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COVID-19: Global Research Shows Wash-Process Effectiveness

TRSA partners with European organizations to gather information

ALEXANDRIA, Va. — The prolonged outbreak of COVID-19 worldwide has created a need within the various sectors of the linen, uniform and facility services industry for information on the stability and survival of SARS-CoV-2 not only on various surfaces, but also its ability to survive the wash process.

TRSA, the association for linen, uniform and facility services, recently partnered with the Textile Services Association-UK, the European Textile Services Association (ETSA) and several other European national associations on a research project to gather this information. De Montfort University (DMU) in Leicester, England, carried out the study.

In a summary of the research, TSA-UK notes, “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.

‘‘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,” explains TSA-UK.

“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% polyester fabric, which is likely to include some nurses’ uniforms, gowns, drapes, furnishings, curtains, etc.’’

The first phase of the DMU study included a literature review, which highlighted a lack of common knowledge about the virus and how it interacts with textiles in the wash process.

Next, DMU developed a detailed project scope to look at the survival of the SARS-CoV-2 virus on several commonly used textiles, and then a review of washing parameters including dilution, agitation, heat and detergents. While the research paper is currently undergoing peer review, there were several key takeaways from the preliminary version of the study.

Survivability of the virus on common fabric types:

  1. The tested strain of coronavirus (HCoV-OC43) remained infectious on polyester fabric for at least 72 hours, 100% cotton for 24 hours and a blended polycotton (50/50) for six hours.
  2. 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.

Survivability of the virus in various wash parameters:

  1. Model coronaviruses can remain infectious in water alone at temperatures up to 140 F for 10 minutes.
  2. Traces of the viruses were found after laundering in a washing machine at ambient temperature in the presence of interfering substances (artificial saliva).
  3. When agitation, temperature and detergent are combined, no trace was found at 104 F and above.

Linen, uniform and facility services industry subject-matter experts contacted by TRSA noted that the overwhelming majority of textile goods processed are blended polycotton fabrics.

“When the pandemic first started, there was very little understanding of how long coronavirus could survive on textiles,” says Dr. Katie Laird, head of the Infectious Disease Research Group at DMU.

“Our findings show that three of the most commonly used textiles in healthcare pose a risk for transmission of the virus. If nurses and healthcare workers take their uniforms home, they could be leaving traces of the virus on other surfaces.”

Results validate initial (March 2020) TRSA guidance to linen, uniform and facility services providers for all business sectors (F&B, healthcare, hospitality, industrial) 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.

Such WHO terminology, directed at healthcare personnel, TRSA reasoned, applies to all outsourced laundries’ production and service teams. Recommended practices included:

  • 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 160 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 is COVID-infected—and perform hand hygiene after removing their personal protective equipment (PPE).

On a March 11, 2020, in a TRSA webinar titled “Coronavirus/COVID-19: Communication Tools for Your Customers, Employees and Leadership Teams,” guest speaker Murray Cohen, a retired U.S. Centers for Disease Control and Prevention (CDC) and World Health Organization (WHO) epidemiologist, discussed how long the virus could last on textile goods.

“People who create guidelines always add safety measures; they say six to 12 hours,” Cohen said. “From the data I’ve seen, it’s really six hours. In laboratory settings, they have been able to recover the virus from porous surfaces, up to, but not past, six hours. Essentially what’s happening is the virus is drying out.

“Packaged in soiled linen bags, there might be an exception there, because if it’s wet, it may not be fully dried out. A safe bet on wet linen would be 12 hours and then it would not be a risk anymore.”

Upon completion of the peer-review process, publication of the research will follow in the next few months. The research will appear in an open-access journal that will make the findings accessible to a wide audience.

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