Killing germs on cloth … Germicidal effects of ordinary laundering and dry cleaning … Chlorine bleach and other disinfectants for the laundry … Laundering away dust mites and mite allergens … Importance of hot water … Lice and nits, fleas … Textile dermatitis … Poison ivy and other plant allergens
The home laundry sometimes has to deal with clothing or bedding that has been contaminated by more than ordinary soil. When microorganisms, dust mites, vermin, or allergic substances adhere to fabrics, the best solution is almost always a trip to the washing machine. Home laundering is usually your most effective means of sanitizing textile goods.
This chapter describes the ways in which ordinary laundering has sanitizing effects and the ordinary means by which we can heighten these effects in our home laundries. None of the methods discussed guarantees germ-free fabrics. They are merely ways of reducing the numbers of pathogens that may adhere to fabrics as part of ordinary good housekeeping. Those who wish to target specific pathogens and those who are dealing with situations that pose serious health threats should seek medical advice or the advice of public health authorities in their own communities.
Infectious Microorganisms
Germs and Cloth. Long before anyone had ever heard of bacteria, it was discovered that cloth could transmit infection from the sick to the well, a fact that was used for both good and ill. The pox was sent to enemies on infected fabrics. The spread of infectious disease was restrained by avoiding contact with contaminated cloth and burning the clothes and linens of victims. The eponymous Velveteen Rabbit has to be saved by magic because it is to be burned, along with all the other fabrics that touched the skin of the child who has just survived scarlet fever.
Scientific research confirms that microorganisms—bacteria, viruses, yeasts—may survive on fabrics for significant periods of time and may survive transfer from one cloth to another. One study, in fact, has found that some fibers are more hospitable than others to certain viruses. In the age of antibiotics, advanced indoor plumbing, and vaccinations, however, sickroom routines that were once familiar in every household through the early twentieth century are now forgotten. No smelly disinfectants are used to wipe down every surface and utensil near the sick one. No linens are burned or boiled, and handkerchiefs, “body linen,” and bed linens of the sick are not laundered separately. By and large, this is as it should be.
In every household, however, there are times when it is valuable to exercise a degree of special caution—for example, in the case of dangerous infectious illness, dirty diapers, or flood-contaminated textiles. It is helpful for all of us to understand how ordinary laundering procedures include physical, thermal, and chemical elements, each of which has profound sanitizing effects. Of course, in the event of a natural disaster or serious illness, you must seek expert advice on what safety measures you need to take. Your local extension service will have valuable information on disinfecting after a flood or other disaster. Your medical advisors will have guidance on household disinfection when there is infection in the home. You may also wish to contact your local public health agency.
Germicidal Aspects of Ordinary Laundering and Dry Cleaning. If you did nothing more than wash cloth goods in plain water in your washing machine, this would to some degree be sanitizing. Plain water physically removes vast numbers of microorganisms and sends them down the drain—alive and well, perhaps, but gone from your clothes and linens. When the water is hot, the sanitizing effect of agitating in plain water is greatly increased, for water that is hot enough kills germs. More water, hotter water, and longer exposure to heat increase the sanitizing effects of laundering. Ordinary detergents inactivate great numbers of microorganisms. Many studies have shown that sodium hypochlorite (household chlorine bleach) is a highly effective germicide in the laundry, and adding chlorine bleach to your wash also increases the sanitizing effect of cooler-water washes. The heat of the dryer kills off still more microorganisms, and so does dryness per se. If you hang your clothes to dry in the sun, the ultraviolet radiation from the sun kills many microorganisms. Hot irons are also highly germicidal. Thus germs are killed very effectively by the procedures of ordinary laundering in hot water with detergent and bleach, tumbling dry in heat or sunning, and ironing.
