The rising popularity of cleaning hacks on social media apps such as Instagram & TikTok in recent years has saved countless people an enormous amount of time. But this can also come at a cost. There are also a lot of bad hacks to be found, and disinformation can have real-life consequences. When that comes to cleaning, that can potentially be damaging to your property or even, worse still, you or those close to you.
In recent years, bleach has become a particularly hot topic for cleaning hacks, but this has also led to bleach becoming a particularly hot topic for bad cleaning hacks too. So, how can you tell the good advice from the bad, what’s the science behind bleach, and how can it be used safely?

Common Myths About Cleaning With Bleach
As a common and inexpensive disinfectant around the house, it is hardly surprising that bleach should have become a subject of myths. So let’s start by debunking a few of the myths that have come to surround it over the years.
Myth: Bleach Cleans Everything
It’s debatable whether bleach even really ‘cleans’ at all. Bleach is a disinfectant rather than a cleaning product. Its job is to kill germs rather than to keep your surfaces clean, and while that may seem like a tiny distinction, it’s an important one. Cleaning removes dirt and germs. This can be done simply with soap and water, or by other cleaning products. Disinfecting uses chemicals to kill germs. It does not clean or remove the germs. In addition to this, some surfaces are simply unsuitable for bleach to be used on them. Porous materials in particular absorb bleach so that it can’t effectively get into or out of to safely sanitise surfaces.
Myth: Bleach Contains Chlorine Gas
Chlorine is the active ingredient in bleach, but bleach in its normal state won’t release any particularly noxious fumes in and of itself. The risk when using bleach comes when you start mixing it with other products. The chemical reactions that can be caused by doing so can cause noxious fumes or worse, all the way up to explosions!
Myth: Bleach Causes Asthma
Bleach doesn’t cause Asthma (the reasons for its causation remain unknown), but it can trigger severe reactions in asthmatic people. According to the Asthma & Allergy Foundation of America, “Bleach is a common asthma trigger. People with asthma should avoid using bleach or areas where bleach is being used when possible.” They add that, “If you must use bleach”:
- Mix it in the right proportion
- Wear a mask and gloves
- Use it in a well-ventilated room
- Don’t mix bleach and ammonia
- Have someone else clean for you, if possible
Myth: Using Bleach Will Damage Surfaces and Equipment
Not necessarily. There are certain surfaces that you shouldn’t use bleach on (more on those shortly), but there’s no problem with using it on some non-porous surfaces, such as porcelain, without damaging them.
Myth: Bleach is Good for Mould Removal
You can use bleach to remove traces of mould on tub and tile surfaces which are hard and impermeable, such as porcelain or tiles. However, bleach can’t kill mould on porous surfaces, such as those made of wood, because mould spreads its roots deep into such surfaces. The best way to remove mould depends on what you’re removing it from; bleach can be used in some circumstances, but far from all. The only way to permanently get rid of black mould is by reducing the build-up of moisture in your home, and that means improving ventilation.
Myth: Bleach Shouldn’t be Diluted (with Water) for Disinfecting
Absolutely untrue! Bleach should always be heavily diluted before using it, especially in household settings. Failure to do so may lead to damaging surfaces that are suitable even for diluted bleach. Always check the label and follow the instructions!
Myth: Premixed Diluted Bleach is Great for Disinfecting
Bleach is less chemically stable in its diluted form, which causes it to degrade in effectiveness, so the best practice is to mix your bleach solution fresh for every application. Premixed bleach will not work as effectively. Also, remember that bleach is not a cleaner, so you will need to pre-clean any surface with soap and water to remove dirt and debris and then let it dry completely before disinfecting with the diluted bleach.
Myth: Bleach is Great for Cleaning Wood
Unfortunately, it isn’t. Wood is a highly porous material. Using bleach on it will often result in stains and potentially warping the wood. Ensure you use products on your wooden items and surfaces that are specifically designed for them. These products will protect and nourish your wood. Bleach is also ineffective at killing mould spores which can discolour wooden surfaces, but it will lighten them, giving you the illusion that you have killed the mould off when you haven’t. Water and washing up liquid will clean up most messes, but there are also specialist disinfectants available which are kinder to wood.
