Mix acidic vinegar with basic baking soda and stow them in a closed container, the mixture can be quite explosive—literally, because vinegar causes baking soda to foam up and explode. But, despite the explosive nature of the two ingredients, you’re left with nothing more than water and sodium acetate—virtually useless at cleaning surfaces.
Do not mix hydrogen peroxide with vinegar in the same bottle as it’s more likely to increase your risk of going to the emergency room. Together they’re quite potent. Combining these two creates peracetic acid which is corrosive and an irritant that can harm your skin, eyes, nose, and throat in high concentrations.
Mixing products containing chlorine bleach with products containing ammonia releases chloramine gas, which is toxic to people and animals.
Bleach and alcohol combine to produce chloroform, a sedative powerful enough to make you pass out or potentially die. Disinfectants are important for preventing the spread of diseases like coronavirus, but don’t mix them!
Bleach smells pungent by itself but the smell grows even more acrid once you add vinegar. The combination releases chlorine and chloramine vapors, which can cause a chemical burn.
Vinegar and castille soap should not be mixed or used together. In great part it’s due to the fact that vinegar is an acid and the Castile Soap is a base. They will directly react with each other and cancel each other out.
Do not mix different brands of drain cleaner. Some drain cleaners are bases (e.g., sodium hydroxide), others are bleach (i.e., sodium hypochlorite), and others are acids (e.g., sulfuric acid or hydrochloric acid). These chemicals do not play nicely together.
Mixing a disinfectant that uses quaternary ammonia with a foaming cleanser may seem like the perfect combo to pick up grime, but the combination results in neutralizing the disinfectant.
Bleach shouldn’t be mixed with oven cleaner. The combination can produce chlorine gas, resulting in irritation of the eyes, nose, throat and lungs.
https://www.familyhandyman.com/list/common-household-cleaning-products-you-should-never-mix/