Health centers are required to comply with protocols established by the Ministry of Health of Peru (MINSA)[1], for the treatment of hospital linen. The directorial resolutions agree on three types of risks: high, medium, and low, and do not show anything related to the use of Ozone (O3). Calvo (2004) found that the use of ozone allows water savings in laundries in the textile industry. Korol et al. (1995) determined that ozone was a better disinfectant than chlorine. A prototype of an ozone system was built to test whether the microbiological load on laundry clothes at the San Francisco health center is reduced, thanks to funding from the Jorge Basadre Grohmann National University (UNJBG) in the city of Tacna. As these results are proven, then, the possibility of reducing occupational risks increases, as well as continuing research, since clothing that can be used outside the protocol could be the origin of cross-infection.    (National Maternal and Perinatal Institute, 2021)  (Hospital de Emergencias José Casimiro Ulloa, 2021) (Hospital Huaycan, 2023) (EsSalud, 2014)

6 samples of used hospital clothing were collected, and each one was subjected to different disinfection methods. The samples are identified as follows. The control sample = 0; Sample 1 = 1; Sample 2 = 2; Sample 3 = 3, Sample 4 = 4; Sample 5 = 5.

If the sample has not yet undergone any treatment, the letter "A" is added, and if it has already undergone the disinfection treatment, then the letter "D" is added.

1. The control sample had normal washing with detergent and bleach for 15 minutes, then 5 rinses of 15 minutes at a time.
2. Sample 1 had a pre-rinse with ozonated water that lasted 8 minutes (5 minutes filling and 3 minutes of contact with the final volume) at all times with ozonated water. She was then subjected to normal washing with detergent for 15 minutes and then to 5 rinses of 15 minutes at a time.
3. Sample 2 was washed with detergent for 15 minutes and then rinsed 5 times with ozonated water for 23 minutes at a time.
4. Sample 3 was moistened with water alone until the clothes were covered, and then all the water was emptied so that ozone gas was immediately applied for 5 minutes, then it was washed with detergent for 15 minutes, and then rinsed with water alone 5 times.
5. Sample 4 was moistened with water alone until the clothes were covered, and then all the water was emptied so that ozone gas was immediately applied for 5 minutes, followed by washing with detergent for 15 minutes and then 5 rinses with ozonated water that lasted 23 minutes at a time.
6. Sample 5 was pre-rinsed with ozonated water for 8 minutes (5 minutes filling and 3 minutes contact with the final volume) at all times with ozonated water. Then it was washed with detergent for 15 minutes and then rinsed with ozonated water for 5 repetitions.

• Each washing machine fill lasted 5 minutes
• Each wash with detergent lasted 15 minutes
• Each rinse was done with 5 repetitions and lasted 15 minutes each time
• Each flush of water lasted 15 minutes
• Each pre-rinse lasted 8 minutes (5 minutes of filling and 3 minutes of rinsing), always with ozonated water
• Each wetting consisted of filling water to cover clothes and then emptying everything, and then releasing ozone gas for 5 minutes

2 samples were taken per sample: before and after treatment.

In each sampling, the garment was spread on a table sanitized with 70° alcohol and approximately 10 cm x 10 cm was delimited to drag the swab moistened with microbiological conservation water (peptonated water) on the surface of the garment the same number of times vertically, horizontally, diagonally to the left and diagonally to the right and then the swab was placed in the vial containing the conservation water. The vial was closed, labeled, and prepared to send to the laboratory.

Once the prototype was located, the described methodology was executed.

Figure 1: Prototype of an ozone washing machine

Table 1: Laboratory Results

For the control sample, where washing was done on a regular basis, a good reduction was obtained. For aerobic mesophiles and no reduction for filamentous fungi.

In sample 1, a total reduction was obtained for aerobic mesophiles, staphylococci, and fungi. These were the only ones that were found.

In sample 2, the reduction was total for aerobic mesophiles, Pseudomonas, and filamentous fungi; these were the only ones that were found."

For sample 3, a total reduction was obtained for Pseudomonas, and a sufficient reduction of more than 5 logarithms for aerobic mesophiles; these were the only ones that were found.

For sample 4, the reduction was total for Pseudomonas and for total fungi; they were the only ones found.

For sample 5, the reduction was total for aerobic mesophiles and for filamentous fungi; these were the only ones found.

By applying ozone technologies, it is perfectly possible to disinfect hospital linen, the best being the one that considers washing with detergent, and with ozone, 100% disinfection is ensured.

Thanks

Jorge Basadre Grohmann National University

San Francisco de Tacna Health Center

1. Calvo, M. D. M. P. . (2004). Saving water in industrial laundries with ozone technology. Retrieved from http://www.cosemarozono.es/pdf/noticia_38.pdf.
2. (2014). Hospital Linen Manual. Retrieved from https://www.essalud.gob.pe/ietsi/pdfs/tecnologias_sanitarias/m_ropa_hosparia.pdf
3. José Casimiro Ulloa Emergency Hospital. (March 24, 2021). Directorial Resolution No. 343-2014-DG-HEJCU. Retrieved from https://hejcu.gob.pe/PortalTransparencia/Archivos/Contenido/1301/210120150914321.pdf
4. Huaycan Hospital. (February 20, 2023). Directorial Resolution No. 37-2023-D-HH/MINSA. Retrieved from https://www.hospitalhuaycan.gob.pe/SIESMAR/Archivos/Comunicaciones/NormasLegales/normaLegal-220823461133769.pdf
5. National Maternal and Perinatal Institute. (2021, 03, 24). Directorial Resolution No. 041-2021-DG-INMP/MINSA. Retrieved from https://cdn.www.gob.pe/uploads/document/file/2022508/RD%20N%C2%BA%20041-2021-DG-INMP/MINSA.pdf
6. Korol, S., FortunatO, M., Paz, M., Sanahuja, M., Lazaro, E., Santini, P., & D'Aquino, M. (1995). Water disinfection: comparative activities of ozone and chlorine on a wide spectrum of bacteria. Revista Argentina de Microbiología, 27(4), 175-183.