How to Use Bleach Safely

Heather says:

I received a concerning email, yesterday, that made me realize it was time to send this post out again as a reminder.

This is the first in our series on household chemicals.

Over the past few years, I have gotten the impression that many people are using chlorine bleach¹ in an unsafe manner. Chlorine bleach aka sodium hypochlorite is a powerful disinfectant and is one of only a few widely available, inexpensive sanitizing agents. It is so powerful in fact that it should only be used in fairly low concentrations.

How to Use Bleach Safely


Chlorine bleach should always be used in a well-ventilated area.

If your eyes are watering. You are using too much bleach. If your skin is peeling: A) you should have worn gloves and B) you are using too much bleach. If you use hot, rather than warm water, chlorine gas can be released and this isn’t recommended. Never mix bleach with other household chemicals such as ammonia or vinegar, both can cause dangerous chemical reactions.

There is a difference between clean, sanitary, and sterile

Don’t waste the power of your bleach on cleaning; reduce your use and save it only for sanitizing.

Chlorine bleach works both as a cleaning and a disinfecting agent. However many less corrosive and dangerous household items also work as highly effective cleaning agents: hot water, scrub brushes, and dish detergents are but a few examples.

Chlorine bleach is a highly effective sanitizing agent, but it needs to be used properly. Repeat after me:

Clean, rinse, sanitize.

When sanitizing food preparation areas: counters, tables, sinks, knives, and cutting boards. All surfaces should be washed to remove organic materials (food bits) and rinsed. It is only at this point that the items should be sanitized with a bleach solution of approximately 200ppm. This is about 1 TBSP of chlorine bleach per gallon of water. Did you catch that? Let me repeat it.

The proper dilution of chlorine bleach for sanitizing food preparation surfaces is 200ppm or 1 TBSP per gallon of warm water.

Get yourself a spray bottle and mix up a batch whenever you’re going to need sanitizing agent. Be aware that chlorine evaporates so only mix a small amount at a time. If you’re making 1 quart of sanitizing solution estimate ¾ teaspoon per quart, and that will get you in the neighborhood of 200 ppm. Just rinse after use.

Bleach and stainless steel are not good playmates. However dilute bleach solutions are still usable. Rinse the surface after sanitizing to avoid the corrosive effects.

Allow the 200ppm bleach solution to sit on the surface for at least a full minute to give the bleach time to work. With a 200ppm dilution rinsing is not necessary and it’s actually best to allow most surfaces to air dry rather than re-contaminating with a towel.

Chlorine bleach is an effective sanitizing agent outside of the kitchen.

When sanitizing other surfaces, such as in the bathroom, bleach may be used in a 500ppm dilution.

A 500ppm dilution is 2½ tablespoons of 5.25% chlorine bleach per 1 gallon of warm water.

While bleach is a cleaning agent, milder methods are highly recommended. Save the bleach for the final, sanitizing step, just as you would in the kitchen.

If you weren’t aware, urine evaporates leaving behind ammonium salts. Always clean and rinse any area that may have urine: near toilets, cat boxes, dog kennels, etc before sanitizing.

How to use chlorine bleach in the laundry

When bleaching a load of whites, use 3/4 cup of liquid bleach in a standard washer and those with high efficiency washers should consult their appliance manuals or call the manufacturer. Typically the amount of bleach per load in a high efficiency washer is equivalent to the maximum fill line of the bleach dispenser, but check to be sure.

When pre-soaking laundry bleach safe fabrics, first  remove as much soil as possible, then use 1/4 cup per gallon of warm water. Anything stronger can damage the fabric.

So for the TL:DR crowd here’s the quick summary:

  • Clean, rinse, sanitize, wait 1 – 5 minutes. Rinse again if it’s stainless steel
  • Food prep surfaces require a 200ppm or 1 TBSP chlorine bleach per gallon of warm water.
  • Other surfaces may use a 500ppm dilution or 2½ TBSP chlorine bleach per gallon of warm water.
  • Laundry pre-soaks 1/4 cup per gallon or 3/4 cup for a full load in a standard, top loading washer.

Send your questions to

¹♪♫Let’s talk about bleach baby, let’s talk about you and me. Let’s talk about all the good things and all the bad things bleach may be. ♪♫ Yeah, I woke up with a song in my head.


guide to chemical cleaners

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  1. says

    Well, you could have published this a week or so ago, couldn't you?! 😉 Thanks for the info. Now you need to tell me how to dye my poor shirt that I can't get the stain out of.

