Unlike a traditional commercial laundry machine, the Xeros laundry systems gets fabrics clean with ambient temperature wash cycles. However, the use of ambient temperature water in the Xeros system has many wondering: “just how well does Xeros sanitize fabrics compared to traditional hot water processes?”
Washing in ambient temperatures has many benefits including lower costs due to lack of expense for heating water, brighter colors, reduced risk of color bleeds and longer linen life.
Customers often ask how the Xeros Systems’ level of hygiene compares to conventional high temperature (149oF /65oC) machines. Steve Jenkins, Chief Scientist at Xeros recently conducted testing to compare. Let’s take a look at the process and results.
Inoculation with Five Bacterial Strains
In order to mimic typical laundry washloads, the systems were tested using five types of bacteria that are commonly encountered in dirty laundry wash loads; Staphylococcus Aureus, Pseudomonas, Aeruginosa, E.Coli, Enterococcus Hirae, and Klebsiella Pneumoniae.
The testing was done on cotton cloths of approximately 12.5 x 2.5 inches (10 x10 cm), weighing 0.064oz /1.8g. At Microbiological Consultant Services’ (MCS) labs in Tideswell, Derbyshire, UK the cloths were separately inoculated with 0.0338 fl. oz of a suspension of each bacteria type. Afterwards, the cloths were transported to Xeros Ltd. (Sheffield, UK) in sterile plastic bags for wash treatments. The level of inoculation was approximately 108 colony-forming units (cfu) per cloth which represents a high level of bacterial contamination compared to a normal washload.
Once at the Xeros facility, inoculated cotton cloths were pinned to cotton towels. Each bacteria type was used to inoculate 2 cotton cloths per washload. These were washed with 44.1lbs/ 20kg of ballast (mixed cotton) along with 20 sebum sheets. Sebum is an oily substance secreted by human skin which attaches to clothing, so sebum sheets were added to the ballast to re-create conditions found in usual washloads.
Washing was carried out in a Xeros machine at temperatures and with varying hygiene agents Sodium Hypochlorite Solution, 200g Xeros PACK 2, 300g Xeros PACK 2, Hydrogen Peroxide Solution, and Thermal Disinfection. In all cases 250g of Xeros PACK 1 biological detergent was added to machines at start of the wash.
The XOrb type and XOrb:water:cloth ratio chosen for the Xeros process were typical for this type of cleaning. Standard Xeros cycle time, including 3 rinses, were used at 68oF (20oC). Either 200g or 300g of Xeros low temperature hygiene liquid, PACK 2, was added in the first rinse.
After washing, the inoculated cloths were recovered and immediately transported in sterile plastic bags to MCS. At MCS the cloths were immersed in 9ml/0.304 fl. oz of an aqueous solution and vigorously agitated to wash out any bacteria remaining. Any bacteria in the wash outs were allowed to grow on a culture medium at appropriate temperatures for 1-3 days, as required for the bacteria. At the end of this time, the number of bacteria on the cloths (expressed as colony-forming units/cloth) were counted.
The test concluded that disinfecting efficacy of the Xeros ambient wash is comparable to that of thermal disinfection 149oF/65oC wash for four bacteria and similar for the fifth one without the energy cost for the thermal method. The equivalency is killing off 99.9999% or greater of four bacteria and 99.99% or greater of Pseudomonas Aeruginosa.
With Xeros you get the same hygiene control as high temperature washing without the costs!