How to wash white clothes and keep them white

Read the label for temperature and bleach

Two symbols matter most for whites. The washtub shows the maximum water temperature, and the triangle tells you about bleach: an empty triangle allows any bleach, a triangle with two diagonal lines allows oxygen bleach but not chlorine, and a crossed out triangle means no bleach at all. GINETEX, the international care labeling association, sets out these meanings, and our guide to reading laundry symbols covers the rest of the label.

Then check the fiber. White cotton and linen tolerate the most heat and, if the label allows, chlorine bleach. White polyester and blends pick up stray dyes easily, as the American Cleaning Institute points out, and do not need hot water. White wool, silk and anything with spandex need gentle care and no chlorine bleach at all; our guide to washing silk covers the delicate route. A white blouse in silk and a white cotton undershirt are both whites, but they should not share a load.

How to wash white clothes in a washing machine

The everyday routine does most of the work. Each step removes a reason whites turn gray.

1. 01

   Wash whites on their own

   The American Cleaning Institute recommends washing whites separately from pastels, brights and darks. Even a cream or light gray item can shed enough dye over many washes to tint whites. Keep towels out of shirt loads too, since their lint dulls smooth fabrics.

2. 02

   Pretreat collars, cuffs and underarms

   Rub a little liquid detergent into these areas and let it sit for a few minutes before washing. This is where body oils build up first, and it is the main answer to how to wash white clothes with stains: treat the stain before the load, not after.

   CheckCheck the guide for the specific stain, since blood and other protein stains want cold water first.

3. 03

   Use the warmest water the label allows

   For sturdy cotton whites, warm or hot water removes body oils better than cold, and the Drycleaning and Laundry Institute recommends the hottest water the fabric can take when restoring whites. Synthetics and blends are happier warm or cool. Cold water is fine for lightly worn whites if you use a detergent designed for cold washing.

4. 04

   Use enough detergent and leave room in the drum

   Follow the dose on the package for the load size and soil level. The American Cleaning Institute notes that both too much and too little detergent leave clothes less clean, and that clothes need room to move. Graying, according to the Drycleaning and Laundry Institute, usually comes from soil that was never fully removed over many washes.

5. 05

   Check before you dry

   Look over collars and stain spots before the load goes in the dryer. Heat can set a stain that survived the wash, so rewash anything still marked. Dry on the setting the label allows, and take whites out promptly.

Oxygen bleach or chlorine bleach

Oxygen bleach, sold as powders or liquids often labeled color safe, is the everyday whitener. The American Cleaning Institute describes it as gentler and suitable for most washable fabrics, best at keeping whites white rather than restoring them, and most effective in warm to hot water. It is still not for wool, and some products exclude silk, so read the package. Adding the recommended scoop to regular white loads is the simplest way to stop yellowing from starting, and our guide to using oxygen bleach covers dosing, soaking times and how to test it.

Chlorine bleach, sodium hypochlorite, is stronger. It disinfects as well as whitens, and it works on white cotton and linen whose label shows an empty triangle. The American Cleaning Institute warns that it damages wool and silk, and the Drycleaning and Laundry Institute adds nylon, rayon and acetate to that list, along with a less obvious drawback: chlorine breaks down the optical brighteners that make new whites look so bright, so overusing it can leave fabric looking yellower over time. It can also intensify rust colored and some sweat related yellow stains. Use it occasionally, diluted and dosed exactly as the bottle directs, never poured straight onto dry fabric.

Bleach safety you should never skip

Never mix chlorine bleach with ammonia, vinegar or any other acid, or with other cleaning products. Chlorine bleach mixed with some household cleaners releases toxic gases; the CDC warns that bleach can release chlorine gas when combined with other products, and the American Cleaning Institute states plainly that bleach and ammonia fumes are hazardous. This matters in laundry because common stain tips call for ammonia on fresh perspiration stains or vinegar on old ones. If you have used either on a garment, rinse it thoroughly in plain water before any chlorine bleach goes near it, and never add vinegar to a load that contains chlorine bleach.

Use bleach with the window open or the fan on, keep it in its original bottle, and store it away from children. If you feel eye, nose or throat irritation while working with cleaning products, leave the room for fresh air. You may also have seen warnings about vinegar and baking soda. Mixing them is not dangerous in the way bleach combinations are; they fizz and largely neutralize each other, which mostly means that using them together in one step does less than using either on its own.

How to get yellowed white clothes white again

Start by working out why the whites yellowed. Even yellowing all over usually means body soil built up over many washes. Patches at the underarms usually come from sweat and antiperspirant, which our guide to removing deodorant and sweat stains treats in detail. Yellowing along fold lines or on the side that faced a window often comes from storage and light; the Drycleaning and Laundry Institute explains that light breaks down fabric brighteners, and that brighteners fade over time, revealing fabric's natural off white tone.

For buildup, soak the whites in warm water with oxygen bleach at the concentration and time the package gives, often several hours, after pretreating collars and underarms with liquid detergent. Then wash them in the hottest water the label allows with a full dose of detergent, and repeat the process if they have improved but are not there yet. Check the result before drying. If a garment stays yellow after two rounds, the fibers themselves or the lost brighteners may be the cause, and no home method will fully reverse it; at that point it is often best retired to sleepwear or a layering piece.