But plain laundering, while sufficiently germ-killing for normal household purposes, should not be overestimated. It does not permit you to be confident that you have killed any particular microorganism that you may be targeting, or that the fabrics have been completely disinfected. Home laundries are not set up to permit you to monitor or maintain the water temperature; few home washing machines even deliver water initially hot enough to kill many microorganisms. The amount of bleach used may not be sufficient. The duration of the germicidal action may not be long enough to be effective. For example, the polio virus would be inactivated within ten minutes if exposed to temperatures exceeding 122°F (50°C), but hepatitis B would require higher temperatures. Candida albicans, a yeastlike pathogen that causes one type of vaginal infection and is thought to be transmittable on underwear, survives in ordinary laundering with a water temperature of 120°F. You would have to launder articles at 158°F or higher to kill it, or iron them with a hot iron. Keep in mind that today’s home washers, even set on hot, often give water cooler than 120°F. See chapter 4, “Laundering,” pages 65-67.
If clothes or furnishings are not washable but must be dry-cleaned, the solvents and heat of the steam used in professional dry cleaning, too, will have a germ-killing effect. But the sort of dry cleaning you do yourself at coin-operated machines does not use steam and is not recommended, for example, as a way of cleaning flood-soiled clothes.
Laundering and Sanitizing Kitchen Cloth. I much prefer cloth for kitchen cleanups and dishwashing to sponges. This is a personal preference, but it is a fact that sponges are harder to keep sanitary. Sponges are havens for bacteria; food particles get deep inside them and they stay wet longer. Studies show that sponges typically hold large numbers of potentially hazardous microorganisms. But dishcloths and towels, too, will breed huge numbers of bacteria if left wet and soiled. Odors in sponges, dishcloths, or other kitchen cleaning implements indicate that bacteria are growing, but if a cloth or sponge lacks odors, this is no guarantee of safety. If you do not want to give up sponges, wash them thoroughly after use in hot sudsy water, sanitize them occasionally (see below), and do not keep them long. Launder dishcloths frequently too; use one or more fresh ones each time you do a kitchen cleanup or wash the dishes.
When you have finished a kitchen cleanup, hang any still-usable rags, cloths, and towels to dry on a rack kept for that purpose. Remove soiled ones for laundering (you can hang them to dry on the side of a laundry basket so that they do not make odors in the laundry room) and put out fresh ones, ready for the next round of cooking. Do not leave anything to dry in the kitchen that you would not want to be used. Someone will surely come along and use it.
Ordinary laundering in hot water and all-purpose detergent of dish towels, hand towels, dishcloths, aprons, potholders, cheesecloths, pastry cloths, rags, and other kitchen cloths will generally make them safely clean. For extra insurance, when you feel it is necessary, you can use chlorine bleach to sanitize them; chlorine bleach is effective in warm or cool water although it is best to avoid washing kitchen cloths in cool. (Sanitizing instructions for kitchen cloths are given below.) Some people do not like to use chlorine bleach, but they might wish to do so when they have some particular reason to be concerned or when the kitchen linens are beginning to look dingy. To give yourself the option of using bleach on kitchen cloths, never buy cloth for the kitchen that you cannot bleach.
Note that the trend to elevate looks over function has infiltrated even the manufacture of these utilitarian articles. Many manufacturers try to sell cloth for the kitchen that not only cannot be bleached but that bleeds dye, shrinks, is inabsorbent, and is heat-sensitive. Read the care label and resist such items no matter how attractive they look in the store. You will hate them in your kitchen.
Disinfecting in the Laundry with Chlorine Bleach. Chlorine bleach is highly effective against a wide range of bacteria, viruses, molds, and mildew and serves as an excellent sanitizer and deodorant in the laundry for all chlorine bleach—safe fabrics. (See chapter 4, “Laundering,” page 59 and “Bleaches” in the Glossary of Laundry Products and Additives, pages 72-74, on the effective use of chlorine bleach in the laundry. Refer to pages 73-74 for information on which fabrics chlorine bleach is safe for.) Nonetheless, if you are targeting some particular microorganism rather than aiming for a general sanitizing effect in your laundry, seek expert advice. The suggestions given below are not suitable for such specific purposes.
After six months or so, household bleach may no longer be fresh and should not be used for sanitizing or disinfection. (After nine to twelve months, bleach kept for laundering purposes should also be replaced.) Note: For sanitizing and disinfection use only plain or regular-scented chlorine bleach, not the perfumed types. In addition, do not use the thicker, nonsplashing or gel versions of chlorine bleach for sanitizing or disinfection.
