Can the tunnel-type washing unit meet the disinfection requirements of WS/T508?

The internal structure of the tunnel-type washing unit is fully interconnected and communicates with the workshop air, causing the bacteria present in the laundry room’s air to accumulate on the surfaces of its interconnected internal structures. Moreover, the interior of the tunnel-type washing unit maintains a humid and warm environment, which is highly conducive to bacterial proliferation. Even more concerning is that the spiral discharge channel inside the unit is not submerged in water. Although this channel is located in the heating zone, its actual position does not receive effective heating from the washing solution; instead, its temperature remains significantly lower than that of the washing liquid, far from reaching the temperature required for disinfection. If the situation is already so precarious in the heating zone, it is even less likely to achieve proper disinfection in non-heating zones. Furthermore, after prolonged use, the surfaces of this channel become heavily encrusted with scale. During the washing process, each batch of textiles must slide down along these scaled surfaces, carried by the water that accumulates in the current chamber, before moving into the next chamber. In summary, in medical laundries that wash medical textiles, the structural design of this particular product fails to meet the technical requirements specified in WS/T 508-2016 regarding microbiological indicators—for instance, it must show no detectable presence of Escherichia coli or Staphylococcus aureus, and the total colony count must also exceed the permissible limits.
The judgment that it fails to meet microbiological standards is theoretically sound—just as the saying goes, “A rod one foot long, if you take half of it each day, will never be exhausted, no matter how many generations pass.” Theoretically, pathogenic bacteria must exist.
Based on data on the types of pathogens typically detected in medical laundry environments, please assess the pathogen levels found on the continuous internal surfaces of tunnel-type washing machines. Additionally, analyze why this product fails to meet the microbial standards specified in the relevant regulations. Use clear and straightforward language for your explanation.

In the environment of medical laundry facilities, common pathogens include Escherichia coli, Staphylococcus aureus, Salmonella, and others. These pathogens typically spread through air, water, or textiles. The internally贯通 structure of tunnel-type washing machines—particularly the spiral discharge channel—provides an ideal breeding environment for these pathogens.
Humid and hot environment: The high humidity and temperature conditions inside the tunnel-type washing unit provide an ideal environment for bacterial proliferation. Although the heating zone reaches relatively high temperatures, the spiral discharge channel is not fully submerged in water, resulting in an actual temperature that falls below the level required for disinfection and thus failing to effectively kill bacteria.
Scale buildup: The surface of the spiral discharge channel tends to become heavily coated with scale. Not only is this scale difficult to clean, but it also provides a hiding place for bacteria. During the washing process, fabrics come into contact with these scaled surfaces, increasing the risk of bacterial contamination.
Microbiological indicators fail to meet the standards: According to WS/T 508—2016, after medical textiles are washed, neither Escherichia coli nor Staphylococcus aureus should be detectable, and the total colony count must also meet the specified requirements. However, the internal structure of tunnel-type washing machines does not allow for effective disinfection, which may result in these pathogens remaining on the textiles and failing to satisfy the standard requirements.
Real-world situation: In actual operation, even if the washing solution is at a relatively high temperature, the temperature in the spiral discharge channel still isn't sufficient to kill bacteria. Consequently, as fabrics pass through this channel, they may become contaminated by residual bacteria, resulting in the washed fabrics failing to meet microbiological standards.
In summary, the design and operating conditions of tunnel-type washing machines make it difficult for them to meet the stringent microbiological requirements of medical laundry facilities. The through-flow nature of their internal structure and the humid, warm environment provide ideal conditions for bacterial proliferation. Moreover, the insufficient temperature in the spiral discharge channel and the accumulation of scale further exacerbate this issue. Consequently, when used in medical laundry facilities, these machines pose a high risk of bacterial contamination and fail to meet the microbiological standards specified in WS/T 508—2016.