Disinfection Of Scuba Equipment And COVID-19 : March 30th, 2020

May 21, 2020 - DAN

We may not be working as diving instructors/ dive guides, or as high level, experienced professional Tech Divers as many out there, but we know what it is to be cautious, secure good teamwork, collaboration to keep each and every diver safe, while scuba/tech diving out there. 

We Care! :) We miss ya guys! 

Amid this heart wrenching and sensitive period of time, due to the virus outbreak, and also to send across our care and gentle reminder to all current active scuba diving/tech diving operators/ dive instructors/ dive guides/ tourist or professional divers to take care, be safe and be well. 

Looking forward to scuba dive with many again soon once the lockdown is lifted and virus outbreak is over...  :)

Will like to share this well written, compiled article with all current active scuba/ technical diving operators, to take heed/ reference from DAN @ South Africa. 

Divers Alert Network has received questions about the virus entering a scuba cylinder as a result of contaminated air being drawn into the compressor. 

During the process of compressing air, using the ideal gas equation T2 = T1 x (P2/P1)(n-1)/n we can calculate that a four-stage compressor with 1 ATA inlet pressure and an 80°F environment pumping air up to 29 ATA or around 4000 psi, would have an inter-stage temperature inside the cylinder of 224 °F. 

This calculation is very basic and does not account for anything outside of ideal conditions. However, it does indicate the instantaneous temperature at the moment of peak pressure.

In reality, the outlet valve temperature will likely be 170°F-190°F, and the gas temperature around 150°F, occurring during each stage of the compressor (i.e. four cycles for a four-stage compressor assuming each stage’s outlet temperature is the same). 

Because this is definitively hot enough to kill SARS-CoV-2, it is therefore unlikely that COVID-19 would survive this process should an infected individual cough into the compressor intake. It is important to note that infected droplets exhaled by a person can be as small as 0.5 micron; the filter systems alone would not remove these, but the virus should be dead at that stage. 

It should be noted, however, that if an individual carried the virus on their hands, either as a result of being infected or unknowingly touching an infected surface, and touches the cylinder valve or fill whip, the virus could potentially enter the cylinder through this route. It has been shown that some viruses are extremely pressure resistant — an order of magnitude above diving gas storage pressures. 

These studies, however, were conducted on noroviruses, a non-enveloped group of viruses that are generally harder to kill than enveloped viruses (12, 13). Other studies conducted on enveloped viruses such as the flu only explored the efficacy of high hydrostatic pressure at 289.6 MPa (42,003 PSI) (14).

It is therefore very important to practice hand washing and disinfection of high-touch areas including cylinders and fill stations, as it is likely that a virus could survive at diving gas storage pressures.