Sanitation in self-service automatic washers

Abstract

The potential for microbial transfer in self-service laundry washing machines was investigated by obtaining swab samples from the interior surfaces of commercial machines and wash water samples before and after disinfectant treatment. Three disinfectants (chlorine, a quaternary ammonium product, and a phenolic disinfectant) were used. Four self-service laundry facilities were sampled, with 10 replications of the procedure for each treatment at each location. Although washers were set on a warmwater setting, the wash water temperatures ranged from 24 to 51°C. The quaternary ammonium product seemed most effective, averaging a 97% microbial kill; chlorine was the second most effective, with a 58% kill, and the phenolic disinfectant was least effective, with only a 25% kill. The efficacies of the chlorine and phenolic disinfectants were reduced at low water temperatures commonly experienced in self-service laundries. Interfamily cross-contamination in self-service facilities is a potential public health problem, which is aggravated by environmental conditions, such as water temperature and the practices of the previous users of the equipment. Procedural changes in laundering are recommended, including the use of a disinfectant to maintain adequate levels of sanitation.

Home Hygiene Practices and Infectious Disease Symptoms Among Household Members

“…A number of investigators have reported that bacteria, including coliforms, are frequently recovered from washed clothing, particularly when low water temperatures are used (Christian, Manchester, & Mellor, 1983; Davis & Ainsworth, 1989; Smith, Neil, Davidson, & Davidson, 1987). Studies of communal laundries demonstrate that the washing machines are contaminated after use and can colonize laundry between loads (Buford, Pickett, & Hartman, 1977; Legnani & Leoni, 1997). Hot water temperature (80 to 90°C) is more microbicidal, but machines are often used at temperatures of 25 to 60°C.…”

The Use of Disinfectants in the Home

“…It has been demonstrated (McNeil & Chopper 1962;Wiksell et al 1973;Buford et al 1977) that appreciable numbers of organisms may be transferred from contaminated to uncontaminated linen when these are included in the same wash cycle and also between linens washed in separate cycles where transfer of contamination is probably effected by organisms adhering to the washer surfaces. Although the studies by Walter & Schillinger (1975) indicate little value in the use of hypochlorites, Wilkhoff et al (1971) and Buford et al (1977) have demonstrated that addition of quaternary ammonium, phenolic disinfectants or hypochlorites to machine-wash cycles will produce significantly greater reduction in the numbers of viable organisms present in fabrics and in the water used for washing them than can be achieved by use of hot water and detergent alone. It is therefore suggested that disinfectants may be of value in preventing transfer of infection in situations where heavy soiling of linens is known to have occurred although at the present time use of chemical disinfectants is not recommended in hospital laundries.…”