Mixing chemicals can be extremely dangerous and in the worst-case scenario can be fatal, and in most cases the desired
increase in performance is not achieved.
During COVID-19 with the increased focus on cleanliness, there was a 20% increase in the reporting of accidental poisonings in the first 3 months of 2020 according to the CDC. This increase was almost entirely due to people mixing household chemicals.
You can read the full paper released by the CDC here.
In this article, we will explain why you never mix chemicals and give some examples of what can happen when chemicals are mixed in an uncontrolled environment.
Mixing chemicals can potentially and unexpectedly cause unwanted chemical reactions.
At the top of the list is household bleach.
Bleach is a common and cheap chemical, used extensively in bathrooms for stain removal and disinfecting, in laundries for whitening whites and brightening colorfast fabrics, and in food preparation to sanitise equipment and food preparation surfaces.
Bleach is extremely reactive. It combines chemically with acids to liberate chlorine gas which when inhaled can cause serious and permanent lung damage and even death. Any chemical with a pH less than 7 is considered acidic. Vinegar has a pH of about 2.5 and reacts vigorously with bleach and the two should never be mixed. Other common acids found around the home may include toilet bowl cleaners, shower cleaners and rust removers.
Other common household chemicals that react with bleach:
Ammonia found in many oven, window and floor cleaners. This may produce chloramine vapour, a toxic gas.
Alcohol found in window cleaners and hand sanitizers. This could produce chloroform and other toxic chemicals.
To be safe bleach SHOULD NEVER BE MIXED WITH ANYTHING other than water.
Cleaning products based on strong acids or caustic alkalis are another group of chemicals that can be very dangerous when mixed.
Common household chemicals containing acids include drain cleaners, rust and concrete floor stain removers and toilet bowl cleaners.
Those containing caustic alkalis include, grill plate and oven cleaners, laundry detergents, some drain openers and floor cleaners.
Poisoning from mixing chemicals often happens accidentally. This is because chemicals that can create a poisonous chemical reaction such as when bleach and toilet bowl cleaner are used in the same location. Care needs to be taken to avoid unintentionally mixing of your cleaning products.
In the example of cleaning a bathroom, the "2-step" cleaning method is best practice for safe cleaning. First step is to clean your dirty surfaces such as the sink, shower and toilet and thoroughly rinse with water before moving to the second step. The second step is to apply bleach or disinfectant and allow to air dry.
Mixing cleaning products based on acids with those based on alkalis, at best ruins their cleaning ability and in the case of strong acids
and alkalis generate enough heat to cause a boil-over, liberate toxic gas and steam.
Another group of chemicals that are often mixed in an effort to improve performance are disinfectants and all-purpose cleaners. The end result is a concoction that is most likely a poor cleaner and without disinfectant properties. Disinfectants generally have enough cleaning power to get the job done. If you find that a disinfectant is not a strong enough cleaner, a 2 step process of cleaning with a suitable detergent, followed by disinfecting with your product of choice is recommended.
Follow the directions on the label, read the Safety Data Sheet and get advice if you consider product performance is not what was expected.
All content in this article, including links is intended as information only and should not be a substitute for professional advice.
Do not rely on information in this email as an alternative to professional advice from a qualified Occupational Health & Safety Officer.
We strongly advise consultation with a qualified Occupational Health & Safety Officer for any questions regarding the safe storage, handling and use of chemicals in the workplace and you should not disregard professional advice because of something you read in this email or linked material.