For instructions on safety in using chlorine bleach, refer to pages 73-74, and read the bottle label. Do not mix chlorine bleach with acids, ammonia, or acid-or ammonia-containing products. Doing so will produce a toxic gas or other dangerous reaction. In fact, you should never mix chlorine bleach with anything other than water and ordinary detergent unless you are specifically instructed to do so by a reliable authority. Be careful not to splash chlorine bleach on clothes, furniture, or other furnishings. Also, never pour undiluted bleach directly on clothes and linens and never use it on dry clothes or clothes that are not immersed in water. Either use your machine’s automatic dispenser or mix bleach with a quart or two of water before pouring it into a washer or laundry tub containing water and clothes.
Disinfect chlorine bleach-safe laundry as follows:
In top-loading agitator-type washing machines: ¾ cup chlorine bleach per load. For extra-large washers, use ¼ cups. Use with detergent. In HE and front-loading machines use the maximum amount of bleach your dispenser permits. (The low volume of water these machines use makes it possible for the lesser amount of bleach to offer a similar sanitizing effect.)
For tub sanitizing, first rinse out any heavy soil. Then soak garments for five minutes in a solution of ¼ cup chlorine bleach to 1 gallon water.
For disinfecting and deodorizing diapers in pails, soak in a solution of ¼ cup chlorine bleach per 1 gallon water for five minutes.
To sanitize dishcloths, dish towels, and rags, first wash soiled items thoroughly in hot sudsy water; be sure to remove all food particles. Then make a chlorine bleach solution using ¾ cup chlorine bleach per gallon of water. Let items soak in the solution for five minutes or more. (This also works for sponges, kitchen brushes, and pot scratchers, but do these implements separately from cloth.)
Hydrogen Peroxide/Oxygen Bleaches. Hydrogen peroxide (H2O2) is effective against molds and many bacteria and viruses. It is the active element, directly or indirectly, in oxygen bleaches. Ordinary, nonactivated oxygen bleaches, or all-fabric or colorsafe bleaches, however, are not nearly as effective as chlorine bleach and are not effective sanitizers in the laundry. Activated oxygen bleaches such as Biz, however, are considerably more germicidal than nonactivated ones. See the Glossary of Laundry Products and Additives, pages 71-72. At this time, unfortunately, I am unable to find a scientific comparison of activated oxygen bleach with chlorine bleach for laundry sanitizing purposes. I note, however, that government extension services and agencies suggest using chlorine bleach for decontaminating flood-damaged fabrics and do not list activated oxygen bleach among other disinfectants recommended for this purpose.
A 3 to 5 percent solution of hydrogen peroxide that you buy in the drugstore in a brown bottle is commonly used in the home as an antiseptic and gentle, all-fabric bleach. (See pages 70-71 in the Glossary of Laundry Products and Additives.) It becomes inactive in nine months to a year.
Other Disinfectants. To disinfect clothes and linens that cannot tolerate chlorine bleach, the use of quaternary compounds or pine oil or other phenolic disinfectants is sometimes suggested. These products will say “disinfectant” on the label and will bear an EPA registration number, as chlorine bleach does, but, unlike chlorine bleach, they are not laundry products, are not especially formulated for use as laundry disinfectants, and usually bear no instructions, or very limited instructions, on how to use them on fabrics. You can find these products in drugstores, janitorial supply stores, home centers, or in supermarkets on the cleaning product shelves—not in the laundry section.
Quaternary Ammonium Compounds. Quaternary ammonium compounds (sometimes called “quats”) are found in a variety of household products—for example, in kitchen and bathroom cleaning products, mouthwashes, and skin washes. There are exceptions, but if a product contains quats you are likely to find in its active ingredients list the names of chemicals ending in “-ium chloride” or “-ium bromide”—for example, cetylmethylbenzyl-ammonium chloride or cetylpyridinium chloride. An exception is alkyl dimethyl benzyl ammonium saccharinate, a type of quat. Some quaternary disinfectants that might be used for sanitizing laundry are Roccal, Zephrin, or End-Bac. They are said to be very effective.
