COVID 19 has forced the complete laundry industry to focus on hygiene as the # 01 priority. And this didn’t happen exclusively in de laundry industry, but also their major customers – being both the hospital and the hospitality industry – had to redefine their priorities. These industries – in addition – have updated collection and transport protocols, simply because of the contagious nature of this new Corona virus. This article explains the specific and most important parameters that effect the decontamination of the linen. And ends with specific recommendations that are needed in order to protect not only the patients in the hospitals and the hotel customers, but also the health of the laundry staff.
Handling linen that is contaminated with virusses isn’t uncommon in the laundry industry. Localised outbreaks of Norovius happen more frequently than one might think. Example: Between Sept 1 2019 and July 31 2020 there have been 1032 reported outbreaks in the USA alone.
Pandemic examples are the Mexican flu [also known as swine flu or H1N1] in 2009/2010. Or SARS in 2003 and MERS in 2012 till now. Fortunately MERS isn’t as contagious as COVID 19 is. Otherwise the world would be in real danger since MERS has a case fatality of as high as 35 percent.
HOW TO DECONTAMINATE LINEN CONTAINING COVID-19 ?
One has identified three routes that eliminate the virus from COVID-19 contaminated linen. And all three of them are being applied in the recommended wash process.
The simple fact that the amount of water applied will dilute the concentration of the virus to very low figures. Most of the virus present will be removed just by water and mechanical action. The exception to this is the virus that is “hidden” inside faeces. So, in order to remove that hidden virus, it is essential that the wash process is capable of removing all faeces present on the linen to be washed.
It is essential to understand that the Corona virus is classified as being an enveloped viruses. Which implies that it has an outer shell consists of glycoproteins. Also known as the lipid shell – as depicted in pink in the photograph on the left. This lipid shell represents the weak point of this particular class of viruses.
Surfactants: The application of surfactants in the wash process destroys that outer layer and is already a major step in the deactivation of the virus. This is why governments are stressing the 20 seconds hand washing procedure- using just soap !
High pH: The lipid shell is easily broken down when the pH of the wash liquor is increased. The higher the Ph the better the destruction of the outer shell.
Implications: Most wash processing applied – when washing hospital linen – have a high pH in the pre wash. This high pH accelerates the removal of protein soil. And it is therefore good to know that the inactivation of the COVID-19 virus already starts in the first minute of the wash process
The COVID-19 virus can be destroyed by Thermal Disinfection or Chemo -Thermal disinfection.
Thermal disinfection guidelines vary greatly from one country to the other. Both temperature and time are prescribed in order to maximise the inactivation of Bacteria, Viruses and Moulds. However not all textiles can withstand high temperature processing. By lowering the main wash temperature, but still achieve world class disinfection, it is essential dosing a disinfecting bleach with rubber stamped disinfection properties. Such a lower temperature process is known as chemo-thermal disinfection.
The disinfecting bleach could be based on peracetic acid or Phtaloimido-peroxy-decanoic-acid [PAP in short].
The World Health Organisation [WHO} and CDC recommend washing for 25 minutes at 70 degrees Celsius. Now this might be safe but isn’t what commercial laundries would like to do. Such a long main wash would be slowing down the whole laundry. Therefore, we would suggest changing this into a minimum 12. 5 minutes at 80 degrees C. Or 10 minutes at 85˚C.
It is essential sticking to every wash parameter that belongs to a defined and rubber-stamped chemo thermal process. These parameters include not only time and temperature, but also the concentration of the detergent and the disinfecting agent as well as keeping the pH within the defined window.
D. SPECIFIC HYGIENE DEMANDS
A 100 % full proof hygiene result comes with some important requirements. All surfaces that come into contact with the clean linen have to incorporated into a cleaning and hygiene plan. These critical control points are: the press membrane, conveyor belts, folding tables, transport carts and all other CCP’s that are mentioned in the RABC of the laundry.