Incompatibility, and the one mixture never to make

The page in this property where being wrong hurts somebody, so it comes first in spirit even though it sits at the end of the list.

The safety page of this property

Cleaning products are mixed by customers, by staff, and by makers experimenting. Some combinations produce toxic gas within seconds.

This is knowledge to hold as a maker, to put on a label, and to say out loud to anybody who helps you.

Bleach and acid

Sodium hypochlorite plus any acid releases chlorine gas.

The acid does not have to be strong. A toilet cleaner containing hydrochloric or sulfamic acid mixed with bleach does it. So does vinegar, which people assume is safe because it is food.

Chlorine gas damages the airway at low concentrations and it is produced immediately, in a small room, usually a bathroom with the door shut.

This kills people every year, and it is nearly always somebody trying to clean harder by combining two products.

Bleach and ammonia

Sodium hypochlorite plus ammonia releases chloramine vapors, which are also seriously toxic.

Ammonia is in many glass cleaners and in some all-purpose products, frequently without being obvious on the front of the label.

And bleach plus hydrogen peroxide, and bleach plus many other things: the general rule is that bleach should never be mixed with any other cleaning product, and that is the version worth teaching because it needs no chemistry.

Formulation incompatibilities

The ones that ruin a batch rather than a person.

Anionic and cationic surfactants neutralize each other and precipitate.

Acids and carbonates fizz, and in a sealed container that is pressure.

Oxidizers with most organics, including fragrance and dye, which degrade.

Some preservatives with some surfactants, which quietly deactivates the preservative.

The maker's rule: add one thing at a time, in a recorded order, and never combine two finished products to see what happens.

References