Myth: Bleach Can be Used on Stainless Steel
It is recommended that bleach is never used for cleaning stainless steel. What makes stainless steel stainless in the first place is a protective coating, and bleach and other cleaners containing chlorine will eat away at that coating, eventually leading to staining and other issues. In severe cases, it could even end with your stainless steel surfaces starting to rust! As with wood, soap and water will be enough for most spillages, but specialist cleaners for stainless steel are also available.

Understanding the Science of Bleach
“Bleach” is something of a catch-all term, but for these purposes, we’re talking about chemical products widely used to whiten clothes and/or remove stains, as a disinfectant to kill germs, and for other uses around the house. So what’s the science behind this oft-misunderstood chemical?
The Chemical Composition of Bleach
Bleach consists of chlorine-based chemicals such as calcium hypochlorite (bleaching powder) and non-chlorine (peroxidase-based). Common household bleach contains 3% to 8 % sodium hypochlorite (NaOCl), with sodium hydroxide (NaOH) added to slow decomposition.
Different Types of Bleach
The most common bleach is normal household chlorine bleach, which is water-based bleach with the active ingredient sodium hypochlorite. The next most common bleach is oxygen bleach, which is also water-based but with the active ingredient of hydrogen peroxide. In addition to both of these is powder-based bleach which uses calcium hypochlorite as the active ingredient.
How Bleach Works as a Cleaner and Disinfectant
Bleaching action occurs through oxidation or reduction. Chlorine bleaches break the chemical bond of the chromophore (a colour-producing portion of pigment) rendering it non-reactive with light. An equally useful property of bleaches can be found in their antimicrobial disinfecting properties. They disinfect by denaturing (unfolding) bacterial proteins, causing them to clump together and become useless. It is, somewhat strangely, a similar reaction to that seen when cooking an egg, and in the same way that an egg cannot be uncooked, clothes and surfaces cannot be ‘unbleached’.
Safe Handling and Storage of Bleach
- Ensure good ventilation by keeping windows open while using bleach.
- Wear suitable protective clothing as bleach can irritate the skin, mucous membranes and airways.
- Use cold water for dilution as hot water will decompose the active ingredient, rendering it less effective.
- Make sure you are using a suitable dilution of bleach for your specific purpose.
- Rinse thoroughly bleached articles with clean water before using.
- Wash your hands with liquid soap after using, even if you’ve been wearing rubber gloves.
- Store bleach in a cool and shaded place, and always well out the reach of children.
- Use diluted bleach within 24 hours; its efficacy will decrease with time.
- Avoid touching your eyes and face while using bleach. If it gets into the eyes, rinse immediately with tap water for at least 15 minutes. If in doubt, always seek medical advice.
- Never mix bleach with other detergents as this reduces its disinfection
- effectiveness and can cause unintended–and sometimes highly unpleasant–chemical reactions.
- Bleach shouldn’t be left on a surface for any sustained period of time. It may corrode or discolour the material.
- Try not to use household bleach on any hair or skin as it will damage it.
- Don’t leave bleach where children can get to it. If bleach is ingested it can be fatal, if not life-changing.
- Always mop up any bleach spillage immediately.
Bleach Alternatives
There are times when it is simply not appropriate to use bleach. We mentioned stainless steel and wood above, but some types of plastic are also unsuitable, and it can also be damaging to granite surfaces and many different types of fabric, including silk and wool. But it’s not only that. We’ve also already discussed how unsuitable it is for asthmatic people.
It’s a good thing, then, there’s never a shortage of alternatives when it comes to cleaning products. Baking soda, or bicarbonate of soda, is a must-have for any cleaning supplies cupboard. It’s possibly the most versatile cleaning material available anywhere. The active ingredient in white vinegar is acetic acid, and it’s great for cutting through grease, limescale, dirt and a huge array of household stains. Importantly, vinegar also possesses antibacterial properties, so it can be used to clean kitchen worktops and toilets.
