Hepatitis, liver inflammation, measles, influenza etc.) There are many different classes of viruses and the Covid-19 virus is a so-called “enveloped” virus, which is described as being surrounded by a membrane of lipids and therefore not very stable. Therefore, it must be expected that Covid-19 is easily killed by chlorine and other oxidizing disinfectants.
WHO and our recommendations
WHO writes in their “Technical brief 3 March 2020” that the Covid-19 virus is inactivated by: “Effective chlorination with a level of free chlorine of at least 0.5 mg/l for 30 minutes at a pH below 8. The chlorine level must be present throughout the entire system.”
However, together with Wendt & Sørensen, we recommend that when bathing in private pools and spas, a level of at least 1 mg/l is maintained at a pH of no more than 7.4
If you have a fever, however, all bathing is discouraged.
There is no data for disinfectants other than chlorine in connection with Covid-19 at this time, so therefore our recommendation is that HTH chlorine is used in pools, SunWac 12 in outdoor spas and SunWac 3 in indoor spas.
Next, you can use some of the fast-oxidizing products immediately before bathing (30 minutes), such as HTH Shock in your pool and Spacare MiniChlor in your outdoor spa. MiniChlor can also be used together with bromine and active oxygen.