difficile spore contamination .
Experts point out that the use of different machinery must be considered in examining the microbial inactivation properties of the laundry process features , as numerous studies in the medical literature focus on use of washer-extractor type washing machines or laboratory equipment that simulates this washing action . But as McLaren , et al . ( 2019 ) point out , “ Large-volume laundry operations in the U . S . and Canada have transitioned away from washer / extractors to large-scale tunnel washers ( TWs ), a laundering technology that enables reduced consumption of thermal energy and fresh potable water . As opposed to the traditional washer / extractor design that utilizes a single drum ‘ water fill / mechanical action / drain ’ sequence , modern TWs use a screw mechanism in which textiles move through a sequence of connecting modules at a constant rate of speed that employ a gradual exchange of the wash liquors . TWs are typically between six and 18 modules long . The speed at which the textiles move through the modules is determined by the desired duration for the laundry process . Modules are used together as needed to lengthen the time that textiles are in during a certain step of the process … The TW process is one that is highly automated , enabling efficient use of laundry chemicals and water in precise amounts based on the weight of each load , type of fabric , and soil amount .”
Researchers lament the relatively sparse information available about the ability of the laundry process to remove and / or inactivate C difficile spores from fabric .
As McLaren , et al . ( 2019 ) emphasize , “ Despite the current popularity of TWs in the laundry industry , there is virtually no publicly available research on the microbial inactivation properties of the TW process . Given the fact that washer-extractor machine technology differs significantly compared with that for a TW , this raises the question whether it is reasonable to extrapolate the observations from washer-extractor experiments and apply these to TWs .” The researchers add , “ More research is needed to evaluate the complex matrix of industrial laundry processes , chemicals , fabrics , and challenge microbes for consistent production of hygienically clean healthcare textiles . Validation studies are needed to establish standard applied research procedures for future health care laundry comparisons to evaluate the complex matrix of industrial laundry processes , chemicals , fabrics , and challenge microbes for consistent production of hygienically clean healthcare textiles . A move in this direction would be beneficial to both the laundry industry and the healthcare community .”
Healthcare Textiles and SARS-CoV-2
Owen and Laird ( 2020 ) emphasize that there is limited published research on the survival of viruses within industrial laundry processes and that “ little is known about the risk of viral transmission by processed linens . The differing environmental stability , disinfectant susceptibility and transmission dynamics between viruses and bacteria means that this cannot be inferred from bacterial studies … There do not appear to be any studies in the published literature on the survival of coronaviruses within laundering processes , which would be required to evaluate any risk of SARS-CoV-2 transmission from laundry during the COVID-19 pandemic .”
Seeking answers about the stability and survival of SARS-CoV-2 through the wash process , TRSA recently partnered with the Textile Services Association-UK , the European Textile Services Association ( ETSA ) and several other European national associations on a research project carried out by De Montfort University ( DMU ) in Leicester , England . In a summary of the research , TSA-UK noted that , “ The conclusion is that it is generally good news for those who are involved with hygiene and cleanliness in textiles . Virtually all wash processes , with potentially the exception of low-temperature domestic washing , will effectively eliminate any infection risk caused by coronavirus . However , other pathogens such as C . difficile , B . cereus , E . faecium , etc . will still require thermal disinfection . The outcome of the research points out that coronavirus does not pose an additional risk that would have required higher temperature wash processes .”
The report acknowledges contamination control and soiled linen management processes as critical considerations . As TSA-UK explained , ‘‘ It is essential that the processing sites are well equipped to manage the risks of cross-contamination and have adequate procedures and practices in place . The fabrics potentially contaminated with the virus should be managed within a controlled environment where the segregation of soiled linen is well managed . This should eliminate the potential for recontamination of clean linen , surfaces and equipment . The risk is highest with 100 percent polyester fabric , which is likely to include some nurses ’ uniforms , gowns , drapes , furnishings , curtains , etc .’’
While DMU ’ s research is currently undergoing peer review , there were several key takeaways from the preliminary version of the study .
Regarding survivability of the virus on common fabric types :
• The tested strain of coronavirus ( HCoV-OC43 ) remained infectious on polyester fabric for at least 72 hours , 100 percent cotton for 24 hours and a blended polycotton ( 50 / 50 ) for six hours .
• The virus was demonstrated to transfer to other surfaces from polyester fabric for up to 72 hours , suggesting that textiles may pose a fomite transmission risk within the healthcare and domestic environments .
Regarding survivability of the virus in various wash parameters :
• Model coronaviruses can remain infectious in water alone at temperatures up to 60 ° C ( 140 ° F ) for 10 minutes .
• Traces of the viruses were found after laundering in a washing machine at ambient temperature in the presence of interfering substances ( artificial saliva ).
• When agitation , temperature and detergent are combined , no trace was found at 104 degrees F / 40 degrees C and above .
These preliminary research results validated initial ( March 2020 ) TRSA guidance that called for the use of laundry-related portions of the World Health Organization ( WHO ) guide to controlling epidemic- and pandemic-prone acute-respiratory infections , whose recommendations called for :
• Placing all soiled textiles directly into containers or bags with minimal manipulation or agitation , to avoid contamination of air , surfaces and people .
• Washing and drying according to routine standards and procedures . For hot-water laundry cycles , detergent or disinfectant in water at 70 degrees C / 160 degrees F for at least 25 minutes . For lower temperatures , chemicals suitable for low-temperature washing when used at the proper concentration .
• In packing and transporting , containing soiled textiles in a manner that prevents containers or bags from opening or bursting during transport .
• Ensuring personnel handling soiled linen and equipment and waste use standard precautions – assuming all they touch