Sometimes, all you need is a blast of steam. A targeted jet of steam can be used for some very precise and effective cleaning in every area of the home. Whether you’re sanitising kitchen work surfaces or cleaning a toilet seat, a steam cleaner can remove stubborn stains and kill 99.9% of bacteria at the same time. And because both dirt and bacteria are removed, so are bad odours. Jet cleaners are not as expensive as you might expect, either.
Can I Mix Bleach With Other Cleaning Products?
No! Chlorine-based bleach products can become highly volatile when mixed with other cleaning products, especially acids. Remember that this whole process should always be two step; clean first, then disinfect. Using bleach won’t work in any way other than cosmetically unless you’ve cleaned the area first!
How Long Should I Leave Bleach on a Surface for It to Disinfect?
Check the instructions on the label of your bottle, but if they’re not available, diluted household bleach doesn’t start to disinfect immediately. It is recommended that you leave it for one minute at an absolute minimum, and that ideally you should leave it for more like five to ten minutes to thoroughly disinfect an area.
Do You Need to Rinse After Cleaning With Bleach?
After disinfection with bleach solutions, surfaces should always be rinsed and dried. Bleach can be irritating to skin and mucous membranes, so any residue should be removed before returning to use. Remember that the residue left behind can be invisible to the human eye.
Is Bleach Still Toxic When Dry?
Yes. When used repeatedly and if allowed to build up over time, the residues can be potentially harmful to surfaces. Not all residues are visible and can chemically react with cleaning products, while textured surfaces can also collect residue, which can be difficult to remove if allowed to build up. Always rinse thoroughly after bleaching.

Can I Mix Bleach With Other Cleaning Products?
No. It is strongly recommended that bleach is never mixed with other cleaning products, as this can cause chemical reactions which may cause damage and, in extreme cases, could even provoke explosions!
And this is where those TikTok and Instagram influencers come in. Since the beginning of 2021 #ProductOverload has been highly fashionable on #CleanTok, the corner of TikTok dedicated to cleaning and cleaning hacks. Product Overload is the act of adding several products down a toilet or drain at the same time, and it reached such a peak that TikTokers were taking requests from viewers to clean in particular colours.
This is, it should go without saying, a phenomenally stupid thing to do. Not only can you damage a toilet by repeatedly doing this–it’s been estimated that up to six months of cleaning supplies can be used in one ‘overload’–but in enclosed and unventilated areas there is a real risk that anyone doing this could even overpower themselves with noxious fumes from chemical reactions that they often do not seem to even understand.
As a spokesperson for Unblocktober, the environmental group that carried out this research, told the Huffington Post, “Not only is it incredibly dangerous to mix chemicals in an uncontrolled setting without prior knowledge or expertise, but excessive use of cleaning products–even those deemed to be eco-friendly and safe to use in our kitchens and bathrooms–can have devastating effects on our environment.”
What Precautions Should I Take When Using Bleach Around Children and Pets?
You should also take extra care when using and storing bleach if you have children or pets. Always store it out of the reach of children, and never in a container that could be mistaken for anything else. Always rinse any surface thoroughly before returning it to use, especially if that normal, everyday use involves children or pets.
What Are the Best Practices for Bleach Disposal?
You can pour bleach down a sink, but it is strongly recommended that you mix it with water as you do so. For smaller amounts, pouring it down the toilet as you pull the flush will work, but don’t do more than half a litre in one go. Make sure the bottle is completely empty before recycling, preferably by rinsing it thoroughly first.
So is bleach a friend or a foe? The answer falls somewhere in between. On the one hand, it’s easy to look at the list of recommended instructions on how to use bleach safely and feel daunted by it, and it’s fair to say that bleach is a noxious substance. But it does work extremely effectively–and cost-effectively–as a disinfectant, and with safe and informed use on surfaces for which it’s suitable, it’s a critical piece of your household cleaning armoury.