Cleaning with chlorine bleach: what it cleans and what it ruins

Step by step

1. 1

   Read the bottle

   For disinfecting, use regular, unscented bleach whose label lists disinfection. Most US household bleach contains 5 to 9% sodium hypochlorite; concentrated, scented and splash-less versions differ.

   Why: The CDC dilutions assume regular bleach. A different strength or formula changes how much you need.

2. 2

   Ventilate and protect your skin and eyes

   Open windows or doors and wear gloves and eye protection as the label directs. Make sure no other cleaner is on the surface or in the bucket.

   Why: Bleach vapor irritates the airways, and leftover ammonia or acid from another product can react with it.

3. 3

   Clean the surface first

   Wash away visible dirt and grime with soap or detergent and water, then rinse.

   Why: The CDC's bleach guidance is for disinfecting surfaces that have already been cleaned of visible dirt.

4. 4

   Dilute with room-temperature water only

   Mix 5 tablespoons (1/3 cup) of bleach per gallon of room-temperature water, or 4 teaspoons per quart. Add nothing else.

   Why: This is the CDC disinfecting dilution. Plain water is the only safe thing to mix bleach with.

5. 5

   Keep the surface wet for at least 1 minute

   Apply the solution and leave the surface visibly wet for at least 1 minute, then let it air-dry or rinse as the label directs.

   Why: Disinfection depends on contact time. Wiping it off at once doesn't give the hypochlorite long enough to work.

6. 6

   Make it fresh each day

   Pour out leftover solution at the end of the day and mix a new batch next time.

   Why: Diluted bleach loses its effectiveness after about 24 hours.

What chlorine bleach is and how it works

Household chlorine bleach is sodium hypochlorite dissolved in water. It's alkaline and a strong oxidizer: it attacks the colored compounds in stains and breaks them into colorless ones, which is how it whitens. The same oxidizing power deodorizes and, at the right dilution and contact time, kills germs on hard surfaces.

That strength cuts both ways. Bleach doesn't distinguish between a stain and a dye or fiber that oxidizes easily, so it removes color from fabrics that aren't colorfast and weakens protein fibers and some synthetics. It also cancels the action of oxygen bleach and enzyme presoaks, so use those separately.

What chlorine bleach is good for, with the ratios

• Disinfecting hard, nonporous surfaces after cleaning (CDC): 5 tablespoons (1/3 cup) per gallon or 4 teaspoons per quart of room-temperature water, wet for at least 1 minute, made fresh daily.
• Final traces of dye and tannin stains (coffee, tea, wine, soft drinks, mustard, grass) on white or colorfast washables: the Kentucky extension guide adds chlorine bleach to the wash if the fabric can take it. Check the care label symbols.
• Mildew on bleach-safe fabric: University of Georgia Extension soaks the item in 1/4 cup bleach plus 3/4 cup water for 10 to 15 minutes, then launders it in the hottest water the fabric allows. See mildew on clothes.
• In the washer: never pour undiluted bleach onto fabric. Use the machine's bleach dispenser, or dilute the bleach in water before adding it.
• Colorfastness test (University of Georgia Extension): mix 1 tablespoon of bleach in 1/4 cup of water, put one drop on a hidden area, wait 1 minute and blot. If the color changes, don't use chlorine bleach on that item.

What chlorine bleach damages, and what never to mix it with

• Wool, silk, spandex and polyurethane foam: bleach damages them, and chlorine stains on wool, silk and spandex can't be removed.
• Resin-treated (permanent-press) and flame-retardant finishes, and some nylon: the finish holds on to chlorine, which yellows and weakens the fabric, and some nylon yellows permanently.
• Dyes that aren't colorfast: the color bleaches out. Run the drop test first.
• Rust and iron stains: chlorine bleach intensifies them or sets them. In homes with iron-rich water, use oxygen bleach for laundry. See rust stains.
• Aluminum, linoleum, shiny enamel and metal containers: bleach darkens aluminum, makes linoleum brittle and can dull enamel if undiluted. Metal containers also speed the bleach's action and can tarnish.