  2. Jennie says

    Thank you so much for posting this. I've always wondering how to safely dilute bleach to use as a cleaning agent!

  3. fawnahareo says

    I no longer buy chlorine bleach — I buy oxygen bleach instead. I haven't done a ton of research on it, but I understand that it's gentler on the environment and on clothes, so the higher cost is worth it to me. Do you have any thoughts on this?

    Also, for disinfecting kitchen / bathroom, I use two spray bottles. A spritz of undiluted vinegar followed by a spritz of undiluted hydrogen peroxide, and then wiped down. This is supposed to be MORE effective than bleach for sanitizing surfaces such as counters and toilets and even food, as the result is non-toxic. (But don't premix the vinegar and hydrogen peroxide; in order to be effective, you need that chemical reaction to happen on the whatever-it-is you are cleaning.)

    • says

      I assume you are using the food grade H202, correct? I do plan on mentioning the alternatives to bleach in future posts, but I'm going to start with the most familiar chemicals and work my way out from there.
      I do want to be very careful with what I recommend. When I was researching the book, I corresponded with the government's consumer question program and asked for alternatives for bleach. I became quite frustrated when the only information they would give me is a version of what you see above.
      As I do not want to be responsible for passing along bad information, I'm researching the alternatives carefully and there will be disclaimers.
      Since no one in my home has an immune deficiency, I'm not especially careful to sanitize, except food surface areas.
      For most of us, provided we practice good personal hygiene. Hands people, wash them. Often. Clean is good enough.

  4. Lucy says

    Just remember that cleaning thoroughly before using bleach to disinfect is a must. Bleach is readily inactivated by organic matter.

  5. debster57s says

    How much bleach to keep the algae down in a 4 foot by three-foot pond nothing in it just water It has a pump It bigger then what the pond needs

  6. Paula says

    Hi, Heather,

    Before I get to my topic I just want to let you know how much I appreciate the nice, clean, easily-navigated layout of your site, with the vintage theme (the cover of your book is great!- boy, does that bring back memories).
    Thanks so much for this post & the correct %ages, most of all my finally being able to find out whether or not I can use hot H20 with bleach, and why [not] (it could be a real gas!). Since a few other readers proffered other alternatives I thought, having a daughter with several chemical/food sensitivities (and with asthma myself), I’d offer up my own long-time, beloved go-to: thyme. Yup, good old, simple thyme. It actually has disinfectant properties superior to bleach – and it smells a whole lot better! Not only do I love how my kitchen, laundry room & bathroom smell when every surface has had a thorough cleaning with thyme; it’s also very satisfying to know I did it in a safe, non-toxic way; and somehow, I feel connected to a long line of forebears who went before us using the good things provided us from the earth instead of some chemical witch’s brew that is going to take off my skin or make my pets horribly ill if it spills. No toxic clouds floating overhead, either, and no disposal issues (moreover, in summer, the insects seem to really hate it, so another side bennie is far fewer cobwebs & invading ants). I used to just purchase a small glass bottle of the essential oil at my local health store and add a few drops to a spray bottle of water (completely dependent on the bottle size and “germiness” of the task at hand), and do still have a bottle made up under the kitchen sink; however, since “Natural” has gone mainstream in a big way there is a host of ready-made, herbal-based cleaning/disinfecting products on the market, and I recently picked up Seventh Generation’s [Botanical] Disinfecting Multi-Surface Cleaner. I compared it to the leading bleach-based cleaner/disinfectant, and it kills one more type of household germs than does the bleach-based cleaner, incl. the H1N1 flu virus – at a comparable price point. A terrific product for anyone who needs to Clean It.

  7. Milton says

    Great article, came upon this when I was suffering from norovirus. I needed a bleach solution to clean up after myself so I didn’t get my family sick. Bleach is great for killing things without a lipid envelope like norovirus.

    One thing tho, I’ve been using a concentrated bleach (clorox concentrated) which has a higher percentage of sodium hypochlorite (I think it’s around 8% vs 6%). I assume that this means the dilution would require lower concentrations of bleach but I’m not sure what the dilution would be.

  8. says

    I have a friend who cleans her bathroom only with bleach. When I go to visit her the whole house smells like bleach and that is awful. I should send her this article! Thanks a lot for sharing this important information here! Earlsfield Carpet Cleaners Ltd.

  9. says

    I need some advice. I have dogs (4) in my home They are all house trained but accidents sometimes happen. What is the best way to clean tile and hardwood floors when accidents happen?

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