You would have to add quaternaries at the beginning of the rinse cycle, as they are inactivated by detergents (unlike chlorine bleach). They are said to be safe for all fibers but not for some dyes; they sometimes cause color change. So be sure to test for safety in an inconspicuous area. Set your washer for its hottest and longest wash cycle. Follow the instructions on the label. If you find no instructions, try using 4 tablespoons of Roccal or 2 tablespoons of Zephrin in top-loading agitator machines; or 2 tablespoons of Roccal or 1 tablespoon of Zephrin in front-loading machines.
Phenolics; Pine Oil. Phenolics are disinfectants that include phenol (C6H5OH) and analogous compounds. Pine oil is a phenol. Be sure to read labels. If pine oil is the only active ingredient, you need 80 percent pine oil to be sure you are getting a disinfectant effect. For this reason, pine oil is sometimes combined with quats or other phenolics. You can sometimes tell that a product contains phenols or phenolic derivatives by looking on the label for chemical names that include the term “phenol”—for example, ortho-phenylphenol. Phenolics and pine oil disinfectants will reduce bacterial counts on clothes but are not considered as effective in this as chlorine bleach or quaternaries.
Note: Phenols should not be used near a baby, in a baby’s room, or on a baby’s things, especially beds and bedding. Phenolics are also toxic to cats.
Phenols and pine oil products cannot be used on wool and silk. Their odors will cling strongly to these fabrics.
To sanitize in your washing machine with pine oil and phenolic disinfectants, dilute them with water before adding them to the wash or mix them well in the water before adding the clothes. They can be added either in the wash or the rinse cycle, as you wish. Again, use the hottest water and the longest cycles you have. Follow instructions on the label.
Pine oil disinfectants that might be used to disinfect laundry include Fyne Pine, King Pine, Pine-o-Pine, or Texize-O-Pine. If you find no instructions on the label, try using ½ cup in top-loading (agitator) machines, or ¼ cup in front-loaders.
Phenolic disinfectants include Pine-Sol, Al-Pine, or Sea-Air. If you find no instructions on the label, try using 1 cup in top-loading (agitator) machines, or ½ plus 2 tablespoons in front-loaders.
For further information on how to use these or other disinfectants effectively in situations where this is important for health or safety, contact your local public health authority, your local extension service, or your doctor.
Dust Mites
Dust mites are actually arachnids—bugs, not germs—that are so tiny that you cannot see them without magnification. They do not cause infection. The presence of dust mites does not imply dirtiness, and they are a normal part of environments that offer favorable physical conditions for their survival. However, they are strongly associated with allergic rhinitis and dermatitis and are thought to be one of the most common triggers of asthma attacks. They can be controlled by a variety of housekeeping measures, including informed laundering. For the most part, this is an issue on which you may choose your level of caution—higher if there are allergies in the house or children you want to avoid sensitizing. Many people happily ignore them and suffer no health effects at all.
Dust mites are killed by laundering at high enough temperatures. One study finds that wash water temperatures of 131 °F kill dust mites after ten minutes and notes that at cooler temperatures the acaricidal (mite-killing) effect is not increased by detergents or other chemicals tested. Some authorities, however, recommend higher wash temperatures, 140°F or 150°F. One study determined that water below 113°F killed no mites at all and that water at 122°F killed 49.7 percent of them. Unfortunately, today’s home washers rarely reach even the lower recommended temperature of 131°F. See chapter 4, pages 65-67. Thus there is speculation that the increase in low-temperature and cold-water home laundering in recent decades is among the many factors that may have caused an increase in the incidence of allergic asthma, as it has inadvertently rendered bedding more mite-ridden than it was in the good old days of hot-washed or boiled bedding.
Because water cools during agitation in home washers, those who can get wash temperatures of 130°F to 140°F or higher might begin with water hotter than necessary just to be sure the water stays in the proper range for ten minutes. Those whose wash water is not very hot might try De-Mite, a popular acaricidal laundry additive that works in cold water. Its active ingredient is benzyl benzoate, and it is advertised as safe for all washable, colorfast fabrics.
