Institute of Engineering Materials and Design
Faculty of Mechanical Engineering
University of Maribor
The main aim of washing laundry is to remove soils and microorganisms from infected and dirty textiles and achieve clean, fresh and disinfected textiles ready for use. Textiles undergo laundering processes, which include: soil removal with special laundering agents; bleaching; disinfecting; and finally neutralising and rinsing. Because textiles from hospitals may contain many kinds of pathogenic bacteria, fungi and viruses, it is essential that the laundering process has not only a cleaning effect but also an antimicrobial one. Since users of hospital textiles are often patients with a weakened immune system, it is recommended that best practice and common sense be employed when washing and disinfecting hospital textiles. Most people assume that the laundry returned to them is in fact clean and, therefore, safe. Experience encourages all infection control teams to take laundering very seriously.(1–15) Inappropriately disinfected textiles are one of the possible sources of nosocomial infections for patients. There are reports of hospital textiles being the source of nosocomial infection with streptococci, enterococci, Bacillus cereus, staphylococci and coliforms.(5–9) There are some documented cases where staff in hospital wards and laundries have been infected with scabies, fungi, salmonellas, gastroenteritis viruses, hepatitis A viruses and coxiellas after treating dirty laundry.(10–15)
Regulations of the Robert-Koch Institute
Robert-Koch Institute (RKI) regulations, the compulsory German hygiene regulations for textiles from medical establishments and laundries, contain valid laundering procedures and conditions for hospital textiles.(16) According to the RKI regulations, hospital textiles must be clean and must not contain any pathogenic microorganisms (see Table 1). The regulations identify two important tests for evaluating the hygiene level in hospital laundries:
- The disinfection effect of a laundering procedure for hospital textiles is tested by using two standard bioindicators: Enterococcus faecium, ATCC 6057, and Staphylococcus aureus, ATCC 6538. Cotton textile substrates (1 cm2) are used as carriers of the suspension of defibrinated sheep blood and microorganisms. The laundering procedure must enable the elimination of 100,000 CFU/ml for both standard bacteria.
- Surface sampling using replicate organism detection and counting (RODAC) agar plates, conducted on 10 random samples of ironed and folded hospital textiles, must not exceed the following limit: nine out of 10 samples must not contain more than 2 CFU/10 cm2. There must not be any pathogenic microorganisms on the sampled textiles.
Risk analysis and biocontamination control
In September 2002, the European Committee for Standardisation (CEN) approved a standard, based on risk analysis and biocontamination control (EN 14065: RABC) principles, for laundry-processed textiles.(17) This document provides a management system that uses the principles of a risk analysis and biocontamination control system based on preventive measures. This enables laundries to continuously assure the microbiological quality of laundered textiles, especially for textiles used in specific sectors, such as pharmaceuticals, medical instruments, food, healthcare and cosmetics. A control point (CP) is any point or step in a process at which control is applied in order to contain, eliminate or reduce biocontamination risk.
German standard for hygiene assurance of hospital textiles
In 1986, directions for laundering hygiene for hospital textiles (RAL-GZ 992/2)(18) were issued by the German Institute for Quality Assurance and Certification (RAL). These directions are valid, important recommendations for laundries in the whole of the EU. The Research Institute Hohenstein, Germany, authorised by RAL, issues certificates of the laundering quality and hygiene of hospital textiles (RAL-GZ 992/2), which include RABC principles and are based on the regulations of the German Robert-Koch Institute. Retaining the certificate depends on the outcome of unannounced annual inspections of the laundering and disinfecting quality and the hygiene levels in the laundries, according to standard methods and in comparison with the limited values.
There are several control points in laundries that need to be controlled in order to reduce bacterial contamination, such as: evaluating the laundering procedure using standard bioindicators; surface sampling using RODAC agar plates of textiles; technical equipment; storage shelves; transport vehicles; hand hygiene; and microbiological evaluation of water samples. The hygienic state of the control points is evaluated through random external controls.