Mix bleach only with water. With ammonia or ammonia-containing products (some glass cleaners, and urine) it forms chloramine gases. With acids (vinegar, lemon juice, some toilet-bowl cleaners, lime and rust removers, some dishwasher detergents, acidic drain cleaners) it releases chlorine gas. With rubbing alcohol it forms chloroform. The New Jersey Department of Health also warns against combining it with hydrogen peroxide, oven cleaners, drain openers, pool chemicals and some insecticides. See which cleaning chemicals never to mix.

By situation

White cotton and linen

Bleach works best here, but only on items whose care label allows it. Use the dispenser or dilute it first, and keep to the amount on the bottle.

Colored clothes

Do the one-drop test on a hidden seam. If the color shifts, switch to oxygen bleach, which is safe for most colorfast fabrics.

Spandex, wool, silk and stretch fabrics

Don't use chlorine bleach at all. It damages these fibers, and any chlorine marks on them are permanent.

Yellowing from iron in the water

Chlorine bleach makes iron stains worse. Switch to oxygen bleach for laundry, and use a fabric rust remover on existing marks.

Mold on walls and hard surfaces

The EPA does not recommend biocides such as chlorine bleach as a routine part of mold cleanup. Scrub hard surfaces with detergent and water, dry them, and fix the moisture problem that let the mold grow.

Toilets, litter boxes and urine spots

Urine contains ammonia compounds, and many toilet-bowl cleaners are acidic. Flush or rinse thoroughly before using bleach, and never pour it on top of another cleaner.

What not to do

• Never mix bleach with ammonia, vinegar or other acids, or rubbing alcohol. These combinations release chloramine, chlorine gas or chloroform.
• Don't pour undiluted bleach directly onto fabric. Undiluted bleach damages fabric and can remove color where it lands.
• Don't use it on rust stains. Chlorine bleach sets or intensifies iron and rust stains instead of removing them.
• Don't use it with oxygen bleach or an enzyme presoak. Chlorine bleach cancels their action, so you lose both treatments.
• Don't keep diluted bleach for later. It loses effectiveness after about 24 hours, so a stored solution may not disinfect.

Other methods that work

Oxygen bleach

For colors, spandex blends and homes with iron-rich water, oxygen bleach (sodium percarbonate) lifts stains without chlorine's damage to dyes.

Caution: Follow its own label, and never use it in the same wash as chlorine bleach, which cancels it.

Detergent and water for mold

The EPA's approach to household mold is to scrub hard surfaces with detergent and water, dry them and stop the moisture source.

Caution: Cleaning without fixing the moisture source lets the mold grow back.

Fabric rust remover

For rust and iron marks on fabric, the extension guides use a commercial rust remover made for fabrics instead of bleach.

Caution: Rust removers are acidic. Keep them well away from chlorine bleach.

Stain still there?

A stain turned yellow or orange after bleaching

It probably contained iron, and chlorine bleach intensified it. Rinse well and treat it with a fabric rust remover.

White nylon or a permanent-press shirt turned yellow

Resin finishes and some nylons hold on to chlorine and yellow. The change in some nylon is permanent. Use oxygen bleach on those items from now on.

Pale spots appeared on colored fabric

Bleach removed the dye, and that can't be reversed. Next time, do the one-drop test first.

You smell a sharp chlorine odor and your eyes or throat burn

Leave the area and get fresh air. If you mixed bleach with something, call Poison Help at 1-800-222-1222, or 911 for trouble breathing.

Safety

• Mix chlorine bleach only with room-temperature water.
• Ventilate and wear gloves and eye protection as the label directs.
• Rinse surfaces thoroughly between different products.
• Store it in its original labeled container, out of reach of children.

Never mix cleaning products; see chemicals you must never combine.

Questions

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