Laundering is perhaps most important, however, in removing the allergens produced by dust mites. Wash water of any temperature removes more than 90 percent of dust mite allergens, even when it leaves the mites alive and well (and clean, presumably). Dry cleaning, by comparison, kills all the mites but does not remove the allergens, which may cling for very long periods of time. This is a strong reason to buy only launderable bedding and blankets. Weekly launderings at 140°F or higher of all bedding—sheets, pillowcases, blankets, and mattress pads—is best to keep dust mites and dust mite allergens at low levels. As stored clothing can also harbor large numbers of mites, you might wash it before wearing, especially if you notice any allergic symptoms when you put such an article on.
Dryer heat probably also helps kill mites, but there is far less research on the effects of hot drying on mites than there is on the effects of washing (and drying does not remove allergens). One study suggests that mites on blankets were killed after several hours in a dryer, a time period too lengthy to encourage anyone to look hopefully to this method. Also, keep in mind that new dryers may not get as hot as old ones. At least until we have more research that might let us know how to use the heat of the dryer to kill mites, we should probably continue to rely on hot washing; dryer heat is a good backup. Ironing would undoubtedly kill mites, but I wonder whether many would not survive tucked into flat-felled seams and similarly protected places. Ironing would not, of course, remove allergens.
Lice and Nits; Fleas
Water temperatures of 150°F will kill lice and nits (leave laundry in the hot water for ten minutes to be sure), so hot laundering is effective to rid fabrics of these miserable pests. Some say you need only a temperature of 140°F or even 130°F, but since the water in your machine cools during the wash, the hotter you begin the wash the better.
Wash all sheets, pillowcases, blankets, comforters (duvets), and clothes, including hats and coats, that the afflicted person has been in contact with, and if it is not head lice but body lice of some sort, you must be sure to do a good job washing underwear. Then dry all items in a hot dryer for twenty minutes too, just for good measure. If you cannot wash certain items, dry cleaning is also effective. Or place things in airtight plastic bags, tightly sealed, and leave them for thirty days, which is longer than nits can survive at room temperature. Away from the human body, the lice themselves die much sooner—within three days. The plastic-bag option is an especially good idea for headsets, helmets, and similar items.
Fleas and their eggs will also be killed by hot-water laundering.
Textile Dermatitis
Many people are allergic to residue left on cloth by detergents and other laundry products. The solution to such problems is using no more detergent than you need, rinsing carefully (doing extra rinses if necessary), using products that contain as few inessential additives (such as perfumes) as possible, and trying to use hypoallergenic products. If these measures fail, change products until you find one that does not irritate or consult your doctor.
There are also allergic reactions to certain textile fabrics. Allergic reactions have been associated with cloth made of nylon, fiberglass, rubber, and wool fibers. When nylon fabric first appeared, many people reported that it made them itch. It turned out that nylon fabric required more rinsing than people were used to doing and that soap was the cause of the itching, which ended with adequate rinsing. In the past, spandex, too, was sometimes associated with allergic problems, but it is apparently no longer made with the problematic substance. And it is not clear that all discomfort described as “allergic” by sufferers is really that. Dermatologists find that many people report “allergies” to polyester or nylon fabric that may reflect experiences of ordinary skin irritation, perhaps the result of these fabrics being unabsorbent.
Whatever the nature of the difficulties, the solution is to stop wearing what itches you, to stop wearing it next to the skin, or, in the case of fiberglass, to stay away from it. If it is synthetics that bother you, switch to natural fibers. If it is wool, substitute acrylics. Acrylic functions and looks like wool and is nonirritating and nonallergenic. Wearing a thin cotton or silk liner or T-shirt under a wool sweater may be enough for many people.
Poison Ivy, Oak, or Sumac
Poison ivy, poison oak, and poison sumac are forms of allergic dermatitis caused by substances contained in these plants. The allergenic substances can be transferred from the plants to clothing or other fabric, or from someone’s skin to fabric. Either way, the next person to touch the fabric can come down with a case of poison ivy, oak, or sumac. Many people have caused themselves a renewed outbreak by rewearing a contaminated garment without first cleaning it. Both ordinary good laundering and dry cleaning will remove the offending substance and render fabric safe.