Laundry hygiene, according to Wikipedia, involves practices that prevent disease and its spread via soiled clothing and household linens such as towels. Items most likely to be contaminated with pathogens are those that come into direct contact with the body, e.g., underwear, personal towels, facecloths, nappies. Cloths or other fabric items used during food preparation, or for cleaning the toilet or cleaning up material such as feces or vomit are a particular risk.
Microbiological And Epidemiological
Microbiological and epidemiological data indicates that clothing and household linens etc. are a risk factor for infection transmission in home and everyday life settings as well as institutional settings. The lack of quantitative data linking contaminated clothing to infection in the domestic setting makes it difficult to assess the extent of this risk.
It also indicates that risks from clothing and household linens are somewhat less than those associated with hands, hand contact and food contact surfaces, and cleaning cloths, but even so these risks needs to be managed through effective laundering practices. In the home, this routine should be carried out as part of a multi barrier approach to hygiene which includes hand, food, respiratory and other hygiene practices.
Infectious diseases risks from contaminated clothing etc. can increase significantly under certain conditions, e.g., in healthcare situations in hospitals, care homes and the domestic setting where someone has diarrhoea, vomiting, or a skin or wound infection. It increases in circumstances where someone has reduced immunity to infection.
Hygiene measures, including laundry hygiene, are an important part of reducing spread of antibiotic resistant strains. In the community, otherwise healthy people can become persistent skin carriers of MRSA, or faecal carriers of enterobacteriaceae strains which can carry multi-antibiotic resistance factors (e.g. NDM-1 or ESBL-producing strains).
The risks are not apparent until, for example, they are admitted to hospital, when they can become “self infected” with their own resistant organisms following a surgical procedure. As persistent nasal, skin or bowel carriage in the healthy population spreads “silently” across the world, the risks from resistant strains in both hospitals and the community increases.
In particular the data indicates that clothing and household linens are a risk factor for spread of S. aureus (including MRSA and PVL-producing MRSA strains), and that effectiveness of laundry processes may be an important factor in defining the rate of community spread of these strains.
Experience in the United States suggests that these strains are transmissible within families and in community settings such as prisons, schools and sport teams. Skin-to-skin contact (including unabraded skin) and indirect contact with contaminated objects such as towels, sheets and sports equipment seem to represent the mode of transmission.
Microbial Contamination Levels
During laundering, temperature and detergent work to reduce microbial contamination levels on fabrics. Soil and microbes from fabrics are severed and suspended in the wash water. These are then “washed away” during the rinse and spin cycles. In addition to physical removal, micro-organisms can be killed by thermal inactivation which increases as the temperature is increased.
Chemical inactivation of microbes by the surfactants and activated oxygen-based bleach used in detergents contributes to the hygiene effectiveness of laundering. Adding hypochlorite bleach in the washing process achieves inactivation of microbes. A number of other factors can contribute including drying and ironing.
Drying laundry on a line in direct sunlight is known to reduce pathogens.
About Surfactants And Other Ingredients
Laundry detergents contain a mix of ingredients including surfactants, builders, optical brighteners, etc. Cleaning action arises primarily from the action of the surfactants and other ingredients, which are designed to maximise release and suspension of dirt and microbes into the wash liquid, together with enzymes and/or an activated oxygen-based bleach which digest and remove stains.
Although activated oxygen bleach is included in many powder detergents to digest and remove stains, it produces some chemical inactivation of bacteria, fungi and viruses. As a rule of thumb, powders and tablets normally contain an activated oxygen bleach, but liquids and all products (liquid or powder) used for “coloureds” do not. Surfactants also exert some chemical inactivation action against certain species although the extent of their action is not known.
Effectiveness Of Laundering
In 2013 the International Scientific Forum on Home Hygiene (IFH) reviewed some thirty studies of the hygiene effectiveness of laundering at temperatures ranging from room temperature to 70 °C, under varying conditions. A key finding was the lack of standardization and control within studies, and the variability in test conditions between studies such as wash cycle time, number of rinses, etc.
The consequent variability in the data (i.e., the reduction in contamination on fabrics) obtained, in turn makes it extremely difficult to propose guidelines for laundering with any confidence, based on currently available data. As a result, there is significant variability in the recommendations for hygienic laundering of clothing etc. given by different agencies.
Of concern is recent data suggesting that, in reality, modern domestic washing machines do not reach the temperature specified on the machine controls.
BACTERIA can remain alive on fabrics a long time. Staphylococcus (“staph”) can live on wool blankets for eighteen weeks and on muslin sheets for twelve weeks.
Contaminated clothing and household textiles can become carriers of disease-producing microorganisms.
Microorganisms—microbes—include bacteria (examples: Staphylococcus Pseudomonas); viruses (examples: influenza, poliomyelitis); fungi (examples: those causing mildew and ringworm); protozoa (examples: those causing amebic dysentery and malaria).
Even at the end of the spin-dry cycle of home laundering, the fabric may contain twenty five thousand bacteria per square inch.
These four types of disinfectants have been found to be effective: Chlorine (hypochlorite), phenolic, pine oil, and quaternary.
It is important to read the label on the bottles in order to be sure of the name and amount of disinfectant in
any product. To insure effectiveness, it is also important to measure the amount to be used.
Future research may, of course, demonstrate the effectiveness of still other types of disinfectants.
When used as directed during home laundering, the four types of disinfectants listed reduce the numbers of bacteria to a safe level.