Hydrogen peroxide 3%

mod hazard

Also: peroxide

CleaningFirst aidGarden

A short-lived oxidizer. Useful on surfaces and as a stain-lifter. A poor routine wound wash (it kills new cells too). Never a drinking-water plan at 3%.

Shelf life: 1–3 years unopened; months after opening. It wants to become water and oxygen.
Container: Original brown bottle, cool, dark. Never a clear drink bottle.
Grade: USP 3% for home. 12–35% ‘food grade’ bulk is a chemical burn in a jug — do not treat it like the brown bottle.

What it does

▸Spot sanitizing of non-porous surfaces
▸Mouth rinse in a pinch (spit, do not swallow)
▸Garden fungus folklore — mixed evidence; ventilation and sanitation matter more

Store

▸Brown bottle, closed. If it does not fizz on a cut or in the sink, it is tired.

Hazards

▸Do not mix with vinegar in a closed bottle (makes peracetic acid — useful industrially, ugly at home).
▸Do not mix with bleach.
▸Concentrations above 3% burn skin and bleach fabric aggressively.

Never mix

Household bleach Calcium hypochlorite White vinegar Lye

Gear

Eye protection if splashing

In the field

Wound care: irrigate with clean water or sterile saline. Save peroxide for dried blood on tools and surfaces.

Source

Pharmacy 3%. Skip the 35% drum unless you already know oxidizer handling.