Bioindicators It was obvious from the results of the hygienic evaluation of laundries in Slovenia (see Table 2) that the laundering procedure F did not have a sufficient disinfection effect since both bioindicator bacteria E faecium and S aureus survived, indicating no disinfecting effect.
Surface sampling The surface sampling showed that the most commonly found microorganisms on the textiles were typical skin bacteria such as coagulase-negative staphylococci, Micrococcus sp and Corynebacterium sp, thus confirming the overall unprofessional textile handling of cleaned textiles (sorting, ironing, folding and packing). Bacillus sp and saprophytic Gram-negative rods were also commonly found and indicate insufficient cleaning and disinfecting measures. Certain pathogenic bacteria were also found, such as Enterococcus sp (storage shelves in laundry C) and Pseudomonas aeruginosa (technical equipment in laundries E and F). In two out of six laundries the tolerance value was exceeded for surface sampling of ironed and folded textiles, damp textiles and hand hygiene. The tolerance value for storage shelves was exceeded in one of six laundries. All six laundries exceeded the tolerance values for technical equipment, thus indicating that overall hygiene in the laundries is not at the best possible level. Regular training and education of workers is the most important element for implementing an appropriate level of hygiene in the procedures for handling clean and disinfected textiles after washing (sorting, ironing, folding and packing), and the basic hygiene demand is a disinfecting laundering procedure.
Water quality The microbiological assessment of the water quality in the laundry shows that the initial water (tap water) reached the required level of hygiene and that contamination occurred at subsequent phases. The level of hygiene for rinsing water was exceeded in laundries C, D and F, thus confirming an inappropriate disinfection effect of laundering. Pseudomonas aeruginosa, an autochthonic water microorganism, was found in the rinsing waters of laundries D, E and F. Representatives of the family Enterobacteriaceae were found in the rinsing water of laundry A.
Overall hygiene results Overall, the worst results were found in laundry F since both limit values according to the RKI regulations were exceeded. The investigated laundering procedure did not have a disinfecting effect against the indicator bacteria, and the limit values for the ironed and folded textiles were exceeded. Laundry C also exhibited an insufficient hygiene level since six control points exceeded the tolerance values (all control points except tap water, softened water and bioindicator survival). Laundries B and E exhibited the best results since only one control point was exceeded (technical equipment). In laundries A and D the tolerance values for two control points were exceeded.
These results confirm that the disinfecting effect of the laundering procedure is most important in preventing dissemination of microorganisms in the clean area of the laundry, where all further work is conducted (sorting, ironing, folding and packing). It is also obvious that laundries with inappropriate laundering procedures usually also have inappropriate cleaning and disinfecting measures for all technical equipment, storage shelves, transport vehicles and hand hygiene. On the other hand, it is obvious from the results obtained with laundries B and E that it is possible to implement cleaning and disinfecting measures which enable a better hygiene level within the tolerance values and thus achieve clean and disinfected textiles for reuse.
The review of the quality and hygiene level of laundries in Slovenia shows that, although the laundries did not achieve the demanded levels of hygiene and/quality, it is possible to reach them if measures are implemented to optimise the laundering procedure in order to have an appropriate disinfection effect and at the same time an appropriate level of quality. It is also very important for all workers, especially in the clean area of the laundry, to apply regular cleaning and disinfecting measures in order to prevent the recontamination of cleaned textiles in the process of handling textiles after washing and drying (sorting, ironing, folding and packing). It is not important which system is used for implementing these measures as long as the measures are performed regularly and by all personnel, since a high level of commitment and involvement is required by management and by all workers.
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- German regulations for textile hygiene from medical institutions, laundries and laundering procedures as well as conditions for delivering textiles to commercial laundries. Chapters 4.4.3 and 6.4 of “Regulations for hospital hygiene and infection prevention.” 1995;38.
- EN 14065. Textiles – laundry-processed textile articles – Biocontamination control system. CEN; 2002.
- RAL, Deutsches Institut für Gütezicherung und Kennzeichnung eV. Proper Linen Care, Quality Assurance RAL-GZ 992. Sankt Avgustin; 2001.