Ascorbic acid

low hazard

Also: vitamin C, ascorbate

FoodPreserveWaterFirst aid

A stable, cheap vitamin and a reducing agent. It preserves color in fruit, knocks the chlorine taste out of treated water, and covers a scurvy gap in a long pantry.

Shelf life: 3–5 years typical; up to 10+ if cool, dark, dry
Container: Opaque, airtight. Keep oxygen and light out.
Grade: USP / food grade

What it does

▸Daily vitamin C when fresh produce is gone
▸Slows browning of cut fruit and helps canning color
▸Neutralizes residual chlorine / chloramine taste in treated water

Store

▸Powder keeps far longer than chewable tablets with flavorings.
▸Heat and humidity clump and oxidize it — desert closets beat garages.

Hazards

▸Large doses can upset the gut. More is not better.

Never mix

No listed pairing among the den compounds.

In the field

A pinch (about 1/8 tsp) in a gallon of freshly bleached water takes the swimming-pool taste down after the 30-minute contact time is finished — do not add it before disinfection or you undo the chlorine.

Source

Bulk powder from a compounding pharmacy or canning supplier. Look for USP.